Liquid treatment device

Abstract

The present invention comprises: a container including at least one inner cylinder; at least one upflow generation part that generates an upflow in an outer flow space formed outside the inner cylinder or in an inner flow space formed inside the inner cylinder; and at least one of an inner swirling flow generation part that causes a flow in the inner flow space to become a swirling flow and an outer swirling flow generation part that causes a flow in the outer flow space to become a swirling flow. The inner flow space and the outer flow space are configured to communicate with each other on the upper side and the lower side of the inner cylinder so as to be capable of forming a circulation flow path through which contents circulate. At least one of the inner swirling flow generation part and the outer swirling flow generation part has a plurality of blade portions provided at predetermined intervals, and the plurality of blade portions have a shape curved in the circumferential direction of the inner cylinder.

Description

Liquid Treatment Equipment

[0001] The present invention relates to a liquid treatment device, particularly to a mixer, a solid-liquid separator, a growth inhibitor, a separator, a biological treatment device, and a filtration device. The present invention also relates to an organic waste treatment system, a liquid purification system, and a filtration system that use a liquid treatment device.

[0002] BACKGROUND ART Conventionally, there has been known an agitation device that agitates a material to be agitated contained in an agitation vessel by rotating an agitation blade with a motor (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2023-171217

[0004] However, the agitation device described in Patent Document 1 has a problem in that it requires high manufacturing costs and running costs because it uses a driving means such as a motor to agitate the material to be agitated.

[0005] The present invention relates to a liquid treatment device that can treat various liquids at low cost.

[0006] The liquid treatment device of the present invention comprises a container including at least one inner cylinder, at least one ascending flow generating section that generates an ascending flow in an outer flow space formed outside the inner cylinder or an inner flow space formed inside the inner cylinder, and at least one of an inner swirling flow generating section that converts the flow in the inner flow space into a swirling flow and an outer swirling flow generating section that converts the flow in the outer flow space into a swirling flow, wherein the inner flow space and the outer flow space are connected to each other above and below the inner cylinder and are configured to be able to form a circulation flow path for circulating the contents, and at least one of the inner swirling flow generating section and the outer swirling flow generating section has a plurality of blade portions arranged at a predetermined interval, and the plurality of blade portions have a shape that is curved circumferentially around the inner cylinder.

[0007] According to the liquid treatment device of the present invention, a swirling flow can be generated simply by flowing the contents between the blades, and the generated swirling flow makes it easier to circulate the contents, making it possible to treat various liquids at low cost.

[0008] 1 is a schematic cross-sectional view showing a mixer according to a first embodiment. FIG. 2 is an enlarged view showing a portion of the mixer according to the first embodiment. FIG. 3 is an enlarged view showing a portion of the mixer according to the first embodiment. FIG. 4 is a schematic plan view showing a lower blade section according to the first embodiment. FIG. 5 is a schematic bottom view showing an upper blade section according to the first embodiment. FIG. 6 is a schematic view showing the flow of mixing. FIG. 7 is a schematic view showing an organic waste treatment system according to a second embodiment. FIG. 8 is a schematic cross-sectional view showing a solid-liquid separation device according to a second embodiment. FIG. 9 is an enlarged view showing a portion of the solid-liquid separation device according to the second embodiment. FIG. 10 is an enlarged view showing a portion of the solid-liquid separation device according to the second embodiment. FIG. 11 is a schematic plan view showing a lower blade section according to the second embodiment. FIG. 12 is a schematic bottom view showing an upper blade section according to the second embodiment. FIG. 13 is a schematic view showing the flow of solid-liquid separation. FIG. 14 is a schematic cross-sectional view showing a liquid purification system according to a third embodiment. FIG. 15 is an enlarged view showing a portion of the growth inhibition device according to the third embodiment. FIG. 16 is an enlarged view showing a portion of the growth inhibition device according to the third embodiment. FIG. 17 is a schematic plan view showing a lower blade section according to the third embodiment. FIG. 18 is a schematic bottom view showing an upper blade section according to the third embodiment. FIG. 19 is a schematic view showing the flow of liquid purification. FIG. 19 is a schematic cross-sectional view showing a separation device according to a fourth embodiment. 10 is an enlarged view showing a portion of the separation device according to the fourth embodiment. FIG. 11 is an enlarged view showing a portion of the separation device according to the fourth embodiment. FIG. 12 is a schematic plan view showing a lower blade section according to the fourth embodiment. FIG. 13 is a schematic bottom view showing an upper blade section according to the fourth embodiment. FIG. 14 is a schematic view showing the separation flow. FIG. 15 is a schematic cross-sectional view showing a biological treatment device according to the fifth embodiment. FIG. 16 is an enlarged view showing a portion of the biological treatment device according to the fifth embodiment. FIG. 17 is an enlarged view showing a portion of the biological treatment device according to the fifth embodiment. FIG. 18 is a schematic plan view showing a lower blade section according to the fifth embodiment. FIG. 19 is a schematic bottom view showing an upper blade section according to the fifth embodiment. FIG. 19 is a schematic view showing the mixing flow. FIG. 19 is a table showing experimental results of examples and comparative examples of the fifth embodiment. FIG. 19 is a schematic view showing a filtration system according to the sixth embodiment. FIG. 19 is a cross-sectional view showing a filtration device and a permeate-supplied device according to the sixth embodiment. FIG. 19 is a view showing a hollow fiber membrane according to the sixth embodiment. FIG. 19 is an enlarged view showing a portion of the separation device according to the sixth embodiment.FIG. 13 is a schematic diagram showing the flow in a filtering device according to a sixth embodiment.

[0009] Preferred embodiments for carrying out the present invention will be described below with reference to the drawings. Note that the following embodiments do not limit the inventions according to the claims, and not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention. Furthermore, in the present embodiments, the scale and dimensions of each component may be exaggerated, and some components may be omitted.

[0010] The liquid treatment device according to this embodiment includes a container including at least one inner cylinder, at least one ascending flow generating unit that generates an ascending flow in an outer flow space formed outside the inner cylinder or an inner flow space formed inside the inner cylinder, and at least one of an inner swirling flow generating unit that generates a swirling flow in the inner flow space and an outer swirling flow generating unit that generates a swirling flow in the outer flow space, the inner flow space and the outer flow space being connected to each other at the upper and lower sides of the inner cylinder and configured to form a circulation flow path for circulating the contents. At least one of the inner swirling flow generating unit and the outer swirling flow generating unit has a plurality of blades arranged at predetermined intervals, the plurality of blades having a curved shape in the circumferential direction of the inner cylinder.

[0011] The liquid treatment device according to this embodiment can be used for various purposes, and can be employed, for example, in a mixing device (first embodiment), a solid-liquid separation device (second embodiment), a growth inhibition device (third embodiment), a separation device (fourth embodiment), a biological treatment device (fifth embodiment), and a filtration device (sixth embodiment).

[0012] Furthermore, the liquid treatment device (solid-liquid separation device) according to the second embodiment can be employed in an organic waste treatment system, the liquid treatment device (growth inhibition device) according to the third embodiment can be employed in a liquid purification system, and the liquid treatment device (filtration device) according to the sixth embodiment can be employed in a filtration system (sixth embodiment).

[0013] The configuration for use in these applications will be described below.

[0014] [Explanation of Use as Mixing Apparatus] First, an example (first embodiment) of the liquid treatment apparatus according to this embodiment being used as a mixing apparatus will be described.

[0015] [Overall Configuration of the Mixing Device] The mixing device according to the first embodiment is a mixing device for mixing two or more objects. The objects to be mixed include gases, liquids, and solids (powders). Examples of mixing include, but are not limited to, (1) a liquid containing sludge and air or ozone; (2) a liquid containing odorous substances or coloring substances and ozone; (3) a liquid and an inert gas such as nitrogen gas or an active gas such as chlorine gas; (4) an oily substance such as water and oil, for example, a liquid ingredient for mayonnaise, a solid ingredient for dressing, a food ingredient for sauce, or a chemical material, whether solid or liquid, such as shampoo or nail polish; and (5) other materials such as water and salt, a food coloring ingredient, a material for a fertilizer, a pharmaceutical material, and a material for a sintered body.

[0016] As shown in FIGS. 1 to 3, the mixing device A1 includes a mixing vessel A10 for mixing two or more mixing targets, an ascending flow generating section A20 for generating an ascending flow inside the mixing vessel A10, a discharge section A30 for discharging discharged material from the mixing vessel A10, a lower swirling flow generating section A40 provided below an inner cylinder A12 (described later), and an upper swirling flow generating section A50 provided above the inner cylinder A12 (described later).

[0017] [Configuration of Mixing Container] As shown in FIGS. 1 to 3, the mixing container A10 has an outer cylinder A11 extending along the vertical direction and an inner cylinder A12 provided inside the outer cylinder A11.

[0018] In this specification, "vertical" includes both completely vertical and approximately vertical. "Almost vertical" means a slight inclination relative to the vertical, specifically, an inclination that does not impede the effects of the mixer A1.

[0019] The outer cylinder A11 and the inner cylinder A12 are each formed in a cylindrical shape with an open upper end and lower end. The outer diameter of the inner cylinder A12 is smaller than the inner diameter of the outer cylinder A11. The vertical length of the inner cylinder A12 is also shorter than the vertical length of the outer cylinder A11. In the first embodiment, only one inner cylinder A12 is provided, but this is not limited thereto, and two or more inner cylinders A12 may be provided.

[0020] The shapes of the outer tube A11 and the inner tube A12 are not limited to cylindrical shapes, and may be, for example, rectangular, conical, or pyramidal. Furthermore, they may have a convex or concave portion formed in a vertical direction, or may be bellows-shaped.

[0021] The mixing vessel A10 has a bottom A13 that closes the lower end of the outer cylinder A11, and a top A14 that closes the upper end of the outer cylinder A11. The bottom A13 is formed in a bottomed cylindrical shape with an open upper end. The bottom A13 is configured to close the lower end of the outer cylinder A11 by fitting the lower end of the outer cylinder A11 into it. The top A14 is formed in a topped cylindrical shape with an open lower end. The top A14 is configured to close the upper end of the outer cylinder A11 by fitting the upper end of the outer cylinder A11 into it.

[0022] The mixing vessel A10 also has an outer flow space A15 formed between the outer cylinder A11 and the inner cylinder A12, and an inner flow space A16 formed inside the inner cylinder A12. The outer flow space A15 and the inner flow space A16 are connected to each other above and below the inner cylinder A12, and are configured to be able to form a circulation flow path CP that circulates two or more mixing targets.

[0023] 1 to 3 , the upward flow generating section A20 has a gas generating section A21 that generates gas, a gas releasing section A22 that releases the gas generated in the gas generating section A21 into the outer flow space A15 or the inner flow space A16, a gas supplying section A23 that supplies the gas generated in the gas generating section A21 to the gas releasing section A22, and a connecting section A24 that connects the gas releasing section A22 and the gas supplying section A23. While only one upward flow generating section A20 is provided in the first embodiment, this is not limited thereto, and two or more may be provided.

[0024] The gas generation section A21 is, for example, a fan or a blower. The gas release section A22 is, for example, a tube and is configured to allow gas to flow. One end of the gas release section A22 is connected to the connection section A24, and the other end of the gas release section A22 is connected to an attachment section A43c of the support section A43, which will be described later. Therefore, the gas release section A22 according to the first embodiment is configured to release gas into the inner flow space A16. Specifically, the gas release section A22 is configured to release gas into the inner flow space A16 via the support section A43, which will be described later.

[0025] From the viewpoint of generating an upward flow, the other end of the gas release section A22 only needs to be located below the vertical middle part of the mixing vessel A10, and may be connected, for example, to the outer cylinder A11 or the inner cylinder A12. When the other end of the gas release section A22 is connected to the outer cylinder A11, the gas release section A22 is configured to release gas into the outer flow space A15.

[0026] The gas supply unit A23 is, for example, a tube and is configured to allow gas to flow. One end of the gas supply unit A23 is connected to the gas generation unit A21, and the other end of the gas supply unit A23 is connected to the connection unit A24. The connection unit A24 is, for example, a tube joint and is inserted into an opening (not shown) formed in the top portion A14.

[0027] The upward flow generating section A20 having the above configuration is configured so that the gas release section A22 releases gas into the inner flow space A16, thereby generating an upward flow in the inner flow space A16. When the gas release section A22 releases gas into the outer flow space A15, the upward flow generating section A20 generates an upward flow in the outer flow space A15.

[0028] 1 and 2, the discharge part A30 has a tubular part A31 that discharges discharged materials from the mixing container A10, and a holding part A32 that holds the tubular part A31. Examples of discharged materials include surplus materials that exceed the capacity of the mixing container A10 (e.g., gas, liquid, etc.) and materials generated by mixing (e.g., foam, etc.).

[0029] The cylindrical portion A31 is formed in a tubular shape with both ends open and is inserted into an opening (not shown) formed in the top portion A14. That is, the upper end of the cylindrical portion A31 is located outside the mixing container A10, and the lower end of the cylindrical portion A31 is located inside the mixing container A10. The cylindrical portion A31 may be formed by connecting two or more tubes as shown in FIG. 1 , or may be formed by a single tube. The cylindrical portion A31 also has multiple inlet holes A31a that allow gas from the mixing container A10 to flow into the cylindrical portion A31. The inlet holes A31a are provided in a portion of the cylindrical portion A31 located inside the mixing container A10 (in the first embodiment, below the axial middle portion of the cylindrical portion A31) and are provided along both the axial and circumferential directions of the cylindrical portion A31. The axial length of the cylindrical portion A31 may be changed depending on the application. For example, the cylindrical portion A31 may be formed longer if it is desired to actively discharge waste, such as bubbles generated by mixing the liquid and ozone. On the other hand, when it is not desired to actively discharge waste, for example, when mixing food ingredients such as mayonnaise, the length of the nozzle may be made short.

[0030] The holding portion A32 is formed in a disk shape and has an attachment hole A32a in the center for attaching the tubular portion A31. The holding portion A32 also has insertion holes A32b at both radial ends for inserting protrusions A51c formed on the upper end of the top plate A51 (described later). The holding portion A32 is configured to hold the tubular portion A31 by inserting the lower end of the tubular portion A31 into the attachment holes A32a. The holding portion A32 is also configured to be attached to the upper end of the top plate A51 by inserting the protrusions A51c into the insertion holes A32b. Attaching the holding portion A32 to the upper end of the top plate A51 prevents the inner tube A12 from floating. The holding portion A32 may be omitted or may be formed integrally with the upper swirl flow generating portion A50 (described later).

[0031] The discharge part A30 having the above-described configuration is configured to discharge the discharged material that has flowed into the cylindrical part A31 from the lower end of the cylindrical part A31 and the inlet hole A31a of the cylindrical part A31 to the outside of the mixing container A10. The discharged material discharged from the discharge part A30 can be supplied to, for example, any storage tank.

[0032] [Configuration of the lower swirling flow generating section] As shown in Figures 1, 3 and 4, the lower swirling flow generating section A40 has a weight section A41 placed on the bottom surface of the bottom section A13, a plurality of (seven in the first embodiment) blade sections A42 (lower blade sections) arranged at predetermined intervals around the inner tube A12, and a support section A43 capable of supporting the inner tube A12.

[0033] The blades A42 are provided on the upper surface of the weight portion A41 and are configured to be non-rotatable. Each blade A42 extends along the radial direction of the inner tube A12 and has a shape that is curved in the circumferential direction of the inner tube A12. In other words, the blades A42 are provided radially around the axis of the inner tube A12.

[0034] The inner end of each blade A42 in the extension direction is located within the area of ​​the inner tube A12 in a plan view. Meanwhile, the outer end of each blade A42 in the extension direction is located within the area between the outer tube A11 and the inner tube A12 in a plan view. Furthermore, each blade A42 is formed so that its height increases from the outer side in the extension direction to the inner side in the extension direction. This has the advantage of allowing efficient swirling without impeding the flow from the outer flow space A15 or the flow from the inner flow space A16.

[0035] The support portion A43 is formed in a cylindrical shape with open upper and lower ends, and has a shape that tapers from the lower end to the upper end. The support portion A43 has an insertion groove A43a at its upper end into which the lower end of the inner tube A12 can be inserted. The insertion groove A43a is formed in a concave shape that recesses downward from the upper end of the support portion A43. The support portion A43 is configured to support the inner tube A12 by inserting the lower end of the inner tube A12 into the insertion groove A43a.

[0036] The support portion A43 has, at its lower end, an annular pipe portion A43b that surrounds the periphery of the blade portion A42. The support portion A43 also has an attachment portion A43c to which the gas release portion A22 is attached.

[0037] The pipe section A43b is formed in a tubular shape having an internal space through which the gas supplied from the gas release section A22 can flow. Outlet holes A43d are formed in the inner periphery of the pipe section A43b (the end on the blade section A42 side) to allow the gas supplied from the gas release section A22 to flow out. In the first embodiment, the outlet holes A43d are multiple openings formed at predetermined intervals in the circumferential direction of the pipe section A43b. The outlet holes A43d may be a single opening or an annular opening extending along the circumferential direction of the pipe section A43b.

[0038] The mounting portion A43c extends upward from a portion of the circumference of the pipe portion A43b and is cylindrical with open top and bottom ends. Therefore, the gas supplied from the gas release portion A22 flows through the mounting portion A43c and is supplied to the pipe portion A43b. The support portion A43 is configured to connect to the gas release portion A22 by inserting the mounting portion A43c into the other end of the gas release portion A22.

[0039] The support portion A43 having the above configuration is provided between the upper surface of the weight portion A41 and the lower end of the inner tube A12, and is configured to communicate the outer flow space A15 and the inner flow space A16 between the lower end of the support portion A43 and the upper surface of the weight portion A41. Specifically, the support portion A43 is attached to the weight portion A41 by fixing a plurality of fixing portions (not shown) extending from the outer periphery of the tubular portion A43b (the end portion on the outer tube A11 side) to the outer edge of the weight portion A41. Note that, although the first embodiment has been described with respect to a configuration in which the support portion A43 includes the tubular portion A43b and the attached portion A43c, the present invention is not limited thereto, and a configuration in which these are not included is also possible.

[0040] [Configuration of the upper swirling flow generating section] As shown in Figures 1, 2 and 5, the upper swirling flow generating section A50 has a top plate section A51 arranged opposite the upper opening A12a of the inner tube A12, a plurality of (six in the first embodiment) blade sections A52 (upper blade sections) arranged at predetermined intervals around the inner tube A12, and an attachment section A53 that can be attached to the inner tube A12.

[0041] The top plate A51 has a circular planar shape. The top plate A51 has an inclined surface A51a that slopes downward at the center in the planar direction. That is, the top plate A51 has a shape in which the center in the planar direction is recessed downward, and is formed in a generally conical shape as a whole. From the viewpoint of efficiently circulating the mixture to be mixed, it is sufficient that at least the lower surface of the top plate A51 has the inclined surface A51a.

[0042] A communication hole A51b is formed in the center of the top plate A51 in the planar direction, which communicates with the inner flow space A16 and the internal space of the cylindrical portion A31. In addition, a plurality of (three in the first embodiment) protrusions A51c are formed on the upper end of the top plate A51 to be inserted into the insertion holes A32b of the holding portion A32.

[0043] The blades A52 are provided on the underside of the top plate A51. Specifically, the blades A52 extend downward from the underside of the top plate A51 and are configured to be non-rotatable. Each blade A52 extends radially of the inner tube A12 and has a curved shape in the circumferential direction of the inner tube A12. In other words, the blades A52 are provided radially around the axis of the inner tube A12.

[0044] The curvature direction of the blade portion A52 may be the same as or different from the curvature direction of the blade portion A42, but from the viewpoint of efficiently mixing the materials to be mixed, it is preferable that they be different. In the first embodiment, the curvature direction of the blade portion A42 is leftward (counterclockwise), and the curvature direction of the blade portion A52 is rightward (clockwise).

[0045] The inner end of each blade A52 in the extension direction is located within the area of ​​the inner tube A12 in a bottom view. Meanwhile, the outer end of each blade A52 in the extension direction is located within the area between the outer tube A11 and the inner tube A12 in a bottom view. Furthermore, each blade A52 is formed so that its height decreases from the outer side in the extension direction to the inner side in the extension direction. This has the advantage of allowing efficient swirling without impeding the flow from the outer flow space A15 or the flow from the inner flow space A16.

[0046] The attachment portion A53 is formed in a ring shape that surrounds the periphery of the lower end of the blade portion A52. That is, the upper swirl flow generating portion A50 according to the first embodiment is configured to communicate the outer flow space A15 and the inner flow space A16 between the lower surface of the top plate portion A51, the surface of the blade portion A52, and the inner periphery of the attachment portion A53 (the end on the blade portion A52 side).

[0047] The mounting portion A53 has a mounting groove A53a at its lower end into which the upper end of the inner tube A12 can be inserted. The mounting groove A53a is formed in a concave shape that recesses upward from the lower end of the mounting portion A53. The mounting portion A53 is configured to be attached to the inner tube A12 by inserting the upper end of the inner tube A12 into the mounting groove A53a.

[0048] [Configuration of the Inner Swirling Flow Generating Section and the Outer Swirling Flow Generating Section] In the first embodiment, either the lower swirling flow generating section A40 or the upper swirling flow generating section A50 functions as the inner swirling flow generating section A60, which generates a swirling flow in the inner flow space A16. Furthermore, the other of the lower swirling flow generating section A40 or the upper swirling flow generating section A50 functions as the outer swirling flow generating section A70, which generates a swirling flow in the outer flow space A15.

[0049] Whether the lower swirl flow generating section A40 and the upper swirl flow generating section A50 function as the inner swirl flow generating section A60 or the outer swirl flow generating section A70 depends on the position at which the upward flow generating section A20 generates the upward flow. Specifically, when the upward flow generating section A20 generates an upward flow in the inner flow space A16, the lower swirl flow generating section A40 functions as the inner swirl flow generating section A60, and the upper swirl flow generating section A50 functions as the outer swirl flow generating section A70. On the other hand, when the upward flow generating section A20 generates an upward flow in the outer flow space A15, the lower swirl flow generating section A40 functions as the outer swirl flow generating section A70, and the upper swirl flow generating section A50 functions as the inner swirl flow generating section A60.

[0050] [Mixing Method] Next, a mixing method using the mixing device A1 will be described with reference to Fig. 6. The mixing method according to the first embodiment includes an inflow step of inflowing the mixture to be mixed into the mixing container A10, and a circulation step of circulating the mixture to be mixed. In the following description, as an example, a case where a solid and a liquid are mixed (solid-liquid mixing) will be described.

[0051] [Inflow Step] The solid and liquid to be mixed are flowed into the mixing vessel A10. The solid and liquid may be flowed from the upper end of the outer cylinder A11 by removing the top portion A14, or may be flowed from an inlet (not shown) provided in the outer cylinder A11.

[0052] [Circulation Step] As shown in Figure 6, an upward flow is generated in the inner flow space A16 (see arrow F1 in Figure 6). Specifically, first, the gas generation section A21 supplies gas to the gas release section A22 via the gas supply section A23 and the connection section A24. Next, the gas release section A22 releases the gas into the inner flow space A16 via the support section A43. This generates an upward flow in the inner flow space A16. Note that the gas released into the inner flow space A16 flows and swirls between the blade sections A42, generating a swirling upward flow in the inner flow space A16. That is, the solids and liquid in the inner flow space A16 rise in the inner flow space A16 while swirling.

[0053] As the solids and liquid in the inner flow space A16 rise in the inner flow space A16, the solids and liquid in the outer flow space A15 are drawn into the inner flow space A16 (see arrow F2 in FIG. 6), and a downward flow is generated in the outer flow space A15 (see arrow F3 in FIG. 6). The solids and liquid drawn from the outer flow space A15 to the inner flow space A16 flow between the blade sections A42, and as a result of the combined swirling force of the gas released from the gas release section A22, they rise in the inner flow space A16 while swirling.

[0054] Meanwhile, solids and liquids ascending in the inner flow space A16 rise to the top plate A51, then flow along the inclined surface A51a of the top plate A51 into the outer flow space A15, and then descend through the outer flow space A15 (see arrow F4 in FIG. 6). The solids and liquids flowing into the outer flow space A15 swirl between the blades A52, creating a swirling downward flow in the outer flow space A15. In other words, the solids and liquids in the outer flow space A15 descend through the outer flow space A15 while swirling.

[0055] The solid and liquid to be mixed circulate through the circulation channel CP in the above manner, and are mixed together during the circulation process through the circulation channel CP.

[0056] [Advantages of the mixing device according to the first embodiment] The mixing device A1 according to the first embodiment is a mixing device for mixing two or more objects to be mixed, and is equipped with a mixing vessel A10 including an outer cylinder A11 extending along the vertical direction and at least one inner cylinder A12 provided inside the outer cylinder A11, and at least one ascending flow generating section A20 that generates an ascending flow in an outer flow space A15 formed between the outer cylinder A11 and the inner cylinder A12 or in an inner flow space A16 formed inside the inner cylinder A12, and the inner flow space A16 and the outer flow space A15 are connected to each other above and below the inner cylinder A12, and are configured to be able to form a circulation flow path CP that circulates the two or more objects to be mixed.

[0057] The mixing device A1 having such a configuration has the advantage that the objects to be mixed are circulated and stirred in the circulation flow path CP, thereby allowing the objects to be mixed. In addition, since there is no need to use a motor to circulate the objects to be mixed, mixing of two or more objects can be achieved at low cost, and there are also advantages in that it is highly reliable and durable.

[0058] In the mixer A1 according to the first embodiment, the upward flow generating section A20 is provided with at least one gas release section A22 that releases gas into the outer flow space A15 or the inner flow space A16, below the vertical middle section of the mixing vessel A10. The mixer A1 having such a configuration can circulate the materials to be mixed simply by releasing the gas from the gas release section A22, which has the advantages of allowing the materials to be mixed at low cost and also of high reliability and durability.

[0059] The mixer A1 according to the first embodiment includes a top plate A51 provided opposite the upper opening A12a of the inner cylinder A12, and the bottom surface of the top plate A51 has an inclined surface A51a that slopes downward from the center in the planar direction. The mixer A1 having such a configuration has the advantage that the rising materials to be mixed flow along the inclined surface A51a, allowing the materials to be circulated efficiently.

[0060] The mixer A1 according to the first embodiment includes at least one of an inner swirl flow generating section A60 that generates a swirling flow in the inner flow space A16 and an outer swirl flow generating section A70 that generates a swirling flow in the outer flow space A15. The mixer A1 having such a configuration has the advantage that the swirl lengthens the circulation path of the materials to be mixed, promoting stirring of the materials, thereby enabling efficient mixing of the materials to be mixed.

[0061] In the mixer A1 according to the first embodiment, the inner swirl flow generating section A60 and the outer swirl flow generating section A70 each include a plurality of blade sections A42 (or blade sections A52) spaced at predetermined intervals, and the plurality of blade sections A42 (or blade sections A52) have a curved shape in the circumferential direction of the inner cylinder A12. The mixer A1 having such a configuration has the advantage that a swirl flow can be generated simply by flowing the material to be mixed between the blade sections A42 (or blade sections A52).

[0062] In the mixer A1 according to the first embodiment, the blade portion A42 (or the blade portion A52) is configured to be non-rotatable. A mixer A1 having such a configuration has the advantage of being able to generate a swirling flow without rotating the blade portion A42 (or the blade portion A52), thereby reducing costs (e.g., the number of parts, power costs, costs associated with part replacement, etc.). Another advantage is that, because the blade portion A42 (or the blade portion A52) does not rotate, solids do not get caught on the blade portion A42 (or the blade portion A52) even when they are circulated.

[0063] [Modifications] The mixing device and mixing method according to the first embodiment are not limited to the above-described embodiment, and various modifications can be made within the scope of the technical concept of the present invention.

[0064] In the above-described embodiment, the mixer A1 has been described as including the outer cylinder A11 and the inner cylinder A12, but is not limited thereto and may include only the inner cylinder A12 (cylindrical member). In this case, the mixer A1 may be used by being placed in, for example, a water tank or a bathtub.

[0065] In the above-described embodiment, the upper swirl flow generating section A50 has been described as including the top plate section A51, but this is not limited thereto, and the top plate section A51 may not be included. Furthermore, the top plate section A51 may be formed flat without including the inclined surface A51a.

[0066] In the above-described embodiment, the mixing device A1 has been described as being equipped with a lower swirling flow generating section A40 and an upper swirling flow generating section A50, but this is not limited to this, and the mixing device A1 may be equipped with only one of these sections, or neither.

[0067] In the above-described embodiment, the mixing device A1 has been described as having a top portion A14 that closes the upper end of the outer cylinder A11 and an exhaust portion A30 that exhausts gas from the mixing container A10, but is not limited to this. The mixing device A1 may have an open-to-atmosphere configuration in which the top portion A14 and the exhaust portion A30 are not provided and the upper ends of the outer cylinder A11 and the inner cylinder A12 are open.

[0068] In the above-described embodiment, the outer tube A11 and the bottom portion A13 are described as being formed independently, but this is not limited thereto, and the outer tube A11 and the bottom portion A13 may be integrally formed. Furthermore, for example, the outer tube A11, the bottom portion A13, the weight portion A41, and the blade portion A42 may be integrally formed, or the bottom portion A13, the weight portion A41, and the blade portion A42 may be integrally formed, or the weight portion A41 and the blade portion A42 may be integrally formed. Furthermore, the weight portion A41 need not be provided.

[0069] It is clear from the claims that the above-mentioned modifications are included within the scope of the present invention.

[0070] [Explanation of Use as Solid-Liquid Separation Device and Organic Waste Treatment System] Next, an example (second embodiment) of using the liquid treatment device according to this embodiment as a solid-liquid separation device will be described, including the background technology and issues of the solid-liquid separation device.

[0071] [Background Technology Regarding Solid-Liquid Separation Apparatus] Conventionally, there has been known an organic waste treatment apparatus that includes an anaerobic tank that separates organic waste into biogas and treated water, an MF membrane that filters the treated water obtained in the anaerobic tank, a reverse osmosis membrane (RO membrane) that performs membrane separation on the treated water filtered by the MF membrane, and an evaporative concentration apparatus that evaporates and concentrates the treated water that has been membrane-separated by the reverse osmosis membrane (Japanese Patent Laid-Open No. 2015-192953, etc.).

[0072] [Issues Related to Solid-Liquid Separation Devices] However, in the organic waste treatment device described in JP 2015-192953 A, although filtration using an MF membrane is performed as a pretreatment for membrane separation of treated water using a reverse osmosis membrane, filtration using the MF membrane alone is insufficient to remove solids contained in the treated water, causing clogging of the reverse osmosis membrane. Furthermore, clogging requires frequent replacement of the reverse osmosis membrane, resulting in high running costs.

[0073] The second embodiment relates to a solid-liquid separator, an organic waste treatment system, and an organic waste treatment method that can achieve separation of digested liquid at low cost.

[0074] [Overall Configuration of Organic Waste Treatment System] The organic waste treatment system according to the second embodiment is a system for treating organic waste. Examples of organic waste include digestive fluids, which are residues after fermentation in a biogas plant, but are not limited to these. For example, any mixture of solids and liquids, such as livestock excrement, food waste, food waste, processing residues or residual liquids from milk and beverages, sludge, and agricultural residues, is acceptable, and the organic waste is not limited to organic "waste." The solids may be organic or inorganic, and the ratio of solids to liquids is not particularly limited.

[0075] As shown in FIG. 7, the organic waste treatment system B1 includes a production tank B100 that reacts organic waste with anaerobic microorganisms to produce biogas and digested sludge, a gas storage tank B200 that stores the biogas produced in the production tank B100, a sludge storage tank B300 that stores the digested sludge produced in the production tank B100, and a digested sludge separator B40 that separates the digested sludge stored in the sludge storage tank B300 into solids and digested liquid. 0 (primary separation device), a solid-liquid separation device B500 (digested fluid separation device, secondary separation device) that further separates the digested fluid separated in the digested sludge separation device B400 into solids and liquids, a concentration device B600 that concentrates the liquid separated in the solid-liquid separation device B500, a permeate storage tank B700 that stores the permeate that has permeated the concentration device B600, and a concentrate storage tank B800 that stores the concentrate concentrated in the concentration device B600.

[0076] Separation methods using the digested sludge separator B400 can include, for example, capturing solids with a filter, precipitating solids, floating solids, and adsorbing solids to an adsorbent. Methods for precipitating solids include, for example, static settling, coagulation settling in which a coagulant is added, and electroprecipitation in which solids are coagulated by charging. Methods for floating solids include, for example, atmospheric flotation in which a foaming agent or foam aid is added, and pressurized flotation in which fine bubbles are injected. In the second embodiment, the digested sludge separator B400 is provided with a screen and is configured to capture solids with the screen.

[0077] In the second embodiment, the digested sludge separation device B400 is described as being installed upstream of the solid-liquid separation device B500, but this is not limited to this and the digested sludge separation device B400 may be installed upstream and downstream of the solid-liquid separation device B500.

[0078] The concentrating device B600 is provided with a filtration membrane such as a known MF membrane or RO membrane, and is configured to concentrate the liquid by the filtration membrane. Note that the concentrating device B600 may also be provided with evaporation means for evaporating the liquid, and may be configured to concentrate the liquid by the evaporation means.

[0079] The organic waste treatment system B1 also includes a gas supply channel B2 that supplies the biogas produced in the production tank B100 to the gas storage tank B200, a first sludge supply channel B3 that supplies the digested sludge produced in the production tank B100 to the sludge storage tank B300, a second sludge supply channel B4 that supplies the digested sludge stored in the sludge storage tank B300 to the digested sludge separator B400, a digested liquid supply channel B5 that supplies the digested liquid separated in the digested sludge separator B400 to the solid-liquid separator B500, a liquid supply channel B6 that supplies the liquid separated in the solid-liquid separator B500 to the concentrator B600, a permeated liquid supply channel B7 that supplies the permeated liquid that has permeated the concentrator B600 to the permeated liquid storage tank B700, and a concentrated liquid supply channel B8 that supplies the concentrated liquid concentrated in the concentrator B600 to the concentrated liquid storage tank B800. The gas supply path B2, the first sludge supply path B3, the second sludge supply path B4, the digested liquid supply path B5, the liquid supply path B6, the permeate supply path B7 and the concentrated liquid supply path B8 are each formed in a tubular shape having an internal space that allows fluid to flow.

[0080] It should be noted that, since known configurations can be adopted for the components of the organic waste treatment system B1 other than the solid-liquid separation device B500, in the following explanation, only the configuration of the solid-liquid separation device B500 will be explained, and explanations of the other components will be omitted.

[0081] [Configuration of Solid-Liquid Separation Apparatus] As shown in Figures 8 to 10, the solid-liquid separation apparatus B500 includes a solid-liquid separation vessel B510 that separates the digestion fluid into solids and liquids, an ascending flow generating section B520 that generates an ascending flow containing gas bubbles inside the solid-liquid separation vessel B510, a discharge section B530 that discharges the discharged material inside the solid-liquid separation vessel B510, a lower swirling flow generating section B540 provided below an inner cylinder B512 that will be described later, and an upper swirling flow generating section B550 provided above the inner cylinder B512 that will be described later.

[0082] <Configuration of Solid-Liquid Separation Container> As shown in FIGS. 8 to 10, the solid-liquid separation container B510 has an outer cylinder B511 extending along the vertical direction and an inner cylinder B512 provided inside the outer cylinder B511.

[0083] In this specification, "vertical" includes both completely vertical and approximately vertical. "Approximately vertical" means a slight inclination relative to the vertical, specifically, an inclination that does not impair the effects of the solid-liquid separation device B500.

[0084] The outer cylinder B511 is formed in a cylindrical shape with open upper and lower ends, and has an inlet B511a through which the digestive fluid can flow in, a solid outlet B511b through which solids obtained by separation of the digestive fluid can be discharged, and a liquid outlet B511c through which liquid obtained by separation of the digestive fluid can be discharged.

[0085] The inlet B511a, solid outlet B511b, and liquid outlet B511c are each openings formed from the inner surface to the outer surface of the outer cylinder B511. Known valves may be provided at the inlet B511a, solid outlet B511b, and liquid outlet B511c, and the valves may be opened and closed at any timing. The inlet B511a is connected to the digestive fluid supply channel B5 by a tube joint TJ. The liquid outlet B511c is connected to the liquid supply channel B6 by a tube joint TJ.

[0086] The inlet B511a, the solid outlet B511b, and the liquid outlet B511c may each be provided in a single number, or in two or more numbers. In the second embodiment, only one inlet B511a and one liquid outlet B511c are provided, and these are located near the middle of the outer flow space B515 (described later). Providing the liquid outlet B511c near the middle of the outer flow space B515 allows the liquid obtained by separating the digestive fluid to be efficiently discharged. On the other hand, two solid outlets B511b are provided, one near the upper part and one near the lower part of the outer flow space B515. Providing the solid outlets B511b near the upper part and the lower part of the outer flow space B515 allows the solids obtained by separating the digestive fluid (floated solids and settled solids) to be efficiently discharged. In the second embodiment, as described later, the lower end of the outer cylinder B511 is fitted into the bottom B513, and therefore the solid discharge outlet B511b provided near the lower part of the outer flow space B515 is formed by penetrating the bottom B513.

[0087] The inner cylinder B512 is formed in a cylindrical shape with open upper and lower ends. The outer diameter of the inner cylinder B512 is smaller than the inner diameter of the outer cylinder B511. The vertical length of the inner cylinder B512 is also shorter than the vertical length of the outer cylinder B511. In the second embodiment, only one inner cylinder B512 is provided, but this is not limited thereto, and two or more inner cylinders B512 may be provided.

[0088] The shapes of the outer tube B511 and the inner tube B512 are not limited to cylindrical shapes, and may be, for example, rectangular, conical, or pyramidal. Furthermore, a convex or concave portion may be formed in a vertical portion, or the tube may be bellows-shaped.

[0089] The solid-liquid separation container B510 has a bottom B513 that closes the lower end of the outer cylinder B511, and a top B514 that closes the upper end of the outer cylinder B511. The bottom B513 is formed in a bottomed cylindrical shape with an open upper end. The bottom B513 is configured to close the lower end of the outer cylinder B511 by fitting the lower end of the outer cylinder B511 into it. The top B514 is formed in a topped cylindrical shape with an open lower end. The top B514 is configured to close the upper end of the outer cylinder B511 by fitting the upper end of the outer cylinder B511 into it.

[0090] The solid-liquid separation vessel B510 also has an outer flow space B515 formed between the outer cylinder B511 and the inner cylinder B512, and an inner flow space B516 formed inside the inner cylinder B512. The outer flow space B515 and the inner flow space B516 communicate with each other above and below the inner cylinder B512, and are configured to be able to form a circulation flow path CP that circulates the digestion liquid and air bubbles.

[0091] 8 to 10 , the upward flow generating section B520 has a gas generating section B521 that generates gas, a gas releasing section B522 that releases the gas generated in the gas generating section B521 into the outer flow space B515 or the inner flow space B516, a gas supplying section B523 that supplies the gas generated in the gas generating section B521 to the gas releasing section B522, and a connecting section B524 that connects the gas releasing section B522 and the gas supplying section B523. While only one upward flow generating section B520 is provided in the second embodiment, this is not limited thereto, and two or more may be provided.

[0092] The gas generating unit B521 is, for example, a fan or a blower. The gas generating unit B521 has a switch B521a that starts or stops the generation of gas. In other words, the switch B521a is configured to start or stop the release of gas by the gas releasing unit B522.

[0093] The gas release section B522 is, for example, a tube and is configured to allow gas to flow. One end of the gas release section B522 is connected to the connection section B524, and the other end of the gas release section B522 is connected to an attachment section B543c of a support section B543, which will be described later. Therefore, the gas release section B522 according to the second embodiment is configured to release gas into the inner flow space B516. Specifically, the gas release section B522 is configured to release gas into the inner flow space B516 via the support section B543, which will be described later.

[0094] From the viewpoint of generating an upward flow, the other end of the gas release section B522 only needs to be located below the vertical middle section of the solid-liquid separation vessel B510, and may be connected, for example, to the outer cylinder B511 or the inner cylinder B512. When the other end of the gas release section B522 is connected to the outer cylinder B511, the gas release section B522 is configured to release gas into the outer flow space B515.

[0095] The gas supply unit B523 is, for example, a tube and is configured to allow gas to flow. One end of the gas supply unit B523 is connected to the gas generation unit B521, and the other end of the gas supply unit B523 is connected to the connection unit B524. The connection unit B524 is, for example, a tube joint and is inserted into an opening (not shown) formed in the top unit B514.

[0096] The upward flow generating section B520 having the above configuration is configured so that the gas release section B522 releases gas into the inner flow space B516, thereby generating an upward flow containing air bubbles in the inner flow space B516. When the gas release section B522 releases gas into the outer flow space B515, the upward flow generating section B520 generates an upward flow containing air bubbles in the outer flow space B515.

[0097] The upward flow generating unit B520 is configured so that the switch B521a stops the release of gas by the gas release unit B522, thereby stopping the circulation of the digestive fluid and bubbles in the circulation flow path CP at any or a predetermined timing. The stoppage by the switch B521a may be performed manually or automatically. Examples of automatic methods for stopping the circulation by the switch B521a include, but are not limited to, a method in which the switch B521a is turned on and then a predetermined time has elapsed, or a method in which the switch B521a is turned on and then a predetermined flow rate has been released, and then the switch B521a is turned off.

[0098] 8 and 9, the discharge unit B530 has a tubular portion B531 that discharges the discharged material in the solid-liquid separation container B510, and a holding portion B532 that holds the tubular portion B531. Examples of the discharged material include surplus material (e.g., gas, liquid, etc.) that exceeds the capacity of the solid-liquid separation container B510.

[0099] The cylindrical portion B531 is formed in a tubular shape with both ends open and is inserted into an opening (not shown) formed in the top portion B514. That is, the upper end of the cylindrical portion B531 is located outside the solid-liquid separation container B510, and the lower end of the cylindrical portion B531 is located inside the solid-liquid separation container B510. As shown in FIG. 8 , the cylindrical portion B531 may be formed by connecting two or more tubes, or may be formed by a single tube. The cylindrical portion B531 also has a plurality of inlet holes B531a that allow gas from the solid-liquid separation container B510 to flow into the cylindrical portion B531. The inlet holes B531a are provided in a portion of the cylindrical portion B531 that is located inside the solid-liquid separation container B510 (in the second embodiment, below the axial middle portion of the cylindrical portion B531) and are provided along both the axial and circumferential directions of the cylindrical portion B531.

[0100] The holding portion B532 is formed in a disk shape and has a mounting hole B532a in the center for mounting the tubular portion B531. The holding portion B532 also has insertion holes B532b at both radial ends for inserting protrusions B551c formed on the upper end of the top plate B551 (described later). The holding portion B532 is configured to hold the tubular portion B531 by inserting the lower end of the tubular portion B531 into the mounting holes B532a. The holding portion B532 is also configured to be attached to the upper end of the top plate B551 by inserting the protrusions B551c into the insertion holes B532b. Attaching the holding portion B532 to the upper end of the top plate B551 prevents the inner tube B512 from floating. The holding portion B532 may be omitted or may be formed integrally with the upper swirl flow generating portion B550 (described later).

[0101] The discharge section B530 having the above configuration is configured to discharge the discharged material that has flowed into the cylindrical section B531 from the lower end of the cylindrical section B531 and the inlet hole B531a of the cylindrical section B531 to the outside of the solid-liquid separation container B510. The discharged material discharged from the discharge section B530 can be supplied to, for example, any storage tank.

[0102] <Configuration of the lower swirling flow generating section> As shown in Figures 8, 10 and 11, the lower swirling flow generating section B540 has a weight section B541 placed on the bottom surface of the bottom section B513, a plurality of (seven in the second embodiment) blade sections B542 (lower blade sections) arranged at predetermined intervals around the inner tube B512, and a support section B543 capable of supporting the inner tube B512.

[0103] The blades B542 are provided on the upper surface of the weight B541 and are configured to be non-rotatable. Each blade B542 extends radially of the inner tube B512 and has a curved shape in the circumferential direction of the inner tube B512. In other words, the blades B542 are provided radially around the axis of the inner tube B512.

[0104] The inner end of each blade B542 in the extension direction is located within the area of ​​the inner tube B512 in plan view. Meanwhile, the outer end of each blade B542 in the extension direction is located within the area between the outer tube B511 and the inner tube B512 in plan view. Furthermore, each blade B542 is formed so that its height increases from the outer side in the extension direction to the inner side in the extension direction. This has the advantage of allowing efficient swirling without impeding the flow from the outer flow space B515 or the flow from the inner flow space B516.

[0105] The support portion B543 is formed in a cylindrical shape with open upper and lower ends, and has a shape that tapers from the lower end to the upper end. The support portion B543 has an insertion groove B543a at its upper end into which the lower end of the inner tube B512 can be inserted. The insertion groove B543a is formed in a concave shape that recesses downward from the upper end of the support portion B543. The support portion B543 is configured to support the inner tube B512 by inserting the lower end of the inner tube B512 into the insertion groove B543a.

[0106] The support portion B543 has, at its lower end, an annular pipe portion B543b that surrounds the periphery of the blade portion B542. The support portion B543 also has an attachment portion B543c to which the gas release portion B522 is attached.

[0107] The pipe section B543b is formed in a tubular shape having an internal space that allows the gas supplied from the gas release section B522 to flow. Outlet holes B543d that allow the gas supplied from the gas release section B522 to flow out are formed in the inner peripheral portion (the end portion on the blade section B542 side) of the pipe section B543b. In the second embodiment, the outlet holes B543d are multiple openings formed at predetermined intervals in the circumferential direction of the pipe section B543b. The outlet holes B543d may be a single opening or may be an annular opening extending along the circumferential direction of the pipe section B543b.

[0108] The mounting portion B543c extends upward from a portion of the circumferential direction of the pipe portion B543b and is cylindrical with open upper and lower ends. Therefore, the gas supplied from the gas release portion B522 flows through the mounting portion B543c and is supplied to the pipe portion B543b. The support portion B543 is configured to connect to the gas release portion B522 by inserting the mounting portion B543c into the other end of the gas release portion B522.

[0109] The support portion B543 having the above configuration is provided between the upper surface of the weight portion B541 and the lower end of the inner tube B512, and is configured to communicate the outer flow space B515 and the inner flow space B516 between the lower end of the support portion B543 and the upper surface of the weight portion B541. Specifically, the support portion B543 is attached to the weight portion B541 by fixing a plurality of fixing portions (not shown) extending from the outer periphery of the tube portion B543b (the end portion on the outer tube B511 side) to the outer edge of the weight portion B541. Note that, although the second embodiment has been described with respect to a configuration in which the support portion B543 includes the tube portion B543b and the attached portion B543c, the present invention is not limited thereto, and a configuration not including these may also be used.

[0110] <Configuration of the upper swirling flow generating section> As shown in Figures 8, 9 and 12, the upper swirling flow generating section B550 has a top plate section B551 arranged opposite the upper opening B512a of the inner tube B512, a plurality of (six in the second embodiment) blade sections B552 (upper blade sections) arranged at predetermined intervals around the inner tube B512, and an attachment section B553 that can be attached to the inner tube B512.

[0111] The top plate B551 has a circular planar shape. The top plate B551 also has an inclined surface B551a that slopes downward at the center in the planar direction. That is, the top plate B551 has a shape in which the center in the planar direction is recessed downward, and is formed in a generally conical shape as a whole. From the viewpoint of efficiently circulating the separation target and air bubbles, it is sufficient that at least the lower surface of the top plate B551 has the inclined surface B551a.

[0112] A communication hole B551b is formed in the center of the top plate B551 in the planar direction, which communicates with the inner flow space B516 and the internal space of the cylindrical portion B531. In addition, a plurality of (three in the second embodiment) protrusions B551c are formed on the upper end of the top plate B551 to be inserted into the insertion holes B532b of the holding portion B532.

[0113] The blades B552 are provided on the underside of the top plate B551. Specifically, the blades B552 extend downward from the underside of the top plate B551 and are configured to be non-rotatable. Each blade B552 extends radially of the inner tube B512 and has a curved shape in the circumferential direction of the inner tube B512. In other words, the blades B552 are provided radially from the axis of the inner tube B512.

[0114] The direction of curvature of the blade portion B552 may be the same as or different from the direction of curvature of the blade portion B542, but it is preferable that they are the same from the viewpoint of efficiently circulating the digestive fluid and air bubbles.

[0115] The inner end of each blade B552 in the extension direction is located within the region of the inner tube B512 in a bottom view. Meanwhile, the outer end of each blade B552 in the extension direction is located within the region between the outer tube B511 and the inner tube B512 in a bottom view. Furthermore, each blade B552 is formed so that its height decreases from the outer side in the extension direction toward the inner side in the extension direction. This has the advantage of allowing efficient swirling without impeding the flow from the outer flow space B515 or the flow from the inner flow space B516.

[0116] The attachment portion B553 is formed in a ring shape surrounding the periphery of the lower end of the blade portion B552. That is, the upper swirl flow generating portion B550 according to the second embodiment is configured to communicate the outer flow space B515 and the inner flow space B516 between the lower surface of the top plate portion B551, the surface of the blade portion B552, and the inner periphery of the attachment portion B553 (the end on the blade portion B552 side).

[0117] The mounting portion B553 has a mounting groove B553a at its lower end into which the upper end of the inner tube B512 can be inserted. The mounting groove B553a is formed in a concave shape that recesses upward from the lower end of the mounting portion B553. The mounting portion B553 is configured to be attached to the inner tube B512 by inserting the upper end of the inner tube B512 into the mounting groove B553a.

[0118] <Configuration of Inner Swirling Flow Generating Section and Outer Swirling Flow Generating Section> In the second embodiment, either the lower swirling flow generating section B540 or the upper swirling flow generating section B550 functions as an inner swirling flow generating section B560 that generates a swirling flow in the inner flow space B516. Furthermore, the other of the lower swirling flow generating section B540 or the upper swirling flow generating section B550 functions as an outer swirling flow generating section B570 that generates a swirling flow in the outer flow space B515.

[0119] Whether the lower swirl flow generating section B540 and the upper swirl flow generating section B550 function as the inner swirl flow generating section B560 or the outer swirl flow generating section B570 depends on the position at which the upward flow generating section B520 generates the upward flow. Specifically, when the upward flow generating section B520 generates an upward flow in the inner flow space B516, the lower swirl flow generating section B540 functions as the inner swirl flow generating section B560, and the upper swirl flow generating section B550 functions as the outer swirl flow generating section B570. On the other hand, when the upward flow generating section B520 generates an upward flow in the outer flow space B515, the lower swirl flow generating section B540 functions as the outer swirl flow generating section B570, and the upper swirl flow generating section B550 functions as the inner swirl flow generating section B560.

[0120] [Organic waste treatment method] Next, an organic waste treatment method using the organic waste treatment system B1 will be described with reference to Figure 13. The organic waste treatment method according to the second embodiment includes a production step of reacting organic waste with anaerobic microorganisms to produce biogas and digested sludge, a digested sludge separation step of separating the digested sludge produced in the production step into a solid and a digested liquid, a solid-liquid separation step of further separating the digested liquid separated in the digested sludge separation step into a solid and a liquid, a drying step of drying the solid separated in the solid-liquid separation step, and a concentration step of concentrating the liquid separated in the solid-liquid separation step.

[0121] [Production Process] Organic waste is introduced into the production tank B100. The organic waste is then reacted with anaerobic microorganisms in the production tank B100 to produce biogas and digested sludge. The biogas produced in the production tank B100 is supplied to the gas storage tank B200 via the gas supply line B2 and stored in the gas storage tank B200. Meanwhile, the digested sludge produced in the production tank B100 is supplied to the sludge storage tank B300 via the first sludge supply line B3 and stored in the sludge storage tank B300.

[0122] [Digested Sludge Separation Process] The digested sludge stored in the sludge storage tank B300 is supplied to the digested sludge separator B400 via the second sludge supply line B4, where it is separated into solids and digested liquid. The digested liquid separated in the digested sludge separator B400 is supplied to the solid-liquid separator B500 via the digested liquid supply line B5.

[0123] [Solid-liquid separation process] The solid-liquid separation process according to the second embodiment includes an inflow process of inflowing the digestive fluid into the solid-liquid separation container B510, a circulation process of circulating the digestive fluid and gas bubbles, a stop process of stopping the circulation of the digestive fluid and gas bubbles, a solid discharge process of discharging the solid obtained by separation of the digestive fluid, and a liquid discharge process of discharging the liquid obtained by separation of the digestive fluid.

[0124] <Inflow Step> The digested liquid is flowed into the solid-liquid separation vessel B510. Specifically, the digested liquid separated in the digested sludge separation apparatus B400 is flowed into the solid-liquid separation vessel B510 from the inlet B511a. Note that although coarse solids contained in the digested sludge are removed in the digested sludge separation apparatus B400, many fine solids remain in the liquid flowing into the solid-liquid separation vessel B510.

[0125] <Circulation Step> As shown in Figure 13, an upward flow containing bubbles B is generated in the inner flow space B516 (see arrow F1 in Figure 13). Specifically, first, gas generation is started by the switch B521a of the gas generation unit B521, and the generated gas is supplied to the gas release unit B522 via the gas supply unit B523 and the connection unit B524. Next, the gas release unit B522 releases the gas into the inner flow space B516 via the support unit B543. This generates an upward flow containing bubbles B in the inner flow space B516. Note that the gas released into the inner flow space B516 flows and swirls between the blade units B542, generating a swirling upward flow in the inner flow space B516. That is, the digestive fluid and bubbles B in the inner flow space B516 rise in the inner flow space B516 while swirling.

[0126] When the digestive fluid in the inner flow space B516 rises in the inner flow space B516, the digestive fluid in the outer flow space B515 is drawn into the inner flow space B516 (see arrow F2 in FIG. 13), and a downward flow is generated in the outer flow space B515 (see arrow F3 in FIG. 13). The digestive fluid drawn from the outer flow space B515 to the inner flow space B516 flows between the blades B542, and thus rises in the inner flow space B516 while swirling, due to the combined swirling force of the gas released from the gas release section B522.

[0127] Meanwhile, the digestive fluid and bubbles B ascending in the inner flow space B516 rise to the top plate B551, then flow along the inclined surface B551a of the top plate B551 into the outer flow space B515, and then descend through the outer flow space B515 (see arrow F4 in FIG. 13). The digestive fluid and bubbles B flowing into the outer flow space B515 swirl between the blades B552, creating a swirling downward flow in the outer flow space B515. In other words, the digestive fluid and bubbles B in the outer flow space B515 descend through the outer flow space B515 while swirling.

[0128] The digestive fluid and bubbles B circulate through the circulation flow path CP in the above manner. During this circulation process, some of the suspended matter (solids) in the digestive fluid settles down in the outer flow space B515 and settles in the lower part of the outer flow space B515.

[0129] Furthermore, during the circulation process, when the digestive fluid and bubbles B are drawn from the outer flow space B515 to the inner flow space B516, the flow rate increases (pressure decreases), and the bubbles B become finer. The bubbles B circulating through the circulation flow path CP become finer as they swirl in the inner flow space B516 and the outer flow space B515 and are sheared by the blades B542 and B55B52. In other words, the bubbles B become finer the more they circulate through the circulation flow path CP. Furthermore, fine solids contained in the digestive fluid are also sheared by the blades B542 and B552, thereby becoming finer.

[0130] As described above, the solid-liquid separator B500 according to the second embodiment is configured to generate fine bubbles. By generating fine bubbles, the total surface area of ​​the bubbles generated in the solid-liquid separation vessel B510 increases, thereby improving separation performance. Note that fine bubbles include microbubbles (bubbles with a diameter of 1 μm or more and less than 100 μm) and ultrafine bubbles (bubbles with a diameter of less than 1 μm).

[0131] <Stopping Step> The generation of gas is stopped at any or predetermined timing by the switch B521a of the gas generation unit B521. This stops the release of gas by the gas release unit B522, and stops the circulation of the digestive fluid and gas bubbles B in the circulation flow path CP.

[0132] When circulation stops, the bubbles B rise in the inner flow space B516 and the outer flow space B515 while adsorbing suspended matter (solids) in the digestive fluid. As a result, settled solids (solids that are too large and heavy to float up due to the buoyancy of the bubbles B) exist in the lower parts of the inner flow space B516 and the outer flow space B515, floated solids (solids that are large and heavy enough to float up due to the buoyancy of the bubbles B) exist in the upper parts of the inner flow space B516 and the outer flow space B515, and liquid with little solids exists in the middle parts of the inner flow space B516 and the outer flow space B515. In this way, the digestive fluid can be separated into solids and liquid.

[0133] <Solid Discharge Step and Liquid Discharge Step> The solid obtained by separating the digestive fluid is discharged from the solid discharge port B511b. The liquid obtained by separating the digestive fluid is discharged from the liquid discharge port B511c. After the solid discharge step, the circulation step and the stopping step may be performed again to further concentrate the liquid.

[0134] [Drying Step] The solid discharged from the solid-liquid separation vessel B510 is dried. Drying can be performed by any method, for example, sun drying. The dried solid can be used as solid fertilizer.

[0135] [Concentration Step] The liquid discharged from the solid-liquid separation vessel B510 is supplied to the concentrator B600 via the liquid supply line B6 and concentrated in the concentrator B600. The permeated liquid that has permeated through the concentrator B600 is supplied to the permeated liquid storage tank B700 via the permeated liquid supply line B7 and stored in the permeated liquid storage tank B700. The permeated liquid stored in the permeated liquid storage tank B700 is circulated to the production tank B100 to be reused for new biogas generation. Meanwhile, the concentrated liquid concentrated in the concentrator B600 is supplied to the concentrated liquid storage tank B800 via the concentrated liquid supply line B8 and stored in the concentrated liquid storage tank B800. The liquid supplied to the concentrated liquid storage tank B800 is used as liquid fertilizer.

[0136] As described above, the concentration method using the concentrating apparatus B600 can be a concentration method using a filtration membrane or a concentration method using an evaporation means, but it is preferable to use a concentration method using a filtration membrane from the viewpoint of suppressing loss of fertilizer components contained in the liquid separated in the solid-liquid separation apparatus B500. Note that examples of concentration methods using an evaporation means include high-temperature drying, reduced-pressure distillation, hot-air drying, and sun drying.

[0137] [Advantages of the solid-liquid separation device and organic waste treatment system according to the second embodiment] The solid-liquid separation device B500 according to the second embodiment is a solid-liquid separation device that separates digestive fluid into solids and liquids, and is equipped with a solid-liquid separation container B510 including an outer cylinder B511 extending vertically and at least one inner cylinder B512 provided inside the outer cylinder B511, and at least one ascending flow generating unit B520 that generates an ascending flow containing bubbles in an outer flow space B515 formed between the outer cylinder B511 and the inner cylinder B512 or in an inner flow space B516 formed inside the inner cylinder B512, the inner flow space B516 and the outer flow space B515 being connected to each other above and below the inner cylinder B512 and configured to be able to form a circulation flow path CP that circulates the digestive fluid and air bubbles, and the ascending flow generating unit B520 is configured to be able to stop the circulation of the digestive fluid and air bubbles.

[0138] The solid-liquid separation apparatus B500 having such a configuration can cause solids contained in the digestive liquid that are too large and heavy to float up even with the buoyancy of the gas bubbles to settle and settle at the bottom of the outer flow space B515 and the inner flow space B516. Furthermore, the solid-liquid separation apparatus B500 can cause solids contained in the digestive liquid that are large and heavy enough to float up with the buoyancy of the gas bubbles to rise up the outer flow space B515 and the inner flow space B516 while being adsorbed by the gas bubbles. That is, the solid-liquid separation apparatus B500 can separate the digestive liquid into solids and liquid by circulating the digestive liquid and the gas bubbles. Furthermore, since the solid-liquid separation apparatus B500 according to the second embodiment can substantially remove solids contained in the digestive liquid, for example, when a filtration process using a filter membrane is performed as post-processing of the solid-liquid separation apparatus B500, clogging of the filter membrane can be suppressed, thereby reducing the frequency of membrane replacement due to clogging and ultimately the running costs.

[0139] Furthermore, in the solid-liquid separator B500 according to the second embodiment, since it is not necessary to use a pressure pump or the like for pressurizing raw water to generate bubbles, separation of the digestive fluid can be achieved at low cost, and there are also advantages in that it is highly reliable and durable. Furthermore, since there is no need to use a pressure pump, there is also no need to use a nozzle, which has the advantage of eliminating the need to replace the nozzle due to wear.

[0140] In the solid-liquid separator B500 according to the second embodiment, the outer cylinder B511 has at least one solid outlet B511b through which solids can be discharged and at least one liquid outlet B511c through which liquids can be discharged. The solid-liquid separator B500 having such a configuration has the advantage that the solids can be used as solid fertilizer and the liquid can be used as liquid fertilizer.

[0141] In the solid-liquid separation apparatus B500 according to the second embodiment, the ascending flow generating section B520 is provided with at least one gas release section B522 that releases gas into the outer flow space B515 or the inner flow space B516, below the vertical middle section of the solid-liquid separation vessel B510. The solid-liquid separation apparatus B500 having such a configuration can generate an ascending flow containing gas bubbles simply by releasing gas from the gas release section B522, and can circulate the digested liquid and gas bubbles, which has the advantages of allowing the digested liquid to be separated at low cost and without loss of fertilizer components contained in the digested liquid, and also of high durability of the apparatus itself.

[0142] The solid-liquid separator B500 according to the second embodiment includes a top plate B551 disposed opposite the upper opening B512a of the inner cylinder B512, and the bottom surface of the top plate B551 has an inclined surface B551a that slopes downward from the center in the planar direction. The solid-liquid separator B500 having such a configuration has the advantage that the rising digestive fluid flows along the inclined surface B551a, thereby enabling efficient circulation of the digestive fluid.

[0143] The solid-liquid separator B500 according to the second embodiment includes at least one of an inner swirling flow generating section B560 that generates a swirling flow in the inner flow space B516 and an outer swirling flow generating section B570 that generates a swirling flow in the outer flow space B515. The solid-liquid separator B500 with this configuration has the advantage of facilitating the circulation of the digestion liquid and air bubbles through the swirling flow. Another advantage is that the swirling air bubbles can be made finer. The reduced air bubble size increases the total surface area of ​​the air bubbles, improving separation performance.

[0144] In the solid-liquid separation apparatus B500 according to the second embodiment, the inner swirling flow generating section B560 and the outer swirling flow generating section B570 each include a plurality of blade sections B542 (or blade sections B552) spaced apart at predetermined intervals, each of which has a curved shape in the circumferential direction of the inner cylinder B512. The solid-liquid separation apparatus B500 having such a configuration advantageously generates a swirling flow simply by moving the sludge between the blade sections B542 (or blade sections B552). Another advantage is that air bubbles are sheared by the blade sections B542 (or blade sections B552), thereby reducing the size of the bubbles. Reducing the size of the bubbles increases the total surface area of ​​the bubbles, thereby improving separation performance. In addition, not only the air bubbles but also the solids contained in the digestive fluid are sheared by the blade portion B542 (or the blade portion B552), which has the advantage of breaking down the solids into smaller particles and making them more likely to float up.

[0145] In the solid-liquid separator B500 according to the second embodiment, the blade portion B542 (or the blade portion B552) is configured to be non-rotatable. The solid-liquid separator B500 having such a configuration can generate a swirling flow without rotating the blade portion B542 (or the blade portion B552), which has the advantage of low costs (e.g., number of parts, power costs, costs associated with part replacement, etc.). Another advantage is that the blade portion B542 (or the blade portion B552) does not rotate, so that fine solids mixed in the digestive fluid do not get caught on the blade portion B542 (or the blade portion B552).

[0146] The organic waste treatment system B1 according to the second embodiment is an organic waste treatment system for treating organic waste, and includes a generation tank B100 that reacts organic waste with anaerobic microorganisms to produce biogas and digested sludge, a digested sludge separator B400 that separates the digested sludge into solids and digested liquid, a solid-liquid separator B500 that further separates the digested liquid separated in the digested sludge separator B400 into solids and liquid, and a concentration device B600 that concentrates the liquid separated in the solid-liquid separator B500. The solid-liquid separator B500 includes an outer cylinder B511 that extends vertically and a The solid-liquid separation container B510 includes at least one inner cylinder B512 provided therein, and at least one ascending flow generating section B520 that generates an ascending flow containing bubbles in an outer flow space B515 formed between the outer cylinder B511 and the inner cylinder B512 or in an inner flow space B516 formed inside the inner cylinder B512, the inner flow space B516 and the outer flow space B515 being connected to each other on the upper and lower sides of the inner cylinder B512 and configured to be able to form a circulation flow path CP that circulates the digestive fluid and bubbles, and the ascending flow generating section B520 is configured to be able to stop the circulation of the digestive fluid and bubbles.

[0147] The organic waste treatment system B1 having such a configuration can remove coarse solids in the digested sludge separator B400 and remove most of the fine and microscopic solids in the solid-liquid separator B500. Therefore, for example, if the concentrator B600 and the solid-liquid separator B600 are equipped with a filter membrane, clogging of the filter membrane can be suppressed, reducing the frequency of filter membrane replacement due to clogging and ultimately the running costs. Furthermore, for example, if the concentrator B600 and the solid-liquid separator B600 are equipped with an evaporation means, the loss of fertilizer components due to high temperature heating can be suppressed. Furthermore, the organic waste treatment system B1 according to the second embodiment does not require the use of a coagulant or a pressure pump for solid-liquid separation, which also has the advantage of low manufacturing and running costs.

[0148] [Modifications] The solid-liquid separation device, organic waste treatment system, and organic waste treatment method according to the second embodiment are not limited to the above-described embodiment, and various modifications can be made within the scope that does not deviate from the technical concept of the present invention.

[0149] In the above-described embodiment, in addition to the solid-liquid separation device B500, the digested sludge separation device B400 and the concentration device B600 are used, but this is not limited to this, and devices and means other than the digested sludge separation device B400, the solid-liquid separation device B500 and the concentration device B600 may also be used.

[0150] In the above-described embodiment, the upper swirl flow generating section B550 has been described as including the top plate section B551, but this is not limited thereto, and the top plate section B551 may not be included. Furthermore, the top plate section B551 may be formed flat without including the inclined surface B551a.

[0151] In the above-described embodiment, the solid-liquid separation device B500 has been described as being equipped with a lower swirling flow generating section B540 and an upper swirling flow generating section B550, but this is not limited to this and the device may be equipped with only one of these sections, or neither.

[0152] In the above-described embodiment, the solid-liquid separation device B500 has been described as including a top B514 that closes the upper end of the outer cylinder B511 and an exhaust section B530 that exhausts gas from the solid-liquid separation container B510. However, the solid-liquid separation device B500 is not limited to this, and may have an open-to-atmosphere configuration in which the top B514 and exhaust section B530 are not included and the upper ends of the outer cylinder B511 and the inner cylinder B512 are open.

[0153] In the above-described embodiment, the outer tube B511 and the bottom B513 are described as being formed independently, but this is not limited thereto, and the outer tube B511 and the bottom B513 may be integrally formed. Furthermore, for example, the outer tube B511, the bottom B513, the weight B541, and the blade B542 may be integrally formed, or the bottom B513, the weight B541, and the blade B542 may be integrally formed, or the weight B541 and the blade B542 may be integrally formed. Furthermore, the weight B541 need not be provided.

[0154] It is clear from the claims that the above-mentioned modifications are included within the scope of the present invention.

[0155] [Explanation of Use as Growth Inhibition Device and Liquid Purification System] Next, an example (third embodiment) of using the liquid treatment device according to this embodiment as a growth inhibition device will be described, along with background technology and problems of the growth inhibition device.

[0156] [Background Technology Regarding Growth Inhibition Devices] Conventionally, solubilization treatments for solubilizing sludge have been known as methods for reducing the volume of sludge. Known solubilization treatments include treatments using chemicals, heat treatments, ultrasonic treatments, and treatments using mills. For example, Japanese Patent Application Laid-Open No. 2002-336898 describes a method for solubilizing sludge using ultrasonic waves.

[0157] [Problems with Growth Inhibition Devices] However, conventional solubilization treatments involve the use of chemicals, heat, ultrasound, mills, etc., which results in a problem of high costs.

[0158] The third embodiment relates to a growth inhibition device, a liquid purification system, and a growth inhibition method that can inhibit the growth of organisms present in a liquid at low cost.

[0159] [Overall Configuration of Liquid Purification System] The liquid purification system according to the third embodiment is a liquid purification system for purifying a liquid. Specifically, the liquid purification system C1 is a system for suppressing the growth of organisms present in the liquid (a system for reducing the volume of sludge). The type of liquid is not particularly limited, and the liquid purification system can be any liquid that requires purification, such as wastewater discharged from homes, factories, etc., water in aquariums installed in homes or facilities (aquariums, fish farms, etc.), water in bathtubs installed in homes or facilities (lodging facilities, etc.), water from ponds, the sea, etc.

[0160] As used herein, "inhibiting the growth of organisms" refers to inhibiting the growth and proliferation of microorganisms (e.g., fungi, algae, etc.) present in a liquid. Specifically, for example, if the object to be inhibited is fungi, this refers to sterilization (sterilization), and if the object to be treated is a liquid containing sludge such as wastewater, this refers to reducing the volume of the sludge. Methods for inhibiting the growth of organisms include, for example, a crushing treatment that breaks down bubbles (erosion), or a combination of a crushing treatment and an ozone treatment using ozone.

[0161] As shown in Figure 14, the liquid purification system C1 comprises a growth inhibition device C100 that inhibits the growth of organisms present in the liquid, a liquid supply mechanism C200 that can supply liquid to the growth inhibition device C100, and a liquid storage mechanism C300 that can store liquid discharged from the growth inhibition device C100.

[0162] [Configuration of the growth inhibition device] As shown in Figures 14 to 16, the growth inhibition device C100 comprises a growth inhibition container C110 that inhibits the growth of organisms present in a liquid, an ascending flow generating section C120 that generates an ascending flow containing air bubbles inside the growth inhibition container C110, a discharge section C130 that discharges waste matter from the growth inhibition container C110, a lower swirling flow generating section C140 provided below the inner cylinder C112 described later, and an upper swirling flow generating section C150 provided above the inner cylinder C112 described later.

[0163] <Configuration of Growth Inhibition Container> As shown in FIGS. 14 to 16, the growth inhibition container C110 has an outer cylinder C111 extending along the vertical direction, and an inner cylinder C112 provided inside the outer cylinder C111.

[0164] In this specification, "vertical" includes both completely vertical and approximately vertical. "Approximately vertical" refers to a slight inclination relative to the vertical, specifically, an inclination that does not impede the action and effect of the growth inhibition device C100.

[0165] The outer cylinder C111 and the inner cylinder C112 are each formed in a cylindrical shape with an open upper end and lower end. The outer diameter of the inner cylinder C112 is smaller than the inner diameter of the outer cylinder C111. The vertical length of the inner cylinder C112 is also shorter than the vertical length of the outer cylinder C111. In the third embodiment, only one inner cylinder C112 is provided, but this is not limited thereto, and two or more inner cylinders C112 may be provided.

[0166] The shapes of the outer tube C111 and the inner tube C112 are not limited to cylindrical shapes, and may be, for example, rectangular tube shapes, conical shapes, pyramidal shapes, etc. Furthermore, a convex or concave portion may be formed in a part of the vertical direction, or the tube may be formed in an accordion shape.

[0167] The growth inhibition container C110 has a bottom C113 that closes the lower end of the outer cylinder C111, and a top C114 that closes the upper end of the outer cylinder C111. The bottom C113 is formed in a bottomed cylindrical shape with an open upper end. The bottom C113 is configured to close the lower end of the outer cylinder C111 by fitting the lower end of the outer cylinder C111 into it. The top C114 is formed in a topped cylindrical shape with an open lower end. The top C114 is configured to close the upper end of the outer cylinder C111 by fitting the upper end of the outer cylinder C111 into it.

[0168] The growth inhibition container C110 also has an outer flow space C115 formed between the outer cylinder C111 and the inner cylinder C112, and an inner flow space C116 formed inside the inner cylinder C112. The outer flow space C115 and the inner flow space C116 communicate with each other above and below the inner cylinder C112, and are configured to be able to form a circulation flow path CP that circulates liquid and bubbles.

[0169] 14 to 16 , the upward flow generating section C120 has a gas generating section C121 that generates gas, a gas releasing section C122 that releases the gas generated in the gas generating section C121 into the outer flow space C115 or the inner flow space C116, a gas supplying section C123 that supplies the gas generated in the gas generating section C121 to the gas releasing section C122, and a connecting section C124 that connects the gas releasing section C122 and the gas supplying section C123. While only one upward flow generating section C120 is provided in the third embodiment, this is not limited thereto, and two or more may be provided.

[0170] The gas generation unit C121 is, for example, a fan, a blower, or an ozone generator. Examples of the gas generated by the gas generation unit C121 include air and ozone. When the gas generation unit C121 generates air, a pulverization process is performed in the growth inhibition container C110. On the other hand, when the gas generation unit C121 generates ozone, a pulverization process and an ozone process are performed in the growth inhibition container C110. Note that the gas generated by the gas generation unit C121 is preferably ozone from the viewpoint of increasing the efficiency of biological growth inhibition (sludge volume reduction efficiency). Furthermore, the flow velocity of the gas generated by the gas generation unit C121 is preferably 10 cm / s or more from the viewpoint of generating cavitation (fine bubbles).

[0171] The gas release portion C122 is, for example, a tube and is configured to allow gas to flow. One end of the gas release portion C122 is connected to the connection portion C124, and the other end of the gas release portion C122 is connected to an attachment portion C143c of the support portion C143, which will be described later. Therefore, the gas release portion C122 according to the third embodiment is configured to release gas into the inner flow space C116. Specifically, the gas release portion C122 is configured to release gas into the inner flow space C116 via the support portion C143, which will be described later.

[0172] From the viewpoint of generating an upward flow, the other end of the gas release section C122 only needs to be located below the vertical middle section of the growth inhibition container C110, and may be connected, for example, to the outer cylinder C111 or the inner cylinder C112. When the other end of the gas release section C122 is connected to the outer cylinder C111, the gas release section C122 is configured to release gas into the outer flow space C115.

[0173] The gas supply unit C123 is, for example, a tube and is configured to allow gas to flow. One end of the gas supply unit C123 is connected to the gas generation unit C121, and the other end of the gas supply unit C123 is connected to the connection unit C124. The connection unit C124 is, for example, a tube joint and is inserted into an opening (not shown) formed in the top portion C114.

[0174] The upward flow generating section C120 having the above configuration is configured so that the gas release section C122 releases gas into the inner flow space C116, thereby generating an upward flow containing gas bubbles in the inner flow space C116. When the gas release section C122 releases gas into the outer flow space C115, the upward flow generating section C120 generates an upward flow containing gas bubbles in the outer flow space C115.

[0175] 14 and 15 , the discharge unit C130 has a tubular portion C131 that discharges waste materials from the growth inhibition container C110, and a holding portion C132 that holds the tubular portion C131. Examples of waste materials include excess materials (e.g., gas, liquid, etc.) that exceed the capacity of the growth inhibition container C110, and materials (e.g., foam, etc.) that are generated during the circulation of liquid and bubbles.

[0176] The cylindrical portion C131 is formed in a tubular shape with both ends open and is inserted into an opening (not shown) formed in the top portion C114. That is, the upper end of the cylindrical portion C131 is located outside the growth inhibition container C110, and the lower end of the cylindrical portion C131 is located inside the growth inhibition container C110. As shown in FIG. 14 , the cylindrical portion C131 may be formed by connecting two or more tubes, or may be formed by a single tube. The cylindrical portion C131 also has a plurality of inlet holes C131a that allow gas from the growth inhibition container C110 to flow into the cylindrical portion C131. The inlet holes C131a are provided in a portion of the cylindrical portion C131 that is located inside the growth inhibition container C110 (in the third embodiment, below the axial middle portion of the cylindrical portion C131) and are provided along both the axial and circumferential directions of the cylindrical portion C131.

[0177] The holding portion C132 is formed in a disk shape and has a mounting hole C132a in the center for mounting the tubular portion C131. The holding portion C132 also has insertion holes C132b at both radial ends for inserting protrusions C151c formed on the upper end of the top plate portion C151 (described later). The holding portion C132 is configured to hold the tubular portion C131 by inserting the lower end of the tubular portion C131 into the mounting holes C132a. The holding portion C132 is also configured to be attached to the upper end of the top plate portion C151 by inserting the protrusions C151c into the insertion holes C132b. Attaching the holding portion C132 to the upper end of the top plate portion C151 prevents the inner tube C112 from floating. The holding portion C132 may be omitted or may be formed integrally with the upper swirl flow generating portion C150 (described later).

[0178] The discharge unit C130 having the above configuration is configured to discharge the effluent that has flowed into the tubular portion C131 from the lower end of the tubular portion C131 and the inlet hole C131a of the tubular portion C131 to the outside of the growth inhibition container C110. This has the advantage of being able to suppress an increase in the internal pressure of the growth inhibition container C110. The effluent discharged from the discharge unit C130 can be supplied to, for example, any storage tank.

[0179] <Configuration of the lower swirling flow generating section> As shown in Figures 14, 16 and 17, the lower swirling flow generating section C140 has a weight section C141 placed on the bottom surface of the bottom section C113, a plurality of (seven in the third embodiment) blade sections C142 (lower blade sections) arranged at predetermined intervals around the inner tube C112, and a support section C143 capable of supporting the inner tube C112.

[0180] The blades C142 are provided on the upper surface of the weight portion C141 and are configured to be non-rotatable. Each blade C142 extends radially of the inner cylinder C112 and has a curved shape in the circumferential direction of the inner cylinder C112. In other words, the blades C142 are provided radially around the axis of the inner cylinder C112.

[0181] The inner end of each blade C142 in the extension direction is located within the area of ​​the inner cylinder C112 in plan view. Meanwhile, the outer end of each blade C142 in the extension direction is located within the area between the outer cylinder C111 and the inner cylinder C112 in plan view. Furthermore, each blade C142 is formed so that its height increases from the outer side in the extension direction to the inner side in the extension direction. This has the advantage of allowing efficient swirling without impeding the flow from the outer flow space C115 or the flow from the inner flow space C116.

[0182] The support portion C143 is formed in a cylindrical shape with open upper and lower ends, and has a shape that tapers from the lower end to the upper end. The support portion C143 has an insertion groove C143a at its upper end into which the lower end of the inner tube C112 can be inserted. The insertion groove C143a is formed in a concave shape that recesses downward from the upper end of the support portion C143. The support portion C143 is configured to support the inner tube C112 by inserting the lower end of the inner tube C112 into the insertion groove C143a.

[0183] The support portion C143 has, at its lower end, an annular pipe portion C143b that surrounds the periphery of the blade portion C142. The support portion C143 also has an attachment portion C143c to which the gas release portion C122 is attached.

[0184] The pipe portion C143b is formed in a tubular shape having an internal space through which the gas supplied from the gas release portion C122 can flow. Outlet holes C143d are formed in the inner periphery (the end portion on the blade portion C142 side) of the pipe portion C143b, through which the gas supplied from the gas release portion C122 flows out. In the third embodiment, the outlet holes C143d are multiple openings formed at predetermined intervals in the circumferential direction of the pipe portion C143b. The outlet holes C143d may be a single opening or may be an annular opening extending along the circumferential direction of the pipe portion C143b.

[0185] The mounting portion C143c extends upward from a portion of the circumferential direction of the pipe portion C143b and is cylindrical with open upper and lower ends. Therefore, the gas supplied from the gas release portion C122 flows through the mounting portion C143c and is supplied to the pipe portion C143b. The support portion C143 is configured to connect to the gas release portion C122 by inserting the mounting portion C143c into the other end of the gas release portion C122.

[0186] The support portion C143 having the above configuration is provided between the upper surface of the weight portion C141 and the lower end of the inner cylinder C112, and is configured to communicate the outer flow space C115 and the inner flow space C116 between the lower end of the support portion C143 and the upper surface of the weight portion C141. Specifically, the support portion C143 is attached to the weight portion C141 by fixing a plurality of fixing portions (not shown) extending from the outer periphery of the pipe portion C143b (the end portion on the outer cylinder C111 side) to the outer edge of the weight portion C141. Note that, although the third embodiment has been described with reference to a configuration in which the support portion C143 includes the pipe portion C143b and the attached portion C143c, the present invention is not limited thereto, and a configuration that does not include these portions is also possible.

[0187] <Configuration of the upper swirling flow generating section> As shown in Figures 14, 15 and 18, the upper swirling flow generating section C150 has a top plate section C151 arranged opposite the upper opening C112a of the inner cylinder C112, a plurality of (six in the third embodiment) blade sections C152 (upper blade sections) arranged at predetermined intervals around the inner cylinder C112, and an attachment section C153 that can be attached to the inner cylinder C112.

[0188] The top plate C151 has a circular planar shape. The top plate C151 has an inclined surface C151a that slopes downward at the center in the planar direction. That is, the top plate C151 has a shape in which the center in the planar direction is recessed downward, and is generally formed in a conical shape as a whole. From the viewpoint of efficiently circulating the liquid and bubbles, it is sufficient that at least the lower surface of the top plate C151 has the inclined surface C151a.

[0189] A communication hole C151b is formed in the center of the top plate C151 in the planar direction, which communicates with the inner flow space C116 and the internal space of the cylindrical portion C131. In addition, a plurality of (three in the third embodiment) protrusions C151c are formed on the upper end of the top plate C151 to be inserted into the insertion holes C132b of the holding portion C132.

[0190] The blades C152 are provided on the underside of the top plate C151. Specifically, the blades C152 extend downward from the underside of the top plate C151 and are configured to be non-rotatable. Each blade C152 extends radially of the inner tube C112 and has a curved shape in the circumferential direction of the inner tube C112. In other words, the blades C152 are provided radially from the axis of the inner tube C112.

[0191] The curvature direction of the blade portion C152 may be the same as or different from the curvature direction of the blade portion C142, but it is preferable that they are the same from the viewpoint of efficiently swirling the liquid and bubbles while increasing the flow rate.

[0192] The inner end of each blade C152 in the extension direction is located within the region of the inner cylinder C112 in a bottom view. Meanwhile, the outer end of each blade C152 in the extension direction is located within the region between the outer cylinder C111 and the inner cylinder C112 in a bottom view. Furthermore, each blade C152 is formed so that its height decreases from the outer side in the extension direction toward the inner side in the extension direction. This has the advantage of allowing efficient swirling without impeding the flow from the outer flow space C115 or the flow from the inner flow space C116.

[0193] The attachment portion C153 is formed in a ring shape that surrounds the periphery of the lower end of the blade portion C152. That is, the upper swirl flow generating portion C150 according to the third embodiment is configured to communicate the outer flow space C115 and the inner flow space C116 between the lower surface of the top plate portion C151, the surface of the blade portion C152, and the inner periphery of the attachment portion C153 (the end on the blade portion C152 side).

[0194] The mounting portion C153 has a mounting groove C153a at its lower end into which the upper end of the inner tube C112 can be inserted. The mounting groove C153a is formed in a concave shape that recesses upward from the lower end of the mounting portion C153. The mounting portion C153 is configured to be attached to the inner tube C112 by inserting the upper end of the inner tube C112 into the mounting groove C153a.

[0195] <Configuration of Inner Swirling Flow Generating Section and Outer Swirling Flow Generating Section> In the third embodiment, either the lower swirling flow generating section C140 or the upper swirling flow generating section C150 functions as the inner swirling flow generating section C160 that generates a swirling flow in the inner flow space C116. Furthermore, the other of the lower swirling flow generating section C140 or the upper swirling flow generating section C150 functions as the outer swirling flow generating section C170 that generates a swirling flow in the outer flow space C115.

[0196] Whether the lower swirl flow generating section C140 and the upper swirl flow generating section C150 function as the inner swirl flow generating section C160 or the outer swirl flow generating section C170 depends on the position at which the upward flow generating section C120 generates the upward flow. Specifically, when the upward flow generating section C120 generates an upward flow in the inner flow space C116, the lower swirl flow generating section C140 functions as the inner swirl flow generating section C160, and the upper swirl flow generating section C150 functions as the outer swirl flow generating section C170. On the other hand, when the upward flow generating section C120 generates an upward flow in the outer flow space C115, the lower swirl flow generating section C140 functions as the outer swirl flow generating section C170, and the upper swirl flow generating section C150 functions as the inner swirl flow generating section C160.

[0197] 14 , the liquid supply mechanism C200 includes a liquid storage tank C210 (first liquid storage tank) capable of storing a liquid, and a liquid supply channel C220 (first liquid supply channel) that supplies the liquid stored in the liquid storage tank C210 to the growth inhibition container C110. One end of the liquid supply channel C220 in the flow direction is connected to an outlet (not shown) provided in the liquid storage tank C210, and the other end of the liquid supply channel C220 in the flow direction is connected to an inlet (not shown) provided in the outer cylinder C111 of the growth inhibition container C110. A known valve may be provided at the inlet provided in the outer cylinder C111 of the growth inhibition container C110, and the valve may be opened and closed at any timing. Since known configurations can be employed for the liquid storage tank C210 and the liquid supply channel C220, detailed description thereof will be omitted.

[0198] 14 , the liquid storage mechanism C300 includes a liquid storage tank C310 (second liquid storage tank) capable of storing liquid discharged from the growth inhibition container C110, and a liquid supply channel C320 (second liquid supply channel) that supplies the liquid discharged from the growth inhibition container C110 to the liquid storage tank C310. One end of the liquid supply channel C320 in the flow direction is connected to an outlet (not shown) provided in the outer cylinder C111 of the growth inhibition container C110, and the other end of the liquid supply channel C320 in the flow direction is connected to an inlet (not shown) provided in the liquid storage tank C310. A known valve may be provided at the outlet provided in the outer cylinder C111 of the growth inhibition container C110, and the valve may be opened and closed at any timing. Since known configurations can be employed for the liquid storage tank C310 and the liquid supply channel C320, detailed description thereof will be omitted.

[0199] [Liquid Purification Method] Next, a liquid purification method using the liquid purification system C1 will be described with reference to Figure 19. The liquid purification method according to the third embodiment includes a first supply step of supplying liquid to a growth inhibition container C110, a growth inhibition step (growth inhibition method) of inhibiting the growth of organisms present in the liquid, and a second supply step of supplying liquid to a liquid storage tank C310. The growth inhibition step also includes an inflow step of inflowing liquid into the growth inhibition container C110, a circulation step of circulating the liquid and bubbles B, and a discharge step of discharging the liquid from the growth inhibition container C110.

[0200] [First Supply Step and Inflow Step] The liquid stored in the liquid storage tank C210 is supplied to the growth inhibition container C110 via the liquid supply channel C220 (see arrow F1 in FIG. 19 ). The liquid supplied from the liquid storage tank C210 flows into the growth inhibition container C110 through an inlet provided in the outer cylinder C111.

[0201] [Circulation Process] As shown in Figure 19, an upward flow containing gas bubbles B is generated in the inner flow space C116 (see arrow F2 in Figure 19). Specifically, first, the gas generation unit C121 supplies gas to the gas release unit C122 via the gas supply unit C123 and the connection unit C124. Next, the gas release unit C122 releases the gas into the inner flow space C116 via the support unit C143. This generates an upward flow containing gas bubbles B in the inner flow space C116. Note that the gas released into the inner flow space C116 flows and swirls between the blade units C142, generating a swirling upward flow in the inner flow space C116. That is, the liquid and gas bubbles B in the inner flow space C116 rise in the inner flow space C116 while swirling.

[0202] When the liquid in the inner flow space C116 rises in the inner flow space C116, the liquid in the outer flow space C115 is drawn into the inner flow space C116 (see arrow F3 in FIG. 19 ), and a downward flow is generated in the outer flow space C115 (see arrow F4 in FIG. 19 ). The liquid drawn from the outer flow space C115 to the inner flow space C116 flows between the blade portions C142, and therefore, coupled with the swirling force of the gas released from the gas release portion C122, the liquid rises in the inner flow space C116 while swirling.

[0203] Meanwhile, the liquid and bubbles B rising in the inner flow space C116 rise to the top plate C151, then flow along the inclined surface C151a of the top plate C151 to the outer flow space C115, and then descend through the outer flow space C115 (see arrow F5 in FIG. 19 ). The liquid and bubbles B flowing into the outer flow space C115 swirl between the blades C152, creating a swirling downward flow in the outer flow space C115. That is, the liquid and bubbles B in the outer flow space C115 descend through the outer flow space C115 while swirling.

[0204] The liquid and bubbles B circulate through the circulation flow path CP as described above. Here, the bubbles B dissolve into the liquid as they circulate through the circulation flow path CP. In particular, the growth inhibition device C100 according to the third embodiment generates a swirling flow in the outer flow space C115 and the inner flow space C116, thereby increasing the efficiency of dissolving the bubbles B. When the gas dissolved in the liquid is ozone, ozone treatment using ozone is performed. Furthermore, dissolving the gas into the liquid makes it easier for cavitation (fine bubbles), which will be described later, to occur.

[0205] Furthermore, the bubbles B are broken down into finer particles by swirling in the outer flow space C115 and the inner flow space C116 and by being sheared by the blade portions C142 and C152. The more the bubbles B circulate through the circulation flow path CP, the finer they become. In other words, the growth inhibition device C100 according to the third embodiment is configured to be capable of generating fine bubbles. By generating fine bubbles, the dissolution efficiency of the bubbles B can be increased.

[0206] The fine bubbles include microbubbles (bubbles with a diameter of 1 μm or more and less than 100 μm) and ultrafine bubbles (bubbles with a diameter of less than 1 μm).

[0207] Furthermore, during the circulation process of the liquid and the bubbles B, the bubbles B break (B' in FIG. 19). That is, the growth inhibition device C100 according to the third embodiment is configured to break the bubbles B by circulating the liquid and the bubbles B in the circulation flow path CP. When the bubbles B break, the growth of organisms present in the liquid is inhibited (the sludge is pulverized). Note that if the bubbles B are fine bubbles, the impact force generated when the bubbles B break is large.

[0208] Furthermore, during the circulation of the liquid, cavitation (microbubbles) occurs in the liquid. Specifically, when the liquid is drawn from the outer flow space C115 to the inner flow space C116, the flow rate increases (the pressure of the liquid decreases), and gas dissolved in the liquid is released, generating microbubbles. In particular, when the liquid is drawn from the outer flow space C115 to the inner flow space C116, it flows between the blade portions C142, further increasing the flow rate and making it more likely for cavitation to occur. This cavitation also causes erosion (breakdown of bubbles) and results in a crushing process.

[0209] That is, the growth suppression device C100 according to the third embodiment is configured to generate erosion due to cavitation by circulating the liquid and bubbles B in the circulation flow path CP.

[0210] The growth inhibition device C100 is also configured to control the size of the bubbles by controlling the pressure of the liquid circulating through the circulation flow path CP, thereby controlling the impact force generated when the bubbles break. Methods for controlling the pressure of the liquid include, for example, controlling the flow rate of the gas supplied to the growth inhibition container C110, or controlling the amount of liquid flowing in to control the water depth (the vertical distance from the liquid surface to the liquid bottom).

[0211] [Discharge Step and Second Supply Step] After stopping circulation in the circulation channel CP, the liquid is discharged from the outlet of the growth inhibition container C110. The liquid discharged from the growth inhibition container C110 is supplied to the liquid storage tank C310 via the liquid supply channel C320 (see arrow F6 in FIG. 19 ). The liquid storage tank C310 stores the liquid supplied from the growth inhibition container C110.

[0212] [Advantages of the growth inhibition device of the third embodiment] The growth inhibition device C100 of the third embodiment is a growth inhibition device that inhibits the growth of organisms present in a liquid, and is equipped with a growth inhibition container C110 including an outer tube C111 extending along the vertical direction and at least one inner tube C112 provided inside the outer tube C111, and at least one ascending flow generating section C120 that generates an ascending flow containing bubbles in an outer flow space C115 formed between the outer tube C111 and the inner tube C112 or an inner flow space C116 formed inside the inner tube C112, the inner flow space C116 and the outer flow space C115 being connected to each other above and below the inner tube C112 and configured to be able to form a circulation flow path CP that circulates the liquid and the bubbles, and the growth inhibition container C110 is configured to break down the bubbles by circulating the liquid and the bubbles in the circulation flow path CP.

[0213] The growth inhibition device C100 having such a configuration has the advantage of being able to suppress the growth of organisms by crushing them with the impact force generated when the bubbles break. Furthermore, since there is no need to use chemicals, heat, ultrasound, mills, etc., the growth of organisms present in liquids can be suppressed at low cost while reducing the environmental impact, and there are also advantages in that it is highly reliable and durable. Furthermore, since there is no need to use chemicals, there is also the advantage that it can be suitably used in liquids such as aquariums and bathtubs (hot springs) where chemicals cannot be used.

[0214] In the growth inhibition device C100 according to the third embodiment, the upward flow generating section C120 is provided with at least one gas release section C122 that releases gas into the outer flow space C115 or the inner flow space C116 below the vertical middle section of the growth inhibition container C110. With the growth inhibition device C100 having such a configuration, bubbles can be broken simply by releasing gas from the gas release section C122, which has the advantages of being able to inhibit the growth of organisms present in the liquid at low cost and also being highly reliable and durable.

[0215] The growth suppression device C100 according to the third embodiment includes at least one of an inner swirl flow generating section C160 that generates a swirling flow in the inner flow space C116 and an outer swirl flow generating section C170 that generates a swirling flow in the outer flow space C115. The growth suppression device C100 with this configuration has the advantage of being able to generate a swirling flow, thereby improving the efficiency of dissolving bubbles. Another advantage is that the swirling bubbles can be made finer. By making the bubbles finer, the efficiency of dissolving bubbles can be further improved.

[0216] In the growth suppression device C100 according to the third embodiment, the inner swirl flow generating section C160 and the outer swirl flow generating section C170 each include a plurality of blades C142 (or blades C152) spaced apart at predetermined intervals, each of which has a curved shape in the circumferential direction of the inner cylinder C112. The growth suppression device C100 having such a configuration advantageously generates a swirling flow simply by flowing liquid between the blades C142 (or blades C152). Another advantage is that bubbles are sheared by the blades C142 (or blades C152), thereby reducing the size of the bubbles. By reducing the size of the bubbles, the efficiency of dissolving the bubbles can be further improved.

[0217] In the growth inhibition device C100 according to the third embodiment, the blade portion C142 (or the blade portion C152) is configured to be non-rotatable. The growth inhibition device C100 having such a configuration can generate a swirling flow without rotating the blade portion C142 (or the blade portion C152), which has the advantage of low costs (e.g., the number of parts, power costs, costs associated with part replacement, etc.). Another advantage is that the blade portion C142 (or the blade portion C152) does not rotate, which prevents foreign matter from getting caught on the blade portion C142 (or the blade portion C152).

[0218] The growth inhibition device C100 according to the third embodiment includes a top plate C151 provided opposite the upper opening C112a of the inner cylinder C112, and the bottom surface of the top plate C151 has an inclined surface C151a that slopes downward from the center in the planar direction. The growth inhibition device C100 having such a configuration has the advantage that the rising liquid flows along the inclined surface C151a, thereby enabling efficient circulation of the liquid.

[0219] [Modifications] The growth inhibition device, liquid purification system, and growth inhibition method according to the third embodiment are not limited to the above-described embodiments, and various modifications can be made within the scope that does not deviate from the technical concept of the present invention.

[0220] In the above-described embodiment, the upper swirl flow generating section C150 has been described as including the top plate portion C151, but this is not limited thereto, and the top plate portion C151 may not be included. Moreover, the top plate portion C151 may be formed in a flat shape without including the inclined surface C151a.

[0221] In the above-described embodiment, the growth inhibition device C100 has been described as being equipped with a lower swirling flow generating section C140 and an upper swirling flow generating section C150, but this is not limited to this, and the device may be equipped with only one of these sections, or neither.

[0222] In the above-described embodiment, the growth inhibition device C100 has been described as including a top portion C114 that closes the upper end of the outer cylinder C111 and an exhaust portion C130 that exhausts gas from the growth inhibition container C110. However, the present invention is not limited to this. The device may have an open-type configuration in which the top portions C114 and C130 are not included and the upper ends of the outer cylinder C111 and inner cylinder C112 are open. Furthermore, such an open-type growth inhibition device may be dropped into a pond, the sea, or the like and used to purify the water therein. Furthermore, the top portion C114 may be periodically opened and closed.

[0223] In the above-described embodiment, the liquid supply mechanism C200 has been described as including the liquid storage tank C210, but this is not limited thereto, and the liquid storage tank C210 may be a biological treatment tank. Similarly, the liquid storage mechanism C300 has been described as including the liquid storage tank C310, but this is not limited thereto, and the liquid storage tank C310 may be a biological treatment tank.

[0224] In the above-described embodiment, the outer cylinder C111 and the bottom portion C113 are described as being formed independently, but this is not limited thereto, and the outer cylinder C111 and the bottom portion C113 may be integrally formed. Furthermore, for example, the outer cylinder C111, the bottom portion C113, the weight portion C141, and the blade portion C142 may be integrally formed, or the bottom portion C113, the weight portion C141, and the blade portion C142 may be integrally formed, or the weight portion C141 and the blade portion C142 may be integrally formed. Furthermore, the weight portion C141 need not be provided.

[0225] It is clear from the claims that the above-mentioned modifications are included within the scope of the present invention.

[0226] [Explanation of Use as Separation Apparatus] Next, an example (fourth embodiment) of the liquid treatment apparatus according to this embodiment being used as a separation apparatus will be described, along with background technology and problems of the separation apparatus.

[0227] [Background Technology Regarding Separation Devices] Conventionally, pressurized flotation devices have been known that generate bubbles in a liquid to be treated stored in a flotation tank, and cause suspended matter, etc. in the liquid to adhere to the generated bubbles, thereby separating the liquid to be treated from the suspended matter, etc. (see, for example, JP 2014-147854 A). The pressurized flotation device described in JP 2014-147854 A mixes raw water pressurized by a pressure pump with air supplied from a compressor to generate mixed water, and releases the generated mixed water from an outlet in the flotation tank, thereby generating bubbles.

[0228] [Issues Related to the Separation Device] However, the pressurized flotation device described in JP 2014-147854 A requires a pressure pump to pressurize the raw water in order to generate bubbles in the liquid being treated, which results in the problem of high manufacturing and running costs.

[0229] The fourth embodiment relates to a separation device and a separation method that can achieve separation of separation targets at low cost.

[0230] [Overall Configuration of Separation Apparatus] The separation apparatus according to the fourth embodiment is a separation apparatus that separates a separation target. An example of the separation target is a solid-liquid mixture. When the separation target is a solid-liquid mixture, the separation apparatus separates the solid-liquid mixture into a solid and a liquid. Examples of solid-liquid mixtures include, but are not limited to, any liquid, such as a liquid containing sludge, a liquid mixed with powder, or a liquid containing sand or gravel.

[0231] The separation device according to the fourth embodiment may be used in combination with other separation methods or devices. Examples of other separation methods include a method of capturing solid components with a filter, a method of precipitating or floating solid components, and a method of adsorbing solid components to an adsorbent. Methods of precipitating solid components include, for example, static precipitation, a flocculation precipitation method in which a flocculant is added, and electroprecipitation in which solid components are flocculated by charging. Methods of floating solid components include, for example, atmospheric flotation using the addition of a foaming agent or foam assistant, and pressurized flotation using the injection of fine bubbles. These methods can also be combined as appropriate.

[0232] As shown in Figures 20 to 22, the separation device D1 includes a separation container D10 that separates the separation target, an ascending flow generating section D20 that generates an ascending flow containing air bubbles inside the separation container D10, a discharge section D30 that discharges the discharged material inside the separation container D10, a lower swirling flow generating section D40 provided below an inner cylinder D12 that will be described later, and an upper swirling flow generating section D50 provided above the inner cylinder D12 that will be described later.

[0233] [Configuration of Separation Container] As shown in FIGS. 20 to 22, the separation container D10 has an outer cylinder D11 extending along the vertical direction and an inner cylinder D12 provided inside the outer cylinder D11.

[0234] In this specification, "vertical" includes both completely vertical and approximately vertical. "Approximately vertical" means a slight inclination relative to the vertical, specifically, an inclination that does not impede the effectiveness of the separation device D1.

[0235] The outer tube D11 and the inner tube D12 are each formed into a cylindrical shape with an open upper end and lower end. The outer diameter of the inner tube D12 is smaller than the inner diameter of the outer tube D11. The vertical length of the inner tube D12 is also shorter than the vertical length of the outer tube D11. In the fourth embodiment, only one inner tube D12 is provided, but this is not limited thereto, and two or more inner tubes D12 may be provided.

[0236] The shapes of the outer tube D11 and the inner tube D12 are not limited to cylindrical shapes, and may be, for example, rectangular, conical, or pyramidal. Furthermore, a convex or concave portion may be formed in a vertical portion, or the tube may be bellows-shaped.

[0237] The separation container D10 has a bottom D13 that closes the lower end of the outer cylinder D11, and a top D14 that closes the upper end of the outer cylinder D11. The bottom D13 is formed in a bottomed cylindrical shape with an open upper end. The bottom D13 is configured to close the lower end of the outer cylinder D11 by fitting the lower end of the outer cylinder D11 into it. The top D14 is formed in a topped cylindrical shape with an open lower end. The top D14 is configured to close the upper end of the outer cylinder D11 by fitting the upper end of the outer cylinder D11 into it.

[0238] The separation container D10 also has an outer flow space D15 formed between the outer cylinder D11 and the inner cylinder D12, and an inner flow space D16 formed inside the inner cylinder D12. The outer flow space D15 and the inner flow space D16 are connected to each other above and below the inner cylinder D12, and are configured to be able to form a circulation flow path CP that circulates the objects to be separated and air bubbles.

[0239] 20 to 22 , the upward flow generating section D20 has a gas generating section D21 that generates gas, a gas releasing section D22 that releases the gas generated in the gas generating section D21 into the outer flow space D15 or the inner flow space D16, a gas supplying section D23 that supplies the gas generated in the gas generating section D21 to the gas releasing section D22, and a connecting section D24 that connects the gas releasing section D22 and the gas supplying section D23. While only one upward flow generating section D20 is provided in the fourth embodiment, this is not limited thereto, and two or more may be provided.

[0240] The gas generation unit D21 is, for example, a fan or a blower. The gas generation unit D21 has a switch D21a that starts or stops the generation of gas. In other words, the switch D21a is configured to start or stop the release of gas by the gas release unit D22.

[0241] The gas release section D22 is, for example, a tube and is configured to allow gas to flow. One end of the gas release section D22 is connected to the connection section D24, and the other end of the gas release section D22 is connected to an attachment section D43c of a support section D43, which will be described later. Therefore, the gas release section D22 according to the fourth embodiment is configured to release gas into the inner flow space D16. Specifically, the gas release section D22 is configured to release gas into the inner flow space D16 via the support section D43, which will be described later.

[0242] From the viewpoint of generating an upward flow, the other end of the gas release section D22 only needs to be located below the vertical middle section of the separation container D10, and may be connected to, for example, the outer cylinder D11 or the inner cylinder D12. When the other end of the gas release section D22 is connected to the outer cylinder D11, the gas release section D22 is configured to release gas into the outer flow space D15.

[0243] The gas supply unit D23 is, for example, a tube and is configured to allow gas to flow. One end of the gas supply unit D23 is connected to the gas generation unit D21, and the other end of the gas supply unit D23 is connected to the connection unit D24. The connection unit D24 is, for example, a tube joint and is inserted into an opening (not shown) formed in the top unit D14.

[0244] The upward flow generating section D20 having the above configuration is configured so that the gas release section D22 releases gas into the inner flow space D16, thereby generating an upward flow containing bubbles in the inner flow space D16. When the gas release section D22 releases gas into the outer flow space D15, the upward flow generating section D20 generates an upward flow containing bubbles in the outer flow space D15.

[0245] Furthermore, the upward flow generating unit D20 is configured so that the circulation of the separation target and bubbles in the circulation flow path CP is stopped at any or a predetermined timing by the switch D21a stopping the release of gas by the gas release unit D22. Note that the stopping by the switch D21a may be performed manually or automatically. Examples of a method for automatically stopping by the switch D21a include a method for turning the switch D21a on and then turning it off a predetermined time later, or a method for turning the switch D21a on and then turning it off after a predetermined flow rate has been released, but this is not limited to these.

[0246] 20 and 21 , the discharge unit D30 has a tubular portion D31 that discharges the discharged material in the separation container D10, and a holding portion D32 that holds the tubular portion D31. Examples of the discharged material include excess material (e.g., gas, liquid, etc.) that exceeds the capacity of the separation container D10.

[0247] The cylindrical portion D31 is formed in a tubular shape with both ends open and is inserted into an opening (not shown) formed in the top portion D14. That is, the upper end of the cylindrical portion D31 is located outside the separation container D10, and the lower end of the cylindrical portion D31 is located inside the separation container D10. The cylindrical portion D31 may be formed by connecting two or more tubes as shown in FIG. 20 , or may be formed by a single tube. The cylindrical portion D31 also has a plurality of inlet holes D31a that allow gas from the separation container D10 to flow into the cylindrical portion D31. The inlet holes D31a are provided in a portion of the cylindrical portion D31 located inside the separation container D10 (in the fourth embodiment, below the axial middle portion of the cylindrical portion D31) and are provided along both the axial and circumferential directions of the cylindrical portion D31.

[0248] The holding portion D32 is formed in a disk shape and has a mounting hole D32a in the center for mounting the tubular portion D31. The holding portion D32 also has insertion holes D32b at both radial ends for inserting protrusions D51c formed on the upper end of the top plate portion D51 (described later). The holding portion D32 is configured to hold the tubular portion D31 by inserting the lower end of the tubular portion D31 into the mounting holes D32a. The holding portion D32 is also configured to be attached to the upper end of the top plate portion D51 by inserting the protrusions D51c into the insertion holes D32b. Attaching the holding portion D32 to the upper end of the top plate portion D51 prevents the inner tube D12 from floating. The holding portion D32 may be omitted or may be formed integrally with the upper swirl flow generating portion D50 (described later).

[0249] The discharge unit D30 having the above configuration is configured to discharge the effluent that has flowed into the tubular portion D31 from the lower end of the tubular portion D31 and the inlet holes D31a of the tubular portion D31 to the outside of the separation container D10. The effluent discharged from the discharge unit D30 can be supplied to, for example, any storage tank. Note that, for example, suction may be applied from the discharge unit D30 side to reduce the pressure in the separation container D10. This can increase the flow rate of the separation target and air bubbles circulating through the circulation flow path CP.

[0250] [Configuration of the lower swirling flow generating section] As shown in Figures 20, 22 and 23, the lower swirling flow generating section D40 has a weight section D41 placed on the bottom surface of the bottom section D13, a plurality of (seven in the fourth embodiment) blade sections D42 (lower blade sections) arranged at predetermined intervals around the inner tube D12, and a support section D43 capable of supporting the inner tube D12.

[0251] The blades D42 are provided on the upper surface of the weight portion D41 and are configured to be non-rotatable. Each blade D42 extends along the radial direction of the inner tube D12 and has a shape that is curved in the circumferential direction of the inner tube D12. In other words, the blades D42 are provided radially around the axis of the inner tube D12.

[0252] The inner end of each blade D42 in the extension direction is located within the region of the inner cylinder D12 in plan view. Meanwhile, the outer end of each blade D42 in the extension direction is located within the region between the outer cylinder D11 and the inner cylinder D12 in plan view. Furthermore, each blade D42 is formed so that its height increases from the outer side in the extension direction to the inner side in the extension direction. This has the advantage of allowing efficient swirling without impeding the flow from the outer flow space D15 or the flow from the inner flow space D16.

[0253] The support portion D43 is formed in a cylindrical shape with open upper and lower ends, and has a shape that tapers from the lower end to the upper end. The support portion D43 has an insertion groove D43a at its upper end into which the lower end of the inner tube D12 can be inserted. The insertion groove D43a is formed in a concave shape that is recessed downward from the upper end of the support portion D43. The support portion D43 is configured to support the inner tube D12 by inserting the lower end of the inner tube D12 into the insertion groove D43a.

[0254] The support portion D43 has, at its lower end, an annular pipe portion D43b that surrounds the periphery of the blade portion D42. The support portion D43 also has an attachment portion D43c to which the gas release portion D22 is attached.

[0255] The pipe section D43b is formed in a tubular shape having an internal space through which the gas supplied from the gas release section D22 can flow. Outlet holes D43d are formed in the inner periphery of the pipe section D43b (the end on the blade section D42 side) to allow the gas supplied from the gas release section D22 to flow out. In the fourth embodiment, the outlet holes D43d are multiple openings formed at predetermined intervals in the circumferential direction of the pipe section D43b. The outlet holes D43d may be a single opening or an annular opening extending along the circumferential direction of the pipe section D43b.

[0256] The mounting portion D43c extends upward from a portion of the circumference of the pipe portion D43b and is cylindrical with open upper and lower ends. Therefore, the gas supplied from the gas release portion D22 flows through the mounting portion D43c and is supplied to the pipe portion D43b. The support portion D43 is configured to connect to the gas release portion D22 by inserting the mounting portion D43c into the other end of the gas release portion D22.

[0257] The support portion D43 having the above configuration is provided between the upper surface of the weight portion D41 and the lower end of the inner tube D12, and is configured to communicate the outer flow space D15 and the inner flow space D16 between the lower end of the support portion D43 and the upper surface of the weight portion D41. Specifically, the support portion D43 is attached to the weight portion D41 by fixing a plurality of fixing portions (not shown) extending from the outer periphery of the tube portion D43b (the end portion on the outer tube D11 side) to the outer edge of the weight portion D41. Note that, although the fourth embodiment has been described with reference to a configuration in which the support portion D43 includes the tube portion D43b and the attached portion D43c, the present invention is not limited thereto, and a configuration that does not include these portions is also possible.

[0258] [Configuration of the upper swirling flow generating section] As shown in Figures 20, 21 and 24, the upper swirling flow generating section D50 has a top plate section D51 arranged opposite the upper opening D12a of the inner tube D12, a plurality of (six in the fourth embodiment) blade sections D52 (upper blade sections) arranged at predetermined intervals around the inner tube D12, and an attachment section D53 that can be attached to the inner tube D12.

[0259] The top plate portion D51 has a circular planar shape. The top plate portion D51 has an inclined surface D51a that slopes downward at the center in the planar direction. That is, the top plate portion D51 has a shape in which the center in the planar direction is recessed downward, and is formed in a substantially conical shape as a whole. From the viewpoint of efficiently circulating the separation target and air bubbles, it is sufficient that at least the lower surface of the top plate portion D51 has the inclined surface D51a.

[0260] A communication hole D51b is formed in the center of the top plate portion D51 in the planar direction, which communicates with the inner flow space D16 and the internal space of the cylindrical portion D31. In addition, a plurality of (three in the fourth embodiment) protrusions D51c are formed on the upper end of the top plate portion D51 to be inserted into the insertion holes D32b of the holding portion D32.

[0261] The blades D52 are provided on the underside of the top plate D51. Specifically, the blades D52 extend downward from the underside of the top plate D51 and are configured to be non-rotatable. Each blade D52 extends along the radial direction of the inner tube D12 and has a curved shape in the circumferential direction of the inner tube D12. In other words, the blades D52 are provided radially around the axis of the inner tube D12.

[0262] The direction of curvature of the blade portion D52 may be the same as or different from the direction of curvature of the blade portion D42, but it is preferable that they are the same from the viewpoint of efficiently circulating the separation target and air bubbles.

[0263] The inner end of each blade D52 in the extension direction is located within the region of the inner cylinder D12 in a bottom view. Meanwhile, the outer end of each blade D52 in the extension direction is located within the region between the outer cylinder D11 and the inner cylinder D12 in a bottom view. Furthermore, each blade D52 is formed so that its height decreases from the outer side in the extension direction toward the inner side in the extension direction. This has the advantage of allowing efficient swirling without impeding the flow from the outer flow space D15 or the flow from the inner flow space D16.

[0264] The attachment portion D53 is formed in a ring shape surrounding the periphery of the lower end of the blade portion D52. That is, the upper swirl flow generating portion D50 according to the fourth embodiment is configured to communicate the outer flow space D15 and the inner flow space D16 between the lower surface of the top plate portion D51, the surface of the blade portion D52, and the inner periphery of the attachment portion D53 (the end on the blade portion D52 side).

[0265] The mounting portion D53 has a mounting groove D53a at its lower end into which the upper end of the inner tube D12 can be inserted. The mounting groove D53a is formed in a concave shape that is recessed upward from the lower end of the mounting portion D53. The mounting portion D53 is configured to be attached to the inner tube D12 by inserting the upper end of the inner tube D12 into the mounting groove D53a.

[0266] [Configuration of the Inner Swirling Flow Generating Section and the Outer Swirling Flow Generating Section] In the fourth embodiment, either the lower swirling flow generating section D40 or the upper swirling flow generating section D50 functions as the inner swirling flow generating section D60 that generates a swirling flow in the inner flow space D16. Furthermore, the other of the lower swirling flow generating section D40 or the upper swirling flow generating section D50 functions as the outer swirling flow generating section D70 that generates a swirling flow in the outer flow space D15.

[0267] Whether the lower swirl flow generating section D40 and the upper swirl flow generating section D50 function as the inner swirl flow generating section D60 or the outer swirl flow generating section D70 depends on the position at which the upward flow generating section D20 generates the upward flow. Specifically, when the upward flow generating section D20 generates an upward flow in the inner flow space D16, the lower swirl flow generating section D40 functions as the inner swirl flow generating section D60, and the upper swirl flow generating section D50 functions as the outer swirl flow generating section D70. On the other hand, when the upward flow generating section D20 generates an upward flow in the outer flow space D15, the lower swirl flow generating section D40 functions as the outer swirl flow generating section D70, and the upper swirl flow generating section D50 functions as the inner swirl flow generating section D60.

[0268] [Separation Method] Next, a separation method using the separation device D1 will be described with reference to Fig. 25. The separation method according to the fourth embodiment includes an inflow step of inflowing the separation target into the separation container D10, a circulation step of circulating the separation target and the gas bubbles B, and a stop step of stopping the circulation of the separation target and the gas bubbles B. In the following description, a case of separating a solid-liquid mixture will be described as an example.

[0269] [Inflow Step] The solid-liquid mixture to be separated is flowed into the separation vessel D10. The solid-liquid mixture may be flowed from the upper end of the outer cylinder D11 by removing the top portion D14, or may be flowed from an inlet (not shown) provided in the outer cylinder D11.

[0270] [Circulation Step] As shown in Figure 25, an upward flow containing gas bubbles B is generated in the inner flow space D16 (see arrow F1 in Figure 25). Specifically, first, gas generation is started by the switch D21a of the gas generation unit D21, and the generated gas is supplied to the gas release unit D22 via the gas supply unit D23 and the connection unit D24. Next, the gas release unit D22 releases the gas into the inner flow space D16 via the support unit D43. This generates an upward flow containing gas bubbles B in the inner flow space D16. Note that the gas released into the inner flow space D16 flows and swirls between the blade units D42, generating a swirling upward flow in the inner flow space D16. That is, the solid-liquid mixture and gas bubbles B in the inner flow space D16 rise in the inner flow space D16 while swirling.

[0271] When the solid-liquid mixture in the inner flow space D16 rises in the inner flow space D16, the solid-liquid mixture in the outer flow space D15 is drawn into the inner flow space D16 (see arrow F2 in FIG. 25), and a downward flow is generated in the outer flow space D15 (see arrow F3 in FIG. 25). The solid-liquid mixture drawn from the outer flow space D15 to the inner flow space D16 flows between the blade sections D42, and therefore rises in the inner flow space D16 while swirling, due to the combined effect of the swirling force of the gas released from the gas release section D22.

[0272] On the other hand, the solid-liquid mixture and gas bubbles B rising in the inner flow space D16 rise to the top plate portion D51, then flow along the inclined surface D51a of the top plate portion D51 into the outer flow space D15, and then descend through the outer flow space D15 (see arrow F4 in FIG. 25 ). Note that the solid-liquid mixture and gas bubbles B flowing into the outer flow space D15 swirl as they flow between the blade portions D52, generating a swirling downward flow in the outer flow space D15. That is, the solid-liquid mixture and gas bubbles B in the outer flow space D15 descend through the outer flow space D15 while swirling.

[0273] The solid-liquid mixture and the bubbles B circulate through the circulation flow path CP as described above. During this circulation process, when the solid-liquid mixture and the bubbles B are drawn from the outer flow space D15 to the inner flow space D16, the flow rate increases (the pressure decreases), and the bubbles B become finer. Furthermore, the bubbles B circulating through the circulation flow path CP become finer by swirling in the inner flow space D16 and the outer flow space D15 and by being sheared by the blade portions D42 and D52. In other words, the more the bubbles B circulate through the circulation flow path CP, the finer they become.

[0274] As described above, the separation device D1 according to the fourth embodiment is configured to be capable of generating fine bubbles. By generating fine bubbles, the total surface area of ​​the bubbles generated in the separation device D1 is increased, thereby improving separation performance. Note that fine bubbles include microbubbles (bubbles with a diameter of 1 μm or more and less than 100 μm) and ultrafine bubbles (bubbles with a diameter of less than 1 μm).

[0275] [Stopping Step] The gas generation is stopped at any or predetermined timing by the switch D21a of the gas generation unit D21. This stops the release of gas by the gas release unit D22, and stops the circulation of the solid-liquid mixture and the bubbles B in the circulation flow path CP.

[0276] When the circulation stops, the bubbles B rise in the inner flow space D16 and the outer flow space D15 while adsorbing suspended matter (solids) in the solid-liquid mixture, thereby separating the solid-liquid mixture into solids and liquid.

[0277] [Advantages of the separation device according to the fourth embodiment] The separation device D1 according to the fourth embodiment is a separation device for separating a separation target, and comprises a separation container D10 including an outer cylinder D11 extending along the vertical direction and at least one inner cylinder D12 provided inside the outer cylinder D11, and at least one ascending flow generating section D20 that generates an ascending flow containing bubbles in an outer flow space D15 formed between the outer cylinder D11 and the inner cylinder D12 or an inner flow space D16 formed inside the inner cylinder D12, the inner flow space D16 and the outer flow space D15 being connected to each other above and below the inner cylinder D12 and configured to be able to form a circulation flow path CP that circulates the separation target and the bubbles, and the ascending flow generating section D20 is configured to be able to stop the circulation of the separation target and the bubbles.

[0278] The separation device D1 having such a configuration has the advantage that, after the circulation of the separation target and the bubbles is stopped, the bubbles rise in the inner flow space D16 and the outer flow space D15 while adsorbing suspended solids in the separation target, thereby separating the separation target. Furthermore, since a pressure pump for pressurizing raw water is not required to generate bubbles, separation of the separation target can be achieved at low cost, and reliability and durability are also high. Furthermore, since a pressure pump is not required, there is no need to use a nozzle, which is another advantage, as there is no need to replace the nozzle due to wear.

[0279] Furthermore, the separation device D1 according to the fourth embodiment can efficiently and inexpensively clean the interior of the separation container D10. That is, even if a highly viscous substance adheres to the separation container D10 and is difficult to clean manually, simply supplying a liquid (e.g., tap water) into the separation container D10 and performing the circulation process described above makes it possible to remove the adhered substance from the separation container D10 by floating it on the liquid surface or settling it therein. Similarly, simply placing the substance to be cleaned (e.g., a dirty container) into the separation container D10, supplying a liquid (e.g., tap water) into the separation container D10, and performing the circulation process described above can separate and clean the substance from the object to be cleaned. Thanks to these features, the separation device D1 according to the fourth embodiment can also be used as a cleaning device that can be easily cleaned. In particular, since no chemicals are required for cleaning, it can also be used in food and beverage-related equipment. Furthermore, since there is no need to provide a reduction section in the outer tube D11 or the inner tube D12, cleaning can be performed without clogging.

[0280] In the separation apparatus D1 according to the fourth embodiment, the ascending flow generating section D20 is provided with at least one gas release section D22 that releases gas into the outer flow space D15 or the inner flow space D16, below the vertical middle section of the separation container D10. The separation apparatus D1 having such a configuration can generate an ascending flow containing bubbles simply by releasing gas from the gas release section D22, and can circulate the separation target and the bubbles, which has the advantages of allowing the separation target to be separated at low cost and also having high reliability and durability.

[0281] The separation device D1 according to the fourth embodiment includes a top plate D51 provided opposite the upper opening D12a of the inner cylinder D12, and the bottom surface of the top plate D51 has an inclined surface D51a that slopes downward from the center in the planar direction. The separation device D1 having such a configuration has the advantage that the elevated separation objects flow along the inclined surface D51a, allowing the separation objects to be circulated efficiently.

[0282] The separation device D1 according to the fourth embodiment includes at least one of an inner swirling flow generating section D60 that generates a swirling flow in the inner flow space D16 and an outer swirling flow generating section D70 that generates a swirling flow in the outer flow space D15. The separation device D1 having such a configuration has the advantage that the swirling flow facilitates the circulation of the separation target and the bubbles. Another advantage is that the swirling of the bubbles can result in the bubbles being refined. The refinement of the bubbles increases the total surface area of ​​the bubbles, thereby improving separation performance.

[0283] In the separation device D1 according to the fourth embodiment, the inner swirl flow generating section D60 and the outer swirl flow generating section D70 each include a plurality of blade sections D42 (or blade sections D52) arranged at predetermined intervals, and the plurality of blade sections D42 (or blade sections D52) have a curved shape in the circumferential direction of the inner cylinder D12. The separation device D1 having such a configuration has the advantage that a swirl flow can be generated simply by flowing the separation target between the blade sections D42 (or blade sections D52). Another advantage is that bubbles can be sheared by the blade sections D42 (or blade sections D52), thereby reducing the size of the bubbles. Reducing the size of the bubbles increases the total surface area of ​​the bubbles, thereby improving separation performance. Another advantage is that solids, as well as bubbles, are sheared by the blade sections D42 (or blade sections D52), thereby reducing the size of the solids and making them more likely to float.

[0284] In the separation device D1 according to the fourth embodiment, the blade portion D42 (or the blade portion D52) is configured to be non-rotatable. The separation device D1 having such a configuration has the advantage of being able to generate a swirling flow without rotating the blade portion D42 (or the blade portion D52), thereby reducing costs (e.g., the number of parts, power costs, costs associated with part replacement, etc.). Another advantage is that the blade portion D42 (or the blade portion D52) does not rotate, so foreign matter does not get caught on the blade portion D42 (or the blade portion D52).

[0285] [Modifications] The separation device and separation method according to the fourth embodiment are not limited to the above-described embodiment, and various modifications can be made without departing from the technical concept of the present invention.

[0286] In the above-described embodiment, the upper swirl flow generating section D50 has been described as including the top plate section D51, but this is not limited thereto, and the top plate section D51 may not be included. Moreover, the top plate section D51 may be formed in a flat shape without including the inclined surface D51 a.

[0287] In the above-described embodiment, the separation device D1 has been described as being equipped with a lower swirling flow generating section D40 and an upper swirling flow generating section D50, but this is not limited to this, and the separation device D1 may be equipped with only one of these sections, or neither.

[0288] In the above-described embodiment, the separation device D1 has been described as having a top D14 that closes the upper end of the outer tube D11 and an exhaust section D30 that exhausts gas from the separation container D10, but this is not limited to this, and the separation device D1 may be configured as an open-to-air type in which the top D14 and exhaust section D30 are not provided and the upper ends of the outer tube D11 and inner tube D12 are open.

[0289] In the above-described embodiment, the outer tube D11 and the bottom portion D13 are described as being formed independently, but this is not limited thereto, and the outer tube D11 and the bottom portion D13 may be integrally formed. Furthermore, for example, the outer tube D11, the bottom portion D13, the weight portion D41, and the blade portion D42 may be integrally formed, or the bottom portion D13, the weight portion D41, and the blade portion D42 may be integrally formed, or the weight portion D41 and the blade portion D42 may be integrally formed. Furthermore, the weight portion D41 need not be provided.

[0290] It is clear from the claims that the above-mentioned modifications are included within the scope of the present invention.

[0291] [Explanation of Use as Biological Treatment Device] Next, an example (fifth embodiment) of using the liquid treatment device according to this embodiment as a biological treatment device will be described, along with background technology and problems of the biological treatment device.

[0292] [Background Technology for Biological Treatment Equipment] As one type of liquid treatment system for treating liquids, a liquid purification system that purifies wastewater using microorganisms has been known. For example, Japanese Patent Application Laid-Open No. 2004-132037 discloses a circulating flush toilet that includes a mechanism for purifying wastewater discharged from a flush toilet and circulating the purified water back into the flush toilet bowl.

[0293] The circulating flush toilet of JP 2004-132037 A includes a biological treatment tank that decomposes organic matter in wastewater and performs nitrification and denitrification treatments, a filtration tank that separates the biologically treated water from the biological treatment tank into solid and liquid, and a decolorization tank that decolorizes the filtrate separated from the solid and liquid in the filtration tank, and is configured to reuse the treated water decolorized in the decolorization tank as flush water for the flush toilet.

[0294] [Issues Related to Biological Treatment Devices] However, conventional liquid purification systems including the circulating flush toilet of JP 2004-132037 A have the problem that persistent substances such as cellulose fibers, the raw material for toilet paper, are difficult to decompose, and biological treatment in the biological treatment tank takes a long time. Furthermore, if the concentration of microorganisms in the biological treatment tank is increased in order to shorten the biological treatment time in the biological treatment tank, there is a problem that oxygen in the biological treatment tank will be insufficient, reducing the biological treatment ability of the microorganisms and potentially leading to a decrease in treatment efficiency.

[0295] The fifth embodiment relates to a biological treatment device and a biological treatment method that can decompose hardly decomposable substances with high efficiency even at a low concentration of microorganisms.

[0296] [Uses of Biological Treatment Device] The biological treatment device E1 according to the fifth embodiment is a biological treatment device that decomposes decomposition target substances using microorganisms. The biological treatment device E1 according to the fifth embodiment can be used for purifying various raw waters, such as domestic wastewater, sewage, rainwater, surface water, and groundwater discharged from consumers, and for recycling the treated water into domestic water that can be used for flushing toilets, baths, showers, laundry, washing dishes, etc., or treated water that can be used as potable water.

[0297] In particular, the biological treatment device E1 of the fifth embodiment can decompose the difficult-to-decompose substances contained in the various raw waters mentioned above in a biological treatment tank with a low microbial concentration, for example, a microbial concentration of MLSS (activated sludge suspended solids) of about 750 mg / L, and therefore can be used in small liquid treatment systems.

[0298] For example, the biological treatment device E1 according to the fifth embodiment can be used in a liquid treatment system incorporated into a building or a mobile object. Examples of buildings include, but are not limited to, residences, villas, mountain cabins, temporary housing, and mobile homes built in mountainous areas where water supply and sewage systems are not available. Examples of mobile objects include, but are not limited to, automobiles, trains, ships, airplanes, and trailer homes.

[0299] The biological treatment device E1 according to the fifth embodiment can also be used in a liquid treatment system independent of a building or a mobile object. For example, the biological treatment device E1 according to the fifth embodiment can be incorporated into a portable system that can be transported and used at a predetermined location, such as an outdoor event venue, construction site, campsite, or disaster evacuation shelter.

[0300] The substances to be decomposed by the biological treatment device E1 according to the fifth embodiment include not only organic matter such as easily decomposable substances for microorganisms, but also organic matter such as difficult-to-decompose substances for microorganisms. Examples of difficult-to-decompose substances include insoluble dietary fiber and protein. Examples of insoluble dietary fiber include cellulose.

[0301] [Overall configuration of biological treatment device]

[0302] As shown in Figures 26 to 28, the biological treatment device E1 comprises a biological treatment tank E10 in which microorganisms are used to perform biological treatment on substances to be decomposed, an upward flow generating section E20 that generates an upward flow inside the biological treatment tank E10, a discharge section E30 that discharges waste from the biological treatment tank E10, a lower swirling flow generating section E40 provided below the inner tube E12 described later, and an upper swirling flow generating section E50 provided above the inner tube E12 described later.

[0303] [Configuration of Biological Treatment Tank] As shown in Figures 26 to 28, the biological treatment tank E10 has an outer cylinder E11 extending vertically and an inner cylinder E12 provided inside the outer cylinder E11. The biological treatment tank E10 is configured to be able to store a mixed liquid containing microorganisms and substances to be decomposed. There are no particular restrictions on the type of microorganisms contained in the biological treatment tank E10, as long as they are capable of decomposing the substances to be decomposed.

[0304] In this specification, "vertical" includes both completely vertical and approximately vertical. "Approximately vertical" means a slight inclination relative to the vertical, specifically, an inclination that does not impede the effects of the biological treatment device E1.

[0305] The outer cylinder E11 and the inner cylinder E12 are each formed in a cylindrical shape with an open upper end and lower end. The outer diameter of the inner cylinder E12 is smaller than the inner diameter of the outer cylinder E11. The vertical length of the inner cylinder E12 is also shorter than the vertical length of the outer cylinder E11. In the fifth embodiment, only one inner cylinder E12 is provided, but this is not limited thereto, and two or more inner cylinders E12 may be provided.

[0306] The shapes of the outer tube E11 and the inner tube E12 are not limited to cylindrical shapes, and may be, for example, rectangular, conical, or pyramidal. Furthermore, a convex or concave portion may be formed in a vertical portion, or the tube may be bellows-shaped.

[0307] The biological treatment tank E10 has a bottom E13 that closes the lower end of the outer cylinder E11, and a top E14 that closes the upper end of the outer cylinder E11. The bottom E13 is formed in a bottomed cylindrical shape with an open upper end. The bottom E13 is configured to close the lower end of the outer cylinder E11 by fitting the lower end of the outer cylinder E11 into it. The top E14 is formed in a topped cylindrical shape with an open lower end. The top E14 is configured to close the upper end of the outer cylinder E11 by fitting the upper end of the outer cylinder E11 into it.

[0308] The biological treatment tank E10 also has an outer flow space E15 formed between the outer cylinder E11 and the inner cylinder E12, and an inner flow space E16 formed inside the inner cylinder E12. The outer flow space E15 and the inner flow space E16 are connected to each other on the upper and lower sides of the inner cylinder E12, and are configured to be able to form a circulation flow path CP that circulates a mixed liquid containing microorganisms and substances to be decomposed.

[0309] 26 to 28 , the upward flow generating section E20 has a gas generating section E21 that generates gas, a gas releasing section E22 that releases the gas generated in the gas generating section E21 into the outer flow space E15 or the inner flow space E16, a gas supplying section E23 that supplies the gas generated in the gas generating section E21 to the gas releasing section E22, and a connecting section E24 that connects the gas releasing section E22 and the gas supplying section E23. While only one upward flow generating section E20 is provided in the fifth embodiment, this is not limited thereto, and two or more may be provided.

[0310] The gas generation unit E21 is, for example, a fan or a blower. The gas release unit E22 is, for example, a tube and is configured to allow gas to flow. One end of the gas release unit E22 is connected to the connection unit E24, and the other end of the gas release unit E22 is connected to an attachment unit E43c of the support unit E43, which will be described later. Therefore, the gas release unit E22 according to the fifth embodiment is configured to release gas into the inner flow space E16. Specifically, the gas release unit E22 is configured to release gas into the inner flow space E16 via the support unit E43, which will be described later.

[0311] From the viewpoint of generating an upward flow, the other end of the gas release section E22 may be located below the vertical middle of the biological treatment tank E10, and may be connected to, for example, the outer cylinder E11 or the inner cylinder E12. When the other end of the gas release section E22 is connected to the outer cylinder E11, the gas release section E22 is configured to release gas into the outer flow space E15.

[0312] The gas supply unit E23 is, for example, a tube and is configured to allow gas to flow. One end of the gas supply unit E23 is connected to the gas generation unit E21, and the other end of the gas supply unit E23 is connected to the connection unit E24. The connection unit E24 is, for example, a tube joint and is inserted into an opening (not shown) formed in the top unit E14.

[0313] The upward flow generating section E20 having the above configuration is configured so that the gas release section E22 releases gas into the inner flow space E16, thereby generating an upward flow in the inner flow space E16. When the gas release section E22 releases gas into the outer flow space E15, the upward flow generating section E20 generates an upward flow in the outer flow space E15.

[0314] 26 and 27, the discharge unit E30 has a tubular section E31 that discharges waste from the biological treatment tank E10 and a holding section E32 that holds the tubular section E31. Examples of waste include excess material (e.g., gas or liquid) that exceeds the volume of the biological treatment tank E10 and waste products (e.g., foam) that are generated by mixing. The biological treatment device E1 may also be configured to include a filter (not shown) that prevents microorganisms from escaping from the biological treatment tank E10, and to discharge the waste from the discharge unit E30 through the filter.

[0315] The cylindrical portion E31 is tubular and open at both ends, and is inserted into an opening (not shown) formed in the top portion E14. That is, the upper end of the cylindrical portion E31 is located outside the biological treatment tank E10, and the lower end of the cylindrical portion E31 is located inside the biological treatment tank E10. As shown in FIG. 26 , the cylindrical portion E31 may be formed by connecting two or more tubes, or may be formed by a single tube. The cylindrical portion E31 also has multiple inlet holes E31a that allow gas from the biological treatment tank E10 to flow into the cylindrical portion E31. The inlet holes E31a are located in a portion of the cylindrical portion E31 that is located inside the biological treatment tank E10 (in the fifth embodiment, below the axial middle of the cylindrical portion E31) and are provided along both the axial and circumferential directions of the cylindrical portion E31. The axial length of the cylindrical portion E31 may be varied depending on the application.

[0316] The holding portion E32 is formed in a disk shape and has a mounting hole E32a in the center for mounting the tubular portion E31. The holding portion E32 also has insertion holes E32b at both radial ends for inserting protrusions E51c formed on the upper end of the top plate portion E51 (described later). The holding portion E32 is configured to hold the tubular portion E31 by inserting the lower end of the tubular portion E31 into the mounting holes E32a. The holding portion E32 is also configured to be attached to the upper end of the top plate portion E51 by inserting the protrusions E51c into the insertion holes E32b. Attaching the holding portion E32 to the upper end of the top plate portion E51 prevents the inner tube E12 from floating. The holding portion E32 may be omitted or may be formed integrally with the upper swirl flow generating portion E50 (described later).

[0317] The discharge section E30 having the above configuration is configured to discharge the effluent that has flowed into the tubular section E31 from the lower end of the tubular section E31 and the inlet holes E31a of the tubular section E31 to the outside of the biological treatment tank E10. The effluent discharged from the discharge section E30 can be supplied to, for example, any storage tank.

[0318] [Configuration of the lower swirling flow generating section] As shown in Figures 26, 28 and 29, the lower swirling flow generating section E40 has a weight section E41 placed on the bottom surface of the bottom section E13, a plurality of (seven in the fifth embodiment) blade sections E42 (lower blade sections) arranged at predetermined intervals around the inner tube E12, and a support section E43 capable of supporting the inner tube E12.

[0319] The blades E42 are provided on the upper surface of the weight portion E41 and are configured to be non-rotatable. Each blade E42 extends along the radial direction of the inner tube E12 and has a shape that is curved in the circumferential direction of the inner tube E12. In other words, the blades E42 are provided radially around the axis of the inner tube E12.

[0320] The inner end of each blade E42 in the extension direction is located within the area of ​​the inner tube E12 in a plan view. Meanwhile, the outer end of each blade E42 in the extension direction is located within the area between the outer tube E11 and the inner tube E12 in a plan view. Furthermore, each blade E42 is formed so that its height increases from the outer side in the extension direction to the inner side in the extension direction. This has the advantage of allowing efficient swirling without obstructing the flow from the outer flow space E15 or the flow from the inner flow space E16.

[0321] The support portion E43 is formed in a cylindrical shape with open upper and lower ends, and has a shape that tapers from the lower end to the upper end. The support portion E43 has an insertion groove E43a at its upper end into which the lower end of the inner tube E12 can be inserted. The insertion groove E43a is formed in a concave shape that recesses downward from the upper end of the support portion E43. The support portion E43 is configured to support the inner tube E12 by inserting the lower end of the inner tube E12 into the insertion groove E43a.

[0322] The support portion E43 has, at its lower end, an annular pipe portion E43b that surrounds the periphery of the blade portion E42. The support portion E43 also has an attachment portion E43c to which the gas release portion E22 is attached.

[0323] The pipe section E43b is formed in a tubular shape having an internal space through which the gas supplied from the gas release section E22 can flow. Outlet holes E43d are formed in the inner periphery of the pipe section E43b (the end on the blade section E42 side) to allow the gas supplied from the gas release section E22 to flow out. In the fifth embodiment, the outlet holes E43d are multiple openings formed at predetermined intervals in the circumferential direction of the pipe section E43b. The outlet holes E43d may be a single opening or an annular opening extending along the circumferential direction of the pipe section E43b.

[0324] The mounting portion E43c extends upward from a portion of the circumferential direction of the pipe portion E43b and is cylindrical with open upper and lower ends. Therefore, the gas supplied from the gas release portion E22 flows through the mounting portion E43c and is supplied to the pipe portion E43b. The support portion E43 is configured to connect to the gas release portion E22 by inserting the mounting portion E43c into the other end of the gas release portion E22.

[0325] The support portion E43 having the above configuration is provided between the upper surface of the weight portion E41 and the lower end of the inner tube E12, and is configured to communicate the outer flow space E15 and the inner flow space E16 between the lower end of the support portion E43 and the upper surface of the weight portion E41. Specifically, the support portion E43 is attached to the weight portion E41 by fixing a plurality of fixing portions (not shown) extending from the outer periphery of the tube portion E43b (the end portion on the outer tube E11 side) to the outer edge of the weight portion E41. Note that, although the fifth embodiment has been described with reference to a configuration in which the support portion E43 includes the tube portion E43b and the attached portion E43c, the present invention is not limited thereto, and a configuration that does not include these may also be used.

[0326] [Configuration of the upper swirling flow generating section] As shown in Figures 26, 27 and 30, the upper swirling flow generating section E50 has a top plate section E51 arranged opposite the upper opening E12a of the inner tube E12, a plurality of (six in the fifth embodiment) blade sections E52 (upper blade sections) arranged at predetermined intervals around the inner tube E12, and an attachment section E53 that can be attached to the inner tube E12.

[0327] The top plate portion E51 has a circular planar shape. The top plate portion E51 also has an inclined surface E51a that slopes downward at the center in the planar direction. That is, the top plate portion E51 has a shape in which the center in the planar direction is recessed downward, and is formed in a generally conical shape as a whole. Note that, from the viewpoint of efficiently circulating the mixed liquid containing the microorganisms and the substances to be decomposed, it is sufficient that at least the lower surface of the top plate portion E51 has the inclined surface E51a.

[0328] A communication hole E51b is formed in the center of the top plate portion E51 in the planar direction, and the communication hole E51b communicates with the inner flow space E16 and the internal space of the cylindrical portion E31. In addition, a plurality of (three in the fifth embodiment) protrusions E51c are formed on the upper end of the top plate portion E51 to be inserted into the insertion holes E32b of the holding portion E32.

[0329] The blades E52 are provided on the underside of the top plate E51. Specifically, the blades E52 extend downward from the underside of the top plate E51 and are configured to be non-rotatable. Each blade E52 extends along the radial direction of the inner tube E12 and has a curved shape in the circumferential direction of the inner tube E12. In other words, the blades E52 are provided radially around the axis of the inner tube E12.

[0330] The curved direction of the blade portion E52 may be the same as or different from the curved direction of the blade portion E42, but is preferably different from the curved direction of the blade portion E42 in order to efficiently mix the mixed liquid containing the microorganisms and the substance to be decomposed and to improve the decomposition rate by the microorganisms. In the fifth embodiment, the curved direction of the blade portion E42 is leftward (counterclockwise), and the curved direction of the blade portion E52 is rightward (clockwise).

[0331] The inner end of each blade E52 in the extension direction is located within the area of ​​the inner tube E12 in a bottom view. Meanwhile, the outer end of each blade E52 in the extension direction is located within the area between the outer tube E11 and the inner tube E12 in a bottom view. Furthermore, each blade E52 is formed so that its height decreases from the outer side in the extension direction toward the inner side in the extension direction. This has the advantage of allowing efficient swirling without impeding the flow from the outer flow space E15 or the flow from the inner flow space E16.

[0332] The attachment portion E53 is formed in a ring shape surrounding the periphery of the lower end of the blade portion E52. That is, the upper swirl flow generating portion E50 according to the fifth embodiment is configured to communicate the outer flow space E15 and the inner flow space E16 between the lower surface of the top plate portion E51, the surface of the blade portion E52, and the inner periphery of the attachment portion E53 (the end on the blade portion E52 side).

[0333] The mounting portion E53 has a mounting groove E53a at its lower end into which the upper end of the inner tube E12 can be inserted. The mounting groove E53a is formed in a concave shape that is recessed upward from the lower end of the mounting portion E53. The mounting portion E53 is configured to be attached to the inner tube E12 by inserting the upper end of the inner tube E12 into the mounting groove E53a.

[0334] [Configuration of the Inner Swirling Flow Generating Unit and the Outer Swirling Flow Generating Unit] In the fifth embodiment, either the lower swirling flow generating unit E40 or the upper swirling flow generating unit E50 functions as the inner swirling flow generating unit E60 that generates a swirling flow in the inner flow space E16. Furthermore, the other of the lower swirling flow generating unit E40 or the upper swirling flow generating unit E50 functions as the outer swirling flow generating unit E70 that generates a swirling flow in the outer flow space E15.

[0335] Whether the lower swirl flow generating section E40 and the upper swirl flow generating section E50 function as the inner swirl flow generating section E60 or the outer swirl flow generating section E70 depends on the position at which the upward flow generating section E20 generates the upward flow. Specifically, when the upward flow generating section E20 generates an upward flow in the inner flow space E16, the lower swirl flow generating section E40 functions as the inner swirl flow generating section E60, and the upper swirl flow generating section E50 functions as the outer swirl flow generating section E70. On the other hand, when the upward flow generating section E20 generates an upward flow in the outer flow space E15, the lower swirl flow generating section E40 functions as the outer swirl flow generating section E70, and the upper swirl flow generating section E50 functions as the inner swirl flow generating section E60.

[0336] [Biological Treatment Method] Next, a biological treatment method using the biological treatment device E1 will be described with reference to Figure 31. The biological treatment method according to the fifth embodiment includes an inflow process of inflowing substances to be decomposed into the biological treatment tank E10, and a circulation process of circulating a mixed liquid containing microorganisms and the substances to be decomposed. Note that the term "inflowing substances to be decomposed" does not only mean flowing a liquid such as wastewater containing the substances to be decomposed into the biological treatment tank E10 via piping or the like, but also includes the meaning of introducing the substances to be decomposed through an opening or the like of the biological treatment tank E10.

[0337] [Inflow Step] The decomposition target substance is introduced into the biological treatment tank E10, and a mixed solution of the microorganisms and the decomposition target substance is stored in the biological treatment tank E10. The introduction of the decomposition target substance may be performed from the upper end of the outer cylinder E11 by removing the top E14, or may be performed from an inlet (not shown) provided in the outer cylinder E11. The liquid and microorganisms that form the mixed solution may be introduced together with the decomposition target substance, or may be stored in the biological treatment tank E10 in advance.

[0338] [Circulation Step] As shown in Figure 31, an upward flow is generated in the inner flow space E16 (see arrow F1 in Figure 31). Specifically, first, the gas generation unit E21 supplies gas to the gas release unit E22 via the gas supply unit E23 and the connection unit E24. Next, the gas release unit E22 releases the gas into the inner flow space E16 via the support unit E43. This generates an upward flow in the inner flow space E16. Note that the gas released into the inner flow space E16 flows and swirls between the blade units E42, generating a swirling, spiral upward flow in the inner flow space E16. In other words, the mixed liquid in the inner flow space E16 rises in the inner flow space E16 while swirling.

[0339] When the mixed liquid in the inner flow space E16 rises in the inner flow space E16, the mixed liquid in the outer flow space E15 is drawn into the inner flow space E16 (see arrow F2 in FIG. 31 ), and a downward flow is generated in the outer flow space E15 (see arrow F3 in FIG. 31 ). The mixed liquid drawn from the outer flow space E15 to the inner flow space E16 flows between the blade portions E42, and therefore rises in the inner flow space E16 while swirling, due to the combined effect of the swirling force of the gas released from the gas release portion E22.

[0340] On the other hand, the mixed liquid rising in the inner flow space E16 rises to the top plate portion E51, then flows along the inclined surface E51a of the top plate portion E51 into the outer flow space E15, and then descends through the outer flow space E15 (see arrow F4 in Figure 31). Note that the mixed liquid flowing into the outer flow space E15 swirls as it flows between the blade portions E52, generating a swirling spiral downward flow in the outer flow space E15. In other words, the mixed liquid in the outer flow space E15 descends through the outer flow space E15 while swirling.

[0341] The mixed liquid circulates through the circulation flow path CP as described above. During the circulation process through the circulation flow path CP, the flow rate increases (pressure decreases) as the mixed liquid and bubbles are drawn from the outer flow space E15 to the inner flow space E16, causing the bubbles to become finer. The bubbles circulating through the circulation flow path CP become finer as they swirl through the inner flow space E16 and the outer flow space E15 and are sheared by the blade portions E42 and E52. That is, the more the bubbles circulate through the circulation flow path CP, the finer they become. The decomposition target substances contained in the mixed liquid are also finer as they are sheared by the blade portions E42 and E52.

[0342] As described above, the biological treatment apparatus E1 and biological treatment method according to the fifth embodiment are capable of generating fine bubbles. By generating fine bubbles, the total surface area of ​​the bubbles generated in the biological treatment tank E10 increases, thereby improving the decomposition performance of the microorganisms. Note that fine bubbles include microbubbles (bubbles with a diameter of 1 μm or more but less than 100 μm) and ultrafine bubbles (bubbles with a diameter of less than 1 μm).

[0343] [Advantages of the biological treatment device according to the fifth embodiment] The biological treatment device E1 according to the fifth embodiment is a biological treatment device E1 that decomposes substances to be decomposed using microorganisms, and is equipped with a tubular member (inner tube E12) extending in the vertical direction, at least one upward flow generating section E20 that generates an upward flow in an outer flow space E15 formed outside the tubular member (inner tube E12) or an inner flow space E16 formed inside the tubular member (inner tube E12), and a plurality of blade sections E42, E52, the inner flow space E16 and the outer flow space E15 being connected to each other on the upper and lower sides of the tubular member (inner tube E12) and configured to be able to form a circulation flow path CP that circulates a mixed liquid containing microorganisms and substances to be decomposed, and the plurality of blade sections E42, E52 are arranged so as not to be rotatable in the circulation flow path CP.

[0344] According to the biological treatment device E1 having such a configuration, the air bubbles contained in the mixed liquid can be sheared by the blades E42, E52 to make the air bubbles finer. Furthermore, not only the air bubbles but also the substances to be decomposed contained in the mixed liquid can be sheared by the blades E42, E52 to make them finer, or can be softened by collision with the blades E42, E52 to reduce their density.

[0345] Due to these factors and others, the biological treatment device E1 of the fifth embodiment is able to dramatically increase the contact efficiency between the substance to be decomposed, microorganisms, and air bubbles (oxygen) compared to when simply performing aeration treatment, and can accelerate biological decomposition using microorganisms, thereby offering the advantage of being able to decompose difficult-to-decompose substances with high efficiency even at low microbial concentrations (for example, microbial concentrations with an MLSS of approximately 750 mg / L).

[0346] Furthermore, since the biological treatment device E1 of the fifth embodiment does not require the blade portions E42 and E52 to rotate, the cost of introducing a motor, the power cost of the blade portions E42 and E52, and the cost of replacing parts can be reduced compared to devices equipped with a stirrer.In addition, since there is no driving part such as a motor that rotates the blade portions E42 and E52, it is less likely to break down even if solid matter such as hair is mixed in, and has the advantage of being highly reliable and durable.

[0347] Furthermore, the biological treatment device E1 according to the fifth embodiment further includes at least one of an inner swirling flow generating section E60 that generates a swirling flow in the inner flow space E16 and an outer swirling flow generating section E70 that generates a swirling flow in the outer flow space E15, and the blades E42, E52 have a curved shape in the circumferential direction of the cylindrical member (inner cylinder E12). With this configuration, the biological treatment device E1 according to the fifth embodiment can generate a spiral swirling flow simply by flowing the mixed liquid between the blades E42, E52. This spiral swirling flow lengthens the circulation path (contact distance) of the mixed liquid, and the curved shape of the blades E42, E52 increases the number of spiral turns, further lengthening the circulation path of the mixed liquid, which has the advantage of further accelerating biodegradation by microorganisms.

[0348] [Modifications] The biological treatment device and biological treatment method according to the fifth embodiment are not limited to the above-described embodiment, and various modifications can be made within the scope that does not deviate from the technical concept of the present invention.

[0349] In the above-described embodiment, the biological treatment device E1 has been described as including an outer tube E11 and an inner tube E12, but is not limited thereto and may include only the inner tube E12 (tubular member). In this case, the biological treatment device E1 may be used by being placed in, for example, a water tank or a bathtub.

[0350] In the above-described embodiment, the upper swirl flow generating section E50 has been described as including the top plate section E51, but this is not limited thereto, and the top plate section E51 may not be included. Furthermore, the top plate section E51 may be formed in a flat shape without including the inclined surface E51 a.

[0351] In the above-described embodiment, the biological treatment device E1 has been described as being equipped with an inner swirling flow generating section E60 and an outer swirling flow generating section E70, but this is not limited to this and the device may be equipped with only one of them.

[0352] In the above-described embodiment, the biological treatment device E1 has been described as having a top E14 that closes the upper end of the outer tube E11 and an exhaust section E30 that exhausts gas from the biological treatment tank E10, but this is not limited to this, and the device may be configured as an open-to-air type that does not have these top E14 and exhaust section E30 and has open upper ends for the outer tube E11 and inner tube E12.

[0353] In the above-described embodiment, the outer tube E11 and the bottom portion E13 are described as being formed independently, but this is not limited thereto, and the outer tube E11 and the bottom portion E13 may be integrally formed. Furthermore, for example, the outer tube E11, the bottom portion E13, the weight portion E41, and the blade portion E42 may be integrally formed, or the bottom portion E13, the weight portion E41, and the blade portion E42 may be integrally formed, or the weight portion E41 and the blade portion E42 may be integrally formed. Furthermore, the weight portion E41 need not be provided.

[0354] It is clear from the claims that the above-mentioned modifications are included within the scope of the present invention.

[0355] The fifth embodiment will be specifically described below based on examples, but these do not limit the scope of the present invention.

[0356] [Examples 1 to 3] In Example 1, dried sliced ​​shiitake mushrooms (2.42 g) were rehydrated at room temperature, and then the rehydrated sliced ​​shiitake mushrooms (14.61 g) were placed in a net and introduced into the biological treatment device E1 according to the above-described embodiment, where they were subjected to aeration treatment. In Example 2, dried sliced ​​shiitake mushrooms (2.43 g) were rehydrated by placing them in boiling water for 5 minutes, and then the rehydrated sliced ​​shiitake mushrooms (16.00 g) were placed in a net and introduced into the same biological treatment device E1 as in Example 1, where they were subjected to aeration treatment. In Example 3, dried sliced ​​shiitake mushrooms (2.41 g) were rehydrated by placing them in boiling water for 5 minutes, and then frozen. The frozen sliced ​​shiitake mushrooms (16.60 g) were placed in a net and introduced into the same biological treatment device E1 as in Examples 1 and 2, where they were subjected to aeration treatment. The MLSS at the time of adding sliced ​​shiitake mushrooms to the biological treatment device E1 of Examples 1 to 3 was 750 mg / L.

[0357] In a comparative example, dried sliced ​​shiitake mushrooms (2.45 g) were rehydrated by boiling water for 5 minutes, then frozen. The frozen sliced ​​shiitake mushrooms (15.20 g) were placed in a net and introduced into a conventional biological treatment device that only supplies air, where they were subjected to aeration treatment. The MLSS of the sliced ​​shiitake mushrooms introduced into the biological treatment device of the comparative example was 750 mg / L.

[0358] [Experimental Results] For Examples 1 to 3 and the Comparative Example, sliced ​​shiitake mushrooms were removed 15 days after the start of the aeration treatment, and their weights were measured and their appearances were observed. The results are shown in Figure 32.

[0359] In Example 1, the weight was 5.98 g (a reduction of about 59% from the state after reconstitution with water) 15 days after the start of the aeration treatment, and a large change in the volume was also observed.

[0360] In Example 2, 15 days after the start of the aeration treatment, the weight was 5.90 g (a reduction of about 63% from the state after reconstitution with water), and a large change in volume was also observed.

[0361] In Example 3, 15 days after the start of the aeration treatment, the weight was 5.42 g (a reduction of about 67% from the state after reconstitution with water), and a large change in volume was also observed.

[0362] On the other hand, in the comparative example, the weight was 8.35 g (a reduction of about 45% from the state after reconstitution with water) 15 days after the start of the aeration treatment, and no significant change in the volume was observed.

[0363] From the results of Examples 1 to 3 above, it became clear that the biological treatment device E1 according to the above-described embodiment is capable of decomposing shiitake mushrooms, which are a difficult-to-decompose substance (insoluble dietary fiber), more efficiently than the comparative example in which aeration treatment is simply performed.

[0364] [Explanation of Use as Filtration Device and Filtration System] Next, an example (sixth embodiment) of using the liquid treatment device according to this embodiment as a filtration device will be described, along with background technology and problems of the filtration device.

[0365] [Background Technology for Filtration Devices] Conventionally, there has been a hollow fiber membrane module comprising a housing having openings at both ends, a hollow fiber membrane bundle that is composed of a plurality of hollow fiber membranes that filter the liquid to be filtered and is accommodated in the housing, a first nozzle provided on a side surface at one end of the housing and capable of discharging the filtrate filtered by the hollow fiber membranes, and a second nozzle provided on a side surface at the other end of the housing and capable of discharging the filtrate (for example, JP 2024-72125 A). Furthermore, the hollow fiber membrane bundle described in JP 2024-72125 A has one end fixed to one opening side and the other end fixed to the other opening side.

[0366] The hollow fiber membrane module described in JP 2024-72125 A is arranged so that the openings at both ends extend vertically, and a liquid to be filtered containing suspended matter is introduced through the opening on the lower side. The liquid to be filtered introduced into the hollow fiber membrane module moves upward through the flow path of the hollow fiber membrane, and suspended matter is filtered out through holes formed in the tube wall of the hollow fiber membrane. Then, a clean filtrate flows out of the hollow fiber membrane. The flowed-out filtrate is taken out from the first nozzle and the second nozzle.

[0367] [Issues Related to Filtration Devices] Conventional hollow fiber membrane modules, such as the hollow fiber membrane module described in JP 2024-72125 A, require a suction pump to suck up the liquid to be filtered from the bottom to the top of the flow path of the hollow fiber membrane. However, hollow fiber membranes have a set pressure resistance, and if the hollow fiber membranes are sucked up at a pressure above a certain pressure resistance (e.g., 0.2 to 0.6 MPa), the hollow fiber membranes become clogged and become unusable. Therefore, conventional hollow fiber membrane modules have the problem of limited suction pressure for the liquid to be filtered, and therefore limited suction speed and filtration speed of the liquid to be filtered.

[0368] In particular, when a hollow fiber membrane module is used for water treatment in a water tank several meters deep, a large water pressure (hydraulic head pressure) is applied to the liquid to be filtered in the flow path of the hollow fiber membrane. Therefore, it is necessary to apply a pressure sufficient to offset the water pressure while sucking the liquid to be filtered within a predetermined pressure resistance range, which results in a significant loss of filtration efficiency.

[0369] The sixth embodiment has been made in consideration of such problems, and aims to provide a filtration device, a filtration system, and a filtration method that can improve filtration efficiency.

[0370] [Configuration of Filtration System According to Sixth Embodiment] First, an overview of the filtration system G1 according to the sixth embodiment will be provided. The filtration system G1 according to the sixth embodiment generally includes a filtration device G30 that filters a liquid, a liquid supply device G10 that supplies a liquid to the filtration device G30, and a permeated liquid supplied device G70 that receives the permeated liquid filtered by the filtration device G30, as shown in Fig. 33 . The filtration system G1 also includes a liquid supply path G3 that connects the liquid supply device G10 and the filtration device G30 and supplies the liquid in the liquid supply device G10 to the filtration device G30, and a permeated liquid supply path G5 that connects the filtration device G30 and the permeated liquid supplied device G70 and supplies the permeated liquid filtered by the filtration device G30 to the permeated liquid supplied device G70.

[0371] In the sixth embodiment, the liquid supplying device G10 is, for example, a biological treatment tank for water treatment, an aquarium, a fermenter used in producing fermented foods and beverages, a biomass reaction tank, or other biological tank. However, the present invention is not limited to these. The liquid in the liquid supplying device G10 contains various impurities. The liquid supplying device G10 also has a pump (not shown) for supplying the liquid to the filtration device G30.

[0372] [Configuration of the Filtration Device] The filtration device G30 includes a storage container G32 capable of storing a liquid and a filtration membrane unit G50 disposed within the storage container G32. The filtration device G30 also includes a separation device (not shown), as shown in FIG. 34 . As shown in FIG. 34 , the storage container G32 includes an outer tube G35 extending in the up-down direction (vertical direction in the sixth embodiment) and an inner tube G36 disposed within the outer tube G35. In the sixth embodiment, "vertical" includes both completely vertical and approximately vertical. "Approximately vertical" refers to a slight inclination relative to vertical, specifically, an inclination that does not impair the effectiveness of the filtration device G30.

[0373] The outer tube G35 and the inner tube G36 are each formed in a cylindrical shape with open upper and lower ends. The outer diameter of the inner tube G36 is smaller than the inner diameter of the outer tube G35. The vertical length of the inner tube G36 is also shorter than the vertical length of the outer tube G35. The shapes of the outer tube G35 and the inner tube G36 are not limited to cylindrical shapes, and may be, for example, rectangular, conical, or pyramidal.

[0374] The storage container G32 has a bottom G33 that closes the lower end of the outer tube G35 and a top G34 that closes the upper end of the outer tube G35. The bottom G33 is formed in a bottomed cylindrical shape with an open upper end. The bottom G33 is configured to close the lower end of the outer tube G35 by fitting the lower end of the outer tube G35 into it. The top G34 is formed in a topped cylindrical shape with an open lower end. The top G34 is configured to close the upper end of the outer tube G35 by fitting the upper end of the outer tube G35 into it. The pressure of the internal space of the storage container G32 is configured to be changeable. In the sixth embodiment, the pressure of the internal space of the storage container G32 is changed by changing the pressure of the internal space G70a of the permeate liquid supply device G70, which will be described later, using a negative pressure generating device, which will be described later. However, the present invention is not limited to this.

[0375] The storage container G32 also has an outer flow space G37 formed between the outer cylinder G35 and the inner cylinder G36, and an inner flow space G38 formed inside the inner cylinder G36. The outer flow space G37 and the inner flow space G38 are connected to each other at the upper and lower sides of the inner cylinder G36 and are configured to form a circulation flow path CP that circulates the separation target and bubbles B (see FIG. 38). Specifically, a liquid containing the separation target and bubbles B circulates within the circulation flow path CP. The storage container G32 also has an inlet (not shown) that allows liquid to flow into the storage container G32 from the liquid supply device G10 via the liquid supply path G3.

[0376] The filtration membrane section G50 includes hollow fiber membranes G52. In the sixth embodiment, the filtration membrane section G50 includes a plurality of hollow fiber membranes G52, which are supported in a bundle by an upper bundling section G66 and a lower bundling section G68. In the sixth embodiment, the plurality of hollow fiber membranes G52 supported in a bundle form a cylindrical membrane module. The filtration membrane section G50 is provided with a permeate supply channel G5 extending in the extension direction of the hollow fiber membranes G52 in the center of the cylindrical membrane module.

[0377] 35, the hollow fiber membrane G52 has a cylindrical filtration circumferential surface G54, a hollow portion G55 defined by the filtration circumferential surface G54, and an outlet G58 for discharging permeated liquid from the hollow portion G55. The outlet G58 is provided at one end of the hollow fiber membrane G52. Furthermore, if the filtration membrane portion G50 does not include an upper bundling portion G66, or if the upper bundling portion G66 is configured in a cylindrical shape rather than a bottomed cylindrical shape as described below, the hollow fiber membrane G52 may have an inlet G56 at the other end of the hollow fiber membrane G52 for allowing liquid to flow into the hollow portion G55.

[0378] In the sixth embodiment, the hollow fiber membrane G52 is a microfiltration (MF) membrane. However, the present invention is not limited to this. The hollow fiber membrane G52 can have any of a variety of configurations depending on the size of the impurities (substances to be separated) contained in the liquid. For example, the hollow fiber membrane G52 may be an ultrafiltration (UF) membrane, a nanofiltration (NF) membrane, or a reverse osmosis (RO) membrane.

[0379] Furthermore, in the sixth embodiment, the hollow fiber membranes G52 are arranged in the storage container G32 so that the longitudinal direction of the hollow fiber membranes G52 is along the up-down direction of the storage container G32 (the vertical direction in the sixth embodiment). Furthermore, the discharge outlets G58 of the hollow fiber membranes G52 are connected to a lower bundling part G68, which will be described later, as shown in Fig. 34. Specifically, the ends of the plurality of hollow fiber membranes G52 on the discharge outlet G58 side are connected to an internal space G68a, which will be described later, of the lower bundling part G68.

[0380] The upper bundling part G66 is configured in a topped cylindrical shape with an open bottom end, and is attached to the upper swirl flow generating part G150 of the separation device, which will be described later. The upper bundling part G66 is configured to close the top ends of the plurality of hollow fiber membranes G52. The lower bundling part G68 is configured in a bottomed cylindrical shape with an open top end. The lower bundling part G68 is also connected to the end of the hollow fiber membrane G52 on the outlet G58 side, and is configured so that the permeate discharged from the outlet G58 accumulates in the internal space G68a.

[0381] One end G5a of the permeate supply channel G5 extends to the internal space G68a of the lower bundling part G68. The permeate supply channel G5 having such a configuration is configured to supply the permeate accumulated in the internal space G68a of the lower bundling part G68 from the lower bundling part G68 to the permeate supply-receiving device G70. The other end G5b of the permeate supply channel G5 is inserted through a top surface G72 (described later) of the permeate supply-receiving device G70 and extends to the internal space G70a (described later) of the permeate supply-receiving device G70. As described later, the other end G5b of the permeate supply channel G5 is preferably located below the liquid level in the storage container G32 of the filtration device G30 in order to filter the liquid by the filtration device G30 by applying negative pressure to the permeate supply-receiving device G70. However, this is not limited to this.

[0382] [Configuration of Separation Device] The separation device according to the sixth embodiment is configured to separate a separation target within a filtration device G30. In the sixth embodiment, the separation target is impurities contained in the liquid within the filtration device G30, specifically, impurities adhering to the filtration peripheral surface G54 of the filtration membrane unit G50 or floating around the filtration peripheral surface G54. As shown in FIG. 34 , the separation device includes an ascending flow generating unit G120 that generates an ascending flow containing bubbles B within the storage container G32, a lower swirling flow generating unit G140 provided below the inner cylinder G36 (described later), and an upper swirling flow generating unit G150 provided above the inner cylinder G36 (described later).

[0383] 34 , the upward flow generating section G120 has a gas generating section G121 that generates gas, a gas releasing section G122 that releases the gas generated in the gas generating section G121 into the outer flow space G37 or the inner flow space G38, a gas supplying section G123 that supplies the gas generated in the gas generating section G121 to the gas releasing section G122, and a connecting section G124 that connects the gas releasing section G122 and the gas supplying section G123. While only one upward flow generating section G120 is provided in the sixth embodiment, this is not limiting and two or more may be provided.

[0384] The gas generation unit G121 is, for example, a fan or the like, and has a switch G121a that starts or stops gas generation. One end of the gas supply unit G123 is connected to the gas generation unit G121, and the other end of the gas supply unit G123 is connected to a connection unit G124. One end of the gas release unit G122 is connected to the gas supply unit G123 via the connection unit G124, and the other end is connected to an attachment unit G143c of a support unit G143 (described later).

[0385] Therefore, the gas release section G122 according to the sixth embodiment is configured to release gas into the inner flow space G38 via the support section G143. From the viewpoint of generating an upward flow, the other end of the gas release section G122 may be located below the vertical middle of the storage container G32, and may be connected to, for example, the outer tube G35 or the inner tube G36. When the other end of the gas release section G122 is connected to the outer tube G35, the gas release section G122 is configured to release gas into the outer flow space G37.

[0386] The upward flow generating unit G120 having the above configuration is configured to generate an upward flow containing bubbles B in the inner flow space G38 by the gas release unit G122 releasing gas into the inner flow space G38. When the gas release unit G122 releases gas into the outer flow space G37, the upward flow generating unit G120 generates an upward flow containing bubbles B in the outer flow space G37. The upward flow generating unit G120 is also configured to be able to stop the circulation of the separation target and the bubbles B by operating the switch G121a. However, this is not limited to this, and the upward flow generating unit G120 does not have to be able to stop the circulation of the separation target and the bubbles B.

[0387] Next, the lower swirl flow generating section G140 will be described with reference to Figures 34 and 36. The lower swirl flow generating section G140 has a plurality of (seven in the sixth embodiment) blade sections G142 (lower blade sections) provided at predetermined intervals around the circumferential direction of the inner cylinder G36, and a support section G143 capable of supporting the inner cylinder G36.

[0388] The blades G142 are provided on the bottom surface of the bottom portion G33 of the container G32 and are non-rotatable. Each blade G142 extends radially from the inner tube G36 and has a curved shape in the circumferential direction of the inner tube G36. That is, the blades G142 are arranged radially around the axis of the inner tube G36. In plan view, the inner end of each blade G142 is located within the region of the inner tube G36, and the outer end of each blade G142 is located within the region between the outer tube G35 and the inner tube G36. Furthermore, each blade G142 is formed so that its height increases from the outer side to the inner side in the extension direction. This has the advantage of allowing efficient swirling without obstructing the flow from the outer flow space G37 or the flow from the inner flow space G38.

[0389] The support portion G143 is cylindrical with open upper and lower ends, tapering from the lower end to the upper end. The support portion G143 has an insertion groove G143a at its upper end into which the lower end of the inner tube G36 can be inserted. The support portion G143 is configured to support the inner tube G36 by inserting the lower end of the inner tube G36 into the insertion groove G143a. The support portion G143 also has an annular tube portion G143b at its lower end that surrounds the blade portion G142. The support portion G143 also has an attachment portion G143c to which the gas release portion G122 is attached.

[0390] The pipe section G143b is formed in a tubular shape with an internal space that allows the gas supplied from the gas release section G122 to flow. An outlet hole G143d is formed in the inner periphery (the end on the blade section G142 side) of the pipe section G143b, through which the gas supplied from the gas release section G122 flows out. In the sixth embodiment, the outlet hole G143d is one or more openings formed at predetermined intervals in the circumferential direction of the pipe section G143b. The outlet hole G143d may be an annular opening extending along the circumferential direction of the pipe section G143b. The attachment section G143c is formed to extend upward from a portion of the circumferential direction of the pipe section G143b, and the gas supplied from the gas release section G122 is supplied to the pipe section G143b via the attachment section G143c.

[0391] The support portion G143 having the above-described configuration is configured to communicate the outer flow space G37 and the inner flow space G38 between the lower end of the support portion G143 and the bottom surface of the bottom portion G33 of the storage container G32. Note that, in the sixth embodiment, the configuration in which the support portion G143 includes the pipe portion G143b and the attached portion G143c has been described, but this is not limiting, and the support portion G143 may be configured not to include these.

[0392] Next, the upper swirl flow generating section G150 will be described with reference to Figures 34 and 37. For ease of explanation, Figure 37 omits a portion of the permeate supply channel G5 and the upper bundling section G66. The upper swirl flow generating section G150 includes a top plate section G151 provided opposite the upper opening G36a of the inner cylinder G36, multiple (six in the sixth embodiment) blade sections G152 (upper blade sections) provided at predetermined intervals around the inner cylinder G36, and an attachment section G153 that can be attached to the inner cylinder G36. The top plate section G151 has a shape that is recessed downward at the center in the planar direction, and is generally formed in a conical shape overall.

[0393] The blades G152 extend downward from the underside of the top plate G151 and are non-rotatable. Each blade G152 extends radially of the inner tube G36 and has a curved shape in the circumferential direction of the inner tube G36. That is, the blades G152 are arranged radially around the axis of the inner tube G36. From the viewpoint of efficiently swirling the separation target and the bubbles B, it is preferable that the curved direction of the blades G152 be the same as the curved direction of the blades G142, but this is not limited thereto.

[0394] In a bottom view, the inner end of each blade G152 in the extension direction is located within the area of ​​the inner cylinder G36, and the outer end of each blade G152 in the extension direction is located within the area between the outer cylinder G35 and the inner cylinder G36. Furthermore, each blade G152 is formed so that its height decreases from the outer side toward the inner side in the extension direction. This has the advantage of allowing efficient swirling without impeding the flow from the outer flow space G37 or the flow from the inner flow space G38.

[0395] The attachment portion G153 is formed in a ring shape that surrounds the periphery of the lower end of the blade portion G152. That is, the upper swirl flow generating portion G150 according to the sixth embodiment is configured to communicate the outer flow space G37 and the inner flow space G38 between the lower surface of the top plate portion G151, the surface of the blade portion G152, and the inner peripheral portion of the attachment portion G153 (the end on the blade portion G152 side).

[0396] In the sixth embodiment, either the lower swirl flow generating section G140 or the upper swirl flow generating section G150 functions as an inner swirl flow generating section G160 that converts the flow in the inner flow space G38 into a swirl flow. The other of the lower swirl flow generating section G140 or the upper swirl flow generating section G150 functions as an outer swirl flow generating section G170 that converts the flow in the outer flow space G37 into a swirl flow.

[0397] Whether the lower swirl flow generating section G140 and the upper swirl flow generating section G150 function as the inner swirl flow generating section G160 or the outer swirl flow generating section G170 depends on the position at which the upward flow generating section G120 generates the upward flow. Specifically, when the upward flow generating section G120 generates an upward flow in the inner flow space G38, the lower swirl flow generating section G140 functions as the inner swirl flow generating section G160, and the upper swirl flow generating section G150 functions as the outer swirl flow generating section G170. On the other hand, when the upward flow generating section G120 generates an upward flow in the outer flow space G37, the lower swirl flow generating section G140 functions as the outer swirl flow generating section G170, and the upper swirl flow generating section G150 functions as the inner swirl flow generating section G160.

[0398] The separation apparatus having the above configuration is configured to be able to clean the filtration peripheral surface G54 of the hollow fiber membrane G52 of the filtration membrane section G50 and remove impurities adhering to the filtration peripheral surface G54 by generating a swirling flow (a spiral swirling flow in the sixth embodiment) containing bubbles B in the inner flow space G38 while the filtration of the liquid by the filtration device G30 is completed and the filtration process is stopped. Note that the separation apparatus may generate a swirling flow during the filtration process by the filtration device G30.

[0399] The permeate liquid supply device G70 is, for example, a vacuum tank. The permeate liquid supply device G70 is configured in a bottomed cylindrical shape and has a top surface G72 that closes the open end of the permeate liquid supply device G70. The other end G5b of the permeate liquid supply path G5 is inserted into the top surface G72, and the permeate liquid filtered by the filtration device G30 is stored in the permeate liquid supply device G70. In the sixth embodiment, the filtration system G1 further includes a negative pressure generator (not shown) that generates negative pressure in the internal space G70a of the permeate liquid supply device G70. The permeate liquid supply device G70 is configured so that the pressure in the internal space G70a can be changed by the negative pressure generator.

[0400] The permeate liquid supplied device G70 also has an outlet G74 through which the permeate liquid stored at the bottom flows out. The outlet G74 is connected to a next-process supply path (not shown), and the permeate liquid flowing out from the outlet G74 is supplied to the next-process device through the next-process supply path. In the sixth embodiment, the permeate liquid supplied device G70 is configured to allow the permeate liquid to flow out from the outlet G74 by creating a negative pressure in the internal space G70a using a negative pressure generator. However, this is not limited to this. The permeate liquid supplied device G70 may also be configured so that the permeate liquid flows out from the outlet G74 due to the weight of the stored permeate liquid (head pressure) when the negative pressure state created by the negative pressure generator is released (the internal space G70a is opened to the atmosphere).

[0401] Furthermore, in the sixth embodiment, the permeate liquid supplied device G70 is disposed to the side of the filtration device G30. However, this is not limited thereto. The permeate liquid supplied device G70 can be disposed in various arbitrary positions, such as below the filtration device G30. When the permeate liquid supplied device G70 is disposed below the filtration device G30, the permeate liquid supply path G5 may extend from the internal space G68a of the lower bundling part G68 toward the bottom G33 of the storage container G32. With this configuration, when the outlet part G74 is opened, the filtration system G1 can allow the permeate discharged from the outlet G58 of the hollow fiber membrane G52 by gravity to flow out of the internal space G68a of the lower bundling part G68 and be supplied to the permeate liquid supplied device G70 without using a negative pressure generator.

[0402] The filtration system G1 having the above configuration is configured so that the filtration device G30 can filter liquid using the filtration membrane unit G50 by creating a negative pressure in the internal space G70a of the permeated liquid supplied device G70. Specifically, the filtration system G1 creates a negative pressure in the internal space G70a of the permeated liquid supplied device G70 using a negative pressure generator while liquid is supplied to the storage container G32 of the filtration device G30, thereby creating a negative pressure in the permeated liquid supply path G5, and ultimately in the lower bundling portion G68 of the filtration membrane unit G50 and the hollow portion G55 of the hollow fiber membrane G52. The liquid in the storage container G32 is then drawn from the filtration circumferential surface G54 of the hollow fiber membrane G52 into the hollow portion G55, and is filtered by the filtration circumferential surface G54.

[0403] The permeate filtered by the hollow fiber membrane G52 is discharged from the outlet G58 of the hollow fiber membrane G52 and accumulates in the internal space G68a of the lower bundling part G68. The permeate accumulated in the internal space G68a of the lower bundling part G68 is then drawn into the permeate supply path G5 from one end G5a of the permeate supply path G5 and supplied to the permeate supplied device G70. Furthermore, by supplying liquid from the liquid supply device G10 to the filtration device G30 so that the water level of the liquid in the storage container G32 is maintained higher than the other end G5b of the permeate supply path G5, as filtration by the filtration membrane part G50 progresses, the permeate supply path G5 and the hollow part G55 of the hollow fiber membrane G52 are constantly filled with permeate.

[0404] Even if the negative pressure generator is stopped in this state, the permeated liquid stored in the internal space G70a of the permeated liquid supply device G70 is discharged from the outlet G74, thereby performing filtration by the filtration membrane unit G50. Furthermore, when the hollow fiber membrane G52 is filled with the permeated liquid, the circular cross section of the hollow section G55 is maintained without being crushed, so that the cross section of the hollow section G55 can be prevented from being blocked and filtration from stopping.

[0405] [Filtration Method According to the Sixth Embodiment] Next, a filtration method using a filtration system G1 according to the sixth embodiment will be described. The filtration method according to the sixth embodiment is generally a filtration method for filtering a liquid using a filtration device G30 that includes an inner cylinder G36 extending in the vertical direction, a storage container G32 that can store a liquid, at least one ascending flow generating unit G120 that generates an ascending flow containing bubbles B in an outer flow space G37 formed outside the inner cylinder G36 or an inner flow space G38 formed inside the inner cylinder G36, and a filtration membrane unit G50 arranged within the inner cylinder G36, the inner flow space G38 and the outer flow space G37 communicating with each other above and below the inner cylinder G36, and capable of forming a circulation flow path CP that circulates the separation target and the bubbles B, and the permeated liquid that has permeated the filtration membrane unit G50 is discharged from the lower end of the filtration membrane unit G50.

[0406] Specifically, in the filtration system G1 according to the sixth embodiment, liquid is first supplied from the liquid supply device G10 to the filtration device G30 through the liquid supply path G3. The liquid flows into the storage container G32 from an inlet provided above the storage container G32. The liquid in the storage container G32 then permeates the filtration peripheral surfaces G54 of the plurality of hollow fiber membranes G52 in the filtration membrane unit G50 (see arrow FF1 in FIG. 38 ).

[0407] The liquid is filtered as it passes through the filtration peripheral surface G54, and the permeated liquid that has passed through the filtration peripheral surface G54 moves downward within the hollow portion G55 (see arrow FF2 in FIG. 38 ). The permeated liquid within the hollow portion G55 is then discharged from the outlet G58 and accumulates in the internal space G68a of the lower bundling portion G68. The permeated liquid accumulated in the internal space G68a is supplied to the permeated liquid supply destination device G70 through the permeated liquid supply path G5.

[0408] After or during the filtration process by the filtration device G30, the separation device generates a swirling flow in the inner flow space G38 formed inside the inner cylinder G36 of the storage container G32 by the gas generation unit G121 of the ascending flow generation unit G120 generating a gas and the lower swirling flow generation unit G140 or the upper swirling flow generation unit G150 making the flow in the inner flow space G38 a swirling flow. Then, the swirling flow generated in the inner flow space G38 removes impurities adhering to the filtration peripheral surface G54 of the hollow fiber membrane G52 of the filtration membrane unit G50 attached inside the inner cylinder G36 from the filtration peripheral surface G54.

[0409] Specifically, gas generation is initiated by the switch G121a of the gas generation unit G121, and the generated gas is supplied to the gas release unit G122 via the gas supply unit G123 and the connection unit G124 of the ascending flow generation unit G120. Next, the gas release unit G122 releases the gas into the inner flow space G38 of the inner cylinder G36 via the support unit G143 of the lower swirl flow generation unit G140. This generates an ascending flow containing bubbles B in the inner flow space G38 (see arrow SF1 in FIG. 38). The gas released into the inner flow space G38 flows and swirls between the blades G142 of the lower swirl flow generation unit G140, generating a swirling ascending flow in the inner flow space G38. That is, the liquid and bubbles B in the inner flow space G38 rise in the inner flow space G38 while swirling.

[0410] When the liquid in the inner flow space G38 rises in the inner flow space G38, the liquid in the outer flow space G37 is drawn into the inner flow space G38 (see arrow SF2 in FIG. 38), and a downward flow is generated in the outer flow space G37 (see arrow SF3 in FIG. 38). The liquid drawn from the outer flow space G37 to the inner flow space G38 flows between the blade portions G142, and therefore rises in the inner flow space G38 while swirling, due to the combined effect of the swirling force of the gas released from the gas release portion G122.

[0411] Meanwhile, the liquid and bubbles B rising in the inner flow space G38 rise to the top plate portion G151 of the upper swirling flow generating portion G150. The filtration peripheral surface G54 of the plurality of hollow fiber membranes G52 of the filtration membrane portion G50 of the filtration device G30 located in the inner flow space G38 is exposed to the flow in the inner flow space G38, so that impurities adhering to the filtration peripheral surface G54 are removed as the liquid and bubbles B in the inner flow space G38 rise to the top plate portion G151. The liquid and bubbles B containing impurities that have risen to the top plate portion G151 then flow along the inclined surface G151a of the top plate portion G151 to the outer flow space G37 and descend through the outer flow space G37 (see arrow SF4 in FIG. 38 ). The liquid and bubbles B flowing into the outer flow space G37 swirl as they flow between the blades G152 of the upper swirl flow generating section G150, generating a swirling downward flow in the outer flow space G37. That is, the liquid and bubbles B in the outer flow space G37 descend through the outer flow space G37 while swirling.

[0412] The liquid and bubbles B circulate through the circulation flow path CP as described above. During this circulation process, when the liquid and bubbles B are drawn from the outer flow space G37 to the inner flow space G38, the flow rate increases (pressure decreases), and the bubbles B become finer. Furthermore, the bubbles B circulating through the circulation flow path CP become finer as they swirl through the inner flow space G38 and the outer flow space G37 and are sheared by the blades G142 of the lower swirl flow generating section G140 and the blades G152 of the upper swirl flow generating section G150. In other words, the more the bubbles B circulate through the circulation flow path CP, the finer they become.

[0413] As described above, the separation device according to the sixth embodiment is configured to be capable of generating fine bubbles. The generation of fine bubbles increases the total surface area of ​​the bubbles B generated within the separation device, thereby improving separation performance. Note that fine bubbles include microbubbles (bubbles with a diameter of 1 μm or more and less than 100 μm) and ultrafine bubbles (bubbles with a diameter of less than 1 μm).

[0414] The switch G121a of the gas generation unit G121 stops the generation of gas at any or predetermined timing. This stops the release of gas by the gas release unit G122, and the circulation of the liquid and bubbles B in the circulation flow path CP stops. When circulation stops, the bubbles B rise in the inner flow space G38 and the outer flow space G37 while adsorbing suspended matter in the liquid (impurities adhering to the filtration peripheral surface G54 of the hollow fiber membrane G52). This allows the liquid to be separated from the impurities contained in the liquid. The filtration method using the filtration system G1 according to the sixth embodiment is carried out through the above series of steps.

[0415] [Advantages of the filtration device, filtration system, and filtration method according to the sixth embodiment] As described above, the filtration device G30 according to the sixth embodiment has an inner tube G36 extending in the vertical direction, a storage container G32 capable of storing a liquid, at least one ascending flow generating section G120 that generates an ascending flow containing bubbles B in an outer flow space G37 formed outside the inner tube G36 or an inner flow space G38 formed inside the inner tube G36, and a filtration membrane section G50 arranged in the inner tube G36, the inner flow space G38 and the outer flow space G37 being connected to each other on the upper and lower sides of the inner tube G36 and configured to be able to form a circulation flow path CP that circulates the bubbles B, and the filtration membrane section G50 has an outlet G58 at its lower end that discharges the permeated liquid that has permeated the filtration membrane section G50.

[0416] The filtration device G30 according to the sixth embodiment has such a configuration that, unlike conventional hollow fiber membrane modules in which the permeate liquid is discharged from above the filtration membrane unit G50, the permeate liquid is discharged from below the filtration membrane unit G50 in the same direction as the hydraulic head pressure, which makes it possible to apply a greater pressure to the liquid to be filtered than before, thereby improving the filtration speed and, ultimately, the filtration efficiency. Furthermore, because the hydraulic head pressure of the liquid in the storage vessel G32 can be used to pressurize the liquid, there is the advantage that filtration can be performed faster than before without using a suction pump to suck the liquid. Furthermore, in conventional hollow fiber membrane modules, in order to prevent the filtration membrane section G50 from becoming clogged with impurities contained in the liquid and reducing filtration efficiency, it is necessary to, for example, interrupt the filtration process at a certain frequency and wash the hollow fiber membrane G52 with a backwash liquid. However, the filtration device G30 of the sixth embodiment has the advantage of being able to remove impurities adhering to the filtration membrane section G50 even during filtration processing by the upward flow generated in the inner flow space G38 of the inner cylinder G36 by the upward flow generating section G120, thereby improving filtration efficiency compared to conventional methods.

[0417] In the filtration device G30 according to the sixth embodiment, the filtration membrane unit G50 includes a hollow fiber membrane G52 having a cylindrical filtration circumferential surface G54, a hollow portion G55 defined by the filtration circumferential surface G54, and an outlet G58 for discharging permeated liquid from the hollow portion G55. Unlike conventional hollow fiber membrane modules in which the liquid to be filtered moves from the bottom to the top of the flow path of the hollow fiber membrane G52 and the permeated liquid is discharged from the upper end of the hollow fiber membrane G52, the filtration device G30 according to the sixth embodiment has such a configuration. This configuration allows for greater pressure to be applied to the liquid to be filtered, thereby improving the filtration rate and, ultimately, the filtration efficiency. Furthermore, the filtration device G30 according to the sixth embodiment has the advantage of being able to remove impurities adhering to the filtration circumferential surface G54 during the filtration process by the upward flow generated by the upward flow generating unit G120, thereby improving the filtration efficiency compared to conventional systems.

[0418] Furthermore, in the filtration device G30 according to the sixth embodiment, the ascending flow generating section G120 has at least one gas release section G122 that releases gas into the outer flow space G37 or the inner flow space G38, below the vertical middle section of the storage container G32. With this configuration, an ascending flow containing bubbles B can be generated simply by releasing gas from the gas release section G122, and the separation target (impurities contained in the filtered liquid in the sixth embodiment) and the bubbles B can be circulated, which has the advantages of allowing the separation target to be separated at low cost and also providing high reliability and durability.

[0419] Furthermore, the filtration device G30 according to the sixth embodiment includes at least one of an inner swirling flow generating unit G160 that generates a swirling flow in the inner flow space G38 along the circumferential direction of the inner tube G36 of the storage container G32 and an outer swirling flow generating unit G170 that generates a swirling flow in the outer flow space G37 along the circumferential direction of the inner tube G36 of the storage container G32. This configuration advantageously generates a swirling flow, thereby facilitating the removal of impurities adhering to the hollow fiber membrane G52. Furthermore, the swirling flow facilitates the circulation of the separation target (the impurities contained in the filtered liquid in the sixth embodiment) and the bubbles B, thereby preventing the separated impurities from adhering again to the filtration surface G54 of the hollow fiber membrane G52. Furthermore, the swirling of the bubbles B also advantageously reduces the size of the bubbles B. Furthermore, reducing the size of the bubbles B increases the total surface area of ​​the bubbles B, thereby improving separation performance.

[0420] Furthermore, in the filtering device G30 according to the sixth embodiment, the inner swirl flow generating section G160 and the outer swirl flow generating section G170 each have a blade section G142 (or a blade section G152). This configuration has the advantage of generating a swirl flow simply by moving the object to be separated (the impurities contained in the filtered liquid in the sixth embodiment) between the blade sections G142 (or a blade section G152). Another advantage is that the bubbles B are sheared by the blade sections G142 (or a blade section G152), which allows the bubbles B to be refined. Furthermore, the shearing of not only the bubbles B but also solid impurities by the blade sections G142 (or a blade section G152) also provides the advantage of refining the impurities and making them more likely to float. In addition, it is possible to generate a spiral swirling flow, which can more reliably remove impurities adhering to the upper part of the hollow fiber membrane G52, thereby having the advantage of preventing the hollow fiber membrane G52 from becoming clogged and blocked.

[0421] [Modifications] While the preferred configuration of the sixth embodiment has been described above, the technical scope of the present invention is not limited to the scope described in the above-described embodiment. Various modifications and improvements can be made to the sixth embodiment.

[0422] For example, in the above-described embodiment, the filtration membrane unit G50 has been described as including a hollow fiber membrane G52 having a cylindrical filtration peripheral surface G54, a hollow portion G55 defined by the filtration peripheral surface G54, and an outlet G58 for discharging permeate from the hollow portion G55, but is not limited thereto. The filtration membrane unit G50 may not include the hollow fiber membrane G52, but may instead include a flat membrane module, a spiral membrane module or pleated membrane module using a flat membrane, a tubular membrane module using a tubular membrane, or the like.

[0423] In the above-described embodiment, the upward flow generating unit G120 has been described as having at least one gas release unit G122 that releases gas into the outer flow space G37 or the inner flow space G38 below the middle part of the storage container G32 in the vertical direction, but is not limited to this. The upward flow generating unit G120 does not necessarily have to have a gas release unit G122.

[0424] In the above-described embodiment, the filtration device G30 has been described as having at least one of an inner swirling flow generating section G160 that generates a swirling flow in the inner flow space G38 along the circumferential direction of the inner tube G36 of the storage container G32 and an outer swirling flow generating section G170 that generates a swirling flow in the outer flow space G37 along the circumferential direction of the inner tube G36 of the storage container G32, but is not limited to this. The filtration device G30 does not necessarily have to have the inner swirling flow generating section G160 or the outer swirling flow generating section G170. Furthermore, the filtration device G30 has been described as having a lower swirling flow generating section G140 and an upper swirling flow generating section G150, but is not limited to this and may have only one of these or neither.

[0425] In the above-described embodiment, the inner swirl flow generating section G160 and the outer swirl flow generating section G170 have been described as having the blade portion G142 (or the blade portion G152), but this is not limited thereto. The inner swirl flow generating section G160 and the outer swirl flow generating section G170 do not have to have the blade portion G142 (or the blade portion G152). Furthermore, in the above-described embodiment, the blade portion G142 (or the blade portion G152) has been described as having a shape curved in the circumferential direction of the inner cylinder G36, but this is not limited thereto. The blade portion G142 (or the blade portion G152) may not have a shape curved in the circumferential direction of the inner cylinder G36, but may have a shape extending radially in the radial direction of the inner cylinder G36, for example.

[0426] In the above-described embodiment, the storage container G32 has a bottom G33 that closes the lower end and a top G34 that closes the upper end. The permeate liquid supply device G70 is configured as a bottomed cylinder and has a top G72 that closes the open end of the permeate liquid supply device G70. The filtration device G30 and the permeate liquid supply device G70 are configured to be able to change the pressure of the internal space G70a and are connected via the permeate liquid supply path G5. The filtration device G30 is configured to be able to filter the liquid using the filtration membrane unit G50 by creating a negative pressure in the internal space G70a of the permeate liquid supply device G70. However, this is not limited to this. The storage container G32 may not have a top G34, and the upper end may be open to the atmosphere. Similarly, the permeate liquid supply device G70 may not have a top G72. Furthermore, the filtration device G30 and the permeate liquid supply device G70 do not have to be configured to be able to change the pressure of the internal space G70a. Furthermore, the filtration device G30 does not have to be configured to be able to filter the liquid using the filtration membrane unit G50 by creating a negative pressure in the internal space G70a of the permeated liquid supply device G70. For example, the filtration device G30 may be configured to be able to filter the liquid using the filtration membrane unit G50 by utilizing the hydraulic head pressure of the liquid in the storage container G32, or may be configured to be able to filter the liquid using the filtration membrane unit G50 by pressurizing the inside of the storage container G32.

[0427] In the above-described embodiment, the plurality of hollow fiber membranes G52 are described as constituting a cylindrical membrane module, but this is not limited thereto, and the plurality of hollow fiber membranes G52 may also constitute a sheet-type membrane module. Also, in the above-described embodiment, the filtration membrane section G50 is described as having an upper bundling section G66 and a lower bundling section G68, but this is not limited thereto, and the filtration membrane section G50 does not have to have the upper bundling section G66 and the lower bundling section G68.

[0428] In the above-described embodiment, the filtration device G30 has been described as including a separation device configured to separate the separation target within the filtration device G30, but is not limited thereto. The filtration device G30 is only required to be able to remove impurities adhering to the filtration membrane unit G50 by the upward flow generated in the inner flow space G38 of the inner cylinder G36 by the upward flow generating unit G120, and does not necessarily have to be able to separate the impurities from the liquid containing the removed impurities.

[0429] It is clear from the claims that the above-mentioned modifications are included within the scope of the present invention.

[0430] A1: Mixing device A10: Mixing vessel A11: Outer cylinder A12: Inner cylinder A15: Outer flow space A16: Inner flow space A20: Upward flow generating section A60: Inner swirling flow generating section A70: Outer swirling flow generating section B1: Organic waste treatment system B500: Solid-liquid separation device B510: Solid-liquid separation vessel B511: Outer cylinder B512: Inner cylinder B515: Outer flow space B516: Inner flow space B520: Upward flow generating section B560: Inner swirling flow generating section B570: Outer swirling flow generating section C1: Liquid purification system C100: Growth inhibition device C110: Growth inhibition vessel C111: Outer cylinder C112: Inner cylinder C115 : Outer flow space C116: Inner flow space C120: Upward flow generating section C160: Inner swirl flow generating section C170: Outer swirl flow generating section D1: Separation device D10: Separation vessel D11: Outer cylinder D12: Inner cylinder D15: Outer flow space D16: Inner flow space D20: Upward flow generating section D60: Inner swirl flow generating section D70: Outer swirl flow generating section E1: Biological treatment device E10: Biological treatment tank E11: Outer cylinder E12: Inner cylinder E15: Outer flow space E16: Inner flow space E20: Upward flow generating section E60: Inner swirl flow generating section E70: Outer swirl flow generating section G1: Filtration system G10: Liquid supply device G120: Upward flow generating section G160: Inner swirling flow generation section G170: Outer swirling flow generation section G37: Outer flow space G38: Inner flow space G50: Filtration membrane section CP: Circulation channel

Claims

a container including at least one inner cylinder; at least one upward flow generating unit that generates an upward flow in an outer flow space formed outside the inner cylinder or an inner flow space formed inside the inner cylinder; at least one of an inner swirl flow generating section that generates a swirling flow in the inner flow space and an outer swirl flow generating section that generates a swirling flow in the outer flow space; Equipped with the inner flow space and the outer flow space are connected to each other at the upper and lower sides of the inner cylinder, and are configured to be able to form a circulation flow path for circulating the contents, At least one of the inner swirl flow generating section and the outer swirl flow generating section has a plurality of blades provided at predetermined intervals, The plurality of blade portions have a shape curved in the circumferential direction of the inner cylinder. Liquid handling equipment. 　 The upward flow generating section has at least one gas release section that releases gas into the outer flow space or the inner flow space below a vertical middle portion of the container. The liquid treatment device of claim 1 . 　 a top plate portion provided opposite an upper opening of the inner cylinder, The lower surface of the top plate portion has an inclined surface that slopes downward at the center in the planar direction. The liquid treatment device according to claim 1 or 2. 　 The blade portion is configured to be non-rotatable. The liquid treatment device according to any one of claims 1 to 3. 　 The liquid treatment device is a mixing device that mixes two or more mixing targets, The circulation flow path is configured to circulate two or more mixture targets. The liquid treatment device according to any one of claims 1 to 4. 　 The liquid treatment device is a solid-liquid separation device that separates the digestive liquid into solids and liquids, The circulation flow path is configured to circulate the digestive fluid and the air bubbles, The upward flow generating unit is configured to be able to stop the circulation of the digestive fluid and air bubbles. The liquid treatment device according to any one of claims 1 to 4. 　 The container includes an outer cylinder provided outside the inner cylinder, The outer cylinder is at least one solids outlet through which the solids can be discharged; at least one liquid outlet through which the liquid can be discharged; have The liquid treatment device of claim 6 . 　 The liquid treatment device is a growth inhibition device that inhibits the growth of organisms present in the liquid, the circulation channel is configured to circulate the liquid and the bubbles; The container is configured to break up bubbles by circulating the liquid and bubbles through the circulation channel. The liquid treatment device according to any one of claims 1 to 4. 　 the liquid treatment device is a separation device that separates a separation target, the circulation flow path is configured to circulate the separation target and the air bubbles, The upward flow generating section is configured to be able to stop the circulation of the separation target and the air bubbles. The liquid treatment device according to any one of claims 1 to 4. 　 the liquid treatment device is a biological treatment device that decomposes a decomposition target substance using microorganisms, the circulation flow path is configured to circulate a mixed liquid in which the microorganisms and the decomposition target substance are mixed, The plurality of blade portions are provided in a non-rotatable manner on the circulation flow path. The liquid treatment device according to any one of claims 1 to 3. 　 the liquid treatment device is a filtration device including a filtration membrane unit disposed in the inner cylinder, The circulation channel is configured to circulate bubbles, The filtration membrane unit has a discharge port at the lower end for discharging permeated liquid that has permeated the filtration membrane unit. The liquid treatment device according to any one of claims 1 to 4. 　 The filtration membrane unit includes a hollow fiber membrane having a cylindrical filtration peripheral surface, a hollow portion defined by the filtration peripheral surface, and the outlet for discharging the permeated liquid from the hollow portion. The liquid treatment device of claim 11. 　 An organic waste treatment system for treating organic waste, comprising: a generation tank in which the organic waste is reacted with anaerobic microorganisms to produce biogas and digested sludge; a digested sludge separator that separates the digested sludge into solids and digested liquid; a liquid treatment device according to claim 6 or 7, which further separates the digested liquid separated in the digested sludge separation device into solids and liquids; a concentrating device for concentrating the liquid separated by the liquid treatment device; Equipped with Organic waste treatment system.

1. A liquid purification system for purifying a liquid, comprising: The liquid treatment device according to claim 8 is provided to suppress the growth of organisms present in the liquid. Liquid purification system. 　 a liquid treatment device according to claim 11 for filtering a liquid; a liquid supply device that supplies the liquid to the liquid treatment device; a permeated liquid supply device to which the permeated liquid filtered by the liquid treatment device is supplied; Equipped with Filtration system. 　 the container of the liquid treatment device has a bottom portion that closes a lower end and a top portion that closes an upper end, the permeated liquid supply device is configured in a cylindrical shape with a bottom and has a top surface portion that closes an open end of the permeated liquid supply device, the liquid treatment device and the permeated liquid supply device are configured to be able to change the pressure of their internal spaces, and are in communication with each other via a permeated liquid supply path; The liquid treatment device is configured to be able to filter the liquid by the filtration membrane unit by creating a negative pressure in the internal space of the permeated liquid supply device.

16. The filtration system of claim 15.

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