Liquid treatment apparatus

Abstract

To provide a liquid treatment apparatus which has a simple configuration.SOLUTION: A liquid treatment apparatus includes: a tank which stores target liquid to be treated; a flow passage into which the target liquid flowing out from the tank flows and which returns the target liquid to the tank; a pump which is provided in the flow passage and makes the target liquid flow out from the tank into the flow passage; and a fluid suction section which is provided upstream of the pump in the flow passage and mixes mixed fluid into the target fluid, the mixed fluid being fluid different from the target liquid. The fluid suction section has a nozzle, a diffuser, and a suction chamber. A supply port communicating with the nozzle and a discharge port communicating with the diffuser are provided in the flow passage. The target liquid passes through a nozzle suction chamber and the diffuser, thereby causing the mixed fluid to be sucked from a suction port, which serves as an inlet to the suction chamber, into the suction chamber. An inner diameter of the nozzle is set so that a flow rate of the target liquid is 5 m / sec. or more and 6 m / sec. or less.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a liquid treatment device. [Background technology]

[0002] Patent Document 1 discloses an open-type continuous pressurized flow type hydrogen gas-dissolved liquid production apparatus including a liquid flow pipe for flowing the raw liquid to a gas-dissolved liquid receiver, a pressurizing means provided in the liquid flow pipe for pressurizing the raw liquid and flowing it through the flow pipe, at least one gas-liquid mixing section provided in the liquid flow pipe, connected to a gas container via a gas supply pipe and for mixing hydrogen gas from the gas container into the liquid, and at least one static mixer provided downstream of the gas-liquid mixing section in the liquid flow pipe for maintaining the pressure of the gas-mixed liquid mixed in the gas-liquid mixing section and promoting dissolution of the gas into the liquid. In this open-type continuous pressurized flow type hydrogen gas-dissolved liquid production apparatus, the liquid is flowed through the liquid flow pipe at a flow rate of 10 to 40 L / min, and hydrogen gas-dissolved liquid is continuously produced while being pressurized. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Utility Model Registration No. 3139460 Summary of the Invention [Problem to be solved by the invention]

[0004] In the invention described in Patent Document 1, the fluid passes through the static mixer only once to be mixed, which may result in poor mixing performance. In addition, in the invention described in Patent Document 1, the fluid passes through the static mixer only once to be mixed, so a large static mixer is required to improve mixing performance, which requires a considerable amount of space for installing the equipment.

[0005] The present invention has been made in consideration of the above circumstances, and aims to provide a liquid treatment device that can efficiently mix two types of fluids (liquid and gas, or liquid and liquid) in a space-saving manner. [Means for solving the problem]

[0006] In order to solve the above problems, a liquid treatment device according to the present invention includes, for example, a tank for storing a liquid to be treated, a flow path through which the liquid to be treated flowing out of the tank flows and through which the liquid to be treated is returned to the tank, a pump provided in the flow path and causing the liquid to be treated to flow out of the tank into the flow path, and a fluid suction unit provided in the flow path upstream of the pump and mixing the liquid to be treated with a mixed fluid that is a fluid different from the liquid to be treated, wherein the fluid suction unit has a nozzle, a diffuser, and a suction chamber, a supply port communicating with the nozzle and a discharge port communicating with the diffuser are provided in the flow path, the liquid to be treated passes through the nozzle, the suction chamber, and the diffuser, and the mixed fluid is sucked into the suction chamber from the suction port which is an inlet to the suction chamber, and the inner diameter of the nozzle is set so that the flow velocity of the liquid to be treated is 5 m / sec or more and 6 m / sec or less.

[0007] In the liquid treatment device according to the present invention, a fluid suction section and a pump are provided in a flow path, and the mixed fluid is sucked into the fluid suction section (suction chamber) by flowing the liquid to be treated through the fluid suction section. Therefore, two types of fluid (here, water as the liquid to be treated and air as the mixed fluid) can be efficiently mixed using only the fluid suction section. Furthermore, when the flow path is a fluid circulation circuit, the same liquid to be treated can be treated multiple times in the fluid suction section, and the mixed fluid can be efficiently mixed into the liquid to be treated. In this way, two types of fluid can be efficiently mixed with a space-saving and simple configuration.

[0008] A dissolving tank may be provided downstream of the pump in the flow path, and dissolves the mixed fluid of the liquid to be treated and the mixed fluid under a pressurized environment. This allows the mixed fluid to be efficiently dissolved in the liquid to be treated in the dissolving tank. Even if a fluid circulation circuit is not used, the mixed fluid passes through the dissolving tank, improving the mixing efficiency.

[0009] The mixing section is provided downstream of the pump and upstream of the dissolving tank in the flow path, and mixes the mixed fluid with the liquid to be treated, the mixing section having a casing with a cylindrical side provided in the flow path and a plurality of plate-like members provided inside the casing, the plate-like members are provided with a plurality of first through holes through which the liquid to be treated passes, and the plurality of plate-like members may be stacked such that the first through hole of a first plate-like member among the plurality of plate-like members partially overlaps with the first through hole of a second plate-like member adjacent to the first plate-like member. This allows efficient mixing of two types of fluids.

[0010] In order to solve the above problems, a liquid treatment device according to the present invention includes, for example, a tank for storing a liquid to be treated, a flow path through which the liquid to be treated flowing out of the tank flows and through which the liquid to be treated returns to the tank, a pump provided in the flow path and for causing the liquid to be treated to flow out of the tank into the flow path, a fluid inlet section provided on the flow path downstream of the pump, the fluid inlet section having a gas tank containing a high-pressure gas that is a mixed fluid, and a connection section connecting the gas tank and the flow path, and a mixing section provided downstream of the flow path and mixing the mixed fluid with the liquid to be treated, the mixing section having a casing with a cylindrical side provided in the flow path and a plurality of plate-shaped members provided inside the casing, the plate-shaped members having a plurality of first through holes through which the liquid to be treated passes, the plurality of plate-shaped members being stacked such that the first through hole of a first plate-shaped member among the plurality of plate-shaped members partially overlaps with the first through hole of a second plate-shaped member adjacent to the first plate-shaped member.

[0011] In the liquid treatment device according to the present invention, a pump, a fluid intake section, and a mixing section are provided in a flow path, and two types of fluid (here, water as the liquid to be treated and air as the mixed fluid) can be efficiently mixed by flowing the liquid to be treated and the mixed fluid through the mixing section. Furthermore, when the flow path is a fluid circulation circuit, the same liquid to be treated can be treated multiple times in the fluid intake section, and the mixed fluid can be efficiently mixed into the liquid to be treated. In this way, a space-saving liquid treatment device can be achieved.

[0012] The system may further include a dissolving tank that is provided downstream of the mixing section of the flow path and dissolves the mixed fluid of the liquid to be treated and the mixed fluid under a pressurized environment. This allows the mixed fluid to be efficiently dissolved in the liquid to be treated in the dissolving tank. Even if the system is not a fluid circulation circuit, the mixed fluid passes through the dissolving tank, improving the mixing efficiency.

[0013] The casing may have a first end provided with a third inlet portion which is an inlet for the liquid to be treated, and a second end provided with a second outlet portion which is an outlet for the liquid to be treated, at both ends of the side surface, and the plate-like member abuts against the first end portion but does not abut against the second end portion and the side surface, and an end of the stacked plate-like members that does not abut against the first end portion may be covered by a third plate-like member. This allows the mixed fluid to be mixed into the liquid to be treated more effectively.

[0014] The liquid to be treated may be water, and the mixed fluid may be at least one of air, carbon dioxide, and nitrogen. The pump may be a positive displacement pump, and the liquid to be treated may be a non-Newtonian fluid. By using a positive displacement pump, a highly viscous fluid can be treated as the liquid to be treated. The pump may be a centrifugal pump, and the liquid to be treated may be a Newtonian fluid. In the case of a Newtonian fluid, a centrifugal pump can be used which is small, lightweight, and usable for a wide range of purposes (water volume, head, etc.). Effect of the Invention

[0015] According to the present invention, two types of fluids (liquid and gas, liquid and liquid) can be efficiently mixed with a simple configuration. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a schematic diagram showing an example of a liquid treatment device 1. [Diagram 2] 2 is a cross-sectional view showing an outline of a fluid suction portion 12. FIG. [Diagram 3] 1 is a graph comparing the amount of mixed fluid (air) mixed into the liquid to be treated (water) with and without the fluid suction portion 12. [Figure 4] FIG. 2 is a schematic diagram showing an example of a liquid treatment device 2. [Diagram 5] 1A is a diagram showing an outline of the mixer 15, and FIG. 1B is a diagram showing an outline of the plate-like member 15b. [Figure 6] 1A is a partial enlarged view of plate-shaped member 15b, FIG. 1B is a partial enlarged view of plate-shaped member 15c, and FIG. 1C is a diagram showing a state in which plate-shaped members 15b and 15c are alternately stacked. [Figure 7] 1 is a graph comparing the amount of mixed fluid (air) mixed into the liquid to be treated (water) with and without the fluid suction section 12 and the mixing section 15. [Figure 8] 1 is a graph comparing the amount of mixed fluid (air) mixed into the liquid to be treated (water) with and without the fluid suction section 12 and the mixing section 15. [Figure 9] FIG. 13 is a schematic diagram showing an example of a liquid treatment device 2A having a mixer 15A according to a modified example. [Figure 10] FIG. 2 is a diagram showing an outline of a mixing section 15A. [Figure 11] 13 is a graph comparing the amount of mixed fluid (air) mixed into the liquid to be treated (water) between mixing section 15 and mixing section 15A. [Figure 12] FIG. 2 is a schematic diagram showing an example of a liquid treatment device 3. [Figure 13] 13 is a graph comparing the amount of mixed fluid (carbon dioxide) mixed into the liquid to be treated (water) with and without the mixer 15. [Figure 14]13 is a graph comparing the amount of mixed fluid (nitrogen) mixed into the liquid to be treated (water) with and without the mixer 15, where (B) is an enlarged view of a portion of (A). [Figure 15] FIG. 1 is a schematic diagram showing a device 100 for measuring the amount of dissolved air. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A liquid treatment apparatus according to an embodiment of the present invention is an apparatus for mixing a fluid with a liquid to be treated and removing gas contained in the liquid to be treated.

[0018] <First embodiment> 1 is a schematic diagram showing an example of a liquid treatment device 1 according to a first embodiment of the present invention. The liquid treatment device 1 mainly includes a tank 11, a fluid suction unit 12, a pump 13, a dissolution tank 16, a flow rate control valve 14, and a flow path 20.

[0019] The tank 11 is a container for storing the liquid to be treated. In this embodiment, water is used as the liquid to be treated, but various liquids other than water can be used as the liquid to be treated.

[0020] The tank 11 is provided with an outlet 111. The outlet 111 is connected to a flow path 20.

[0021] The flow path 20 includes pipes, hoses, joints, etc. through which a fluid (liquid, gas) flows. The flow path 20 constitutes a fluid circulation circuit through which the liquid to be treated flowing out of the tank 11 flows and which returns the liquid to be treated to the tank 11. The flow path 20 is provided with a fluid intake part 12, a pump 13, a dissolving tank 16, and a flow rate regulating valve 14.

[0022] The fluid suction part 12 is a component that mixes a fluid with the liquid to be treated, and is provided upstream of the pump 13. Fig. 2 is a cross-sectional view showing an outline of the fluid suction part 12. The fluid suction part 12 is cylindrical, and has a first housing 121, a second housing 122, and a third housing 123 as main components.

[0023] The first housing 121 has a supply port 121a for the liquid to be treated. A nozzle 121b is provided on the opposite side of the supply port 121a of the first housing 121. The supply port 121a is in communication with the nozzle 121b, and an upstream portion 21a of the outflow path 21 is provided in the supply port 121a. The nozzle 121b is formed so as to taper in the flow direction of the liquid to be treated.

[0024] Nozzle 121b of the present invention is characterized in that the inner diameter d of nozzle 121b is set so that the flow rate is 5 m / sec or more and 6 m / sec or less, without abruptly narrowing the inner diameter. For example, when the flow rate of the liquid to be treated is 100 L / min, the inner diameter d of nozzle 121b is 18.8 mm or more and 20.6 mm or less. In this way, by widening the inner diameter of nozzle 121b, the negative pressure can be lowered to an appropriate suction pressure (negative pressure of -0.02 MPa to -0.03 MPa).

[0025] The third housing 123 has an outlet 123a for the liquid to be treated, a reduction section 123b in which the cross section of the hollow section gradually decreases, and a diffuser 123c in which the cross section gradually increases. Note that the reduction section 123b is not essential. The outlet 123a is in communication with the reduction section 123b and the diffuser 123c, and the downstream section 21b of the outflow path 21 is provided in the outlet 123a.

[0026] Second housing 122 is provided between first housing 121 and third housing 123, and has suction port 122a. The inside of second housing 122 is suction chamber 122b. A fluid to be mixed with the liquid to be treated (mixed fluid) is sucked into suction chamber 122b from suction port 122a. In this embodiment, suction port 122a is open to the atmosphere, and air flows into suction chamber 122b from suction port 122a as the mixed fluid.

[0027] The liquid to be treated is supplied as a driving fluid from the supply port 121a and discharged from the discharge port 123a. The liquid to be treated flows into the third housing 123 with its flow velocity increased in the nozzle 121b, which reduces the pressure in the suction chamber 122b and causes the mixed fluid (here, air) to be sucked into the suction chamber 122b.

[0028] Returning to the explanation of FIG. 1, the pump 13 is provided downstream of the fluid suction section 12. Since the pump 13 is provided downstream of the fluid suction section 12, there is no need to worry about the pressure during pumping (when sucking in the fluid). The downstream side of the pump 13 is pressurized, and it is difficult to stably control the amount of air under pressure, but the upstream side of the pump 13 is basically less affected by pressure, so the suction force can be adjusted only by the nozzle diameter of the fluid suction section 12. The upstream side of the pump 13 of the flow path 20 is the outflow path 21, and the downstream side is the return path 22. The pump 13 causes the treated liquid to flow out of the tank 11 to the outflow path 21, and also returns the treated liquid to the tank 11 from the return path 22. A centrifugal pump (such as a cascade pump or a centrifugal pump) or a positive displacement pump can be used for the pump 13. In this embodiment, a centrifugal pump is used for the pump 13.

[0029] The dissolving tank 16 is provided downstream of the pump 13. The dissolving tank 16 is pressurized to a pressure equal to or higher than atmospheric pressure (for example, 0.3 MPa or higher), and dissolves the fluid after the liquid to be treated and the mixed fluid are mixed in a pressurized environment. As a result, the mixed fluid is dissolved in the liquid to be treated in the dissolving tank 16. It is desirable that the dissolving tank 16 has a volume sufficient for mixing two types of fluids. The dissolving ratio in the dissolving tank 16 is increased by retaining the liquid in the dissolving tank 16 for a period of time of approximately 5 seconds or more and approximately 24 seconds or less (see Tables 1 and 2). Therefore, for example, it is desirable that the inflow speed of the fluid into the dissolving tank 16 is approximately 2 m / sec or more, and the height dimension of the dissolving tank 16 is 2 times or more and 5 times or less than the inner diameter dimension (see Tables 1 to 3).

[0030] Table 1 shows the relationship between the shape of the dissolution tank 16 and the dissolution ratio, Table 2 shows the relationship between the shape of the dissolution tank 16 and the residence time of the fluid in the dissolution tank, and Table 3 shows the relationship between the shape of the dissolution tank 16 and the inflow rate. In Tables 1 to 3, the dissolution tank 16 with an internal capacity of 3.7 L has an inner diameter of 100 mm and a height of 450 mm, and the dissolution tank 16 with an internal capacity of 7.8 L has an inner diameter of 110 mm and a height of 450 mm. In Tables 1 to 3, the ejection nozzle diameters of the inflow ports of the dissolution tanks 16 are 10A, 15A, 20A, and 27.6 mm, respectively. Tables 1 to 3 show the results when the flow rate of the liquid flowing into the dissolution tank 16 from the inlet was set to 20 l / min, 30 l / min, 40 l / min, 50 l / min, 60 l / min, and 70 l / min. [Table 1] [Table 2] [Table 3]

[0031] In addition, it is desirable that a boundary layer between the liquid and the gas exists in the dissolution tank 16. For example, a bowl-shaped plate-like member can be provided in the dissolution tank 16 to generate a turbulent bubble vortex in the dissolution tank 16. In addition, for example, a turbulent bubble vortex can be generated in the dissolution tank 16 by increasing the flow rate of the liquid flowing into the dissolution tank 16. By having a boundary layer, the gas is sufficiently dissolved in the dissolution tank 16, and undissolved gas is not discharged from the dissolution tank 16. Therefore, the amount of gas consumed can be minimized. If the gas is discharged undissolved, the only way to increase the dissolution ratio is to increase the amount of gas injected, which increases the amount of gas consumed. However, when the dissolution ratio in the dissolution tank 16 is high, the amount of gas injected can be reduced, i.e., the amount of gas consumed can be reduced.

[0032] The flow rate control valve 14 is provided downstream of the dissolution tank 16. Here, the upstream side of the dissolution tank 16 of the flow path 20 is referred to as an upstream section 22a, and the downstream side of the flow rate control valve 14 is referred to as a downstream section 22b. Note that a pressure gauge may be provided in the upstream section 22a, and a flow meter may be provided in the downstream section 22b.

[0033] The dissolving tank 16 is not essential. When the mixed fluid is a gas, the mixed fluid will dissolve in the liquid to be treated without the dissolving tank 16, but it is desirable to provide the dissolving tank 16 in order to dissolve efficiently. Also, when both the liquid to be treated and the mixed fluid are liquids, the dissolving tank 16 is not necessary. When the dissolving tank 16 is provided, the flow rate control valve 14 is installed downstream of the dissolving tank 16.

[0034] Next, the operation of the liquid treatment device 1 will be described. When the pump 13 is driven, the liquid to be treated (here, water) flows from the tank 11 into the flow path 20. The liquid to be treated that has flowed into the upstream section 21a flows into the downstream section 21b through the fluid suction section 12. In the fluid suction section 12, the liquid to be treated flows through the hollow section of the first housing 121, the hollow section (suction chamber 122b) of the second housing 122, and the hollow section of the third housing 123 in this order, and the mixed fluid (here, air) flows into the suction chamber 122b through the suction port 122a due to the flow of the liquid to be treated. In the suction chamber 122b, the liquid to be treated and the mixed fluid are mixed, and the mixed liquid of the liquid to be treated and the mixed fluid flows into the diffuser 123c. In the diffuser 123c, the boundary layer is easily separated by the flow of the fluid from the low pressure side to the high pressure side, so that the flow of the mixed liquid of the liquid to be treated and the mixed fluid becomes unstable in the diffuser 123c. As a result, the mixed fluid turns into fine bubbles, and the fine bubbles are mixed into the liquid to be treated.

[0035] In liquid treatment device 1, flow path 20 constitutes a fluid circulation circuit, and the mixed liquid treated in fluid intake unit 12 is pressurized and dissolved in dissolution tank 16, returned to atmospheric pressure, returned to tank 11, and again flows through flow path 20 to be treated in fluid intake unit 12. In the case of a fluid circulation circuit, the same liquid to be treated can be treated multiple times in fluid intake unit 12, and the mixed fluid can be efficiently mixed into the liquid to be treated. Even in the case of not using a fluid circulation circuit, the mixed liquid passing through dissolution tank 16 improves mixing efficiency.

[0036] Fig. 3 is a graph comparing the amount of mixed fluid (air) mixed into the liquid to be treated (water) with and without the fluid suction section 12. In Fig. 3, the dotted line shows the air dissolution ratio (described in detail later) in the case of only the pump 13 (when the fluid suction section 12 is not provided), and the solid line shows the air dissolution ratio in the case of both the fluid suction section 12 and the pump 13. The dissolution ratio is an index expressed as the ratio between the amount of dissolved air, which is the amount of fine bubbles when released to the atmosphere, and the amount of saturated air, and it can be seen that the higher the dissolution ratio, the more gas is dissolved in the liquid to be treated.

[0037] In FIG. 3, the vertical axis indicates the dissolution ratio (%), and the horizontal axis indicates the amount of air injected (NL / min). NL is normal liters. The amount of air injected is the amount of air injected into the liquid to be treated, and can also be expressed as the ratio (%) of the amount of air injected to the amount of liquid to be treated passing through the pump 13 (the discharge amount of the pump 13). For example, in FIG. 3, the ratio is 0.9% when the amount of air injected is 5 NL / min, 1.9% when the amount of air injected is 10 NL / min, 2.8% when the amount of air injected is 15 NL / min, 3.8% when the amount of air injected is 20 NL / min, 4.8% when the amount of air injected is 25 NL / min, and 6.6% when the amount of air injected is 35 NL / min.

[0038] As shown in Fig. 3, it can be seen that a larger amount of gas (here, air) is dissolved in the liquid to be treated (here, water) in the liquid treatment device 1 of this embodiment provided with the fluid suction unit 12 and the pump 13, compared to the case of only the pump 13. The discharge pressure of the pump 13 in Fig. 3 is the same as the pressure in the dissolution tank 16, 0.5 MPa. The flow rate of the pump 13 is omitted because it varies depending on the amount of injected air.

[0039] Here, the dissolution ratio will be explained. Fig. 15 is a diagram showing a method for measuring the amount of dissolved air. The device 100 for measuring the amount of dissolved air mainly includes a dissolution tank 16, flow paths 20 and 106, an air tank 103, a water tank 104, and a pressure release valve 105.

[0040] A flow path 102 is connected to the flow path 20 downstream of a dissolving tank 16 provided in the flow path 20 of the liquid treatment device 1. First, the liquid to be treated flowing through the flow path 20 is pressurized and dissolved in the dissolving tank 16, undissolved large air bubbles are separated and removed, and the liquid to be treated from which the undissolved air bubbles have been separated and removed is made to flow through the flow path 102. Next, the liquid to be treated flowing through the flow path 102 is depressurized to atmospheric pressure by a pressure release valve 105 and released into an air reservoir 103. Air bubbles are separated from the liquid to be treated in the air reservoir 103, and the air bubbles float and accumulate at the top of the air reservoir 103, while the liquid to be treated accumulates in a water tank 104 connected through a flow path 106. The pressure release valve 105 adjusts the amount (speed) of the liquid to be treated released so that the air bubbles do not flow into the water tank 104.

[0041] When 1 L of the liquid to be treated is stored in the water tank 104, the amount of air in the air tank 103 is measured. The amount of air in the air tank 103 is the amount of air precipitated from 1 L of the liquid to be treated, i.e., the amount of dissolved air. These measurements are performed using scales provided on the transparent air tank 103 and the water tank 104.

[0042] Since the amount of dissolved air is affected by the water temperature, the amount of air separated from the treated liquid is converted into a dissolution ratio based on the water temperature at the time of measurement. The dissolution ratio is expressed as the ratio of the amount of dissolved air to the amount of saturated air at the temperature at which the amount of dissolved air was measured, as shown in formula (1).

number

[0043] According to this embodiment, two types of fluid (here, water as the liquid to be treated and air as the mixed fluid) can be efficiently mixed using only the fluid suction section 12. In particular, since pressurized dissolution is performed in the dissolution tank 16, the mixed fluid can be efficiently dissolved in the liquid to be treated. Therefore, the liquid treatment device 1 can have a simple configuration.

[0044] Furthermore, according to this embodiment, when the flow path 20 is a fluid circulation circuit, the same liquid to be treated can be treated multiple times in the fluid intake section 12, and the mixed fluid can be efficiently mixed into the liquid to be treated.

[0045] Furthermore, according to this embodiment, by setting the inner diameter of the nozzle 121b so that the flow velocity of the liquid to be treated is 5 m / sec or more and 6 m / sec or less, the negative pressure can be lowered and the mixed fluid can be sucked in at an appropriate suction pressure (negative pressure of -0.02 MPa to -0.03 MPa). If the suction force of the mixed fluid is too low, the amount of the mixed fluid sucked in decreases and the dissolution ratio deteriorates. If the suction force of the mixed fluid is too high, depending on the type of pump 13 (for example, in the case of a centrifugal pump), the pump 13 itself may cause an airlock (pump 13 cannot pump water) with respect to the amount of the mixed fluid sucked in. Therefore, by setting the flow velocity of the liquid to be treated at an appropriate value, the suction force of the mixed fluid can be adjusted and the mixed fluid can be efficiently mixed into the liquid to be treated.

[0046] In this embodiment, air is supplied to the fluid intake section 12 as a mixed fluid, and the air is dissolved in the water, which is the liquid to be treated, but the gas is not limited to air. For example, gases such as carbon dioxide and nitrogen may be supplied to the fluid intake section 12 to dissolve the gas in the liquid to be treated, or the air in the liquid to be treated may be replaced with carbon dioxide, nitrogen, etc.

[0047] In this embodiment, the mixed fluid is not limited to gas. For example, the mixed fluid may be a liquid. For example, the liquid to be treated may be water, the mixed fluid may be oil, and the oil may be dissolved in the water. Although water and oil do not mix easily, by using the liquid treatment device 1, fine oil particles can be mixed into the water.

[0048] Furthermore, in this embodiment, the liquid to be treated is water, but the liquid to be treated is not limited to water. For example, the liquid to be treated may be oil. Furthermore, the liquid to be treated may be a non-Newtonian fluid. For example, in the case where the liquid to be treated is mayonnaise, which is a non-Newtonian fluid, the mixed fluid is nitrogen, and the oxygen in the mayonnaise is replaced with nitrogen by the liquid treatment device 1, thereby improving the shelf life of the mayonnaise. Furthermore, in the case where the liquid to be treated is a dairy product such as milk, oxidation can be prevented by replacing the oxygen contained in the dairy product with nitrogen.

[0049] <Second embodiment> In the first embodiment of the present invention, the fluid is mixed into the liquid to be treated using the fluid suction part 12, but the method of mixing the fluid into the liquid to be treated is not limited to this. A liquid treatment device 2 of the present invention will be described below. Note that the same parts as those in the first embodiment are given the same reference numerals and descriptions thereof will be omitted.

[0050] 4 is a schematic diagram showing an example of a liquid treatment device 2 according to a second embodiment of the present invention. The liquid treatment device 2 mainly includes a tank 11, a fluid intake section 12, a pump 13, a mixing section 15, a dissolving tank 16, a flow rate control valve 14, and a flow path 20. The flow path 20 is provided with the fluid intake section 12, the pump 13, the flow rate control valve 14, the mixing section 15, and the dissolving tank 16.

[0051] Mixing section 15 is a component that mixes the liquid to be treated with a fluid, and is provided downstream of pump 13. Mixing section 15 generates pressure loss, and if mixing section 15 is provided upstream of pump 13, mixing section 15 will create resistance and make it difficult to adjust the suction force, so mixing section 15 is provided downstream of pump 13.

[0052] The dissolving tank 16 is provided downstream of the mixing section 15, and the flow rate control valve 14 is provided downstream of the dissolving tank 16. The upstream side of the mixing section 15 of the flow path 20 is referred to as the upstream section 22c, the downstream side of the mixing section 15 and the upstream side of the dissolving tank 16 is referred to as the midstream section 22d, and the downstream side of the flow rate control valve 14 is referred to as the downstream section 22b. A pressure gauge may be provided in the upstream section 22c, and a flow meter may be provided in the downstream section 22b.

[0053] 5(A) is a diagram showing an outline of the mixer 15. The mixer 15 mainly has a casing 15a and a plurality of plate-like members 15b and 15c.

[0054] The casing 15a is cylindrical and is provided in the flow path 20 (here, return path 22). The casing 15a has a cylindrical side surface 15j, and an end 15h (corresponding to a first end of the present invention) and an end 15i (corresponding to a second end of the present invention) covering both ends of the side surface 15j. One end 15h is provided with an inlet 15e through which the liquid to be treated and the fluid sucked into the fluid suction section 12 flow in, and the other end 15i is provided with an outlet 15f through which the liquid to be treated and the fluid sucked into the fluid suction section 12 flow out.

[0055] Plate-shaped members 15b and 15c are provided inside the casing 15a. In this embodiment, two each of the plate-shaped members 15b and 15c are provided, but the number of the plate-shaped members 15b and 15c is not limited to this. The plate-shaped members 15b and 15c are disk-shaped and have the same peripheral size. The plate-shaped members 15b and 15c are alternately stacked. Note that the plate-shaped members 15b and 15c are not limited to being disk-shaped, and may have a rectangular shape in a plan view (shape when viewed along the plate thickness direction).

[0056] Plate-like members 15b and 15c are provided so as to abut against end 15h but not abut against end 15i. Furthermore, plate-like members 15b and 15c are provided so as not to abut against side surface 15j connecting end 15h and end 15i. Furthermore, one end of each of plate-like members 15b and 15c (the end not abutting end 15h) is covered by plate-like member 15d.

[0057] 5(B) is a schematic diagram of plate-shaped member 15b. Plate-shaped member 15b is provided with a plurality of through holes 15g (corresponding to the first through holes of the present invention) through which the liquid to be treated passes. Through holes 15g are, for example, hexagonal in shape. In this embodiment, through holes 15g are provided on the entire surface of plate-shaped member 15b. Although not shown, plate-shaped member 15c is also provided with a plurality of through holes 15g (on the entire surface) in the same manner as plate-shaped member 15b.

[0058] Fig. 6(A) is a partially enlarged view of plate-shaped member 15b (corresponding to the first plate-shaped member of the present invention), Fig. 6(B) is a partially enlarged view of plate-shaped member 15c (corresponding to the second plate-shaped member of the present invention), and Fig. 6(C) is a diagram showing a state in which plate-shaped members 15b and 15c are alternately laminated. In Fig. 6, plate-shaped member 15c is shown by a dotted line for the sake of explanation.

[0059] The difference between the plate-shaped member 15b and the plate-shaped member 15c is the positional relationship between the peripheries of the plate-shaped members 15b and 15c and the through-holes 15g (the positions of the through-holes 15g). For example, the positions of the through-holes 15g in the plate-shaped member 15b and the positions of the through-holes 15g in the plate-shaped member 15c are shifted by half the pitch of the through-holes 15g in the horizontal direction of Fig. 6 and by ¼ the pitch of the through-holes 15g in the vertical direction of Fig. 6. As a result, when the plate-shaped member 15b and the plate-shaped member 15c are stacked so that the peripheries match, the through-holes 15g of the plate-shaped member 15b and the through-holes 15g of the plate-shaped member 15c partially overlap.

[0060] Returning to the explanation of FIG. 5(A), the liquid to be treated and the mixed fluid flowing in from the inlet 15e are stirred through the through-hole 15g and flow into the hollow part of the casing 15a from the periphery of the plate-like members 15b and 15c. As a result, the flow of the fluid (mixture of the liquid to be treated and the mixed fluid) becomes unstable when passing through the through-hole 15g, and the liquid to be treated and the mixed fluid are mixed. The mixed fluid then flows out from the outlet 15f.

[0061] Next, the operation of liquid treatment device 2 will be described with reference to Fig. 4. When pump 13 is driven, the liquid to be treated (here, water) flows from tank 11 into flow path 20 (upstream section 21a), and then flows into downstream section 21b through fluid suction section 12. When the liquid to be treated flows through fluid suction section 12, air (here) flows into suction chamber 122b via suction port 122a, where the liquid to be treated and the mixed fluid are mixed, and in diffuser 123c, the mixed fluid becomes fine bubbles and is mixed with the liquid to be treated.

[0062] Thereafter, the liquid to be treated flows into the mixing section 15 in a state in which fine bubbles are mixed in the fluid intake section 12. The flow of the fluid (mixture of the liquid to be treated and the mixed fluid) that has flowed into the mixing section 15 becomes unstable when passing through the through-holes 15g, and the mixed fluid that has become fine bubbles is further mixed into the liquid to be treated.

[0063] In liquid treatment device 2, flow path 20 constitutes a fluid circulation circuit, and the liquid to be treated is treated in fluid intake section 12 and mixing section 15, pressurized and dissolved in dissolution tank 16, and returned to atmospheric pressure, and then returns to tank 11, flows through flow path 20 again, and is treated in fluid intake section 12 and mixing section 15. In the case of a fluid circulation circuit, the same liquid to be treated can be treated multiple times in fluid intake section 12 and mixing section 15, and the mixed fluid can be efficiently mixed into the liquid to be treated.

[0064] FIG. 7 is a graph comparing the amount of mixed fluid (air) mixed into the liquid to be treated (water) with and without the fluid intake section 12 and the mixing section 15. In FIG. 7, the dotted line indicates the dissolution ratio of air in the case of the pump 13, the dissolving tank 16, and the flow rate control valve 14 (when the fluid intake section 12 and the mixing section 15 are not provided), and the solid line indicates the dissolution ratio of air in the case of the fluid intake section 12, the pump 13, the mixing section 15, the dissolving tank 16, and the flow rate control valve 14. As shown in FIG. 7, when the fluid intake section 12, the pump 13, the mixing section 15, the dissolving tank 16, and the flow rate control valve 14 are provided, it was found that more air was mixed into the water than when the pump 13, the dissolving tank 16, and the flow rate control valve 14 were provided. Note that the discharge pressure of the pump 13 in FIG. 7 is the same as the pressure in the dissolving tank 16, 0.5 MPa.

[0065] FIG. 8 is a graph comparing the amount of mixed fluid (air) mixed into the liquid to be treated (water) with and without the mixer 15. In FIG. 8, the dotted line indicates the dissolution ratio of air in the case of the fluid intake 12, pump 13, dissolving tank 16, and flow rate control valve 14 (when the mixer 15 is not provided), and the solid line indicates the dissolution ratio of air in the case of the fluid intake 12, pump 13, mixer 15, dissolving tank 16, and flow rate control valve 14. As shown in FIG. 8, when the fluid intake 12, pump 13, mixer 15, dissolving tank 16, and flow rate control valve 14 are provided, it was found that more air was mixed into the water than when the pump 13, fluid intake 12, dissolving tank 16, and flow rate control valve 14 were provided. Note that the discharge pressure of the pump 13 in FIG. 8 is the same as the pressure in the dissolving tank 16, 0.3 MPa.

[0066] According to this embodiment, two types of fluids can be mixed efficiently by providing the fluid suction section 12 and the mixing section 15. In particular, since dissolution under pressure is performed in the dissolution tank 16, the mixed fluid can be efficiently dissolved in the liquid to be treated.

[0067] Furthermore, according to this embodiment, when the flow path 20 is a fluid circulation circuit, the same liquid to be treated can be treated multiple times in the fluid intake section 12 and the mixing section 15, and the mixed fluid can be efficiently mixed into the liquid to be treated.

[0068] In the present embodiment, the through hole 15g is hexagonal, but the through hole 15g is not limited to a hexagonal shape. For example, the through hole 15g may be a polygonal shape such as a rhombus, a rectangle, a triangle, or a pentagon, or may be a circular shape, an elliptical shape, or the like. However, in order to efficiently mix two types of fluids, it is preferable that the through hole 15g is polygonal.

[0069] In the present embodiment, the mixing section 15 has two types of plate-like members 15b and 15c, but the mixing section 15 may have three or more types of plate-like members. In addition, in the mixing section 15, it is sufficient that different types of plate-like members are stacked adjacent to each other.

[0070] In the present embodiment, the plate-shaped members 15b and 15c are provided so as to abut against the end 15h and not to abut against the end 15i and the side surface 15j, but the form in which the plate-shaped members 15b and 15c are provided is not limited to this. For example, the plate-shaped members 15b and 15c may be provided so as to abut against the side surface 15j and not to abut against the ends 15h and 15i. Even when the plate-shaped members 15b and 15c are provided so as to abut against the side surface 15j and not to abut against the ends 15h and 15i, the through holes 15g of the plate-shaped members 15b and 15c partially overlap each other, and the mixed liquid of the liquid to be treated and the mixed fluid repeatedly flows in and out of the through holes 15g, so that the liquid to be treated and the mixed fluid are efficiently mixed.

[0071] In addition, in this embodiment, the liquid to be treated is water and the mixed fluid is air, but as in the first embodiment, the liquid to be treated is not limited to water and the mixed fluid is not limited to air.

[0072] <Modification of the second embodiment> Although the liquid treatment device 2 has the mixing section 15 in which the plate-like members 15b and the plate-like members 15c are alternately stacked, the shape of the mixing section is not limited to this. Fig. 9 is a schematic diagram showing an example of a liquid treatment device 2A having a mixing section 15A according to a modified example. The liquid treatment device 2A differs from the liquid treatment device 2 only in the mixing section 15A.

[0073] 10 is a diagram showing an outline of the mixer 15A. The mixer 15A is mainly composed of two plate-like members 15b and 15c stacked one on the other, and two plate-like members 15c stacked on the two plate-like members 15b.

[0074] Even in the mixing section 15A, since the through hole 15g of the plate-shaped member 15b and the through hole 15g of the plate-shaped member 15c partially overlap, the flow of the fluid (the mixed liquid of the liquid to be treated and the mixed fluid) passing through the through hole 15g becomes unstable, and the liquid to be treated and the mixed fluid are mixed.

[0075] Fig. 11 is a graph comparing the amount of mixed fluid (air) mixed into the liquid to be treated (water) between mixing section 15 and mixing section 15A. As described above, it can be seen that mixing section 15 and mixing section 15A have similar functions. Note that the discharge pressure of pump 13 in Fig. 11 is the same as the pressure in dissolving tank 16, 0.5 MPa.

[0076] In addition, the number of plate-like members 15b and 15c in the mixing section 15A is not limited to two, as in the mixing section 15. Furthermore, the mixing section 15A may have three or more types of plate-like members. In addition, in the mixing section 15A, it is sufficient that the same types of plate-like members are stacked and these are stacked.

[0077] <Third embodiment> In the first embodiment of the present invention, the fluid is mixed into the liquid to be treated using the fluid suction part 12, but the method of mixing the fluid into the liquid to be treated is not limited to this. A liquid treatment device 3 of the present invention will be described below. Note that the same parts as those in the first and second embodiments are given the same reference numerals and descriptions thereof will be omitted.

[0078] 12 is a schematic diagram showing an example of a liquid treatment device 3 according to a third embodiment of the present invention. The liquid treatment device 3 mainly includes a tank 11, a pump 13, a mixing section 15, a dissolving tank 16, a flow control valve 14, a flow path 20, and a fluid inlet section 30.

[0079] The fluid inlet section 30 is provided on the flow path 20 downstream of the pump 13 (the return path 22). The fluid inlet section 30 mainly includes a gas tank 31 and a connection section 32.

[0080] The gas tank 31 is filled with a high-pressure gas. The high-pressure gas includes compressed gas and liquefied gas. The compressed gas is defined as a compressed gas having a pressure of 1 MPa or more at a normal temperature, and the actual pressure is 1 MPa or more, or a compressed gas having a pressure of 1 MPa or more at 35°C. Examples of the compressed gas include hydrogen, oxygen, and nitrogen. The liquefied gas is defined as a liquefied gas having a pressure of 0.2 MPa or more at a normal temperature, and the actual pressure is 0.2 MPa or more, or a liquefied gas whose temperature when the pressure becomes 0.2 MPa is 35°C or less. Examples of the liquefied gas include carbon dioxide, ammonia, and nitrogen. In this embodiment, carbon dioxide and nitrogen are adopted as a fluid (mixed fluid) to be mixed with the liquid to be treated.

[0081] The connection part 32 is a member that connects the gas tank 31 and the flow path 20 (the return path 22), and includes a pipe, a hose, a joint, etc. The upstream side of the connection part 32 of the return path 22 is the upstream part 22e, and the downstream side is the midstream part 22f.

[0082] Next, the operation of the liquid treatment device 3 will be described. When the pump 13 is driven, the liquid to be treated (here, water) flows from the tank 11 into the flow path 20. The liquid to be treated that flows into the upstream section 22a is mixed with the mixed fluid sealed in the gas tank 31 via the connection section 32, and flows into the midstream section 22f. The mixed liquid then flows into the mixing section 15, and passes through the through hole 15g, causing the flow to become unstable. As a result, the high-pressure gas turns into fine bubbles, and the fine bubbles are mixed into the water.

[0083] In liquid treatment device 3, flow path 20 constitutes a fluid circulation circuit, and after being treated in mixing section 15 and being pressurized and dissolved in dissolution tank 16, the liquid to be treated returns to tank 11, flows through flow path 20 again, and is treated in mixing section 15. In the case of a fluid circulation circuit, the same liquid to be treated can be treated multiple times in mixing section 15, and the mixed fluid can be efficiently mixed into the liquid to be treated.

[0084] FIG. 13 is a graph comparing the amount of dissolved mixed fluid (here, carbon dioxide) in the liquid to be treated (water) with and without the mixing unit 15. In FIG. 13, square plots indicate the concentration of carbon dioxide (carbonic acid gas) when the pump 13, dissolving tank 16, and flow rate control valve 14 are provided (when the mixing unit 15 is not provided), and circle plots indicate the concentration of carbon dioxide when the pump 13, mixing unit 15, dissolving tank 16, and flow rate control valve 14 are provided. From FIG. 13, it was found that when the mixing unit 15 is provided, the carbon dioxide gas concentration is higher than when the mixing unit 15 is not provided, that is, more carbon dioxide is dissolved in the water. Note that the discharge pressure of the pump 13 in FIG. 13 is the same as the pressure in the dissolving tank 16, 0.4 MPa, the pressure of carbon dioxide in the gas tank 31 is 0.5 MPa, and the injection rate of carbon dioxide is 3 NL / min.

[0085] FIG. 14 is a graph comparing the amount of mixed fluid (here, nitrogen) mixed into the liquid to be treated (water) with and without the mixing unit 15. Note that FIG. 14(B) is an enlarged view of a part of FIG. 14(A). When nitrogen is mixed into the liquid to be treated, oxygen is replaced by nitrogen (nitrogen replacement), and the amount of dissolved oxygen in the liquid to be treated decreases. Therefore, by measuring the amount of dissolved oxygen, the amount of nitrogen mixed can be indirectly measured. From FIG. 14, it was found that when the mixing unit 15 is provided, the amount of dissolved oxygen decreases more quickly than when the mixing unit 15 is not provided, that is, more nitrogen is mixed into the water. Note that the discharge pressure of the pump 13 in FIG. 14 is the same as the pressure in the dissolving tank 16, 0.4 MPa, the pressure of nitrogen in the gas tank 31 is 0.5 MPa, and the injection amount of nitrogen is 3 NL / min.

[0086] According to this embodiment, two types of fluids can be efficiently mixed by providing the mixing section 15. In particular, since pressurized dissolution or nitrogen substitution is performed in the dissolution tank 16, the mixed fluid can be efficiently dissolved or substituted in the liquid to be treated.

[0087] Furthermore, according to this embodiment, flow path 20 is a fluid circulation circuit through which the treated liquid flowing out of tank 11 flows and also returns the treated liquid to tank 11, so that the same treated liquid can be treated multiple times in mixing section 15 and the mixed fluid can be efficiently mixed into the treated liquid.

[0088] In this embodiment, the liquid to be treated is water and the mixed fluid is air, but as in the first and second embodiments, the liquid to be treated is not limited to water and the mixed fluid is not limited to air.

[0089] Although an embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes and the like that do not deviate from the gist of the present invention are also included.

[0090] In addition, "substantially" is a concept that includes not only the case of being strictly identical, but also an error or deformation to the extent that the identity is not lost. For example, "substantially orthogonal" is a concept that includes the case where it can be regarded as the same as orthogonal, for example, not limited to the case of being strictly orthogonal. In addition, for example, when expressing orthogonal, parallel, coincident, etc., it includes not only the case of being strictly orthogonal, parallel, coincident, etc., but also the case of approximately parallel, approximately orthogonal, approximately coincident, etc.

[0091] In addition, "vicinity" means including a certain range (which can be determined arbitrarily) near a reference position. For example, in the case of "near an end," it is a concept indicating a certain range of an area near the end, which may or may not include the end. [Explanation of symbols]

[0092] 1, 2, 2A, 3: Liquid treatment equipment 11: Tank 12:Fluid suction part 13: Pump 14: Flow control valve 15, 15A: Mixing section 15a: Casing 15b, 15c, 15d: Plate-shaped members 15e:Inlet 15f: Outlet 15g:Through hole 16: Dissolving tank 20: Flow path 21: Outflow route 22: Reflux route 21a, 22a, 22c, 22e: Upstream part 21b, 22b: downstream 22d, 22f: Middle part 30:Fluid inlet 31: Gas tank 32: Connection part 100: Measuring device 102, 106: flow path 103: Air storage tank 104: Water tank 105: Pressure relief valve 111: Outlet 121: First unit 121a: Supply port 121b: Nozzle 122: Second unit 122a: Inlet 122b: Suction chamber 123: 3rd unit 123a: Outlet 123b: Reduced part 123c: Diffuser

Claims

1. A tank for storing the liquid to be treated, A flow path through which the liquid to be treated flows out of the tank and returns the liquid to be treated to the tank, A pump provided in the aforementioned flow path, which discharges the liquid to be treated from the tank into the flow path, The fluid suction section is provided on the upstream side of the flow path of the pump and mixes a mixed fluid, which is a fluid different from the liquid to be treated, with the liquid to be treated. The fluid intake section comprises a nozzle, a diffuser, and an intake chamber. A supply port communicating with the nozzle and an outlet communicating with the diffuser are provided in the flow path. As the liquid to be processed passes through the nozzle, the suction chamber and the diffuser, the mixed fluid is drawn into the suction chamber from the suction port, which is the entrance to the suction chamber. The inner diameter of the nozzle is set such that the flow velocity of the liquid to be processed is 5 m / s or more and 6 m / s or less. A liquid processing apparatus characterized by the following:

2. The liquid processing apparatus according to claim 1, further comprising a dissolution tank provided downstream of the pump in the flow path, for dissolving the fluid after the liquid to be processed and the mixed fluid have been mixed under a pressurized environment.

3. A mixing unit is provided on the downstream side of the flow path of the pump and on the upstream side of the dissolution tank, and mixes the mixed fluid with the liquid to be processed. The mixing unit comprises a casing having cylindrical sides provided in the flow path, and a plurality of plate-like members provided inside the casing. The plate-like member is provided with a plurality of first through-holes through which the liquid to be processed passes. The multiple plate-like members are stacked such that the first through-hole of the first plate-like member and the first through-hole of the second plate-like member adjacent to the first plate-like member partially overlap. The liquid processing apparatus according to claim 2.

4. A tank for storing the liquid to be treated, A flow path through which the liquid to be treated flows out of the tank and returns the liquid to be treated to the tank, A pump provided in the aforementioned flow path, which discharges the liquid to be treated from the tank into the flow path, A fluid inlet provided downstream of the pump in the flow path, comprising a gas tank containing a high-pressure gas which is a mixed fluid, and a connecting portion connecting the gas tank and the flow path, A mixing unit is provided downstream of the fluid inlet of the flow path, and mixes the mixed fluid with the liquid to be treated. Equipped with, The mixing unit comprises a casing having cylindrical sides provided in the flow path, and a plurality of plate-like members provided inside the casing. The plate-like member is provided with a plurality of first through-holes through which the liquid to be processed passes. The multiple plate-like members are stacked such that the first through-hole of the first plate-like member and the first through-hole of the second plate-like member adjacent to the first plate-like member partially overlap. A liquid processing apparatus characterized by the following:

5. The liquid processing apparatus according to claim 4, further comprising a dissolution tank provided downstream of the mixing section of the flow path, for dissolving the fluid after the liquid to be processed and the mixed fluid have been mixed under a pressurized environment.

6. The casing has a first end on its side surface, which is provided with a third inlet, which is the inlet for the liquid to be treated, and a second end on its side surface, which is provided with a second outlet, which is the outlet for the liquid to be treated. The plate-like member abuts against the first end, but does not abut against the second end or the side surface. The end of the stacked plate-like members that is not in contact with the first end is covered by a third plate-like member. The liquid processing apparatus according to any one of claims 3 to 5.

7. The liquid to be treated is water. The aforementioned mixed fluid is at least one of the following: air, carbon dioxide, or nitrogen. A liquid processing apparatus according to any one of claims 1 to 4.

8. The aforementioned pump is a positive displacement pump, The liquid being treated is a non-Newtonian fluid. A liquid processing apparatus according to any one of claims 1 to 4.

9. The pump mentioned above is a centrifugal pump, The liquid being treated is a Newtonian fluid. A liquid processing apparatus according to any one of claims 1 to 4.

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