JP2019122923A - Extrusion type centrifugal separator and operation method thereof - Google Patents

Abstract

To secure fluidity of a processed product on an inclined filter screen of a pre-thickener.SOLUTION: An extrusion type centrifugal separator comprises a cylindrical basket 2 rotating around the axis O by providing a cylindrical filter screen 2a in a trunk part, a processing product supply pipe 9 inserted along the axis O into the basket 2 and supplying a processed product in the basket 2, an extrusion plate 7 stored in the basket 2, integrally rotatable with the basket 2, provided so as to be capable of relatively advancing-retreating in the axial O direction to the basket 2 and opposed at an interval to an opening part of the processed product supply pipe 9, a pre-thickener 10 provided on a side surface of the extrusion plate 7 opposed to the opening part of the processed product supply pipe 9 and having an inclined filter screen 10a toward the outer peripheral side in the radial direction to the axis O toward the processing product supply pipe 9-side and cleaning liquid supply means 11 for supplying a cleaning liquid toward the inclined filter screen 10a of the pre-thickener 10.SELECTED DRAWING: Figure 1

Description

  The present invention filters a treatment supplied in a basket which is rotated about an axis by a filtration screen provided on a body of the basket, and stores a cake filtered from the treatment in the basket. The present invention relates to an extrusion type centrifuge which discharges from the open end of a basket by an extrusion plate which is integrally rotatable and relatively movable in the axial direction with respect to the basket, and a method of operating the same.

  As such an extrusion type centrifugal separator, for example, in Patent Document 1, an outer basket which is rotated about an axis, and coaxially disposed in the outer basket so as to be integrally rotated, and in an axial direction with respect to the outer basket A two-stage basket type centrifugal separator having an inner basket which is advanced and retracted and a cylindrical filtration screen provided on the inner and outer baskets, the outer basket being supported by the outer basket and facing the opening of the feed pipe And an annular plate-like distributor disposed so as to surround the opening of the supply pipe at a distance between the extrusion plate and the extrusion plate, and the outside of the inner basket. It is disposed on the side of the push plate facing in the forward direction with respect to the basket so as to surround the outer periphery of the distributor, and the outer periphery follows the forward direction. It has been described having a Pureshikkuna inclined filter screen is provided which is inclined toward the.

  In such a centrifugal separator, the processed material supplied between the extrusion plate and the distributor from the opening of the supply pipe is moved toward the outer peripheral side on the inclined filtration screen of the prethicker by the centrifugal force, while the liquid content and the particles Particles such as crystals in the small diameter product are filtered to some extent and preconcentrated. Then, the processed material is deposited while being deposited on the inner peripheral surface of the cylindrical filtration screen of the inner basket by centrifugal force and filtered to form a cake, and the axis of the inner basket is advanced by advancing the inner basket toward the open end of the outer basket. It is also deposited in the direction and then pushed out by the push plate by retraction of the inner basket relative to the outer basket and discharged onto the inner circumferential surface of the outer basket. In addition, the cake of the treated material thus discharged to the inner circumferential surface of the outer basket is further filtered by the cylindrical filtration screen of the outer basket, pushed out by the advancement of the inner basket, and discharged from the open end thereof.

  As described above, in the extrusion type centrifugal separator equipped with the pre-siccina, since the processing material is preconcentrated by the inclined filtration screen of the pre-siccina, the filtration efficiency of the cylindrical filtration screen of the inner basket and the outer basket can be improved. . In addition, it is also required to selectively separate large crystal particles having a predetermined particle size or more to obtain a product, as in the case of separating crystal particles from a treated product obtained in, for example, a crystallization step of ammonium sulfate. Sometimes, as mentioned above, particles with small particle size can be separated from the processed material together with liquid components and classified by the inclined filtration screen of the pre-siccina, so there is no need to separately provide a classification device etc. at the rear stage of the centrifuge. Thus, it is possible to efficiently obtain large particles with reduced equipment cost and running cost.

JP, 2014-091093, A

  However, in the extrusion type centrifugal separator equipped with such a pre-siccina, the movement of the treatment deposited on the cylindrical filtration screen of the inner and outer baskets is due to the mechanical advancing and retracting of the inner basket, while the inclination of the pre-sicccha The movement of the particles of the processed material after being filtered in the filtration screen depends only on the centrifugal force generated by the rotation of the basket. For this reason, when the solid content concentration of the supplied processing material is high or high, the flowability of the processing material becomes poor, and retention or accumulation of solid content occurs in the inclined filtration screen, or the inclined filtration screen There is a concern that

  In addition, when the solid content concentration of the processing material supplied in this manner is high or high, if the flowability of the processing material becomes poor, the movement of the solid content in the processing material tends to be restrained. And thereby, the particles of small particle size which should be separated and removed from the processed material together with the liquid are captured by the cake of solid content on the inclined filtration screen and moved to the inner basket, which is required. There is a risk that classification performance can not be obtained.

  The present invention has been made under such a background, and even when the solid concentration of the treated product is high or high, the flowability of the treated product on the inclined filtration screen of the prethicker is secured to retain or It is possible to prevent accumulation and clogging of the inclined filtration screen, and also to effectively remove particles with small particle sizes together with liquid to obtain the required classification performance, and an extrusion type centrifugal separator and its operation It is intended to provide a way.

  In order to solve the above problems and achieve such an object, the extrusion type centrifugal separator of the present invention comprises a cylindrical basket provided with a cylindrical filtration screen on a body and rotated about an axis; A treatment supply pipe inserted into the basket along the axis and supplying the treatment material into the basket, and housed in the basket and rotatable integrally with the basket and axially relative to the basket Provided on the side of the extrusion plate facing the opening of the processing material supply pipe at a distance from the opening of the processing material supply pipe and facing the opening of the processing material supply pipe, And an inclined filter screen directed radially outward with respect to the axis toward the treated material supply pipe side. Characterized by comprising a cleaning liquid supply means for supplying a cleaning liquid Te. In addition, according to the operation method of the present invention, the processing material is centrifuged while the cleaning liquid is supplied by the cleaning liquid supply unit toward the inclined filtration screen of the pre-thickener using such an extrusion type centrifugal separator. It is characterized by

  In the extrusion type centrifugal separator thus configured and the operation method thereof, since the cleaning liquid supply means for supplying the cleaning liquid toward the inclined filtration screen of the pre-thickener is provided, the solid content concentration of the processed material is high or high. Even in the case where it does not, the flowability of the processed material on the inclined filtration screen can be secured. For this reason, it is possible to discharge the treated material to the cylindrical filtration screen of the basket while reliably preconcentrating the treated material by the centrifugal force caused by the rotation of the basket, and to prevent the stagnation and deposition of the treated material and the clogging of the inclined filtration screen. Also, it is possible to prevent the movement of solid content in the processed material from being restrained, accelerate the movement of small-sized particles to the liquid side by the washing liquid, and discharge mainly large-sized particles to the basket Therefore, it becomes possible to obtain the necessary classification performance.

  Here, as the cleaning solution supply means, for example, one provided with a cleaning solution supply pipe inserted in the basket and a spray nozzle attached to the tip of the cleaning solution supply pipe toward the inclined filtration screen is used. Can. Since the inclined filter screen of the pre-siccina rotates with the basket, even if these cleaning liquid supply pipes and spray nozzles are fixed, it is possible to uniformly supply the cleaning liquid over the entire circumference of the processed product of the inclined filter screen. Become.

  In addition, it is desirable that the opening amount in the inclined filtration screen be larger than the opening amount in the cylindrical filtration screen. As a result, the discharge of the particles having a small particle size and the liquid component of the treated product and the washing liquid from the inclined filtration screen can be further promoted to further improve the classification performance.

  As described above, according to the present invention, the flowability of the treated material on the inclined filtration screen can be secured even when the solid concentration of the treated material is high or high, and the retention and deposition of the treated material can be achieved. The clogging of the inclined filtration screen can be prevented, and the movement of the small-sized particles to the liquid separation side can be promoted by the washing liquid to obtain the necessary classification performance.

FIG. 1 is a cross-sectional view along an axis of a basket illustrating one embodiment of the present invention.

  FIG. 1 shows one embodiment of the extrusion type centrifugal separator of the present invention, which comprises a two-stage basket provided with an outer basket 1 and an inner basket 2 as described in Patent Document 1. It is applied to a type of centrifugal separator. That is, the centrifugal separator according to the present embodiment has a horizontal outside in which the cylindrical outer filtration screen 1a is attached to one end side (right side in FIG. 1) of the inner peripheral surface of the cylindrical body centering on the axis O The basket 1 and the inner basket 2 coaxially housed in the outer basket 1 and having a cylindrical inner filtration screen 2a attached to one end of the inner peripheral surface of the cylindrical body also, Among these, the inner basket 2 is used as a basket in the present invention, and the inner filtration screen 2a is used as a cylindrical filtration screen in the present invention. For example, a cylindrical wire screen or a plate screen is used as the outer filtration screen 1a and the inner filtration screen 2a.

  The cylindrical outer basket 1 and the inner basket 2 have circular open ends 1b and 2b at one end, and the other end (left end in FIG. 1) attached to the disk-shaped holding plates 1c and 2c. The inner basket 2 is held in a cylindrical shape with a bottom, and the inner basket 2 is shorter in length in the direction of the axis O than the outer basket 1 and is housed together with the outer basket 1 in the casing 3 and around the axis O It can be rotated together. The outer diameter of the open end 2 b of the inner basket 2 is slightly smaller than the inner circumferential surface of the outer filtration screen 1 a of the outer basket 1. Further, a large number of through holes 1d and 2d are formed in the barrels of the outer basket 1 and the inner basket 2, and the gap between the outer filtration screen 1a and the inner filtration screen 2a is communicated with these through holes 1d and 2d, respectively. doing.

  At positions of both ends of the outer basket 1 in the direction of the axis O in the casing 3, partition walls 3a having an inner diameter slightly larger than the outer diameter of the outer basket 1 extending inward toward the outer peripheral surface of the outer basket 1 Each is provided. In the casing 3, a portion between the partition walls 3a is a discharge chamber 3b of the liquid separated from the processing material, and the inside of the casing 3 at one end side further than the partition wall 3a at one end side is It is made into the discharge chamber 3c of the solid content (cake) from which the liquid component was isolate | separated from the processed material by the outer filtration screen 1a of the basket 1. FIG.

  The holding plate 1c of the outer basket 1 is attached to one end of a hollow cylindrical main shaft 5 rotatably supported by the bearing 4 and inserted into the casing 3 along the axis O, and is not shown The outer basket 1 is rotated at a high speed around the axis O as a result of the rotational force of the rotational drive means being transmitted to rotate the main shaft 5. Also, inside the main shaft 5, the push-out shaft 6 is rotatably inserted integrally with the main shaft 5 and is inserted forward / backward in a fixed stroke in the direction of the axis O by forward / backward driving means such as hydraulic cylinders and electric cylinders not shown. The one end portion of the pushing shaft 6 penetrates the holding plate 1c of the outer basket 1 and is attached to the holding plate 2c of the inner basket 2 so that the inner basket 2 can also rotate integrally with the outer basket 1 and the outer basket At the other end side in 1, it is possible to advance and retract in the direction of the axis O.

  Furthermore, in the holding plate 1c of the outer basket 1, a plurality of support shafts 1e are circumferentially spaced at positions away from the axis O to the outer peripheral side, and extend parallel to the axis O toward the one end. The support shafts 1e are attached and project through the holding plate 2c into the inner basket 2. A disc-shaped push plate 7 is attached to one end of the support shafts 1e. Therefore, the pushing plate 7 can be integrally rotated about the axis O coaxially with the outer basket 1 and the inner basket 2 and can be advanced and retracted with respect to the inner basket 2 in a fixed stroke in the direction of the axis O.

  Further, an annular plate-like dispersion plate (distributor) 8 having an opening at the center with a radius smaller than that of the extrusion plate 7 at one end side of the extrusion plate 7 is integrally supported with the extrusion plate 7 at an interval. It is done. Furthermore, the treatment material supply pipe 9 is attached to and inserted into the casing 3, and the treatment material supply pipe 9 passes through the inside of the open ends 1 b and 2 b of the outer basket 1 and the inner basket 2 and the opening of the dispersion plate 8. The feed port is inserted between the pushing plate 7 and the dispersing plate 8. Therefore, the pushing plate 7 faces the opening of the processing material supply pipe 9 with a gap.

  Furthermore, on the side surface of the extrusion plate 7 opposite to the opening of the processing material supply pipe 9, the opening of the processing material supply pipe 9 on the outer peripheral side of the opening of the processing material supply pipe 9 in the radial direction with respect to the axis O Is provided so as to surround it. This pre-thickener 10 has a truncated cone-shaped inclined filtration screen 10a formed of a wire screen or the like directed from the above side of the extrusion plate 7 toward the outer peripheral side in the radial direction with respect to the axis O In the embodiment, the opening amount in the inclined filtration screen 10a, that is, the size of the gap portion of the inclined filtration screen 10a is larger than the opening amount in the inner filtration screen 2a which is the cylindrical filtration screen of the present invention. .

  Furthermore, the inner peripheral portion of the inclined filtration screen 10a is covered by the cover 10b at least in the range to the end edge of the other end side of the dispersion plate 8 toward the one end side at the other end side in the axial line O direction. As a result, the portion on the other end side of the end edge on the other end side of the dispersion plate 8 is not exposed to the inner periphery of the pre-thickener 10. In addition, an annular plate-like scraper 10c having an outer peripheral edge whose outer peripheral edge has an outer diameter slightly smaller than the inner diameter of the inner filtration screen 2a is attached to the outer peripheral portion of the prethicker 10.

  And in the extrusion type centrifuge comprised in this way, the washing | cleaning-liquid supply means 11 which supplies a washing | cleaning liquid toward the said inclined filtration screen 10a of this pre-thickener 10 is provided further. In the present embodiment, the cleaning solution supply means 11 is attached to the cleaning solution supply pipe 11a inserted into the inner basket 2 from one end side of the inner basket 2 and the tip of the cleaning solution supply pipe 11a toward the inclined filtration screen 10a. And the spray nozzle 11b.

  More specifically, the cleaning liquid supply pipe 11 a is inserted in the inner basket 2 in parallel with the axis O below the processing substance supply pipe 9. Further, the spray nozzle 11b is bent obliquely downward with respect to the cleaning liquid supply pipe 11a so as to move downward toward the other end side at the tip of the inner basket 2 which is the other end of the cleaning liquid supply pipe 11a. As shown in FIG. 1, the supplied cleaning solution can be ejected in a conical radial direction about a center line perpendicular to the inclined filtration screen 10a in a cross section along the axis O.

  In the extrusion type centrifuge configured as described above, the processed material (slurry) in which the solid and liquid components supplied from the processed material supply pipe 9 become turbid hits the extruded plate 7 rotating at high speed with the outer basket 1 and the inner basket 2. In this embodiment, due to centrifugal force, the dispersion plate 8 is dispersed to the outer peripheral side from between the dispersion plate 8 and adheres to the inner peripheral surface of the inner filtration screen 2 a of the inner basket 2. Therefore, when the inner basket 2 is advanced from the state where the inner basket 2 is retracted with respect to the pushing plate 7 while supplying the processed material in this way, the processed material is transferred to the inner circumferential surface of the inner filtration screen 2a of the inner basket 2 which advances. It is filtered by centrifugal force while being continuously deposited in the direction of the axis O, and a cake of the processed material is formed.

  Next, when the inner basket 2 thus advanced reaches the forward stroke end and turns to reverse, the cake of the treatment deposited on the inner peripheral surface of the inner filtration screen 2a is relative to the inner basket 2 to be retracted. The outer filtration screen of the outer basket 1 is sequentially pushed out to one end side of the inner basket 2 by the scraper 10c of the prethicker 10 attached to the extrusion plate 7 which is to be advanced forward, and deposited on this one end side from the open end 2b. It is discharged to the inner peripheral surface of 1a, and is further filtered by centrifugal force while being continuously deposited in the direction of the axis O as well. That is, in the present embodiment, the pushing plate 7 pushes the processed material to the outer basket 1 through the pre-thickener 10.

  Then, the cake thus deposited and filtered on the inner peripheral surface of the outer filtration screen 1a is sequentially moved to one end side by the open end 2b of the inner basket 2 by the next advance of the inner basket 2 reaching the stroke end of retraction. The extruded material is also deposited on one end side and discharged from the open end 1 b of the outer basket 1 into the cake discharge chamber 3 c of the casing 3. Further, the liquid fraction separated from the treated product by the outer filtration screen 1a and the inner filtration screen 2a passes through the through holes 1d and 2d formed in the barrels of the outer basket 1 and the inner basket 2 and the liquid fraction of the casing 3 Are discharged into the discharge chamber 3b of the

  Here, in the extrusion type centrifugal separator having the above-described configuration provided with the pre-siccina 10, the treated material supplied from the treated material supply pipe 9 and dispersed on the outer circumferential side by the centrifugal force adheres to the inner circumferential surface of the inner filtration screen 2a. Before being processed, it first adheres to the inclined filtration screen 10a of the pre-thickener 10. The inclined filtration screen 10a removes to some extent particles of liquid and small solid particles, and pre-concentrates the processed material. Thus, the treatment adhered to the inclined filtration screen 10a is pushed outward by the centrifugal force and deposited on the inner circumferential surface of the inner filtration screen 2a as described above.

  And, in the extrusion type centrifugal separator, the cleaning liquid supply means 11 for supplying the cleaning liquid toward the inclined filtration screen 10 a of the pre-siccina 10 is provided, and in the embodiment of the operation method of the present invention, the inclined filtration The cleaning liquid is supplied to the processing material to be preconcentrated while being pushed outward on the screen 10 a by centrifugal force. For this reason, even when the solid content concentration of the processed material is high or high, the flowability of the processed material on the inclined filtration screen 10a can be secured by the cleaning liquid supplied by the cleaning liquid supply means 11 in this way.

  Therefore, even when the solid concentration of the treated product is high or high in this manner, the treated material deposited on the inclined filtration screen 10a is surely pre-concentrated while being preconcentrated by the centrifugal force of the rotation of the inner basket 2 It can be discharged to the internal filtration screen 2a of 2 and it is possible to prevent the stagnation and deposition of processed matter and the blocking of the inclined filtration screen 10a. In addition, by ensuring the flowability of the treated product, it is also possible to prevent the movement of the solid content in the treated product from being restrained, thereby preventing the particles having a small particle size from being captured by the solid content. The transfer to the liquid separation side can be promoted by the washing solution, and mainly the large-size particles are discharged into the basket to ensure the classification performance necessary to obtain many such large-size particles. Is also possible.

  Further, in the present embodiment, as the cleaning solution supply means 11, a cleaning solution supply pipe 11a inserted into the inner basket 2 and a spray nozzle 11b attached to the tip of the cleaning solution supply pipe 11a toward the inclined filtration screen 10a. Is used. Here, since the inclined filtration screen 10 a of the pre-siccna 10 rotates with the inner basket 2 and the push plate 7, even if the cleaning liquid supply pipe 11 a and the spray nozzle 11 b of these cleaning liquid supply means 11 are fixed, the inclined filtration screen 10 a It is possible to uniformly supply the cleaning solution to the above processing products all around.

  Furthermore, in the present embodiment, the opening amount in the inclined filtration screen 10 a is larger than the opening amount in the inner filtration screen 2 a which is a cylindrical filtration screen of the inner basket 2. That is, for example, when both the inclined filtration screen 10a and the inner filtration screen 2a are wire screens, the distance between adjacent wires of the inclined filtration screen 10a is made larger than the distance between adjacent wires of the inner filtration screen 2a. ing. Therefore, this makes it possible to further accelerate the discharge of the small particle of particle diameter from the inclined filtration screen 10a and the liquid portion of the treated product and the washing liquid, and the classification performance by the inclined filtration screen 10a can be further improved. .

  The cleaning liquid supplied by the cleaning liquid supply means 11 may be water depending on the processed product, and the liquid and the cleaning liquid in the processed product separated from the processed product by the inclined filtration screen 10a are also separated from the processed product. A liquid filtered from small particles having a particle diameter which is allowed to circulate may be supplied. In the present embodiment, although the present invention is applied to a two-stage basket type centrifugal separator including the outer basket 1 and the inner basket 2, the single-stage basket type centrifugal separation of only the inner basket 2 is described. It is also possible to apply the present invention to an apparatus or a centrifuge having three or more stages.

  Furthermore, in addition to the cleaning solution supply means 11 for supplying the cleaning solution toward the inclined filtration screen 10a of the pre-siccna 10, even though the cleaning solution supply means for supplying the cleaning solution toward the inner filtration screen 2a and the outer filtration screen 1a is provided. Good.

1 outer basket 1a outer filtration screen 1b open end of outer basket 1 2 inner basket (basket)
2a Internal filtration screen (cylindrical filtration screen)
2b Opening end of inner basket 2 3 Casing 5 Spindle 6 Extrusion shaft 7 Extrusion plate 8 Dispersion plate 9 Treated material supply pipe 10 Presiccator 10a Inclined filtration screen 11 Cleaning solution supply means 11a Cleaning solution supply pipe 11b Spray nozzle O Inner basket 2 (basket) Axis

Claims (4)

A cylindrical basket provided on the barrel with a cylindrical filtration screen and rotated about an axis;
A processing material supply pipe inserted into the basket along the axis to supply the processing material into the basket;
An extrusion plate housed in the basket and rotatable integrally with the basket and axially movable relative to the basket is provided so as to be relatively movable in the axial direction, and faces the opening of the processing material feed pipe at a distance. When,
And a pre-thicker provided on a side surface of the extrusion plate facing the opening of the processed material supply pipe and having an inclined filtration screen directed radially outward with respect to the axis toward the processed material supply pipe.
An extrusion type centrifugal separator comprising: a washing liquid supply means for supplying a washing liquid toward the inclined filtration screen of the pre-thicker.   The cleaning solution supply means includes a cleaning solution supply pipe inserted into the basket, and a spray nozzle attached to the tip of the cleaning solution supply pipe toward the inclined filtration screen. The extrusion type centrifuge as described in.   The extrusion type centrifugal separator according to claim 1 or 2, wherein the opening amount in the inclined filtration screen is larger than the opening amount in the cylindrical filtration screen.   A processing solution is supplied to the above-mentioned inclined filtration screen of the above-mentioned pre-siccina by the above-mentioned washing solution supply means using the extrusion type centrifugal separator according to any one of claims 1 to 3, An operation method of an extrusion type centrifuge characterized by centrifugation.

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