JP2013049006A - Variable dam of centrifugal separation apparatus and centrifugal separation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a variable dam of a centrifugal separation apparatus and in which an adjustable range of a depth of a dam is wide and which is excellent in adjusting accuracy.SOLUTION: The variable dam of the centrifugal separation apparatus includes a centripetal pump (51) in which a plurality of positioning pins (56) are erected on one surface of an annular member in which a separated liquid introducing opening (52) and a separated liquid discharge opening (53) are formed, a supporting ring (71) arranged such that the center of the same is positioned in the location decentered from a rotary axis center of a rotary ball (3) and into which a center opening part of the centripetal pump is slidably fitted, a fixing part (7) in which the supporting ring is arranged, and an annular member slidably fitted into the center opening part of the fixing part while sandwiching the centripetal pump, and has a dam depth adjusting mechanism for adjusting the dam depth by changing the position of the introducing opening of the centripetal pump in the peripheral direction of the supporting ring by rotating an orbiting parts (8) in which circular locking holes for locking the positioning pins in an inner peripheral surface are formed in each of the positioning pins and the orbiting part.

Description

  The present invention relates to a variable dam of a centrifugal separator that adjusts the dam depth of a liquid to be treated in a rotating bowl, and a centrifugal separator that includes the variable dam.

  As a device for performing solid-liquid separation using centrifugal force, a centrifugal device called a decanter is known. FIG. 10 schematically shows the basic structure of a horizontal decanter. In the horizontal decanter 1, a rotating bowl 11 that can rotate around a horizontal axis and a screw conveyor 12 inserted in the rotating bowl 11 are accommodated in a casing 13.

  One end side of the rotating bowl 11 that imparts centrifugal force to the liquid to be processed containing solids by rotating is formed in a conical shape. This conical portion forms a beach from which the solid material transferred by the screw conveyor 12 is detached from the liquid, and a solid material outlet 14 is formed on the tip side thereof. The body of the rotary bowl 11 forms a liquid pool (pool) in which the liquid to be treated supplied into the rotary bowl 11 stays, and a separation liquid outlet 15 is formed on the other end side of the rotary bowl 11. ing. On the other hand, the screw conveyor 12 is formed with a spiral screw blade 12a and a supply port 12b for supplying the liquid to be processed into the rotating bowl.

  In such a configuration, when the liquid to be treated is supplied while rotating the rotating bowl 11, solid matter settles on the inner peripheral surface of the rotating bowl 11 due to the action of centrifugal force. The screw conveyor 12 is rotated with a differential speed relative to the rotating bowl 11. As a result, the solid material is transferred toward the beach by the screw blade 12a and separated from the liquid. The separated solid matter is discharged from the solid matter outlet 14. On the other hand, by continuously supplying the liquid to be treated, the liquid from which the solid is separated (separated liquid) overflows from the separated liquid outlet 15 and is discharged.

  The liquid depth (= dam depth) H1 in the rotating bowl 11 is one of the factors affecting the separation efficiency of the decanter 1. Therefore, it may be desired to adjust the dam depth according to various operating conditions such as the liquid property of the liquid to be treated, the achieved value of the moisture content of the solid, and the achieved value of the solid concentration in the separated liquid. However, many of the conventional decanters do not have a mechanism for changing the dam depth, and for example, a dam as shown in Patent Documents 1 and 2 is attached to adjust the dam depth. In this case, it is necessary to stop the apparatus and attach a weir, and there is a problem in that the operating rate of the apparatus decreases. Moreover, when adjusting the dam depth by the weir, there is a problem that a plurality of weirs having different heights must be held.

  Patent Document 3 discloses a mechanism for making the dam depth variable (hereinafter referred to as “variable dam”). However, the variable dam disclosed in Patent Document 3 has a problem that the adjustment range of the dam depth is small and the adjustment accuracy is poor. In particular, for difficult-to-discharge solids that are difficult to discharge from the solids outlet 14 and processed products that require fine adjustment of the moisture content of the solids, fine adjustment of the dam depth may be required, In the variable dam of Patent Document 3, it is difficult to meet the demand. Furthermore, in the structure of the variable dam disclosed in Patent Document 3, there is a concern that the durability is low, such as a pin missing when the dam depth is changed.

JP 2009-136790 A Japanese Patent Laid-Open No. 61-167468 Japanese Patent Publication No. 50-6667

  The present invention has been made based on such circumstances, and an object thereof is to provide a variable dam having a wide adjustable range of dam depth and excellent adjustment accuracy. Another object of the present invention is to provide a centrifugal separator that can be set to a good dam depth according to processing conditions and can maintain a good separation efficiency.

  Another object of the present invention is to provide a variable dam that can prevent a positioning pin from being lost when the dam depth is changed and is excellent in durability.

  The variable dam of the present invention is a variable dam of a centrifugal separator that applies a centrifugal force to a liquid to be treated by a rotating bowl, and includes a separation liquid inlet formed on the outer peripheral surface and a separation formed on the inner peripheral surface. A sentry pedal pump including an annular member in which a liquid discharge port and a flow path for a separation liquid communicating from the introduction port to the discharge port are formed, and a plurality of positioning pins are erected on one surface of the annular member A support ring that is arranged so that its center is located eccentrically from the center of rotation of the rotating bowl and in which a central opening of the sentry pedal pump is slidably fitted, and a drain of the sentry pedal pump A separation liquid discharge passage formed in the support ring so as to communicate with the outlet; a fixed part fixedly disposed at an end of the rotary bowl on the separation liquid discharge side; and the sentry pedal pump between A peripheral part including an annular member slidably fitted in the central opening of the fixed part, and a circular locking hole for locking the positioning pin on the inner peripheral surface is formed for each positioning pin; A dam depth adjustment mechanism that adjusts the dam depth by changing the position of the introduction port of the sentry pedal pump in the circumferential direction of the support ring by rotating the peripheral part. To do.

  As a preferred example, there are two positioning pins, and these two pins are arranged on a concentric circle at the center of the support ring and on the diameter line with the center of the support ring in between. The two circular locking holes that lock the pin are concentric with the center of the peripheral part located on the rotational axis of the rotating bowl, and are arranged on the diameter line across the center of the peripheral part. To do.

  Further, when it is desired to realize L1 [mm] as the maximum variable amount from the deepest dam depth to the shallowest dam depth, the amount of eccentricity from the rotation axis center of the rotating bowl is L1 [mm]. Furthermore, it is preferable that the diameter [mm] of the locking hole is L2 (= 2L1 + L3, L3 is the diameter [mm] of the positioning pin), and an amount of so-called “play” is added (2L1 + L3) or more More preferably. Further, the sentry pedal pump includes a liquid resistance reducing unit in which a water entrance angle θ with respect to the liquid level of the separation liquid formed in the rotating bowl at the time of performing centrifugation is in a range of 30 ° ± 5 ° on at least a part of the outer peripheral edge. Is preferably formed. Furthermore, it is preferable that the variable dam is arranged between the rotating bowl and the bearing mechanism of the rotating bowl in the rotating shaft direction of the rotating bowl.

  A centrifugal separator according to the present invention includes the above-described variable dam.

  According to the variable dam of the present invention, the sentry pedal pump is structured to be rotatable in the circumferential direction at a position eccentric from the rotation axis center of the rotary bowl, and the rotating part that locks the positioning pin standing on the sentry pedal pump By making the locking hole of the circular shape, the distance to move the positioning pin when rotating the sentry pedal pump can be increased, and the adjustable range of the dam depth can be expanded, and the adjustment accuracy can be improved. It becomes.

  Further, according to the variable dam of the present invention, unlike the variable dam of Patent Document 3 in which the pin moves in a simple shear direction, the positioning pin becomes a circular motion and the stress is dispersed, so that the dam depth is changed. It is possible to suppress excessive stress from being concentrated on the positioning pin when the peripheral part is rotated. As a result, the durability of the variable dam can be improved.

1 is a longitudinal sectional view of a centrifugal separator according to a preferred embodiment of the present invention. It is the elements on larger scale which expanded the variable dam of the said centrifuge. 1 is a perspective view of a variable dam according to a preferred embodiment of the present invention. It is a side view of the said variable dam. It is a longitudinal cross-sectional view of the said variable dam. It is a figure which shows operation | movement of the said variable dam. It is a figure explaining the mechanism which changes dam depth by the said variable dam. It is a top view which shows the outer periphery shape of the sentry pedal pump of the said variable dam. It is a figure which shows the change of the adjustment allowance by the shape of the locking hole of the said variable dam. It is a figure which shows the structure of the conventional centrifuge.

  Hereinafter, a variable dam according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows an example of a centrifugal separator equipped with a variable dam according to the present embodiment, and specifically shows a horizontal decanter equipped with a variable dam. FIG. 2 is an enlarged partial view of the variable dam of the decanter. Moreover, FIGS. 3-5 has each shown the detailed structure of the variable dam according to this embodiment. However, the technical scope of the present invention is not construed as being limited by the embodiments described below.

  As shown in FIG. 1, the decanter 1 includes a casing 2 in which a solid material outlet 21 is formed on the lower surface on one end side, a rotating bowl 3 that forms a rotating cylindrical body disposed in the casing 2, and a rotating bowl 3. The screw conveyor 4 which transfers the solid substance S isolate | separated in the inside, and the variable dam 5 arrange | positioned at the other end side of the casing 2 are provided. The rotating bowl 3 is supported by a main bearing mechanism 22 such as a bearing disposed outside the casing 2, and the screw conveyor 4 is supported by a bearing mechanism 23 such as a conveyor bearing. Can rotate independently around the horizontal axis. A plurality of plates in the casing 2 indicated by 24 in the figure are partition plates that divide the inside of the casing 2 so that the separated solid and the separated liquid are not mixed again.

  When the power of the main motor 25 that is a driving mechanism is transmitted to the pulley 25b on the side of the rotating bowl 3 via the rotating belt 25a, the rotating bowl 3 rotates, and further, the gear box 26 that is the differential speed generating mechanism and the spline. Power is transmitted to the screw conveyor 4 through the shaft 26a, and the rotating bowl 3 and the screw conveyor 4 rotate with a relative differential speed. Although it is not limited, as an example, the rotating bowl 3 can be rotated at 3000 rpm, and the screw conveyor 4 can be rotated at a differential speed of 1 to 3 rpm.

  A motor called a back drive motor 27 is connected to the gear box 26 via a rotating belt 27a and a pulley 27b. The back drive motor 27 is for applying a brake so that the screw conveyor 4 rotates slower than the rotating bowl 3. The regenerative electric power generated in the back drive motor 27 by applying the brake is supplied to the main motor 25, thereby suppressing the power consumption of the entire apparatus. However, the back drive motor 27 is not necessarily provided.

  The decanter 1 further includes a supply nozzle 6 for supplying the liquid to be processed into the rotating bowl 3. The supply nozzle 6 is inserted into a cavity (buffer part) 41 formed inside the screw conveyor 4 so as not to contact the rotating bowl 3 and the screw conveyor 4. For example, the liquid to be processed sent by liquid feeding means (not shown) such as a pump is discharged from the tip of the supply nozzle 6 into the buffer unit 41, and by the centrifugal force of the rotating screw conveyor 4, It is supplied into the rotating bowl 3 from a supply hole 42 formed in the side peripheral surface.

  The rotating bowl 3 includes a body portion including a conical portion 31 formed on one end side and a cylindrical portion 32 formed on the other end side, and a cover member 33 for closing an opening portion of the cylindrical portion 32. Yes. The cover member 33 is fixed so as to be detachable from the cylindrical portion 32 by a fixing means such as a bolt. The cover member 33 is formed of an annular member having an opening at the center and a substantially L-shaped cross section. The cover member 33 is enclosed so that the sentry pedal pump 51 of the variable dam 5 is located in the inner space of the rotating bowl 3, and the L-shaped end portion (that is, the inner peripheral edge of the cover member 33) is interposed through a slight gap. It arrange | positions so that the side peripheral surface of the variable dam 5 may adjoin. When the rotating bowl 3 is rotated at the time of performing the centrifugal separation, the cover member 33 rotates, but the variable dam 5 is a fixed arrangement that does not rotate, so a slight gap is provided between them. Of course, in order to prevent liquid leakage from the gap, sealing may be performed using a seal member.

  At the time of performing the centrifugal separation, the liquid to be treated is brought closer to the inner peripheral surface side of the rotating bowl 3 by the action of the centrifugal force to form a pool (liquid reservoir). At this time, since the solid matter is transferred to the conical portion 31 side by the screw conveyor 4, a liquid pool of a separated liquid having a low solid matter concentration is formed on the cover member 33 side. When the liquid to be treated is continuously supplied with the centrifugal force applied, as shown in FIG. 2, the liquid level of the separation liquid increases and the liquid inlet 52 of the sentry pedal pump 51 is in the liquid. It will be in a state immersed in. Then, the separation liquid enters the liquid introduction port 52 of the sentry pedal pump 51 using the centrifugal force as a driving force, flows through the flow path formed inside the variable dam, and the separation liquid discharge port 53 formed outside the casing 2. Discharged from. For example, a flow path such as a hose or a pipe is connected to the separation liquid discharge port 53, and a separation liquid storage tank (not shown) is connected through the flow path. The decanter 1 according to the present embodiment, unlike the overflow methods disclosed in Patent Documents 1 and 2, discharges the separation liquid out of the apparatus by such an action.

  Returning to FIG. 1, the conical portion 31 of the rotating bowl 3 forms a beach from which the solid material transferred by the screw conveyor 4 is separated from the liquid, and a solid material discharge port 34 is formed at the tip of the beach. Is formed. The screw conveyor 4 is formed with screw blades 43 spirally on the outer peripheral surface, and the solid matter is transferred by the screw blades 43. The beach has a function of causing the solid matter to slip on the inclined surface and causing the squeezing force of the screw blades 43 to act on the solid matter, and a function of increasing the retention volume of the liquid to be treated by increasing the effective volume of the pool (liquid reservoir). There is.

  Next, the detailed structure of the variable dam 5 will be described with reference to FIGS. As shown in the exploded views of FIGS. 3 and 4, the variable dam includes a sentry pedal pump 51, a fixing part 7 that supports the sentry pedal pump 51, and the sentry pedal pump 51 in the circumferential direction to change the dam depth. A rotating part 8 (81, 82, 83) that rotates within a range of up to 180 ° is provided, and these parts are assembled as shown in FIG.

  As shown in FIG. 3 to FIG. 5, the sentry pedal pump 51 is configured by a generally ring-shaped annular member having a circular opening at the center. The sentry pedal pump 51 has a liquid introduction port 52 formed on the outer peripheral surface, a liquid discharge port 54 formed on the inner peripheral surface, and the liquid introduction port 52 and the liquid discharge port 54 communicate with each other through an internal channel 55. The outer peripheral edge of the sentry pedal pump 51 is curved so that the distance from the center of the central opening changes in the circumferential direction, as shown in the plan views of FIGS. Is formed at a position (phase) farthest from the center of the central opening in the circumferential direction.

  More specifically, a liquid resistance reducing portion 58 is formed on the outer peripheral edge of the sentry pedal pump 51 along the direction opposite to the rotation direction of the rotary bowl 3 from the liquid introduction port 52 (see FIG. 8). The liquid resistance reducing unit 58 cuts the outer peripheral edge of the sentry pedal pump 51 so that the angle θ with the tangent to a circle (virtual circle) centered on the rotation axis of the rotating bowl 3 is 30 ° ± 5 °. It is configured by taking a shape.

  That is, at the time of performing the centrifugal separation, the liquid is brought closer to the inner peripheral surface side of the rotating bowl 3 by the action of the centrifugal force, and a donut-shaped liquid layer centering on the rotating shaft of the rotating bowl 3 is formed. Therefore, by forming a portion where the angle θ with the tangent to the circle (virtual circle) centered on the rotation axis of the rotating bowl 3 is 30 ° ± 5 °, that portion (that is, the liquid resistance reducing portion 58) is Since water enters at an angle of 30 ° ± 5 ° with respect to the liquid surface, the liquid resistance due to wave-making resistance can be kept small. If the wave-making resistance can be reduced, turbulence of the liquid in the rotating bowl 3 can be suppressed, and power can be reduced by reducing power.

  Further, as shown in FIG. 8, if the outer peripheral edge (generally the area indicated by a two-dot broken line) excluding the liquid resistance reducing portion 58 and the liquid introduction port 52 is formed so as to be located inside the virtual circle. Since this region is not immersed in the liquid when performing the centrifugation, the liquid resistance can be further reduced. This region is preferably circular in consideration of air resistance, and has a smooth surface without sharp corners. However, the shape of the outer periphery shown in FIGS. 7 and 8 is a preferable example, and is not limited to this shape. As another example, the outer peripheral edge is circular, the circular central opening is formed at a position eccentric from the center of the outer peripheral edge, and the liquid introduction port 52 is formed at a position (phase) where the width is widest in the circumferential direction. The shape may be sufficient.

  The internal flow passage 55 of the sentry pedal pump 51 has a curved shape that warps in the rotational direction of the rotating bowl 3 as shown in the plan view of FIG. Yes. The method of using the sentry pedal pump 51 according to the present embodiment does not suck the liquid by continuously rotating itself, but introduces the liquid to be treated using the centrifugal force of the rotating bowl 3 that rotates continuously as a driving force as described above. To do. Therefore, when performing the centrifugal separation, the sentry pedal pump 51 is fixedly arranged and is rotated by a predetermined angle only when changing the dam depth.

  The sentry pedal pump 51 is supported by the support ring 71 of the fixed part 7 so as to be rotatable at a position eccentric from the rotation axis of the rotating bowl 3 in order to realize the function of making the dam depth variable. When changing the dam depth, the sentry pedal pump 51 is rotated to an arbitrary angle within the range of 0 ° to 180 °, for example, within the range of 0 ° to 150 ° in actual operation, with the support ring 71 as a bearing. The position (phase) of the liquid inlet 52 in the circumferential direction is changed. In order to execute rotation and phase positioning of the sentry pedal pump 51, a plurality of positioning pins 56 are provided upright on one surface side of the sentry pedal pump 51. In FIGS. 3 to 5, as a preferred example, two positioning pins 56 are arranged at symmetrical positions on the diameter line around the circular central opening of the sentry pedal pump 51. The positioning pin 56 is locked in the locking hole 84 of the peripheral part 8. Note that the number of positioning pins 56 may be one, or conversely, three or more. Even in the case of three or more, the positioning pins 56 are arranged at equal intervals in the circumferential direction.

  The liquid introduction port 52 of the sentry pedal pump 51 is provided at one location on the outer peripheral surface, but the separation liquid is supported by the support ring 71 no matter what phase the liquid introduction port 52 is set by rotating the sentry pedal pump 51. A groove 57 is formed on the inner peripheral surface of the sentry pedal pump 51 so as to flow into the liquid inlet 72.

  The fixed part 7 is constituted by a member formed in a substantially cylindrical shape. The fixed part 7 is arranged so that the center of the circular opening is located on the central axis of the rotating bowl 3, and the rotating shafts of the rotating bowl 3 and the screw conveyor 4 are passed through the opening. A flange 73 is formed in the fixing part 7 over the entire circumference in the circumferential direction, and the flange 73 is fixed to the side wall of the casing 2 through a fixing means such as a bolt in an in-plane through hole (see FIG. 2). Thereby, the side opening part of the casing 2 is sealed. On the other hand, a support ring 71 is formed on one surface of the fixed part 7 at a position eccentric from the central axis of the rotating bowl 3. The outer peripheral edge of the support ring 71 is formed in a circular shape, and the circular central opening of the sentry pedal pump 51 is slidably fitted therein. As a result, the liquid introduction port 52 of the sentry pedal pump 51 is configured to rotate in a perfect circular orbit around the position eccentric from the central axis of the rotating bowl 3.

  As described above, the liquid inlet 52 of the sentry pedal pump 51 is formed at a position farthest from the center of the central opening. In addition, the support ring 71 is formed at an eccentric position on one surface of the fixed part 7. When the variable dam 5 is assembled, it is assembled so that the liquid introduction port 52 is positioned at a position (phase) where the distance from the outer peripheral edge of the support ring 71 to the outer peripheral edge of the fixed part 7 is the longest. For convenience of explanation, this phase is set to 0 °.

  A liquid introduction port 72 for the separation liquid is formed on the side peripheral surface of the support ring 71 with a gap in the circumferential direction. Further, a separation liquid discharge port 53 is formed in the fixed part 7 at a position outside the casing 2 with a gap in the circumferential direction. The discharge ports 72 and 53 communicate with each other through the internal flow path 75 of the fixed part 7. Therefore, the separation liquid discharged from the liquid discharge port 54 and the groove 57 formed on the inner peripheral surface of the sentry pedal 51 flows into the liquid introduction port 72 of the support ring 71 and is disposed outside the casing 2 through the internal flow path 75. It is discharged from the discharged outlet 53. A flow path (not shown) such as a hose or a pipe is connected to the discharge port 53, and the separation liquid is transferred to the storage tank through this flow path.

  In the example shown in the figure, the peripheral parts are configured by an operation plate 81, an operation lever 82, and a connecting member 83 that connects the operation plate 81 and the operation lever 82. Of course, it is not necessary to comprise three members.

  The operation plate 81 has a circular plate portion in which a circular opening is formed at the center, and a cylindrical portion formed on one side (fixed part 7 side) along the edge line of the opening. The cylindrical portion is rotatably fitted in the circular opening of the fixed part 7. Further, two circular locking holes 84 are formed in the plane of the operation plate 81 at symmetrical positions on the diameter line across the opening. The locking hole 84 locks the positioning pin 56 of the sentry pedal pump 51 at its inner periphery. When the peripheral part 8 is rotated, the positioning pin 56 is restricted in movement so as to move along the inner peripheral edge of the locking hole 84, thereby controlling the phase of the liquid inlet 52 of the sentry pedal pump 51 ( Will be adjusted).

  The two locking holes 84 have the same size and are formed on concentric circles centered on the central opening. In this example, when the liquid introduction port 52 of the sentry pedal 51 is at the 0 ° position, the positioning hole 56 is locked at the 180 ° position, and the sentry pedal pump 51 is rotated to introduce the liquid. The locking hole 84 is formed so that the locking hole 84 locks the positioning pin 56 at the position of 0 ° when the opening 52 reaches the position of 180 ° (see FIGS. 6 and 7). . Therefore, when it is desired to realize L1 [mm] as the maximum variable amount from the deepest dam depth to the shallowest dam depth, the size of the locking hole 84 is from the rotational axis center of the rotating bowl 3 shown in FIG. The eccentric amount of the center axis of the sentry pedal pump 51 is L1 [mm], and the diameter [mm] of the locking hole 84 is L2 (= 2L1 + L3, L3 is the diameter [mm] of the positioning pin 56). It is preferable to add a so-called “play” to more than (2L1 + L3). As an example, when the target maximum variable amount L1 is 13.5 [mm] and the diameter L3 of the positioning pin 56 is 6.4 [mm], the play amount L4 is 1.6 [mm] (= 2 × 0). .8 [mm]), and the diameter L2 of the locking hole 84 is 35.0 [mm].

  The operation lever 82 is configured by a ring-shaped member to which a lever 82a used by an operator to rotate the operation plate 81 from outside the apparatus when changing the dam depth is fixed. However, the configuration is not limited to manual operation using the lever 82a, and remote control may be performed using a drive mechanism such as a motor and a control device that controls the drive amount. Further, for the purpose of indicating how much the operator should rotate the lever 82a, and further to enable the operator to grasp the current dam depth, for example, a scale is provided on the side surface of the fixed part 7. You may make it provide.

  The connecting member 83 has a structure in which a cylindrical portion 83a and a circular flange portion 83b are formed on one end side of the cylindrical portion 83a. A ring-shaped member of the operation lever 82 is fixed to the flange portion 83b through fixing means such as bolts. Furthermore, the cylindrical portion 83a of the connecting member 83 is fitted into the opening of the fixing part 7 until the flange portion 83b contacts the opposing surface of the fixing part 7, and the cylindrical portion 83a is passed through fixing means such as a bolt. The peripheral part 8 is completed by fixing the end of this and the cylindrical part of the operation plate 81.

  Accordingly, when the variable dam 5 is disposed as shown in FIG. 1 and the lever 82a is rotated in the circumferential direction as shown in FIG. 6, the operation plate 81 rotates in the circumferential direction around the rotation axis of the rotating bowl 3. To do. Then, when the positioning pin 56 of the sentry pedal pump 51 is regulated by the locking hole 84 of the rotating operation plate 81, the sentry pedal pump 51 rotates with the support ring 71 as a bearing. However, the rotation axis of the operation plate 81 is the same as the rotation axis of the rotary bowl 3, but the rotation axis of the sentry pedal pump 51 is in a position eccentric from the rotation axis of the rotary bowl 3. Further, the outer peripheral edge of the sentry pedal pump 51 is formed such that the distance from the center of the central opening is different in the circumferential direction, and the liquid introduction port is located farthest from the center of the circular opening in the circumferential direction. (Phase). Therefore, as the lever 82a is rotated from the 0 ° position, the liquid introduction port 52 of the sentry pedal pump 51 protrudes outward, and when the lever 82a is rotated to the 180 ° position, the liquid introduction port 52 is most outward. It will be in the state of protruding.

  The position where the lever 82a is rotated 180 ° and the liquid introduction port 52 protrudes outward is the distance between the liquid introduction port 52 and the inner peripheral surface of the rotating bowl 3 as shown in FIG. This is the shortest position. In other words, it is the position where the dam depth is the shallowest. On the contrary, the position where the lever 82a is set to 0 ° and the liquid introduction port 52 is retracted to the most center side means that the liquid introduction port 52 and the inner peripheral surface of the rotating bowl 3 are as shown in FIG. It is the position where the distance to is the longest. In other words, it is the position where the dam depth is deepest.

  Thus, the variable dam 5 of this embodiment can be set to the position where the dam depth is the shallowest and the deepest position by setting the lever 82a to the positions of 0 ° and 180 °. Further, as shown in FIG. 6, the liquid introduction port 52 sequentially protrudes as the lever 82 a is rotated. Therefore, by turning the lever 82 a to an arbitrary angle within the range of 0 to 180 °, the step is continuously performed. It is possible to adjust the dam depth. However, during actual operation, it is preferably used in the range of 0 ° to 150 °. The reason why high-precision adjustment can be realized within this movable range is that this embodiment employs a circular locking hole 84. In the case of a non-circular shape, for example, a groove as in Patent Document 3, the adjustment accuracy is remarkably lowered or cannot be adjusted in some regions.

  FIG. 9 shows the result of verifying the change in the adjustment allowance of the variable dam 5 according to the present embodiment using an actual product. FIG. 9 shows the dam depth adjustment margin (in other words, the range of change) (unit: mm) when the sentry pedal pump 51 is rotated at intervals of 5 °. As a comparison, a variable dam having the same structure as that of the present embodiment was manufactured except that the locking hole had a groove shape, and the change in the adjustment allowance was verified. As is apparent from the results of FIG. 9, when the locking hole has a groove shape, the adjustment allowance decreases from around 90 °, and the adjustment range is out of the adjustment range in the range of 140 ° to 150 °. End up. On the other hand, in the case of a circular locking hole, the adjustment margin is maintained after 90 °, the groove shape can be used even in an area outside the adjustment range, and the dam depth can be finely adjusted. .

  As described above, according to the variable dam 5 of the present embodiment, the sentry pedal pump 51 is configured to be rotatable in the circumferential direction at a position eccentric from the rotation axis center of the rotating bowl 3, and is erected on the sentry pedal pump 51. Since the locking hole 84 of the peripheral part 8 that locks the positioning pin 56 is circular, the movement distance of the positioning pin 56 when the sentry pedal pump 51 is rotated is increased, and the dam depth can be adjusted. The range can be expanded and the adjustment accuracy can be increased. Further, as is apparent from the drawings described above, the variable dam 5 of the present embodiment has an advantage that maintenance is easy because the component configuration is simple.

  Furthermore, according to the variable dam 5 of the present embodiment, unlike the variable dam of Patent Document 3 in which the pin moves in the simple shear direction, the positioning pin 56 rotates in a circular motion and the stress is dispersed. It is possible to suppress excessive stress from being concentrated on the positioning pin 56 when the peripheral part 8 is rotated in order to change. As a result, the durability of the variable dam 5 can be improved. When the size of the apparatus is increased, it is possible to further distribute the stress by increasing the number of positioning pins.

  Furthermore, since the locking hole 84 is circular, the opening area becomes larger than that of the groove shape. For this reason, there is an advantage that the clogging due to the intrusion of the solid matter hardly occurs, and even if the solid matter adheres, the adhering matter can be removed by performing a normal variable operation. On the other hand, when the locking hole has a groove shape, the opening is small and blockage is likely to occur. Further, if the solid matter adheres to the groove, the moving pin squeezes and hardens the deposit in the groove, so that it cannot be removed unless the device is disassembled.

  Furthermore, since the variable dam 5 of this embodiment is completely separated from the main bearing mechanism 22, there is an advantage that the shaft seal can be easily sealed. In the case of Patent Document 3, since the separation liquid transfer pipe passes through the inside of the bearing, there is a concern about trouble due to liquid intrusion into the main bearing mechanism.

  If the variable dam 5 having the above-described features is used, in addition to the conventional use of the decanter 1, it is possible to centrifuge a processed product containing a difficult-to-discharge solid material (protein residue, etc.) and finely adjust the moisture contained in the solid material. Application of the necessary processed material to centrifugation (especially when using a pump in a downstream process, etc.) and centrifugal separation of a processed material in which the particle size distribution of the contained solid matter changes can be realized. Further, the present invention can be applied to centrifugal separation of a processed material whose separation conditions change during operation.

  That is, the variable dam 5 is a mechanism that can adjust the amount of liquid staying inside the rotating bowl 3 steplessly without stopping the machine during the operation of the decanter 1. In the normal decanter 1, it is necessary to stop the apparatus in order to adjust the amount of the staying liquid inside, but this is not necessary in the decanter 1 having the variable dam 5 according to the present embodiment. Therefore, it is possible to perform stepless adjustment while confirming the operation state even with liquids whose properties and specific gravity change during continuous processing (for example, cutting oil, waste oil, etc.). Moreover, it is suitable for operation in a situation where the separation conditions such as preliminary tests are uncertain, and it is possible to adjust to the optimal separation conditions while continuing the continuous operation.

  Although the present invention has been described in detail with reference to specific embodiments, various substitutions, modifications, changes, etc. in form and detail are defined in the claims. It will be apparent to those skilled in the art that this can be done without departing from the spirit and scope. Therefore, the scope of the present invention should not be limited to the above-described embodiments and the accompanying drawings, but should be determined based on the description of the claims and equivalents thereof.

2 Casing 3 Rotating bowl 4 Screw conveyor 5 Variable dam 51 Centripedal pump 52 Liquid inlet 53 Liquid outlet 7 Fixed parts 81 Operation plate 82

Claims (6)

A variable dam of a centrifugal separator that applies centrifugal force to a liquid to be treated by a rotating bowl,
A separation liquid inlet formed on the outer peripheral surface, a separation liquid outlet formed on the inner peripheral surface, and an annular member formed with a separation liquid flow path communicating from the inlet to the discharge port; A sentry pedal pump in which a plurality of positioning pins are erected on one surface of the annular member;
A support ring that is arranged so that its center is located eccentrically from the rotation axis center of the rotating bowl and in which a central opening of the sentry pedal pump is slidably fitted; and a discharge port of the sentry pedal pump; A fixed part that has a separation liquid discharge channel formed in the support ring so as to communicate, and is fixedly disposed at an end of the rotary bowl on the separation liquid discharge side;
A circular locking hole that includes an annular member that is slidably fitted into the central opening of the fixed part across the sentry pedal pump and that locks the positioning pin on the inner peripheral surface is provided for each positioning pin. The circumferential parts that are formed,
A dam depth adjustment mechanism that adjusts the dam depth by changing the position of the introduction port of the sentry pedal pump in the circumferential direction of the support ring by rotating the peripheral part. Variable dam of centrifuge. The positioning pins are two, and these two pins are arranged concentrically around the center of the support ring and positioned on the diameter line across the center of the support ring,
The two circular locking holes for locking the two pins are concentric with the center of the peripheral part located on the rotational axis of the rotating bowl and on the diameter line across the center of the peripheral part. The variable dam of the centrifugal separator according to claim 1, wherein the variable dam is arranged in a vertical direction. When you want to realize L1 [mm] as the maximum variable amount from the deepest dam depth to the shallowest dam depth,
The amount of eccentricity from the rotation axis center of the rotating bowl is L1 [mm], and the diameter [mm] of the locking hole is at least L2 (= 2L1 + L3, L3 is the diameter of the positioning pin [mm]) or more. The variable dam of the centrifugal separator according to claim 1 or 2, wherein   In the sentry pedal pump, a liquid resistance reducing portion is formed on at least a part of the outer peripheral edge so that the water entrance angle θ with respect to the liquid surface of the separated liquid formed in the rotating bowl at the time of centrifugal separation is in a range of 30 ° ± 5 °. The variable dam according to any one of claims 1 to 3, wherein the variable dam is formed.   5. The centrifugal separator according to claim 1, wherein the variable dam is disposed between the rotating bowl and a bearing mechanism of the rotating bowl in a rotating shaft direction of the rotating bowl. Variable dam.   A centrifugal separator comprising the variable dam according to any one of claims 1 to 5.

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