JP2015080730A - Belt press - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a belt press which can executes high pressure dehydration at a travel distance of short filter cloth and is compact.SOLUTION: In the belt press, a pair of upper-lower filter cloths 2 and 2 are hooked around a large number of paralleled rolls so as to freely travel, and an undiluted solution is supplied between these filter cloths 2 and 2, and the filter cloth 2 wound-hooked on a central roll 1 is compressed by pressing by pressurizing filter cloth 13. In the belt press, the pressurizing filter cloth 13 wound-hooked on the central roll 1 from above the filter cloth 2, is regressed between the central roll 1 and the pressurizing filter cloth 13 by the other roll, and is again wound-hooked on the central roll 1, and thereby, the pressurizing filter cloth 13 is wound-hooked in a plurality of times on the central roll 1, and compression force is enhanced by imparting pressing force of the pressurizing filter cloth 13 in the central roll 1 direction. By the belt press, the high pressure dehydration can be executed, and a device itself can also be made compact without requiring to make the filter cloth travel for a long period.

Description

The present invention relates to a belt press that uses the tension of a filter cloth as a pressing force of a pressure mechanism and hangs the pressure filter cloth around a central roll a plurality of times to increase the pressing force and perform high pressure dehydration.

Conventionally, belt presses that spin a filter cloth around a roll and dewater it are a type in which a large number of rolls are arranged in rows and columns, and a filter cloth is hung around a roll with a large diameter. There are those with a pressure device that is pressed by a pressure roll.
In Patent Document 1, a filter cloth hung around a center roll is folded back, and a pressure roll is interposed between the filter cloth and the center roll again. A belt press that performs the adjustment is disclosed.

JP 57-184500 A

A conventional belt press has a large number of rolls in order to perform dehydration by the shearing force, surface pressure, and filter cloth tension of the roll winding part. Further, in order to ensure the dehydration time, it is necessary to increase the number of rolls and increase the length of the filter cloth, and the size of the apparatus is also increased. A pressurizing device such as a pressurizing belt becomes complicated, and the maintenance cost and consumables cost including the price become expensive. Also, the filtration performance was not sufficient with the conventional belt press because the pressure was small.

The belt press disclosed in Patent Document 1 is dehydrated by sandwiching sludge between one filter cloth and a roll, and is dehydrated only at a portion in contact with the main roll. Accordingly, when the sheet is folded back from the final stage pressure roll, the cake can only be discharged due to the mechanism of the apparatus. The dehydration time is a short time because the filter cloth is in contact with the roll, and sufficient dehydration cannot be performed.
At the time of squeezing, since the pressure suddenly increases from the place where the pressure roll comes into contact, high pressure squeezing is applied to the sludge having a high water content, and a side leak occurs. Therefore, ideal dehydration that gradually dehydrates cannot be performed.

In the belt press that squeezes a pair of upper and lower filter cloths so that they can run freely on a large number of parallel rolls, supplies the stock solution between the filter cloths, and presses and compresses the filter cloth wound around the center roll with a pressure filter cloth. The pressure filter cloth wound around the center roll from the top of the filter cloth is returned between the center roll and the pressure filter cloth with another roll, and wound around the center roll again, so that multiple pressure filter cloths are wound around the center roll. In order to increase the squeezing force by applying the pressing force of the pressure filter cloth in the center roll direction, it is not necessary to arrange many rolls and lengthen the dehydration period, and the apparatus can be made compact.

A plurality of indirect rolls are arranged between the pressure filter cloths wound around the center roll a plurality of times, and the indirect rolls can be separated from the circumferential surface of the center roll, so that A pressing force is applied by the pressure filter cloth, and the pressure applied to the filter cloth in contact with the center roll can be adjusted by the arrangement position of the indirect roll.

The plurality of indirect rolls can gradually increase the pressure applied to the filter cloth in contact with the indirect rolls by gradually increasing the arrangement interval and the roll diameter toward the discharge portion.

A plurality of reduced pressure rolls are disposed in contact with the central roll, and a filter cloth is wound around the central roll via the reduced pressure roll, and the reduced pressure roll is not disposed on the moving shaft of the adjacent indirect roll. The pressing force applied from the indirect roll can be reduced, and the pressing pressure can be adjusted.

By not disposing the indirect roll on the moving shaft of the indirect roll in the adjacent stage, it is possible to reduce the variation in pressure applied to the filter cloth wound around a plurality of stages.

The indirect roll is supported by a frame erected on both ends of the center roll, and the frame moves in a radial pattern of the center roll by providing a support hole through which the indirect roll can be inserted and moved. Supports freely.

Since the indirect material is radially movable from the center of the center roll to the filter cloth that is in contact with the center roll, a pressing force is applied by the pressure filter cloth wound around the indirect material. In the same manner, by applying the pressure filter cloth that has been returned to the center roll many times, the pressing force applied to the filter cloth that is in contact with the center roll is equal to the number of pressure filter cloths that have been wound. Can do. Therefore, since the filter cloth wrapped around the outside gives a pressing force to the pressure filter cloth wrapped around the inside, the pressure gradually increases from the outside to the inside, and the filter cloth wound around the center roll is Squeezed at the highest pressure. If the section where the pressure filter cloth overlaps is arbitrarily set and a large number of pressure filter cloths overlap in the latter stage of dewatering, the pressure gradually increases, so that side leak does not occur and ideal dewatering can be performed.

Since the filter cloth wound around the center roll is pressed with a high pressure by the pressure filter cloth, it is not necessary to secure a dehydration time by arranging a number of other rolls. Therefore, the device becomes compact and the filter cloth becomes short.

Since an indirect material that reduces the friction between the pressure filter cloths is placed between the pressure filter cloth hung around the center roll and the pressure filter cloth hung around the other rolls, the pressure filter The cloth runs smoothly.
By changing the size and arrangement position of the indirect material, the pressure at a predetermined position can be freely adjusted.

A pair of filter cloths for filtration do not apply high tension, so filter cloths with low strength can be used, and fine filter cloths with small fiber diameters can prevent high-pressure dehydration. .
Since a high pressure is obtained by applying the pressure filter cloth a plurality of times, there is no need to provide a hydraulic device or a special high-pressure belt as the pressure mechanism.

It is a schematic side view of the belt press which applied the pressure filter cloth concerning this invention twice. Similarly, it is the principal part side view of the belt press which applied the pressure filter cloth twice. Similarly, it is the principal part side view of the pressure gradual increase type belt press which applied the pressure filter cloth twice. Similarly, it is the principal part side view of the low-pressure specification type belt press which applied the pressure filter cloth twice. Similarly, it is the principal part enlarged view of the low-pressure specification type belt press which applied the pressure filter cloth twice. Similarly, it is the principal part side view of the low pressure gradual increase specification type belt press which applied the pressure filter cloth twice. Similarly, it is the schematic side view of the belt press which applied the pressure filter cloth in quadruplicate. Similarly, it is the principal part side view of the belt press which applied the pressure filter cloth in quadruplicate. Similarly, it is the principal part side view of the low-pressure specification type belt press which applied the pressure filter cloth 4 times. Similarly, it is a side view of the frame which supports the indirect material of a belt press.

≪Belt press≫
The belt press of the present invention includes a pair of upper and lower filter cloths, a pressure filter cloth that presses the filter cloth, a plurality of rolls that endlessly stretch the filter cloth and the pressure filter cloth, and a frame that supports them. It is comprised and dewaters sludge between a pair of filter cloths. It is equipped with a mechanism that allows dehydration while applying high pressure by applying a pressure filter cloth to the center roll multiple times. An indirect material that reduces friction between the pressure filter cloths is disposed between the pressure filter cloths that have been wound around a plurality of times. The indirect material is movable radially from the center of the center roll, and transmits the tension of the pressure filter cloth wound around the indirect material to the inner filter cloth to apply pressure. Press the filter cloth while running along the rotation direction of the center roll, and run the pressure filter cloth from the pressure filter cloth wrapped around the indirect material to the pressure filter cloth in contact with the filter cloth. Perform dehydration.

≪Double pressure filter cloth≫
FIG. 1 is a schematic side view of a belt press in which a pressure filter cloth according to the present invention is doubled.
The belt press in which the pressure filter cloth 13 is applied to the center roll 1 in a double manner includes a stock solution supply unit 3 for supplying sludge, a pair of upper and lower endless filter cloths 2 and 2 for dewatering the sludge, and a filter cloth 2. The pressure filter cloth 13 that presses the filter cloth, the center roll 1 that hangs around the filter cloth 2, the shear roll 4 that guides the filter cloth 2 to the center roll 1, and the guide roll that guides the filter cloth 2 and the pressure filter cloth 13 14, a plurality of indirect members 6 disposed between the pressure filter cloths 13 that run on the filter cloth 2 that is hung around the center roll 1 in a double-opposed manner, and a drive that drives the filter cloth 2. It comprises rolls 7 and 7, a discharge part 8 that discharges sludge, and a tension roll 9 that adjusts the tension of the filter cloth 2 and the pressure filter cloth 13.
A known filter cloth tensioning device can be used to adjust the tension.

The plurality of indirect members 6 are arranged at an equal distance from the center roll 1 and are arranged so as to be movable radially from the center of the center roll 1. After the pressure filter cloth 13 is wound from the outside of the indirect member 6, the pressure filter cloth 13 is continuously wound around the shear roll 4 from under the filter cloth 2, and is returned to the center roll 1 along the filter cloth 2. The pressure filter cloth 2 is wound around the center roll 1 through the indirect material 6 by winding the recirculated pressure filter cloth 13 so as to pass through the inside of the indirect material 6 and contact the filter cloth 2 on the center roll 1. It becomes the structure wound twice.

≪Indirect material≫
As the indirect member 6, a known technique that can reduce friction between the pressure filter cloths 2 can be adopted, and a rotatable cylindrical roll is used here. Hereinafter, the roll used as the indirect material 6 is referred to as an indirect roll 6. Since the rotation direction of the indirect roll 6 coincides with the traveling direction of the pressure filter cloth 2, the friction of the pressure filter cloths 13 and 13 is greatly reduced. Further, the filtrate may be discharged from the gap between the pressure filter cloths 13, 13 configured by the indirect roll 6, and it is preferable to use a plurality of rolls as the indirect roll 6. The indirect roll 6 is disposed so as to be movable radially from the center of the center roll 1. Therefore, pressure is applied to the filter cloth 2 that is in contact with the center roll 1 via the indirect roll 6 due to the tension of the pressure filter cloth 13 that travels outside the indirect roll 6. Accordingly, since the filter cloth 2 in contact with the center roll 1 is also subjected to linear pressure due to the pressing force of the indirect roll 6 in addition to the surface pressure of the center roll 1 and the pressing force of the pressurized filter cloth 13, high pressure dehydration is performed. Is called.
In the present invention, the moving direction of the indirect roll 6 is a radial shape. However, the moving direction may be a radial curve shape, a parallel shape, or the like as long as the indirect roll 6 can be separated from the circumferential surface of the center roll 1. Such a moving direction may be used.

A plurality of indirect rolls 6 are arranged with small diameters at narrow intervals so that the linear pressure by the indirect roll 6 is continuously applied, and the pressure applied to the filter cloth 2 in contact with the center roll 1 is made uniform. be able to. If a large number of indirect rolls 6 are arranged in the circumferential direction and the section in contact with the pressure filter cloth 13 is lengthened, it is possible to squeeze for a long time. Thus, the size of the indirect roll 6, the arrangement interval, and the like can be appropriately changed according to the treatment sludge.

Moreover, since the indirect roll 6 is movable, workability | operativity at the time of winding the pressure filter cloth 13 around each roll is good. Although the movement of the indirect roll 6 is limited by the supporting frame 10, the effect of the present invention can be obtained by supporting the filter cloth 2, the pressure filter cloth 13, and the sludge to be supplied so as to move.

In addition, a resin sheet having a low frictional resistance can be used as the indirect member 6. A resin sheet is disposed between the pressure filter cloths 13 and 13, and the pressure filter cloth 13 is caused to run by sliding on the resin sheet. Since the resin sheet applies pressure across the filter cloth 2 that is in contact with the center roll 1, more uniform dehydration can be performed.
≪Details of double-hanging≫

FIG. 2 is a side view of an essential part of a belt press in which a pressure filter cloth according to the present invention is doubled.
The belt press of the present invention is subjected to four stages of dewatering: a concentration process A, a shearing process B, a pressing process C, and a pressing process D.

In the concentration step A, the sludge supplied from the supply unit is concentrated between the pair of filter cloths 2 and 2 whose intervals are gradually reduced. Since the pair of filter cloths 2 and 2 asymptotically approach the shear roll 4, even sludge having high fluidity is gradually filtered.

In the shearing process B, the pair of filter cloths 2 and 2 are wound around the shear roll 4 to dehydrate sludge. The shear roll 4 applies surface pressure to the filter cloth 2. Further, in the pair of filter cloths 2, 2 wound around the shear roll 4, shearing force is generated inside because the traveling speed of the inner filter cloth 2 is high. Accordingly, in the shearing process B, the surface pressure by the shear roll 4 and the shearing force of the filter cloth 2 are applied, and the sludge liquid is discharged to the outside through the filter cloth 2.
The diameter of the shear roll 4 is appropriately set according to the moisture content and sludge properties necessary for the subsequent pressing step.

In the pressurizing step C, the filter cloth 2 is wound around the center roll 1, and the pressure filter cloth 13 presses the filter cloth 2 to dehydrate it. Similar to the surface pressure applied from the center roll 1 and the shearing step B, a shearing force is applied to the filter cloth 2. Further, since the pressure filter cloth 13 is in contact with and pressed against the filter cloth 2, the pressing force by the pressure filter cloth 13 is also applied to perform dehydration.

In the pressing step D, the pressure filter cloth 13 that presses the filter cloth 2 and the pressure filter cloth 13 that wraps around the indirect roll 6 and applies a pressing force in the direction of the center roll 1 are pressed.
Here, as in the pressurizing step C, the surface pressure from the center roll 1, the shearing force, and the pressure by the pressurizing filter cloth 13 are applied. Furthermore, since the tension of the pressure filter cloth 13 wound around the indirect roll 6 presses the indirect roll 6 toward the center roll 1, linear pressure by the indirect roll 6 is also applied. Therefore, the pressing process D is subjected to the highest pressure among the processes described above and is dehydrated.

The dehydrated cake that has passed through the pressing step D is discharged at the discharge unit 8.
When the diameter of the shear roll 4 is increased, the periods of the shearing process B and the pressing process C are lengthened, and the period of the pressing process D can be shortened. The diameter of the shearing roll 4 is appropriately set according to the sludge properties. To do.

≪Double-gradual incremental specification≫
In FIG. 1, the indirect members 6 are arranged at equal intervals as indirect rolls 6 having the same size, but by changing the configuration of the indirect members 6, it is possible to operate according to the purpose.
FIG. 3 is a side view of an essential part of a pressure gradual increase type belt press in which a pressure filter cloth according to the present invention is doubled.
In the pressure-increase-type belt press, the filtration pressure is gradually increased by the configuration of the indirect roll 6.
As the squeezing action proceeds in the final stage of the squeezing step D, the indirect roll 6 to be used is arranged so that the diameter of the roll and the interval between the rolls increase stepwise.
Specifically, the indirect roll 6 that first comes into contact with the pressure filter cloth 13 in the pressing step D is the smallest indirect roll 6 and is directed toward the discharge unit 8 so as to be the largest indirect roll 6 on the discharge side of the dehydrated cake. The diameter of the indirect roll 6 is gradually increased, and the distance between the indirect rolls 6 is increased accordingly.

In the concentration step A, the shearing step B, and the pressurizing step C of the pressure gradual increase type belt press in which the pressure filter cloth 13 is doubled, dehydration is performed in the same manner as in a normal double hung belt press.
In the pressing step D, the indirect roll 6 having a small diameter is disposed between the pressure filter cloths 13, and the indirect roll 6 that is gradually increased toward the discharge side of the dehydrated cake is disposed.

When the indirect roll 6 applies pressure to the filter cloth 2 in contact with the center roll 1, the pressure applied varies depending on the diameter of the indirect roll 6 and the arrangement interval. When the small-diameter indirect rolls 6 are arranged at a narrow interval, the wrapping angle of the pressure filter cloth 13 wound around one indirect roll 6 is increased. When the winding angle is large, the pressing force in the direction of the center roll 1 is reduced, and therefore the linear pressure applied to the filter cloth 2 in which the indirect roll 6 is in contact with the center roll 1 is reduced. Conversely, when large-diameter indirect rolls 6 are arranged at wide intervals, the wrapping angle of the pressure filter cloth 13 wound around one indirect roll 6 is small, and the pressing force in the direction of the center roll 1 is large. Therefore, the linear pressure applied to the filter cloth 2 with which the large indirect roll 6 is in contact with the center roll 1 is increased.

From these facts, the filter cloth 2 sandwiched between the center roll 1 and the indirect roll 6 is disposed most on the sludge discharge side by arranging the diameter and interval of the indirect roll 6 to gradually increase toward the discharge side. You will receive a large linear pressure.

≪Double hanging low pressure specifications≫
FIG. 4 is a side view of a main part of a low-pressure specification type belt press in which a pressure filter cloth according to the present invention is doubled.
The low-pressure specification type belt press has a plurality of pressure-reducing rolls 11 rotatably arranged between the center roll 1 and the filter cloth 2 in contact with the center roll 1 without changing the size of the indirect roll 6. is there.
The decompression roll 11 and the indirect roll 6 are arranged in a staggered manner, and the decompression roll 11 is not arranged on the moving shaft of the indirect roll 6.
In this embodiment, the pressure reducing rolls 11 and the indirect rolls 6 are arranged in a staggered manner, but if the pressure reducing rolls 11 are not arranged on the moving shafts of the adjacent indirect rolls 6, the pressing force of the indirect roll 6 is increased. Since the decompression effect of dispersing is obtained, the position of the decompression roll 11 is appropriately set depending on the sludge properties.

FIG. 5 is an enlarged view of a main part of a low-pressure specification type belt press in which a pressure filter cloth according to the present invention is doubled.
Unlike the structure of an ordinary double belt press, the pressure reducing roll 11 is disposed on the center roll 1 so that the filter cloth 2 does not contact the center roll 1. Since the indirect roll 6 is arranged in a zigzag manner with the decompression roll 11, the pressing force transmitted from the indirect roll 6 is dispersed, and a strong linear pressure is not applied to the filter cloth 2.
Accordingly, the filter cloth 2 and the pressure filter cloth 13 are alternately brought into contact with the pressure reducing roll 11 and the indirect roll 6 in the pressing step D, and are pressed while being applied with a surface pressure.
By disposing the decompression roll 11 in this way, low-pressure dehydration is also possible, and the operation of the belt press can be changed by the treated sludge.

≪Double hanging low pressure gradually increasing specification≫
FIG. 6 is a side view of a main part of a low-pressure incremental specification type belt press in which the pressure filter cloth according to the present invention is doubled.
FIG. 6 is a combination of the gradually increasing pressure specification (FIG. 3) and the low pressure specification (FIG. 4). A plurality of vacuum rolls 11 are disposed between the center roll 1 and the filter cloth 2 that is in contact with the center roll 1, and the indirect roll 6 that is in contact with the pressure filter cloth 13 in the pressing step D is the diameter and the spacing of the rolls. Are arranged so as to be gradually increased.

Between the filter cloth 2 and the center roll 1, a plurality of reduced pressure rolls 11 are disposed. Further, the decompression roll 11 and the indirect roll 6 are arranged in a staggered manner, and are shifted from each other on the moving shaft. Accordingly, since the interval between the indirect rolls 6 is gradually increased in the pressing step D, the interval between the pressure reducing rolls 11 that are in contact with the filter cloth 2 is also gradually increased.

In the pressing step D, the filter cloth 2 and the pressure filter cloth 13 are alternately brought into contact with the pressure reducing roll 11 and the indirect roll 6 to apply a surface pressure. Although the pressing force of the indirect roll 6 is dispersed by the decompression roll 11, the indirect roll 6 gradually increases, so the pressing force of the indirect roll 6 increases stepwise.
Accordingly, although the pressure is gradually lower than the gradually increasing pressure specification by the pressure reducing roll 11, dehydration in which the pressure gradually increases can be performed as in the gradually increasing pressure specification.

≪Four-folding≫
FIG. 7 is a schematic side view of a belt press in which four pressure filter cloths according to the present invention are hung.
The belt press that hangs the pressure filter cloths 13 on the center roll 1 in four layers includes a sludge supply unit 3 that supplies sludge, a pair of upper and lower endless filter cloths 2 and 2 that dehydrate the sludge, and a filter cloth 2. A pressure filter cloth 13 that presses the pressure filter cloth, a center roll 1 that wraps the pressure filter cloth 13 four times, a shear roll 4 that guides the filter cloth 2 and the pressure filter cloth 13 to the center roll 1, and a pressure filter cloth An indirect material disposed between the first roll 5a and the second roll 5b that are wound around the center roll 1 so as to return to the center roll 1 and the pressure filter cloth 13 that runs on the center roll 1 in a quadruple manner. 6, drive rolls 7 and 7 that drive the filter cloth 2, a discharge unit 8 that discharges sludge, and a tension roll 9 that adjusts the tension of the filter cloth 2 and the pressure filter cloth 13. Hereinafter, the indirect material 6 uses the indirect roll 6 in the same manner as the double hanger.

The indirect roll 6 is composed of three stages along the periphery of the center roll 1, and the first stage from the outside is the indirect roll 6a, the second stage is the indirect roll 6b, and the third stage is the indirect roll 6c.
First, the pressure filter cloth 13 is wound around an indirect roll 6 a disposed around the center roll 1. The pressure filter cloth 13 wound around the indirect roll 6a is continuously wound around the first roll 5a. The pressure filter cloth 13 wound around the first roll 5a is returned to the center roll 1 direction and wound around the indirect roll 6b disposed inside the indirect roll 6a. At this time, the pressure filter cloth 13 is caused to travel so as to pass through the center roll 1 side of the indirect roll 6a.
Similarly, after the pressure filter cloth 13 wound around the indirect roll 6b is wound around the second roll 5b and returned, it is wound around the indirect roll 6c disposed inside the indirect roll 6b. Here too, the pressure filter cloth 13 travels so as to pass through the center roll 1 side of the indirect roll 6b, and the pressure filter cloth 13 travels so as to be sandwiched between the indirect roll 6b and the indirect roll 6c.
Then, the pressure filter cloth 13 wound around the indirect roll 6 c is wound around the shear roll 4 from under the filter cloth 2 and wound around the center roll 1 along the filter cloth 2. The pressure filter cloth 13 wound around the center roll 1 is caused to travel so as to pass through the center roll 1 side of the indirect roll 6c, and the pressure filter cloth 13 is sandwiched between the indirect roll 6c and the filter cloth 2 wound around the center roll 1. Let it run.
The pressure filter cloth 13 that travels along the pair of filter cloths 2 and 2 in contact with the center roll 1 is separated from the filter cloth 2 by the cake discharge portion 8 and travels endlessly via the guide roll 14.

Since the indirect rolls 6a, 6b, 6c are arranged so as to be radially movable from the center of the central roll 1, when the pressurized filter cloth 13 is run, the tension of the pressurized filter cloth 13 is indirect rolls, respectively. The pressing force is transmitted to the pressure filter cloth 13 traveling on the center roll 1 side via 6a, 6b, 6c.

As the indirect member 6, the same material as a double belt press can be used. When the indirect roll 6 is used, the indirect rolls 6a, 6b, and 6c at each stage are arranged in a staggered manner in order to continuously apply the surface pressure by the rolls.
In addition, if the moving axes of the indirect rolls 6a, 6b, 6c in each stage are on the same line, it is possible to apply a linear pressure to the pressure filter cloth 13 between the indirect rolls 6, and a strong pressure can be applied.

The pressure filter cloth 13 traveling around the center roll 1 travels from the outer pressure filter cloth 13 wound around the indirect rolls 6a, 6b, and 6c toward the pressure filter cloth 13 on the center roll 1 side. . Since the outer pressure filter cloth 13 applies a pressing force to the inner pressure filter cloth 13 via the indirect rolls 6a, 6b, and 6c, the outer pressure filter cloth 13 approaches the pressure filter cloth 13 on the center roll 1 side. The pressing force of the filter cloth 13 is applied and a high pressure is applied. Therefore, if the section where the pressure filter cloths 13 overlap is shifted so that all the pressure filter cloths 13 overlap in the latter stage of dehydration, the pressure will be dehydrated gradually from a low pressure to a high pressure. There is no side leak that occurs when it is applied, and appropriate dehydration can be performed.

≪Four-fold details≫
FIG. 8 is a side view of an essential part of a belt press in which four pressure filter cloths according to the present invention are hung.
A pair of filter cloths 2 and 2 hung around the center roll 1 of the quadruple belt press of the present invention are concentrated step A, shearing step B, pressurizing step C, and pressing step D, similarly to the double belt press. It comprises. These filter cloths 2 are configured by overlapping a pair of endless filter cloths 2, 2, and sludge is supplied between the filter cloths 2, 2.

In the belt press concentration process A, shearing process B, and pressurizing process C in which the pressure filter cloth is applied in quadruplicate, dehydration is performed in the same manner as in a normal double applied belt press.

Unlike the belt press which folds the pressure filter cloth 13 in quadruple, the squeezing step D has three steps, ie, squeezing steps D1, D2 and D3.

The pressing process D is a pressing process D1 from a place where the pressure filter cloth 13 is wound around the indirect roll 6c, and is similarly wound around the pressing process D2 and the indirect roll 6a from a place wound around the indirect roll 6b. Let's say from a certain place is pressing process D3.

In the pressing step D1, the pressing force of the pressure filter cloth 13 in contact with the filter cloth 2 is applied, and the pressing force of the pressure filter cloth 13 wound around the indirect roll 6c in a place where the indirect roll 6c contacts. However, it adds via the indirect roll 6c. Therefore, squeezing at a higher pressure than the pressurizing step C is performed. The section of the pressing step D1 can be appropriately set depending on the diameter of the shear roll and the arrangement position of the first roll 5a.

In the pressing step D2, in addition to the pressing force applied to the filter cloth 2 in the pressing step D1, the pressing force of the pressure filter cloth 13 wound around the indirect roll 6b is applied. Therefore, higher pressure is applied to the filter cloth 2 than in the pressing step D1. The section of the pressing step D2 can be set according to the diameter and arrangement position of the first roll 5a.

In the pressing step D3, in addition to the pressing force applied to the filter cloth 2 in the pressing steps D1 and D2, the pressing force of the pressure filter cloth 13 wound around the indirect roll 6a is applied. Therefore, the pressure higher than the pressing process D2 is applied to the filter cloth 2, and the highest pressure is applied in the pressing process D. That is, in the pressing step D, the pressing force gradually increases in the order of D1, D2, and D3. The section of the pressing step D3 can be set depending on the diameter and arrangement position of the first roll 5a.

≪4-fold pressure reduction≫
FIG. 9 is a side view of a main part of a low-pressure specification belt press in which pressure filter cloths according to the present invention are quadrupled.
The belt press that wraps the pressure filter cloth 13 in a quadruple manner around the center roll 1 can have a low-pressure configuration like the double belt press. A plurality of decompression rolls 11... Are disposed between the center roll 1 and the filter cloth 2 that has been in contact with the center roll 1.
The decompression roll 11 is in contact with the center roll 1 in a rotatable manner, and the filter cloth 2 is wound around the center roll 1 via the decompression roll 11.

The decompression rolls 11 and the indirect rolls 6 are arranged in a staggered manner. Thereby, a strong linear pressure that directly sandwiches the filter cloth 2 and the pressure filter cloth 13 between the decompression roll 11 and the indirect roll 6 is not applied.
The filter cloth 2 wound around the pressure reducing roll 11 receives a pressing force by the indirect roll 6, but the filter cloth 2 and the pressure filter cloth 13 are alternately in contact with the pressure reducing roll 11 and the indirect roll 6 to apply a surface pressure. . Since the pressing force is dispersed by the pressure reducing roll 11, the pressing pressure is lower than that of a normal quadruple belt press.

By disposing the decompression roll 11 in this way, low-pressure dehydration is also possible, and the operation of the belt press can be changed to an appropriate one by the treated sludge.
Further, although the belt press of this embodiment has the pressure filter cloth 13 doubled and quadruple, it is also possible to take a form in which it is wrapped in multiples of triples, quadruples or more.

≪Frame≫
FIG. 10 is a side view of a frame that supports the indirect member of the belt press according to the present invention.
The frame 10 is erected on the left and right sides of the center roll 1, and the indirect member 6, here the indirect roll 6, is disposed in the movable range of the indirect member 6 so that it can move radially from the center of the center roll 1. The frame 10 has a radial support hole 12 for inserting and supporting the indirect member 6. The indirect member 6 can be inserted through the frame 10 and further supported in a radial manner from the center of the center roll 1.

Although not shown, in the other belt press forms, the indirect member 6 can be supported by forming the corresponding support holes 12 in the frame 10, so that the same frame 10 can be used. It can also be used as a frame for supporting the decompression roll 11.

A protective plate may be provided on the frame 10 so that the indirect member 6 does not move in the axial direction. By disposing a protective plate outside the frame 10 during the operation of the belt press, it is possible to prevent the indirect member 6 from shifting to the left and right due to meandering of the filter cloth 2 and to fall from the support hole 12. Moreover, by making the protective plate detachable, the indirect member 6 can be easily attached and detached if it is removed during maintenance. If a transparent material such as acrylic glass is used, a number of problems with the indirect material 6 can be found during the belt press operation.
The frame 10 may be anything as long as it can support the indirect member 6. However, in the embodiment, the frame 10 is flat and has an opening around the shaft of the center roll 1, so that maintenance work and the like are performed. Sex is getting better.

By supporting the indirect member 6 with such a frame 10, the pressing force from the outside by the filter cloth 2 can be transmitted in the direction of the center roll 1.
Further, in the present embodiment, the support holes 12 are formed in a radial shape, but the support holes 12 can be supported so as to be detachable from the circumferential surface of the center roll 1 such as a radial curve shape or a parallel shape. Any support hole 12 may be used.

The belt press according to the present invention applies the filter cloth wound around the center roll by pressing the pressure filter cloth that has been wound around the center roll a plurality of times. It is a belt press to press. A high dewatering pressure is obtained for the filter cloth by applying the pressure filter cloth to the center roll many times. Further, since the dehydration time can be secured with a small number of rolls, the apparatus can be made compact. Since the number of rolls may be small, the length of the filter cloth is shorter than before, the consumables cost is suppressed, and the dehydrator is suitable for sludge treatment for high-pressure squeezing.

1 center roll 2 filter cloth 6 indirect roll 8 discharge part 10 frame 12 support hole 13 pressure filter cloth

Claims (6)

A pair of upper and lower filter cloths (2, 2) are hung around a plurality of parallel rolls so that they can run freely. The stock solution is supplied between the filter cloths (2, 2) and the filter cloth (2) wound around the center roll (1). In a belt press that presses and compresses a pressure filter cloth (13),
The pressure filter cloth (13) wound around the center roll (1) from the top of the filter cloth (2) is returned between the center roll (1) and the pressure filter cloth (13) with another roll, and is again centered. The pressure filter cloth (13) is wound around the center roll (1) a plurality of times by being wound around the roll (1), and the pressing force of the pressure filter cloth (13) is applied in the direction of the center roll (1) and compressed. Belt press characterized by increasing power. A plurality of indirect rolls (6 ...) are disposed between the pressure filter cloths (13) wound around the center roll (1) a plurality of times,
The belt press according to claim 1, wherein the indirect roll (6) is detachable from the circumferential surface of the center roll (1). 3. The belt press according to claim 2, wherein the plurality of indirect rolls (6...) Gradually increase in arrangement interval and roll diameter toward the discharge portion (8). A plurality of vacuum rolls (11...) Are disposed in contact with the central roll (1), and a filter cloth (2) is wound around the central roll (1) via the vacuum roll (11). The belt press according to claim 2 or 3, wherein the roll (11) is not disposed on the moving shaft of the indirect roll (6) in the adjacent stage. The belt press according to any one of claims 2 to 4, wherein the indirect roll (6) is not disposed on a moving shaft of an indirect roll (6) in an adjacent stage. The indirect roll (8) is supported by a frame (10) erected on both ends of the center roll (1), and the frame (10) supports the indirect roll (6) so that it can be inserted and moved. The belt press according to any one of claims 2 to 5, wherein 12) is provided.

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