Vertical centrifugal separator

Abstract

[Problem] To prevent a separated liquid that has flowed into a collection chamber from overflowing. [Solution] The present invention is characterized by including: a cylindrical rotary cylinder in which a supply port for a liquid to be treated is formed in a lower side, and a discharge port for a separated liquid which has been centrifugally separated is formed in an upper side, the cylindrical rotary cylinder rotating around a vertical axis during the execution of centrifugal separation; a casing in which the cylindrical rotary cylinder is accommodated so as to be rotatable around the vertical axis; a collection cover that includes a bottom plate part in which a circular opening that has the cylindrical rotary cylinder inserted therein is formed, the collection cover forming a collection chamber which is for the separated liquid and which is in communication with the discharge port; and a separated-liquid discharge nozzle that is connected to the collection chamber, wherein the bottom plate part of the collection chamber inclines downward toward the outer periphery, and the edge of the circular opening of the bottom plate part is provided with a weir part including a vertical wall portion and a flange portion that protrudes from the upper end of the vertical wall portion toward the outer peripheral side of the bottom plate part.

Description

Technical Field

[0005]

[0001] The present invention relates to a vertical centrifuge for solid-liquid separation of a liquid to be treated.

Background Art

[0002] A centrifuge is a device that can perform separation operations such as solid-liquid separation, liquid-liquid separation, or solid-liquid-liquid separation by applying centrifugal force to the liquid to be treated by supplying the liquid to be treated into a rotating bowl.

[0003] In Patent Document 1, a supply port for the liquid to be treated is formed on the lower side, a discharge port for the centrifuged separated liquid is formed on the upper side, a cylindrical rotating cylinder that rotates around a vertical axis during centrifugation, a casing in which the cylindrical rotating cylinder is rotatably accommodated around the vertical axis, a circular opening whose inner peripheral edge is disposed close to the outer peripheral surface of the cylindrical rotating cylinder is formed on the bottom plate, a collection chamber for the separated liquid that is disposed so as to surround the circumferential orbit of the discharge port of the cylindrical rotating cylinder over the entire circumference, a discharge nozzle for the separated liquid connected to the collection chamber, a collection cover for the separated liquid disposed on the upper side of the casing, and one or more rectifying vanes disposed on the back surface of the bottom plate of the collection chamber, with at least the surface on the rotation axis side of the cylindrical rotating cylinder inclined inward, are provided. The surface of the rectifying vane is inclined such that the end on the side closer to the rotation axis of the cylindrical rotating cylinder is lower than the end on the side separated from the rotation axis. A vertical centrifuge is disclosed.

[0004] The purpose of this vertical centrifuge is to suppress the influence of the swirling flow of air generated by the high-speed rotation of the cylindrical rotating cylinder and prevent the mist of the separated liquid from leaking from the collection cover.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

[0006] However, in the configuration of Patent Document 1, the separated liquid that flowed into the collection chamber sometimes overflowed and adhered to the underside of the bottom plate of the collection cover. The first objective of the present invention is to prevent the separation liquid flowing into the collection chamber from overflowing. A second objective of the present invention is to prevent the mist-like separation liquid floating in the collection chamber from flowing out of the collection chamber into the casing. [Means for solving the problem]

[0007] The first configuration of the vertical centrifugal separator according to the present invention is characterized in that (1) a cylindrical rotating cylinder that rotates around a vertical axis when centrifugal separation is performed, having a supply port for the liquid to be processed formed on the lower side and an outlet for the separated liquid formed on the upper side, a casing in which the cylindrical rotating cylinder is rotatably housed around a vertical axis, and a collection cover including a bottom plate portion through which the cylindrical rotating cylinder is inserted, the collection cover forming a collection chamber for the separated liquid that communicates with the outlet, and a discharge nozzle for the separated liquid connected to the collection chamber, wherein the bottom plate portion of the collection chamber is inclined downward toward the outer circumference, and a weir portion including a vertical wall portion and a flange portion projecting from the upper end of the vertical wall portion toward the outer circumference of the bottom plate portion is provided at the edge of the circular opening of the bottom plate portion.

[0008] A second configuration of the vertical centrifugal separator according to the present invention is characterized in that (2) an airflow generating unit that generates an airflow from the casing toward the circular opening is provided in the vertical centrifugal separator of (1) above. [Effects of the Invention]

[0009] According to the first configuration of the present invention, it is possible to prevent the separated liquid flowing into the collection chamber from overflowing and adhering to the underside of the bottom plate of the collection cover, etc. (in other words, the first objective can be achieved). According to the second configuration of the present invention, it is possible to further prevent the mist-like separated liquid floating in the collection chamber from flowing out of the collection chamber into the casing (in other words, both the first and second objectives can be achieved). [Brief explanation of the drawing]

[0010] [Figure 1] This is a front view of a vertical centrifugal separator (first embodiment). [Figure 2] This is a side view of a vertical centrifugal separator (first embodiment). [Figure 3] This is a plan view of the collection cover. [Figure 4] This is a magnified view of a portion of Figure 1. [Figure 5] This is a magnified view of a portion of Figure 4. [Figure 6] This is an enlarged view of a part of the vertical centrifugal separator of Modification 1, and corresponds to Figure 4. [Figure 7] This is an enlarged view of a part of the vertical centrifugal separator (second embodiment), corresponding to Figure 4. [Modes for carrying out the invention]

[0011] (First Embodiment) Hereinafter, one embodiment of the vertical centrifugal separator of the present invention will be described in detail with reference to the drawings. However, the technical scope of the present invention shall not be limited in any way by the embodiment described below.

[0012] Figure 1 is a front view of a vertical centrifugal separator according to this embodiment, with the casing partially cut out. Figure 2 is a side view of the vertical centrifugal separator according to this embodiment, with a partial perspective view of the apparatus. Figure 3 is a plan view of the repair cover. This embodiment is a vertical centrifugal separator that achieves the first objective described in the problem section.

[0013] Referring to the figure thereof, the vertical centrifuge 1 includes a bowl 2 which is a cylindrical rotating cylinder arranged in the vertical direction, a casing 3 as an exterior body for rotatably accommodating the bowl 2, a drive motor 4 as a drive device for generating power to rotate the bowl 2 around the vertical axis, and a support device 5 for supporting these components.

[0014] The casing 3 includes a casing main body 31, and a collection cover 32 as an upper casing is detachably mounted on the upper part of the casing main body 31. The collection cover 32 receives the separated liquid discharged from the upper side of the bowl 2 under the action of centrifugal force during the execution of centrifugation, and guides this separated liquid toward the discharge nozzle 34.

[0015] A pipe (not shown) is detachably connected to the tip of the discharge nozzle 34, and this pipe is connected to a storage tank (not shown). Note that although the bowl 2 of the vertical centrifuge 1 in the present embodiment has a structure for separating the liquid to be treated into a solid-liquid two-phase, the present invention is not limited thereto.

[0016] The bowl 2 has a cylindrical body portion 21 with a hollow interior, a supply port 22 for the liquid to be treated is formed on the lower side, and a separated liquid discharge port 23 for discharging the separated liquid is formed on the upper side. A supply nozzle 24 for the liquid to be treated is inserted into the supply port 22 formed on the lower side of the bowl 2. The supply nozzle 24 is arranged at a distance from the inner wall surface of the bowl 2. Thereby, when the bowl 2 rotates, it is possible to prevent the inner wall surface of the bowl 2 and the supply nozzle 24 from coming into contact.

[0017] The liquid to be treated is sent, for example, by a liquid sending means (not shown) such as a pump, discharged from the tip of the supply nozzle 24, and supplied into the bowl 2. Although not shown in the figure, inside the bowl 2, a blade member (for example, a three-wing) for partitioning the internal space of the bowl 2 in the circumferential direction is arranged.

[0018] Of the separated liquid and the solid content obtained by centrifugation, the separated liquid is continuously discharged from the bowl 2, and the solid content is accumulated in the bowl 2. This accumulated solid content is recovered after stopping the vertical centrifuge 1 and removing the bowl 2 from the casing 3. That is, the vertical centrifuge 1 of the present embodiment is a batch-type centrifuge.

[0019] The dimensions of the bowl 2 are not particularly limited. As an example, the inner diameter is included in the range of 95 to 160 mm, and the length is included in the range of 457 to 730 mm. The bowl 2 is detachably connected to the rotating shaft 26a of the bearing assembly 26 by a coupling nut 25 which is a detaching means. The bearing assembly 26 is connected to the rotating pulley 42 of the drive motor 4 through a rotating belt 41. The bowl 2 is suspension-supported by connecting the bowl 2 and the bearing assembly 26 during centrifugation, and rotates around the vertical axis by the power generated by the drive motor 4. On the other hand, when removing the bowl 2 from the casing 3, the connection state between the bowl 2 and the bearing assembly 26 is released by releasing the connection by the coupling nut 25.

[0020] The collection cover 32 will be described in detail while referring to FIGS. 4 and 5. FIG. 4 is an enlarged view of a part of the vertical centrifuge in which the area surrounded by the dotted line in FIG. 1 is enlarged. FIG. 5 is an enlarged view of a part of the vertical centrifuge in which the area surrounded by the dotted line in FIG. 4 is enlarged. The collection cover 32 is composed of a bottom plate portion 32a, a side plate portion 32b, and a top plate portion 32c, and functions as a collection chamber for collecting the separated liquid obtained by centrifugation. The separated liquid discharge port 23 is formed at a desired position in this collection chamber.

[0021] A circular opening 7 is formed in the center of the bottom plate portion 32a, and the tip (shaft portion) of the bowl 2 is inserted through this circular opening 7. The bottom plate portion 32a is tapered and slopes downward toward the outer circumference. By sloping the bottom plate portion 32a downward toward the outer circumference, a flow path can be formed for the separated liquid that flows in from the separated liquid outlet 23 toward the outer circumference. Since a circular opening 7 is formed in the center of the bottom plate portion 32a, the shape of the bottom plate portion 32a in plan view is a so-called donut shape.

[0022] A dam section 320 is arranged in a ring shape around the edge of the circular opening 7 of the bottom plate section 32a. The weir section 320 includes a vertical wall section 321 and a flange section 322 that protrudes from the upper end of the vertical wall section 321 toward the outer circumference of the bottom plate section 32. The vertical wall section 321 and the flange section 322 are integrally provided with each other. The vertical wall section 321 extends in the longitudinal direction (i.e., vertical direction) of the bowl 2. The protruding direction of the flange section 322 may be perpendicular to the longitudinal axis of the bowl 2, or it may be in an inclined direction that is inclined toward the perpendicular direction. By providing the weir section 320 at the edge of the circular opening 7 of the bottom plate section 32a, it is possible to prevent the separated liquid from overflowing from the circular opening 7 and leaking to the back side of the bottom plate section 32a. Details of these effects will be described later.

[0023] The side plate portion 32b is formed to rise from the outer edge of the bottom plate portion 32a. A partial notch is formed in the side plate portion 32b, and the discharge nozzle 34 is connected to this notch. The bottom plate portion 32a and the side plate portion 32b can be formed integrally.

[0024] The top surface portion 32c is attached to the upper end of the side plate portion 32b and covers the upper opening of the collection cover 32. In other words, the top surface portion 32c is the top lid of the collection cover 32. The top surface portion 32c has a flat shape on its inner edge that extends in a direction perpendicular to the longitudinal axis of the bowl 2, and a sloped shape on its outer edge that slopes toward the upper end of the side plate portion 32b. In other words, the top surface portion 32c is formed in a stepped shape.

[0025] Here, the inventors discovered that the separated liquid flowing into the collection chamber overflows the vertical wall portion 321 and leaks out of the circular opening 7, and that this leaked separated liquid (not in mist form) adheres to the back side of the bottom plate portion 32a, etc. It is presumed that a swirling flow is generated in the collection chamber by the rotational movement of the bowl 2, and that this swirling flow causes the separated liquid to spread along the bottom plate portion 32a and overflow the vertical wall portion 321. To solve this problem, it was discovered that overflow of the separated liquid can be prevented by providing a weir section 320 consisting of a vertical wall section 321 and a flange section 322 at the edge of the circular opening 7. It should be noted that whether or not the separated liquid has overflowed can be determined by visual inspection. After centrifugation, the back surface of the bottom plate section 32a can be observed, and if the separated liquid is thickly adhered to it, it can be determined that overflow has occurred.

[0026] The liquid to be treated is not particularly limited, but may include, for example, any of the following: baker's yeast, baking soda, ink, cocoa mass, a mixture of minced chicken bones and dried fish, minced beef and pork, tea leaves, cross-linked acrylic polymer, collagen, saccharified grain (rice, barley, etc.), or vegetable pigment extract. The inventors have previously confirmed that when a separation liquid with a lower surface tension than water (e.g., ink pigment) flows into the collection chamber, the separation liquid tends to spread along the bottom plate portion 32a. In other words, even if airflow control is performed using a flow straightening vane (see Patent Document 1), the spreading phenomenon at the bottom plate portion 32a cannot be suppressed for separation liquids with a lower surface tension than water. Therefore, the means to solve the leakage of the separation liquid were re-examined from scratch, and it was discovered that a weir portion 320 is provided at the edge of the circular opening 7. Therefore, the vertical centrifugal separator of the first embodiment is more suitable for separation liquids with a lower surface tension than water. However, it goes without saying that even with separation liquids with a higher surface tension than water, the dam effect is achieved through the cooperation of the vertical wall portion 321 and the flange portion 322.

[0027] Referring to Figure 5, when the height dimension of the vertical wall portion 321 is defined as W and the distance between the lower end of the separation liquid outlet 23 and the upper end of the flange portion 322 is defined as Z, the height dimension W is preferably 10 mm or more, and the distance between the edges Z is preferably 2 mm or more. Increasing the height dimension W increases the amount of separation liquid that can be received by the weir portion 320, thereby further enhancing the weir effect. However, if the height dimension W becomes excessively large and the distance between the edges Z falls to less than 2 mm, the inflow of separation liquid into the collection chamber may be obstructed, and there is a risk that the separation liquid will leak out from the circular opening 7. For these reasons, the height dimension W is preferably 10 mm or more, and the distance between the edges Z is preferably 2 mm or more. Note that the dimensions W and the distance between the edges Z can be changed by adjusting the inclination angle of the bottom plate portion 32a. For example, if the inclination angle is made smaller during the design stage, the dimension W can be made longer.

[0028] When the horizontal distance (hereinafter also referred to as clearance) between the vertical wall portion 321 and the outer surface of the bowl 2 is X, the clearance X is preferably 2.0 mm or more and 3.5 mm or less. If the clearance X is excessively small, the bowl 2 and the vertical wall portion 321 may come into contact during centrifugal separation. If the clearance X is excessively large, the separated liquid may leak out of the circular opening 7 when the separated liquid flows into the collection chamber from the separated liquid outlet 23.

[0029] When the horizontal length of the flange portion 322 (hereinafter also referred to as the protruding length) is Y, the protruding length Y is preferably 5 mm or more. If the protruding length Y is excessively small, the damming effect of the flange portion 322 may be reduced. There is no particular upper limit to the protruding length Y, but if the protruding length Y is excessively long, the cleaning work of the collection cover 32 will become complicated, and the separated liquid may stagnate on the flange portion 322, preventing it from flowing into the collection chamber. Therefore, it is desirable to set the protruding length Y to 15 mm or less.

[0030] Next, the operation (centrifugation) of the vertical centrifugal separator 1 described above will be explained. First, the bowl 2 is rotated around a vertical axis, and the liquid to be processed is continuously supplied into the bowl 2 through the supply nozzle 24. The centrifugal force of the bowl 2 is preferably 10,000 G or more, more preferably 20,000 G or more.

[0031] The liquid to be processed supplied to bowl 2 is separated into two phases, solid matter and separation liquid, by centrifugal force and the difference in specific gravity. The solid matter accumulates on the inner surface of bowl 2, and the separation liquid is discharged from the separation liquid outlet 23 toward the collection chamber.

[0032] The separated liquid that flows into the collection chamber is discharged from the discharge nozzle 34 along the tapered surface of the bottom plate 32a, but some of the separated liquid remains in the collection chamber and spreads along the bottom plate 32a due to the action of a swirling flow. At this time, the dam 320, which consists of the vertical wall 321 and the flange 322, dams the separated liquid, thus preventing it from overflowing from the circular opening 7. In this embodiment, however, a small amount of mist-like separation liquid may leak from the circular opening 7 and adhere to the wall surface of the casing body 31. Whether or not mist-like separation liquid has leaked can be determined by visual inspection. If the separation liquid is scattered in a dot-like pattern on the wall surface of the casing body 31, it can be determined that mist-like separation liquid has leaked.

[0033] (Variation 1) In the above-described embodiment, the dam section 320 was constructed by integrally forming the vertical wall section 321 and the flange section 322, but the present invention is not limited thereto, and the vertical wall section 321 and the flange section 322 may be separate components. Figure 6 is a cross-sectional view of a part of the vertical centrifugal separator of this modified example corresponding to Figure 4. The dam section 320 consists of a vertical wall section 321 and a ring-shaped flange section 323. The ring-shaped flange section 323 consists of a flange body 323a and a leg section 323b, which are integrally formed. The leg section 323b is formed in a ring shape and is pressed against the outer surface of the vertical wall section 321. The flange body 323a is provided at the upper end of the leg section 323b and protrudes toward the outer surface of the bottom plate section 32a. The above-described dam effect can also be obtained with the vertical wall section 321 and ring-shaped flange section 323 of this modified example.

[0034] (Modification 2) In the above-described embodiment, the collection chamber formed by the collection cover 32 is configured as a single stage, but the present invention is not limited to this, and a two-stage configuration is also possible (see, for example, Patent Document 1). In this case, for example, the lower stage can be used as a collection chamber for heavy liquids and the upper stage as a collection chamber for light liquids, and a dam can be provided at the edge of the circular opening of the bottom plate of at least one of the heavy liquid collection chamber and the light liquid collection chamber.

[0035] (Second Embodiment) Figure 7 is an enlarged view of a part of the vertical centrifugal separator of this embodiment, corresponding to Figure 4. The direction of the airflow generated by the rectifying vanes is schematically indicated by dashed arrows. This embodiment relates to a vertical centrifugal separator that achieves both the first and second objectives described in the problem section. The separated liquid flowing into the collection chamber collides with the inner wall of the collection cover 32, causing some of the separated liquid to atomize. Although the amount is small, the mist-like separated liquid may be drawn into the swirling flow within the collection chamber and leak out of the circular opening 7 toward the casing body 31. This problem is described in paragraphs 0007 to 0008 of Patent Document 1, so the details will be omitted here.

[0036] Referring to Figure 7, a plurality of rectifying blades 51 (corresponding to the "airflow generation section") are arranged on the back surface of the bottom plate 32a. By tilting the surface of the rectifying blades 51 inward, when the vertical centrifugal separator is operated, it is possible to generate an airflow that directs the air drawn from the supply nozzle 24 into the casing body 31 toward the circular opening 7, that is, an upward airflow. The structure of the rectifying blades 51 that produces this effect is prior art, as disclosed in, for example, Patent Document 1, so a detailed explanation is omitted. By providing flow-straightening blades 51 in addition to the weir section 320, it is possible to prevent leakage of separated liquid due to overflow while also preventing leakage of mist-like separated liquid due to the draw-in of swirling flow.

[0037] In this embodiment, the airflow generation unit is realized by a straightening vane 51, but the present invention is not limited thereto. For example, an upward airflow toward the circular opening 7 may be forcibly generated by blowing air from the supply nozzle 24 into the interior of the casing body 31 using a blowing means such as a blower (corresponding to the "airflow generation unit").

[0038] Here, by setting the dimension W to 10 mm or more, the air generated in the airflow generation unit can be taken in almost uniformly from the entire circumference of the circular opening 7. Furthermore, by setting the protrusion length Y of the flange portion 322 to 5 mm or more, a portion of the air taken in through the circular opening 7 can be allowed to flow along the flange portion 322. As a result, leakage of the mist-like separated liquid can be prevented more effectively. The other dimensional conditions of W, X, Y, and Z described in the first embodiment can also be applied to this embodiment. It goes without saying that the configurations of the above-described modifications 1 and 2 can also be applied to this embodiment.

[0039] Although the present invention has been described in detail with reference to specific embodiments, it will be apparent to those with ordinary skill in the art that various substitutions, modifications, and changes to the form and details can be made without departing from the spirit and scope of the invention as defined by the claims. Therefore, the scope of the present invention is not limited to the embodiments and accompanying drawings described above, but should be determined based on the claims and equivalents. [Explanation of Symbols]

[0040] 1. Vertical Centrifugal Separator 2 bowls 3. Casing 23 Separated liquid outlet 32 Collection cover 32a Bottom plate part 320 Dam section 321 Vertical wall section 322 Guard section 51 Rectifying blades 7 Circular opening

Claims

1. A supply port for the liquid to be processed is formed on the lower side, and an outlet for the separated liquid, whose surface tension is lower than that of water, is formed on the upper side. A cylindrical rotating cylinder rotates around a vertical axis when centrifugal separation is performed. A casing in which the cylindrical rotating cylinder is housed so as to be rotatable around a vertical axis, A collection cover including a bottom plate portion having a circular opening through which the cylindrical rotating cylinder is inserted, the collection cover forming a collection chamber for the separated liquid that communicates with the discharge port, A discharge nozzle for the separated liquid connected to the collection chamber, It has, The direction of the discharge port is in the horizontal direction perpendicular to the vertical axis of the cylindrical rotating cylinder. The bottom plate of the collection chamber is inclined downward toward the outer circumference. The edge of the circular opening in the base plate is provided with a weir section that includes a vertical wall and a flange that protrudes from the upper end of the vertical wall toward the outer circumference of the base plate. A vertical centrifugal separator characterized by the following features.

2. When the dimension of the vertical wall portion in the vertical direction is defined as W, and the distance between the lower end of the discharge port and the upper end of the flange portion is defined as Z, W is 10 mm or more, and Z is 2 mm or more. The vertical centrifugal separator according to feature 1.

3. When the protruding length of the flange is defined as Y, Y is 5 mm or more. A vertical centrifugal separator according to feature 1 or 2.

4. (delete)

5. (delete)

6. The vertical centrifugal separator has an airflow generating unit that generates an airflow from the casing toward the circular opening during operation. A vertical centrifugal separator according to feature 1 or 2.

7. The vertical centrifugal separator has an airflow generating unit that generates an airflow from the casing toward the circular opening during operation. The vertical centrifugal separator according to feature 3.

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