JP2001149813A - Decanter type centrifuge with rinsing function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a decanter type centrifuge with a rinsing function wherein a washing effect and its drainage effect on a solid content are good, its installing cost is low and its installing space is small. SOLUTION: In a decanter type centrifuge with a rinsing function, which comprises a rotary bowl and a screw conveyor provided coaxially in the rotary bowl, a cylindrical part of the rotary bowl is constituted as a separation zone and a truncated conical part is constituted as a beach zone, and it comprises a stock solution slurry feed pipe which is inserted into the separation zone from an end board of the cylindrical part and feeds stock solution slurry to the separation zone, and a rinse liquid feed pipe which is inserted through the stock solution slurry feed pipe and feeds the rinse liquid to the beach zone, the beach zone is constituted as a washing liquid pool zone, a rinse zone and a filter zone from a large diameter end side of the truncated conical part to its small diameter end side, a plurality of filter bushes for drainage acceleration are provided in wall surface parts of the rinse zone and the filter zone, and a washing liquid feed pipe line for backward washing a filter medium is arranged to its filter liquid exhaust side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centrifugal separator with a rinsing function, and more particularly, to a filter bush for facilitating drainage provided on a wall surface which is a rinsing zone and a filtration zone for solids, and a filtrate discharging side on the filtrate discharging side. The present invention relates to a decanter-type centrifuge with a rinsing function provided with a washing liquid supply pipe for back washing of a filter medium.

[0002]

2. Description of the Related Art A decanter-type centrifuge with a rinsing function requires solid-liquid separation in a centrifugal force field among intermediate products and products in the production process of foods, pharmaceuticals, and the like.
Further, it is often used in a place where cleaning of the separated object is immediately required.

As shown in FIG. 7, a conventional decanter-type centrifuge 100 with a rinsing function has a truncated cone portion 101A and a cylindrical portion 10 connected to the large-diameter end of the truncated cone portion 101A.
1B, a screw conveyor 102 provided coaxially in the rotating bowl 101 and rotating at a slight speed difference, and a center of an end plate 105 of a cylindrical portion 101B of the rotating bowl 101. The stock solution slurry and the rinsing solution (cleaning solution) are inserted into the supply lines 107A and 107B respectively.
Supply pipe 1 that can be supplied to a predetermined position in the rotating bowl 101 by using
07 constitutes a main part.

Next, the operation of the decanter-type centrifuge 100 with a rinsing function will be described. When the undiluted slurry is supplied to the separation zone shown in FIG. 7 in the rotating bowl 101 rotating at a high speed, the solid content in the slurry is settled on the inner wall side of the rotating bowl 101 under the centrifugal force. The sedimented solid content is fed to the frustoconical section 10 by the screw conveyor 102.
1A, is washed and dewatered in the beach zone by a rinsing liquid (cleaning liquid) supplied to the beach zone at the same time as the supply of the stock slurry, and then the truncated cone portion 1
The cleaning cake is discharged to the outside from the solids discharge port 108 provided on the small-diameter end side of 01A. On the other hand, the clarified liquid separated in the separation zone overflows the annular weir plate 103 through the clarified liquid discharge port 104 provided on the end plate 105 of the cylindrical portion 101B of the rotating bowl 101, and is then discharged to the outside as a separated liquid. Is done.

[0005]

However, in the conventional decanter-type centrifuge 100 having a rinsing function, since the length of the beach zone is short and the space is small, sufficient time for washing and draining the solids cannot be obtained. (1) the particle size is relatively small (for example, 5 to 40 micrometers);
When washing and dewatering solids having poor washability and filterability, dirt in the washing liquid staying in the beach zone is reattached to the solids that have been washed in the previous stage, and the solids washing effect is reduced. There was a problem. In addition, since the dewatering time was short, the dewatering effect of the solid was not improved. Therefore, as a cleaning method for solving this problem, (a) As a method for improving the cleaning effect, a solid content outlet 1
The solids discharged from 08 are once received in a separate stirring tank containing a washing liquid and then re-slurried and washed. (B) As a method for increasing the dewatering effect, the re-slurried liquid is further pumped up. A tank replacement cleaning method is adopted, which combines a method of performing a high-liquid removal process again with a solid-liquid separator provided at a later stage. Further, as another washing method for solving this problem, a washing method in which a plurality of the decanter-type centrifuges 100 with the rinsing function are connected in series to perform washing and dewatering treatments in multiple stages, and the decanter with the rinsing function A washing method in which a washing treatment and a dewatering treatment are performed by a combination of a centrifugal separator with another solid-liquid separator is employed. However, both of these cleaning methods have a problem that not only the equipment cost and the operating cost are high, but also the installation space of the equipment becomes large. In addition, in order to increase the washing effect of the solid content, a large amount of the rinsing liquid must be used, so that there is a problem that the operating cost is increased.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and has a decanter type centrifugal centrifuge with a rinsing function, which has a good effect of washing and draining solids, has a low equipment cost, and has a small installation space. It is an object to provide a separator.

[0007]

The gist of the invention described in claim 1 for solving the above-mentioned problems is that a frusto-conical portion having a solids discharge port at a small-diameter end side; A rotating bowl consisting of a cylindrical portion having a fining liquid discharge port provided with an annular weir plate at the other end, connected to the large diameter end of the conical portion, and provided coaxially within the rotating bowl, with a slight differential speed It consists of a rotating screw conveyor, the cylindrical portion is configured as a separation zone, the truncated cone portion is configured as a beach zone, inserted into the shaft center from the insertion hole of the cylindrical portion end plate of the rotating bowl, and inserted into the separation zone. In a decanter-type decanter centrifuge with a rinsing function configured to include an undiluted slurry supply pipe that supplies undiluted slurry and a rinse liquid supply pipe that is inserted through the undiluted slurry supply pipe and supplies a rinse liquid to the beach zone, The beach zone is configured as a washing liquid pool zone, a rinsing zone, and a filtration zone from the large-diameter end side to the small-diameter end side of the truncated conical portion, and a plurality of liquid removals are provided on the wall surfaces of the rinsing zone and the filtration zone. A filter bush for promotion is provided, and a cleaning liquid supply pipe for back-rinsing the filter medium is provided on the filtrate discharge side.

The beach zone of the truncated conical portion of the rotating bowl is constituted as a washing liquid pool zone, a rinsing zone and a filtration zone from the large-diameter end to the small-diameter end, and the washing liquid pool zone formed on the solids discharge port side. The solid washing effect is improved by the two-stage washing of the hold washing in step 1 and the replacement washing with the rinsing liquid in the rinsing zone. Also,
By providing a plurality of filter bushes for facilitating dewatering on the wall portion of the rinsing zone and the filtration zone, drainage of the cleaning liquid and the filtrate to the outside of the beach zone at the later stage is improved, and it is used for once cleaning. Rinse solution
It hardly stays in the rotating bowl and passes through the filter medium as it is and immediately goes to the outside, so that re-attachment of dirt to the solid content is eliminated. Therefore, the effect of washing solids is improved. Further, the liquid component contained in the solid content also immediately becomes a filtrate and escapes to the outside, so that the dewatering effect is improved. In addition, a single centrifuge with a rinsing function can provide sufficient dewatering and cleaning effects, eliminating the need for conventional equipment such as stirring tanks and reslurry pumps, reducing equipment costs and installing equipment. Space can be reduced. In addition, the amount of rinsing liquid necessary for cleaning can be reduced. Further, a clogging period of the filter medium can be extended by providing a cleaning liquid supply pipe for back cleaning on the filtrate discharge side of the filter medium provided in the filter bush and performing reverse cleaning. As a result, the operating time of the decanter centrifuge with a rinsing function can be extended.

According to another aspect of the present invention, the truncated conical portion is reduced in diameter to two steps toward the solids discharge port. 2. The decanter centrifuge with a rinsing function according to claim 1, wherein a frustoconical part of the eye is formed as the rinsing zone and the filtration zone.

The frustoconical portion of the rotating bowl is reduced in diameter in two stages toward the solids discharge port, and a rinse zone and a filtration zone are provided on the wall surface (inclined portion) of the second frustoconical portion. As a result, the liquid after the washing treatment can be more suitably prevented from going to the solids discharge port side as compared with the case where the rinsing zone and the filtration zone are provided on the horizontal wall surface. As a result, the cleaning effect and the dewatering effect are also improved.

The gist of the invention described in claim 3 for solving the above problem is that a part of the truncated conical portion on the small diameter end side is a small diameter cylindrical portion toward the solids discharge port. The decanter centrifuge with a rinsing function according to claim 1, wherein the small-diameter cylindrical portion is configured as the rinsing zone and the filtration zone.

By providing a small-diameter cylindrical portion at a part of the small-diameter end side of the truncated conical portion of the rotating bowl to form a rinsing zone and a filtration zone, the washing time and the liquid removing time can be lengthened. Compared with the conventional decanter centrifuge with a rinsing function, the effect of washing solids and the effect of removing liquid can be improved.

The gist of the present invention described in claim 4 for solving the above problem is that a partition press plate and a filtration zone are provided at a position between the washing liquid pool zone and the rinsing zone. The at least one or more press plates for draining are provided in the axial direction between the screw blades of the screw conveyor at a fixed distance from the inner wall of the rotary bowl, respectively. A decanter-type centrifuge with a rinsing function as described.

A partition press plate is provided at a position between the washing liquid pool zone and the rinsing zone, and a dewatering press plate is provided at the position of the filtration zone. The screw press of the screw conveyer is disposed at a fixed interval from the inner wall of the rotary bowl. By arranging at least one or more in the axial direction, the washing effect and the dewatering effect of the solid coming out of the solid outlet can be further improved.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A decanter-type centrifuge with a rinsing function according to the present invention will be described with reference to the embodiments shown in FIGS. FIG. 1 is a longitudinal sectional view showing a first embodiment of a decanter type centrifuge with a rinsing function according to the present invention. FIG. 2 (a) is a longitudinal sectional view of a first embodiment of a filter bush according to the present invention. FIG. 2B is a longitudinal sectional view of a second embodiment of the filter bush according to the present invention, FIG. 2C is a longitudinal sectional view of a third embodiment of the filter bush according to the present invention, and FIG. Longitudinal sectional view showing a second embodiment of a decanter type centrifuge with a rinse function according to the present invention, FIG. 4 is a longitudinal sectional view showing a third embodiment of the decanter type centrifuge with a rinse function according to the present invention, FIG. 5 is a longitudinal sectional view showing a fourth embodiment of a decanter-type centrifuge with a rinsing function according to the present invention.
(A) is a perspective view of a partition press plate according to the present invention, FIG.
(B) is a perspective view of the dewatering press plate according to the present invention.

First, a first embodiment of a decanter-type centrifuge with a rinsing function according to the present invention will be described with reference to FIG. The decanter-type centrifuge 1 with a rinsing function according to the present invention has a solid content outlet 9 on the small diameter end side,
A plurality of filter bushes f are provided on the inclined wall portion 2a on the small diameter end side.
A conical portion 2b provided with 1, f2 and f3, and a refining device in which an annular weir plate 3 is provided on the outside of an end plate 6 which is connected to a large diameter end side of the truncated conical portion 2b. A rotary bowl 2 composed of a large-diameter cylindrical portion 2c having a liquid discharge port 4 and a coaxial rotor provided in the rotary bowl 2;
A screw blade 5a that rotates at about 50 rpm) and is helically surrounded and fixed around the screw shaft 5b;
The slurry distribution port 5c provided in the separation zone, which is the large-diameter cylindrical portion 2c of the rotary bowl 2, and the truncated cone portion 2
and a hollow screw shaft 5b having a rinsing liquid distribution port 5d provided over the filtration zone and the rinsing zone of b, and a screw conveyor 5 having a main part protruding from the center of the end plate 6 of the rotary bowl 2. Raw material slurry supply pipe 8 which is inserted through insertion hole 7
a cleaning liquid supply pipe 8b, which is inserted into the raw liquid slurry supply pipe 8a and extends to the rinse zone of the beach zone, and the filtration bushes f1, f
The main part is constituted by the cleaning liquid supply pipes BW1, BW2, BW3 for backwashing, which are disposed opposite to the filtrate discharge side of 2, f3.

Next, the operation of the centrifugal separator 1 with a rinsing function having the above-described configuration will be described. High speed (for example, 30
An undiluted slurry is supplied to a separation zone in the rotating bowl 2 rotating at a speed of 00 to 5000 rpm, and a rinsing liquid (washing liquid) is supplied to a rinsing zone to a predetermined position by respective supply pipes 8a and 8b. The solid content in the slurry supplied from the slurry distribution port 5c to the separation zone is settled on the inner wall side of the large-diameter cylindrical portion 2c of the rotating bowl 2 under the centrifugal force. The sedimented solid is scooped up by the screw blade 5a of the screw conveyor 5 toward the frustoconical portion 2b, and is preliminarily held and washed in the washing liquid pool zone, and further provided with a plurality of filtration bushes f1, f2 and f3. It is conveyed to the inclined wall portion 2a on the small diameter end side. Here, the hold cleaning refers to cleaning while transporting the solid content in the cleaning liquid pool zone in the cleaning liquid pool zone by the screw conveyor 5. The solid matter suitably washed and drained by the action of the filtration bushes f1, f2, f3 described later on the inclined wall part 2a in the truncated conical part 2b is provided on the small diameter end side of the truncated conical part 2b. It is discharged from the minute discharge port 9 as a washing cake to the outside. On the other hand, the clarified liquid separated in the separation zone overflows the annular weir plate 3 through the clarified liquid discharge port 4 provided in the end plate 6 of the large-diameter cylindrical portion 2c of the rotary bowl 2, and is discharged outside as a separated liquid. Is done. When the filter bushes f1, f2, and f3 are closed, the rotation speed of the rotary bowl 2 is reduced, and the cleaning solution supply pipe BW1 for backwash provided opposite to the filtrate discharge side of the filter bushes f1, f2, and f3. , BW
2. It is possible to eliminate clogging by spraying a cleaning liquid from the BW 3 to back-wash the filter medium. By doing so, clogging of the filter medium can be reduced, and the operating time of the decanter centrifuge with a rinsing function can be extended.

The partition plate 10 shown in FIG. 1 is a plate member provided to separate the separation zone from the beach zone, and is provided in the washing liquid pool zone formed on the solids discharge port 9 side of the partition plate 10. This is for forming a liquid pool of the cleaning liquid and preliminarily holding and cleaning the solid content. here,
The hold washing refers to washing while transporting a solid content in the washing solution pooled in the washing solution pool zone by the screw conveyor 5.

Next, the structure and operation of the filter bushes f1, f2 and f3 according to the present invention will be described with reference to FIG. The filter bushes f1, f2, and f3 according to the present invention are provided on the inclined wall surface 2a on the small diameter end side of the truncated conical portion 2b of the rotary bowl 2, which is a rinse zone and a filtration zone of the decanter centrifuge 1 with a rinse function. A plurality of screw holes are provided in a plurality of rows, and a filter medium is loaded in a hollow portion of a bush, and a plurality of rows are screwed into the plurality of screw holes. The hollow portion of the bush is configured such that a filter medium is loaded on an upper portion and a space is secured on a lower portion in order to improve the drainage of the filtrate. The number of the filter bushes f1, f2, f3 varies greatly depending on the properties of the solid content, but is usually set to 6 to 18.

FIG. 2A shows filter bushes f1, f2,
FIG. 4 is a longitudinal sectional view showing the first embodiment of f3, in which a sintered metal SM manufactured by powder metallurgy is loaded on a support member ST1 (for example, a perforated plate) as a filter material in a hollow portion of a bush BS1. Depending on the properties of the processed material, not only the sintered metal SM but also a ceramic filter medium or a plastics filter medium can be used. Main filtration bush BH1
Is suitable for filtering a processed material having a small average particle diameter of solid content (for example, 5 to 20 micrometers) and poor filterability. SP1 is the inclined wall portion 2 of the truncated conical portion 2b.
This is a screw portion for screwing the main filtration bush BH1 to a.

FIG. 2 (b) shows the filter bushes f1, f2,
FIG. 6 is a longitudinal sectional view showing a second embodiment of f3, in which a filter cloth FC is loaded as a filter material into a hollow portion of a bush BS2 on a support member ST2 (for example, a stainless steel wire mesh). The present filtration bush BH2 is suitable for filtering a processed material having a relatively large average particle diameter of a relatively solid content (for example, 20 to 40 micrometers) and poor filterability.
SP2 is a screw portion for screwing the main filtration bush BH2 to the inclined wall surface portion 2a of the truncated conical portion 2b.

FIG. 2C shows filter bushes f1, f2 and f2.
FIG. 14 is a longitudinal sectional view showing a third embodiment of f3, on a support member ST3 (for example, a member having a hole made of ceramics), using a screen WS as a filter wire net as a filter material.
It is loaded in the hollow part of the bush BS3. The present filtration bush BH3 is suitable for filtering a processed material having a large average particle diameter of solid content (for example, 40 micrometers to several millimeters) and poor filterability. SP3 is provided on the inclined wall portion 2a of the truncated conical portion 2b by the main filtration bush BH3.
This is a screw part for screwing.

Next, the filter bushes f1, f according to the present invention will be described.
The operation of 2, f3 will be described with reference to FIG. The solids separated in the separation zone of the rotating bowl 2 and conveyed to the beach zone by the screw conveyor 5 are subjected to preliminary hold cleaning in the cleaning liquid pool zone, and then provided with the filter bushes f1, f2, f3 according to the present invention. It is conveyed to a rinsing zone and a filtration zone.

First, the solid content passes through a filter bush f3 provided in a rinse zone for countercurrent washing with a rinse liquid. Here, relatively easy-to-remove dirt on the solid content is washed and removed. From the filtration bush f3, a liquid after the cleaning treatment whose composition is substantially the same as that of an unused rinse liquid is mainly discharged as a filtrate.

Next, the solid content passes over a filter bush f2 provided below the rinse liquid distribution port 5d for showering the rinse liquid. Here, the cleaning effect of the solid content can be further improved by strongly cleaning the dirt that is difficult to remove solid content with a large amount of a showering liquid having kinetic energy.

During this time, the liquid after the washing treatment preferably flows out from the filtration bush f2 to the filtrate discharge side, so that the liquid after the washing treatment containing the dirt does not stay in the washing region of the solid content. Recontamination of the contaminants in the liquid after the cleaning process is reduced, and the solid content is always washed with a new rinsing liquid, so that the cleaning effect of the solid content is improved.

Further, the solid content is conveyed onto a filtration bush f1 provided in the filtration zone. Here, the liquid content contained in the solid content (for example, the void liquid wedge capillary liquid adhering liquid adsorbing liquid, etc.) in which the sufficient cleaning effect was obtained in the previous stage
Is a zone for mainly removing liquid, and a liquid component contained in the solid content is separated by centrifugal force, and the filtration bush f1
Since the liquid is immediately discharged to the outside through the liquid, the liquid is sufficiently removed even in a short time, and the liquid removing effect of the solid content is improved.

Since the washing property and the filtering property are different depending on the type of the stock slurry, a plurality of filtering bushes f1, f2 and f3 are provided on the inclined wall portion 2a from the beginning and a plurality of rows are provided. , F3, the washing state and the draining state can be controlled by the incorporation position and the number of the filter bushes f1, f2, f3. As a result, one stock decanter centrifuge with a rinsing function can process many types of stock solution slurries.

As described above, the frusto-conical portion 2 of the rotating bowl 2
b, the length of the beach zone is longer than the conventional length, and the cleaning solution pool zone, the rinsing zone, and the filtration zone are formed from the large-diameter end to the small-diameter end, and the inclined wall portion 2a of the rinsing zone and the filtration zone is formed. A plurality of filter bushes f1, f2, and f3 for promoting liquid removal, and a washing liquid supply pipe BW1, BW2, and BW3 for back-washing the filter medium facing the filtrate discharge side. It is possible to obtain not only an optimum washing effect and a dewatering effect, but also to extend the operation time of the decanter-type centrifuge with a rinsing function.

Next, a second embodiment of a decanter-type centrifuge with a rinsing function according to the present invention will be described with reference to FIG. Note that the same members as those of the decanter-type centrifugal separator with a rinsing function 1 of the first embodiment are denoted by the same reference numerals, and redundant description will be omitted. In the centrifugal separator 1 'with a rinsing function, the frusto-conical portion 2'b is reduced in diameter in two steps toward the solids discharge port 9 (a small frusto-conical portion 2'a and a large frusto-conical portion 2'b). 2'b). The second stage frusto-conical portion 2'a is configured as a rinsing zone and a filtration zone.

The frusto-conical portion of the rotating bowl is connected to the solids outlet 9
The diameter is reduced in two steps toward
a and a large frustoconical portion 2'b are connected to each other to lengthen the beach zone), and a rinse zone and a filtration zone are provided on the wall surface (inclined portion) of the second-stage frustoconical portion 2'a. As a result, the liquid after the washing treatment can be prevented from accompanying the solid content and going to the solid content outlet 9 side as compared with the case where the rinsing zone and the filtration zone are provided on the horizontal wall surface. As a result, the washing effect and the liquid removing effect of the solid can be improved.

Next, a third embodiment of a decanter type centrifuge with a rinsing function according to the present invention will be described with reference to FIG. Note that the same members as those of the decanter-type centrifugal separator with a rinsing function 1 of the first embodiment are denoted by the same reference numerals, and redundant description will be omitted. The centrifugal separator 1 ″ with a rinsing function has a small-diameter cylindrical portion 2 ″ a that has a part on the small-diameter end side of the truncated conical portion 2 ″ b toward the solids discharge port 9. The present invention is characterized in that the cylindrical portion 2''a is constituted as a rinsing zone and a filtration zone.

A small-diameter cylindrical portion 2 "a is provided at a part of the small-diameter end side of the truncated conical portion 2" b of the rotating bowl 2 "to extend the beach zone, and the small-diameter cylindrical portion 2" a is rinsed. By configuring the zone and the filtration zone, the washing time and the dewatering time can be prolonged. Therefore, compared with the conventional decanter centrifuge 100 with a rinsing function (see FIG. 7), the washing effect and the solid content can be improved. The drainage effect can be improved.

Next, a fourth embodiment of a decanter type centrifuge with a rinsing function according to the present invention will be described with reference to FIG. The same members as those of the decanter-type centrifuge 1 with a rinsing function of the first embodiment are denoted by the same reference numerals. The configuration of the decanter-type centrifuge with a rinsing function of the present invention is such that the shaft between the screw blades 5a of the screw conveyor 5 is fixed at a fixed distance from the inner wall of the rotary bowl 2 of the decanter-type centrifuge with rinsing function 1 of the first embodiment. In the center direction, a partition press plate 11 and a liquid removal press plate 1
2, at least one of which is erected.

The construction and operation of the partition press plate 11 and the liquid removal press plate 12 will be described with reference to FIG. The partition press plate 11 is a water-impermeable plate material for isolating the rinse zone of the beach zone and the cleaning liquid pool zone of the preceding stage. As shown in FIG. 6A, the screw conveyor 5 is fixed to a screw shaft 5b having a hollow portion with a bolt by bolts, and stands upright. The main body WM15 is made of a fine stainless steel wire mesh, and both corners RP are made of soft rubber.
Tip HC bent in the anti-rotation direction of screw shaft 5b
1 is subjected to a processing for increasing abrasion resistance.

When the partitioning press plate 11 is rotated integrally with the screw shaft 5b of the screw conveyor 5, the solids preliminarily held in the cleaning liquid pool zone are pressed by the main body WM15 of the partitioning press plate 11, and the undiluted slurry It is possible to reduce the amount of the liquid content accompanying the solid content. By doing so, the amount of rinsing liquid in the rinsing zone necessary for washing solids can be further reduced as compared with the decanter-type centrifuge 1 with a rinsing function of the first embodiment, so that the operating cost can be reduced. .

On the other hand, the dewatering press plate 12 is provided in the filtration zone, and is a water-permeable plate material for isolating the filtration zone from the preceding rinsing zone. As shown in FIG. 6 (b), the screw conveyor 5 is fixed to a screw shaft 5b having a hollow portion with a bolt by bolts, and stands upright. Body W
M50 is a coarse stainless steel wire mesh, and both corners PB are formed by press plates. The tip HC2 bent in the anti-rotation direction of the screw shaft 5b is subjected to a processing for edging to increase wear resistance. Have been.

The dewatering press plate 12 is a permeable plate material provided in the filtration zone. When the press plate 12 is rotated integrally with the screw shaft 5b of the screw conveyor 5, the solid content sufficiently cleaned of dirt in the rinse zone is: The liquid mesh which is squeezed by the wire mesh which is the main body WM50 of the dewatering press plate 12 and which accompanies the solid content can be suitably drained. By squeezing in this manner, in the filtration zone, only the liquid that is difficult to remove can be removed over time, so that the removal effect is improved.

According to the above configuration and operation, the screw conveyor 5 of the decanter centrifuge 1 with a rinsing function of the first embodiment and the inner wall of the rotary bowl 2 are spaced from the screw blade 5a of the screw conveyor 5 at a constant distance. By arranging at least one or more of the partition press plate 11 and the dewatering press plate 12 in the axial direction, the solid content is more washed than the decanter-type centrifuge 1 with a rinsing function of the first embodiment. The effect and the drainage effect can be improved.

As described above, the beach zone of the rotating bowl of the conventional decanter centrifuge with a rinsing function is lengthened, and the washing liquid pool zone and the rinsing zone are moved from the large-diameter end to the small-diameter end of the truncated cone. And a filtration zone,
By providing a plurality of filtration bushes for promoting liquid removal on the wall surface of the rinsing zone and the filtration zone, a rinse effect of solid content and a liquid removing effect are good, and equipment cost is low and a rinsing space is small. A decanter centrifuge with a function can be provided. Further, at least one or more partition press plates and dewatering press plates are provided upright in the axial direction between the screw blades of the screw conveyor and the screw conveyor at a fixed distance from the inner wall of the screw conveyor and the rotating bowl. A decanter-type centrifuge with a rinsing function can be provided which can further improve the washing effect and dewatering effect of solids than the decanter-type centrifuge with a rinsing function of the embodiment.

[0041]

According to the present invention having the above-described structure and operation, 1) a plurality of filter bushes for facilitating drainage are provided on the wall surface on the small diameter end side of the truncated conical portion of the rotating bowl; By improving the drainage of the washing liquid and the filtrate in the latter stage of the zone, the rinse liquid once used for washing passes through the filter medium as it is and almost immediately passes through the filter medium without remaining in the rotating bowl. The re-adhesion of dirt is eliminated. Therefore, the effect of washing solids is improved. 2) In addition, since the liquid component contained in the solid content is relatively easy to be drained, it is drained by the first-stage filtration bush. Can be liquid. Therefore, the drainage effect is also improved. 3) Therefore, a sufficient washing effect and dewatering effect can be obtained with only one centrifuge having a rinsing function, so that equipment such as a stirring tank and a reslurry pump, which were required in the past, becomes unnecessary, and equipment costs are reduced. Inexpensive, and installation space for equipment can be reduced. 4) In addition, a clogging period of the filter medium can be extended by providing a liquid supply pipe for back cleaning on the filtrate discharge side of the filter medium provided in the filter bush and performing reverse cleaning. As a result, the operating time of the decanter centrifuge with a rinsing function can be extended. 5) Furthermore, a partition press plate and a dewatering press plate at a position between the washing liquid pool zone and the rinsing zone, and a dewatering press plate at the position of the filtration zone, respectively, are provided between the screw blades of the screw conveyor at a fixed interval from the inner wall of the rotating bowl. By arranging at least one or more in the axial direction, the washing effect and the draining effect of the solid coming out of the solid outlet can be further improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a first embodiment of a decanter type centrifuge with a rinsing function according to the present invention.

FIG. 2 (a) is a longitudinal sectional view of a first embodiment of a filter bush according to the present invention. (B) It is a longitudinal section of a 2nd embodiment of a filtration bush concerning the present invention. (C) It is a longitudinal section of a 3rd embodiment of a filtration bush concerning the present invention.

FIG. 3 is a longitudinal sectional view of a second embodiment of a decanter-type centrifuge with a rinsing function according to the present invention.

FIG. 4 is a longitudinal sectional view of a third embodiment of a decanter-type centrifuge with a rinsing function according to the present invention.

FIG. 5 is a longitudinal sectional view of a decanter-type centrifuge with a rinsing function according to a fourth embodiment of the present invention.

FIG. 6 (a) is a perspective view of a partition press plate according to the present invention. (B) It is a perspective view of the press plate for drainage concerning this invention.

FIG. 7 is a longitudinal sectional view of a conventional decanter type centrifuge with a rinsing function.

[Explanation of symbols]

 Reference Signs List 1 Decanter centrifuge with rinsing function 2 Rotating bowl 2a Inclined wall 2b Truncated cone 2c Large diameter cylindrical part 3 Annular weir 4 Refined liquid discharge port 5 Screw conveyor 5a Screw blade 5b Screw shaft 5c Slurry distribution port 5d Rinse Liquid (washing liquid) distribution port 6 End plate 7 Injection hole 8 Liquid supply pipe 8a Undiluted slurry supply pipe 8b Rinse liquid (washing liquid) supply pipe 9 Solid content outlet 10 Partition wall plate 11 Partition press plate 12 Drain press plate f1 f3 Filtration bush BW1 to BW3 Cleaning liquid supply pipe for reverse cleaning

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Akiaki Tamura 2-1 Okawa-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture F-term (reference) 4D057 AA01 AA03 AB01 AC01 AC06 AD01 AE03 AF05 BA36

Claims (4)

[Claims] 1. A truncated cone portion having a solids discharge port at a small diameter end side, and a cylinder having a fining liquid discharge port connected to a large diameter end side of the truncated cone portion and provided with an annular weir plate at the other end. A rotating bowl comprising:
It consists of a screw conveyor rotating with a slight differential speed, the cylindrical portion is configured as a separation zone, the truncated cone portion is configured as a beach zone, and inserted into the shaft center portion from the insertion hole of the cylindrical portion end plate of the rotating bowl. A decanter-type centrifuge with a rinsing function, comprising: a raw liquid slurry supply pipe for supplying a raw liquid slurry to the separation zone; and a rinse liquid supply pipe inserted through the raw liquid slurry supply pipe and supplying a rinse liquid to the beach zone. In the machine, the beach zone is configured as a washing liquid pool zone, a rinsing zone and a filtration zone from the large-diameter end side of the truncated cone to the small-diameter end side; The filter bushing for accelerating liquid removal is provided, and a washing liquid supply pipe for back washing the filter medium is provided on the filtrate discharge side. Decanter-type centrifuge with rinsing function. 2. The truncated cone portion is reduced in diameter in two steps toward the solids discharge port, and the second-stage truncated cone portion is configured as the rinsing zone and the filtration zone. The decanter-type centrifuge with a rinsing function according to claim 1. 3. A part of the truncated conical part on the small diameter end side has a small diameter cylindrical part toward the solid content discharge port,
The decanter centrifuge with a rinsing function according to claim 1, wherein the small-diameter cylindrical portion is configured as the rinsing zone and the filtration zone. 4. A screw press plate at a position between the washing liquid pool zone and the rinsing zone, and a depressurizing press plate at a position of the filtration zone, and the screw at a fixed distance from the inner wall of the rotary bowl. The decanter-type centrifuge with a rinsing function according to claim 1, wherein at least one or more is set up in the axial direction between the screw blades of the conveyor.