JP5890883B2 - centrifuge - Google Patents

Description

  The present invention relates to a centrifuge provided with a screw conveyor that is driven to rotate coaxially with a differential speed inside a rotating bowl that is driven to rotate about an axis.

  As such a centrifugal separator, for example, in Patent Documents 1 and 2, a rotating cylinder (rotating bowl) composed of a conical inclined part and a cylindrical part and a concentric arrangement in the rotating cylinder are provided at different rotational speeds. Using a decanter-type centrifuge equipped with a rotating screw conveyor, the sludge as a treated product to which a polymer flocculant has been added in advance or a polymer flocculant has been added in the cylindrical region of the rotating cylinder Furthermore, it has been proposed to reduce the moisture content of the solid content (dehydrated sludge) by supplying an inorganic flocculant in the inclined region of the rotating cylinder.

Japanese Patent No. 2540198 Japanese Patent Publication No. 6-41000

  By the way, in the centrifuge described in these patent documents 1 and 2, according to conveying the solid content separated from the processed material toward one end side in the direction of the rotation axis of the rotary cylinder and the screw conveyor. The inorganic flocculant supply pipe is inserted into the screw conveyor along the axis coaxially with the processed material supply pipe from one end side in the axial direction, and the inorganic flocculant supplied from the flocculant supply pipe is It is made to supply to the solid content in the inclination part area | region of a rotating cylinder from the supply hole drilled in the screw conveyor toward the radial direction with respect to an axis.

  However, contrary to the fact that the flocculant supply pipe is inserted from one end side in the axial direction in which the solid content is conveyed in this way, the flocculant supply pipe is inserted into the screw conveyor from the other axial end side, When trying to supply the flocculant to the solid component that has been solid-liquid separated, the length of the flocculant supply pipe becomes long, so that the structure of the centrifuge is complicated, and the flocculant supply pipe is connected to the axis. It is difficult to support the flocculant straight along the rotary bowl, and the flocculant supply pipe comes into contact with the screw conveyor due to the vibration of the rotating bowl or the screw conveyor rotating at high speed, which may be broken in some cases. In particular, the longer the flocculant supply pipe, the lower its natural frequency, and there is a risk that it will resonate with the vibration caused by the rotation of the rotating bowl or screw conveyor, and contact will easily occur.

  The present invention has been made under such a background. Even when the flocculant supply pipe is inserted into the screw conveyor from the side opposite to the side on which the solid content is conveyed as described above, the structure of the apparatus is complicated. It is an object of the present invention to provide a centrifuge capable of reliably supplying a flocculant to a solid content without causing damage to a supply pipe.

In order to solve the above problems and achieve such an object, according to the present invention, a screw conveyor that is driven to rotate coaxially with a speed difference from the rotating bowl is provided inside a rotating bowl that is driven to rotate about an axis. The processed material supplied between the rotary bowl and the screw conveyor is solid-liquid separated by the centrifugal force of the rotary bowl, and the separated solid is conveyed to one end in the axial direction by the screw conveyor. A coagulant supply pipe through which a coagulant is supplied is inserted into the screw shaft of the screw conveyor from the other end in the axial direction, and is supplied from the coagulant supply pipe. A flocculant supply path for supplying the solidified flocculant to the solid content extends to one end side in the axial direction on the outer peripheral portion of the screw shaft. It is formed on the outer circumferential surface of the screw shaft of the screw conveyor, a long plate-shaped sealing member, the outer peripheral surface with a space between Rutotomoni, the axial direction of the other sealing member The flocculant supply pipe communicates with the end portion and is joined so as to extend in the axial direction, and the opening on the other end side in the axial direction of the sealing member is closed , whereby the sealing member The flocculant supply path having an opening on one end side in the axial direction as the flocculant supply port is formed.

  In the centrifuge configured in this way, a flocculant supply path is formed in the screw shaft itself of the screw conveyor, the flocculant is supplied to one end in the axial direction, and supplied to the solid content conveyed to this one end. Therefore, it is not necessary to extend the flocculant supply pipe, the apparatus structure can be simplified, and there is no possibility that the flocculant supply pipe is damaged due to contact by vibration or resonance of the rotating bowl or screw conveyor. For this reason, it is possible to reliably supply the flocculant to the solid content conveyed to one end side in the axial direction, and thus it is possible to achieve a stable, effective and smooth centrifugal separation of the processed material over a long period of time. .

  Here, in order to form the flocculant supply path extending in the axial direction one end side in the screw shaft outer peripheral portion of the screw conveyor in this way, for example, an elongated hole extending in the axial direction is formed in the outer peripheral wall portion of the screw shaft. Although it is possible to connect the end side to the flocculant supply pipe and to open one end of the screw shaft on the outer peripheral surface of the screw shaft, in such a case, the elongated hole is connected to the one end side from the other end surface of the screw shaft. Must be drilled towards.

Therefore, without drilling such elongated hole, to easily form a coagulant supply path, the present invention, the outer peripheral surface of the screw shaft of the screw conveyor, the long plate-shaped sealing member, the Rutotomoni a space between the outer peripheral surface, and communicates the flocculant supply tube to the axial direction of the other end portion of the sealing member, and joined so as to extend in the axial direction, of the sealing member by closing the opening of the axial direction other end side, it forms the cohesive agent supply path to the opening of the axial direction one end side of the sealing member and the coagulant supply port, such sealing Since the sealing with the stopper member is processing from the outer periphery side of the screw shaft, the formation of the flocculant supply path is easier and the time, labor, and cost can be reduced compared to the case where the long hole as described above is drilled. Reduction can be achieved.

  As described above, according to the present invention, the solid content conveyed to one end of the rotating bowl is reliably agglomerated without complicating the structure of the centrifuge and damaging the flocculant supply pipe. An agent can be supplied and agglomerated to effectively reduce the moisture content. Therefore, for example, when the treated material is sewage sludge, it is possible to improve the fuel efficiency of the incineration equipment when incinerating the discharged dewatered sludge. Therefore, it is possible to increase the efficiency of sludge removal and extend the life of landfill sites.

It is a sectional side view which shows the reference example in describing one Embodiment of the centrifuge of this invention. It is AA expanded sectional drawing in FIG.

  1 and 2 are schematic views showing a reference example for explaining an embodiment of the centrifuge of the present invention. Note that the following reference examples and descriptions of the embodiments are merely illustrative, and are not intended to limit the present invention, its application, or its use. In this reference example, the rotating bowl 1 has a cylindrical portion 1A centered on the axis O, and is connected to one end side (left side in FIG. 1) of the cylindrical portion 1A in the axis O direction. A conical inclined portion 1B centering on an axis O with a small diameter, and an annular end plate portion 1C perpendicular to the axis O closing the other end side (right side in FIG. 1) of the cylindrical portion 1A in the axis O direction; A cylindrical bowl shaft portion 1F extending from the inner peripheral edge of the end plate portion 1C to the other end side in the direction of the axis O is integrally formed. Such a rotating bowl 1 is accommodated in the casing C so that the axis O is horizontal, and is supported rotatably around the axis O via a bearing (not shown). A bowl rotation driving means (not shown) is also provided. By being connected to the bowl shaft portion 1F extended to the outside of the casing C, it can be rotated around the axis O in one direction at a high speed.

  Inside the rotating bowl 1, a screw conveyor 2 is accommodated around the axis O. The screw conveyor 2 includes a screw shaft and a screw blade (not shown). The screw shaft is inserted into the inner peripheral portion of the bowl shaft portion 1F of the rotating bowl 1 so as to be rotatable relative to the bowl shaft portion 1F. A hollow outer cylindrical shape that is connected to one end side in the axis O direction of the conveyor shaft portion 2A and has a constant outer diameter that is slightly smaller than the inner diameter of the cylindrical portion 1A of the rotating bowl 1 The straight body portion 2B and the cone portion 2C having a conical shape that is continuously provided on one end side in the axis O direction of the straight body portion 2B and gradually decreases in outer diameter toward the one end side. Among these, the screw blades are provided on the outer circumferences of the straight body portion 2B and the cone portion 2C.

Such a screw conveyor 2 is located in the rotating bowl 1 such that the straight body portion 2B is located on the inner circumference of the cylindrical portion 1A of the rotating bowl 1 and the cone portion 2C is located on the inner circumference of the inclined portion 1B. As in the case of the rotating bowl 1, it is supported so as to be rotatable around the axis O via a bearing (not shown) as in the case of the rotating bowl 1, and also with a differential speed in the same direction as the rotating bowl 1 around the axis O by a conveyor rotation driving means (not shown). It can be rotated.

Here, the outer diameter of the cone portion 2 </ b> C is made slightly smaller so that a radial interval with respect to the axis O is formed between the outer diameter of the inclined portion 1 </ b> B of the rotating bowl 1, and this interval is further reduced. It is smaller than the distance between the outer periphery of the inner circumference and the straight body portion 2B of the cylindrical portion 1A of. Accordingly, the outer diameter of the cone portion 2C is made larger than the outer diameter of the straight barrel portion 2B at the other end in the axis O direction. In the meantime, the convex wall portion 2D that faces the other end side and projects radially outward with respect to the axis O is formed so as to be continuous over the entire circumference of the straight body portion 2B. In the present reference example, the convex wall portion 2 </ b> D protrudes to the outer peripheral side in the radial direction perpendicular to the axis O.

The outer diameters of the screw blades provided on the outer circumferences of the straight body portion 2B and the cone portion 2C are smaller than the interval between the inner circumference of the cylindrical portion 1A of the rotating bowl 1 and the inner circumference of the inclined portion 1B. It is said that the gap is open. The pitch of the screw blades is such that the pitch at the cone portion 2C is smaller than the pitch at the straight body portion 2B. By reducing the pitch, the moving distance of the processed material in the direction of the axis O is extended, and the separation time can be secured. Furthermore, the inclination angle with respect to the axis O of the conical surface formed by the outer peripheral surface of the cone portion 2C is made equal to or larger than the inclination angle with respect to the axis O of the conical surface formed by the inner peripheral surface of the inclined portion 1B of the rotating bowl 1, and thus the cone portion. The interval between the outer peripheral surface of 2C and the inner peripheral surface of the inclined portion 1B is made constant or gradually increased toward one end side in the axis O direction.

  The hollow portion of the straight body portion 2B is divided by a partition wall 5 into a flocculant supply chamber 3 on the other end side in the axis O direction and a processed material supply chamber 4 on one end side. Here, in this partition wall 5, a circular through hole 5 </ b> A having an inner diameter substantially equal to the inner peripheral portion of the conveyor shaft portion 2 </ b> A of the screw conveyor 2 is formed around the axis O.

  Further, a circular processed product supply pipe 6 having an outer diameter slightly smaller than the inner diameter of the inner peripheral portion and the through hole 5A is provided in the processed product supply chamber 4 from the inner peripheral portion of the conveyor shaft portion 2A through the through hole 5A. However, it is fixed to the rotating screw conveyor 2 in a non-rotating manner and is inserted along the axis O, and an opening on one end side thereof is opened in the workpiece supply chamber 4. Further, from the processed product supply chamber 4 to the outer peripheral surface of the straight body portion 2B, processed product supply ports 4A penetrating in the radial direction with respect to the axis O are formed in one or a plurality of locations in the circumferential direction.

  Furthermore, a flocculant supply pipe 7 is inserted into the processed product supply pipe 6. The flocculant supply pipe 7 is a circular pipe whose inner and outer diameters are sufficiently smaller than the processed product supply pipe 6. In this reference example, one such flocculant supply pipe 7 is a bottom surface in the processed product supply pipe 6. The other end side from the other end side in the direction of the axis O is inserted to the position of the flocculant supply chamber 3 along the portion, and the bottom surface portion is joined and fixed by welding or the like.

  In addition, at one end portion of the flocculant supply pipe 7 positioned in the flocculant supply chamber 3 in the direction of the axis O, the opening of the circular pipe facing the one end side is closed, and the bottom surface portion of the processed product supply pipe 6 An opening is formed in the side surface facing the. On the other hand, an opening is also formed in the bottom surface of the processed product supply pipe 6 facing the opening of the flocculant supply pipe 7, and these openings are separated from the inside of the processed product supply pipe 6 by a cover 7A or the like. As a result, a flocculant supply pipe opening 7B is formed in which one end of the flocculant supply pipe 7 opens into the flocculant supply chamber 3.

Further, coagulant supply chamber 3, the inner wall of the hollow portion of the cylindrical body portion 2B (the inner peripheral surface) is surrounded by a partition wall 5, the axis O at intervals between the outer peripheral surface of the cylindrical body portion 2B The orthogonal cross section is formed in a circular shape. In the through hole 5A of the partition wall 5 constituting the flocculant supply chamber 3, the processed material supply pipe 6 is inserted so that the flocculant supply pipe opening 7B is positioned in the flocculant supply chamber 3. . In addition, the inner wall of the hollow portion of the straight body portion 2B constituting the flocculant supply chamber 3 has one or a plurality of locations (for example, 4 to 8 locations) so as to avoid the position of the processed product supply port 4A in the circumferential direction. In this reference example, as shown in FIG. 2, the coagulant supply holes 3A are formed so as to penetrate through the outer peripheral surface of the straight body portion 2B at six equal intervals in the circumferential direction.

  In the screw conveyor 2, a flocculant supply path 8 that communicates with the flocculant supply chamber 3 through the flocculant supply hole 3A and extends to one end side in the axis O direction is formed in the straight body portion 2B. In the present reference example, the flocculant supply path 8 has a flocculant supply port 8A that opens in the outer peripheral direction of the axis O between the convex wall portion 2D of the screw conveyor 2 in the axis O direction and the processed product supply port 4A. Is forming.

Here, in this reference example, a groove 8B is provided on the outer peripheral surface of the straight body portion 2B, with the other end in the axis O direction communicating with the flocculant supply hole 3A and extending parallel to the axis O to one end. The same number of holes 3A as the number of the holes 3A are formed, and the recessed grooves 8B extend in the direction of the axis O to the front of the convex wall portion 2D while avoiding the workpiece supply port 4A in the circumferential direction. Further, on the outer peripheral surface of the straight body portion 2B, a long-plate-shaped sealing member 8C having a cross-sectional arc having a radius substantially equal to the outer peripheral surface of the straight body portion 2B is removed except for one end portion in the axis O direction of the groove 8B. The concave groove 8B portion closed by the sealing member 8C is used as a flocculant supply path 8, and the outer peripheral surface opening of the straight body portion 2B is not blocked. One end of the opening is a flocculant supply port 8A.

  In addition, at one end side in the axis O direction of the rotating bowl 1, the solid content separated from the processed material P and conveyed to the one end side by the screw conveyor 2 passes through the gap between the inclined portion 1B and the cone portion 2C. The solid content discharge port 1 </ b> D is provided, and is opened to the processed product discharge chamber D on one end side in the axis O direction of the casing C. On the other hand, in this reference example, the end plate portion 1C on the other end side in the axis O direction of the rotary bowl 1 is separated from the processed material P by solid-liquid separation, and the other direction in the axis O direction is opposite to the conveyance to one end side of the solid content. A liquid discharge path 1E for the liquid pushed out to the end side is formed, and is opened to the liquid discharge chamber E on the other end side of the casing C in the axis O direction. The liquid discharge path 1E may be formed in the conveyor shaft portion 2A of the screw conveyor 2.

Next, the case where the sludge such as sewage sludge is solid-liquid separated as the processed material P by the centrifuge configured as described above will be described. The processed product P is prepared by mixing the sludge with a polymer flocculant and, if necessary, a part of the inorganic flocculant, and supplying the processed product P to the processed product supply chamber 4 through the processed product supply pipe 6. It is supplied between the rotating bowl 1 and the screw conveyor 2 that rotate at high speed with a differential speed from the material supply port 4A.

The processed product P supplied between the rotating bowl 1 and the screw conveyor 2 is separated into solid and liquid by the centrifugal force of the rotating bowl 1, and the separated solid content is moved to one end side in the axis O direction by the screw blades of the screw conveyor 2. Be transported. On the other hand, the liquid component separated from the processed product P is moved to the other end side in the axis O direction between the rotary bowl 1 and the screw conveyor 2 so as to be pushed out by the solid component, and the liquid discharge path It is discharged from 1E.

Here, in the centrifugal separator of the present reference example, the outer diameter of the cone portion 2C is made larger than the outer diameter of the straight body portion 2B on one end side in the axis O direction of the screw conveyor 2, so that the radial direction with respect to the axis O is increased. A convex wall portion 2D projecting to the outer peripheral side is formed over the entire circumference of the straight body portion 2B, and a solid flow path is formed between the rotating bowl 1 and the screw conveyor 2 on one end side of the convex wall portion 2D . The solid content flow path is low on the inner peripheral side in the radial direction with respect to the axis O, on the opposite side (on the other end side in the axis O direction) of the convex wall portion 2D.

Therefore, the solid content conveyed to one end side of the rotating bowl 1 stays in front of the convex wall portion 2D, and is consolidated and further separated by the solid content continuously conveyed, thereby reducing its moisture content. with provoking produces a stirring action by the convex wall portion solids staying in front of the 2D flows into the low since the radial inner peripheral side of the solid divisional channel. Here, this stirring action is due to the solid content thus transported to one end side in the direction of the axis O flowing into the radial inner peripheral side of the flow path and being dispersed. Stirring by the rotation of the screw blades of the screw conveyor 2 for conveying the solid content at high speed, for example, stirring by the stirring blades attached to the screw conveyor 2, etc. is significant.

In addition, the solid portion on the radially outer peripheral side thus consolidated flows into the solid portion flow path formed between the outer periphery of the cone portion 2C on one end side of the convex wall portion 2D and the inner periphery of the inclined portion 1B. Since the solid content flow path is narrowed, a stirring action also occurs when the solid content passes between the outer periphery of the convex wall portion 2D and the inner periphery of the rotating bowl 1. Furthermore, since the solid content flow path between the outer periphery of the cone portion 2C and the inner periphery of the inclined portion 1B extends toward the radially inner periphery as it goes toward one end, its cross-sectional area gradually decreases. Again, the solids are consolidated and further separated.

  Further, in the centrifuge of the above configuration, the flocculant supply port 8A is opened between the convex wall portion 2D and the processed product supply port 4A, and the rotation of the rotary bowl 1 from the sludge as the processed product P is performed. The solid content separated by solid-liquid separation by the centrifugal force of the inorganic flocculant as the flocculant L from the flocculant supply port 8A (if the inorganic flocculant is partly mixed with the processed material P in advance, the remaining inorganic Flocculant) is supplied.

That is, the coagulant L supplied to the coagulant supply pipe 7 inserted into the processed product supply pipe 6 flows into the coagulant supply chamber 3 in the screw conveyor 2 from the coagulant supply pipe opening 7B, and the screw conveyor 2 Is pressed to the outer peripheral side in the radial direction with respect to the axis O by the centrifugal force caused by the rotation of, and flows into the coagulant supply path 8 from the coagulant supply hole 3A. Further, the coagulant L flowing into the coagulant supply path 8 in this way passes through the coagulant supply path 8 in the direction of the axis O by the pressing force of the coagulant L continuously supplied from the coagulant supply pipe 7 to the coagulant supply chamber 3. It is pushed out to one end side and supplied from the flocculant supply port 8 </ b> A between the rotary bowl 1 and the screw conveyor 2, which becomes a solid flow path.

Thus, in this way supplied flocculant L has a stirring action of the solids in front of the convex wall portion 2D described above, when the solid content is passed between the outer and the inner periphery of the rotating bowl 1 of the convex wall portion 2D With the agitation action, the solid content is sufficiently mixed, whereby the aggregation of the solid content is effectively promoted and the water content is further reduced. Thus, according to the centrifuge of the above configuration, the solid content separated from the processed product P by solid-liquid separation by the solid content compaction by the convex wall portion 2D of the straight body portion 2B and the stirring action of the flocculant L. It becomes possible to significantly reduce the moisture content. Moreover, since aggregation of solid content is effectively promoted in this way, the amount of the coagulant L used for reducing the solid content to a predetermined moisture content can be reduced.

  For this reason, when the treated product P is sludge such as the sewage sludge described above, when the dewatered sludge, which is a solid content discharged from the centrifuge, is incinerated, the water content of the dewatered sludge is low. Fuel consumption can be improved by reducing fuel consumption in the incineration facility. In addition, even when the dewatered sludge discharged in this way is disposed of in landfill, the amount of dewatered sludge can be reduced, so that more dewatered sludge can be carried out at a time when it is transported to the landfill site. It is possible to extend the life until the disposal site is completely reclaimed.

Then, in the centrifugal separator of the above configuration, for supplying thus the flocculant L from the axis O direction one end side of the convex wall portion 2D of the coagulant supply port 8A which opens forward solids, coagulant supply pipe The flocculant supply path 8 communicating with the flocculant supply chamber 3 via the flocculant supply chamber 3 is formed on the outer peripheral portion of the screw shaft of the screw conveyor 2 so as to extend to one end side in the axis O direction. Damage and complication of the apparatus structure can be prevented, and smooth and effective centrifugation of the processed material P can be achieved.

That is, in the centrifuge that conveys the solid content separated from the processed material P to the one end side in the axis O direction of rotation of the rotating bowl 1 or the screw conveyor 2 as in this reference example, the other end side in the axis O direction. The processed product supply pipe 6 and the flocculant supply pipe 7 are inserted through the outer peripheral surface of the straight barrel portion 2B on the other end, and the processed product supply port 4A is opened. In the case where the flocculant supply port 8A is opened between the convex wall portion 2D on the one end side, for example, the flocculant supply chamber 3 is arranged on the one end side in the axis O direction with respect to the processed product supply chamber 4 contrary to the present reference example. The flocculant supply pipe 7 extends along the axis O to the flocculant supply chamber 3 through the through hole 5A of the partition wall 5 and communicates with the flocculant supply chamber 3 to the straight barrel portion 2B. It is also conceivable to directly open the flocculant supply port 8A on the outer peripheral surface.

  However, in such a centrifuge, since the length of the flocculant supply pipe 7 becomes long, the structure becomes complicated, and the flocculant supply pipe 7 having a smaller diameter than the processed product supply pipe 6 is used. Is difficult to support straight along the axis O, and the flocculant supply pipe 7 may come into contact with the through hole 5A of the partition wall 5 due to vibrations of the rotating bowl 1 and the screw conveyor 2 rotating at high speed, and may be broken in some cases. There is. In particular, when the flocculant supply pipe 7 becomes longer, the natural frequency thereof becomes lower, so that there is a possibility that the contact with the vibration due to the rotation of the rotating bowl 1 or the screw conveyor 2 is likely to occur.

  However, in contrast to such a centrifuge, in the centrifuge having the above-described configuration, the flocculant L is supplied to the outer peripheral portion of the screw conveyor 2 itself from the other end side in the axis O direction to the one end side as described above. The agent supply path 8 is formed, and the flocculant supply port 8A is opened between the convex wall portion 2D on one end side and the processed product supply port 4A without making the flocculant supply pipe 7 longer than necessary. Can do. For this reason, there is no fear of contact between the coagulant supply pipe 7 and the through hole 5A due to resonance or the like, and it is possible to prevent the coagulant supply pipe 7 from being damaged such as breakage, and to simplify the structure of the apparatus. However, it is possible to reliably supply the flocculant L to the solid content between the convex wall portion 2D and the processed product supply port 4A, and thus the stable, effective and smooth processed product P can be obtained over a long period of time. Centrifugation can be performed.

  In order to form the flocculant supply path 8 in the screw conveyor 2 in this way, for example, a long hole extending in the direction of the axis O is formed in the peripheral wall portion of the straight body portion 2B, and the other end communicates with the flocculant supply chamber 3. It is also possible to open one end of the straight body portion 2B on the outer peripheral surface. In such a case, it is necessary to drill the long hole from the other end surface of the straight body portion 2B to the space between the convex wall portion 2D and the workpiece supply port 4A.

However, in this reference example, on the other hand, the groove 8B is formed in the axis O direction on the outer peripheral surface of the straight body 2B of the screw conveyor 2, and the other end of the groove 8B is agglomerated in the flocculant supply chamber 3. The flocculant is supplied through the agent supply hole 3A, and the outer peripheral side of the concave groove 8B is closed by a sealing member 8C except for one end in the direction of the axis O, so that the one end is a flocculant supply port 8A. A path 8 is formed. For this reason, compared with the case where the above long holes are drilled, formation of the flocculant supply path 8 is easy, and time, labor, and cost can be reduced.

  The screw blades of the screw conveyor 2 may have a structure in which a spiral blade is directly attached to the outer periphery of the straight body portion 2B or cone portion 2C of the screw shaft, and a plurality of attachment members such as brackets are provided on the screw shaft. You may use the ribbon screw structure which attaches a spiral blade | wing via an attachment member.

Furthermore, in this reference example, the inclined portion 1B of the rotating bowl 1 is formed in a conical shape whose inner and outer diameters gradually decrease toward one end side and is configured integrally with the cylindrical portion 1A, and the cone portion 2C of the screw conveyor 2 is formed. Although the outer diameter gradually decreases toward the one end side in the axis O direction and is formed into a conical shape with the straight body portion 2B, the inclined portion 1B and the cone portion 2C are formed on the inner periphery of the inclined portion 1B . The portion between the surface and the outer peripheral surface of the cone portion 2C may be configured so as to tend toward the axis O side without going toward the outer peripheral side at least toward the one end side in the axis O direction. A horizontal portion parallel to the axis O may be provided in the middle of the inclination approaching the axis O side, or the angle of the inclination with respect to the axis O may be changed. Further, the inclined portion 1B and the cone portion 2C may be attached to the cylindrical portion 1A and the straight body portion 2B so as to be divided. Furthermore, the separated solid content is caused by the conveying force of the screw blades in the straight body portion 2B of the screw conveyor 2 or the centrifugal head pressure acting on the solid content that is in a compacted state before the convex wall portion 2D. When it is possible to discharge from the discharge port 1D, the screw blades on the outer periphery of the cone portion 2C can be omitted.

  Furthermore, in this reference example, the concave groove 8B has a “U” -shaped cross section as shown in FIG. 2, and the flocculant supply path 8 covered with the sealing member 8C has a substantially square cross section. However, the concave groove 8B may be formed in a semicircular cross section, a U shape, a V shape, or the like, and the outer peripheral side thereof may be covered with the sealing member 8C.

In the centrifuge of one embodiment of the present invention, instead of forming such a concave groove 8B, or in combination with the concave groove 8B, the cross-sectional “U” shape, semicircular shape, U shape the long plate-shaped sealing member 8C of the V-shape or the like, Rutotomoni a space between the outer peripheral surface and the groove 8B of the straight body portion 2B, coagulant supply hole into the other end of the axial line O direction 3A is communicated , joined so as to extend in the direction of the axis O, and the opening on the other end side in the axis O direction is closed, so that the opening on one end side serves as the flocculant supply port 8A. Form.

DESCRIPTION OF SYMBOLS 1 Rotating bowl 1A Cylindrical part 1B Inclined part 1C End plate part 2 Screw conveyor 2A Conveyor shaft part 2B Straight trunk part 2C Cone part 2D Convex wall supply part 3 Coagulant supply chamber 4 Processed substance supply chamber 4A Processed substance supply port 5 Bulkhead 6 Process Material supply pipe 7 flocculant supply pipe 8 flocculant supply path 8A flocculant supply port 8B concave groove 8C sealing member O axis of rotation of rotating bowl 1 and screw conveyor 2 P processed material L flocculant

Claims (2)

A screw conveyor that is driven to rotate coaxially with a speed difference from the rotating bowl is provided inside a rotating bowl that is driven to rotate about an axis, and the processed material supplied between the rotating bowl and the screw conveyor is rotated as described above. A centrifuge that carries out solid-liquid separation by the centrifugal force of the bowl and transports the separated solids to one end in the axial direction by the screw conveyor and discharges the flocculant on the screw shaft of the screw conveyor. A flocculant supply pipe through which the flocculant is supplied from the other end side in the axial direction, and a flocculant supply path for supplying the flocculant supplied from the flocculant supply pipe to the solid content of the screw shaft. It is formed in the outer peripheral part so that it may extend to the said one end side of the said axial direction, The said screw shaft of the said screw conveyor The outer peripheral surface of the long plate-like sealing member, and Rutotomoni a space, the coagulant feed pipe into the other end portion of the axial direction of the sealing member is communicated between the outer circumferential surface , it is bonded so as to extend in the axial direction, by the opening of the axial direction other end side of the sealing member is closed, flocculant opening of the axial direction one end side of the sealing member A centrifuge characterized in that the flocculant supply path serving as a supply port is formed. A processed product supply port for supplying the processed product is formed between the rotating bowl and the screw conveyor on the outer peripheral surface of the screw shaft of the screw conveyor, and the flocculant supply port is configured to supply the processed product. The centrifuge according to claim 1, wherein the centrifuge is opened to one end side in the axial direction from the mouth.

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