KR102076278B1 - Belt press with circulating filter fabric and Sludge dewatering device having the same - Google Patents

Abstract

The present invention relates to a belt press having a closed circulation filter cloth and a sludge dewatering apparatus having the same. The belt press, a plurality of pressure rollers and idle rollers arranged in parallel with each other; The first filter cloth and the first filter cloth having a predetermined width and thickness to press and dewater the sludge that is in close contact with each other while passing through the pressure roller while circulating along the path while being supported by the pressure roller and the idle roller And two filtration cloths, and first and second filtration cloths positioned at both ends in the width direction of the first and second filter cloth sheets and having blocking means for preventing the sludge from flowing outward in the width direction.
The belt press provided with the closed circulation filter cloth of the present invention made as described above stably maintains the sludge introduced between the two layers of the filter cloth inside the filter cloth, so that the amount of flocculant can be limited to a minimum, and thus the treatment efficiency is excellent. It also reduces costs.

Description

Belt press with closed circulation filter cloth and Sludge dewatering device having the same

The present invention relates to a sludge dewatering device employing a belt press and a belt press, and more particularly, has a structure capable of minimizing the amount of flocculant used because there is no loss of compressed sludge and thus a closed circulation filter cloth having excellent processing efficiency. It relates to a belt press provided and a sludge dewatering device having the same.

Since a large amount of sludge generated in the treatment of industrial wastewater, livestock wastewater or sewage or manure is itself a pollutant that can greatly pollute the environment, various methods and apparatuses for efficiently treating the same have been developed. The apparatus includes a centrifuge, a filter press, or a belt press that lowers the water content of the sludge to make it cake, thereby allowing the sludge to be embedded or incinerated.

The filter press is a device configured to separate solid and liquid by injecting sludge at a high pressure between a plurality of filter plates on which the filter cloth is mounted. The filtrate, which is a liquid, is drained out of the filter plate during the compression process, and the solid cake remains between the filter plates. The dehydrated cake is dropped and discharged downward by its own weight when the filter plate is separated.

In addition, the belt press has a structure in which sludge is introduced between two layers of filter cloths circulating along a plurality of pressure rollers, and the sludge is compressed between the filter cloths while the sludge is circulated. Compared to the filter press, it uses less power and can be processed continuously.

In the belt press, the nature and form of the sludge have a great influence on the treatment efficiency. For example, if the sludge is too low in viscosity due to poor coagulation, the phenomenon of leaking in the lateral direction of the filter cloth occurs. On the contrary, if the viscosity is high, the dewatering efficiency may decrease and the sludge may not be easily dropped from the filter cloth.

If the sludge viscosity is as low as possible and there is no leakage of the filter cloth in the lateral direction, then the treatment efficiency is good. However, the conventional belt press does not have an appropriate structure that can prevent the leakage of sludge, and had to mix and stir a large amount of flocculant before introducing the sludge into the machine. The use of flocculants leads to problems associated with the cost of treatment.

Korean Registered Patent Publication No. 10-0991040 (filtration method of filtration cloth belt filter and toner particles) Korean Patent Publication No. 10-2014-0136661 (Scraping device of belt filter press)

The present invention has been created to solve the above problems, and since the sludge injected between two layers of filter cloth is maintained stably in the filter cloth, the amount of flocculant can be limited to a minimum, so that the treatment efficiency is excellent and the processing cost is also closed. An object of the present invention is to provide a belt press having a type circulation filter cloth and a sludge dewatering device having the same.

Belt press provided with a closed circulation filter fabric of the present invention for achieving the above object, a plurality of pressure rollers and idle rollers disposed in parallel with each other; The first filter cloth and the first filter cloth having a predetermined width and thickness as the compression and dehydration of the sludge that is in close contact with each other while passing through the pressure roller while being circulated in the path supported by the pressure roller and the idle roller And two filtration cloths, and first and second filtration cloths positioned at both ends in the width direction of the first and second filter cloth sheets and having blocking means for preventing the sludge from flowing outward in the width direction.

In addition, the blocking means; First side dams positioned at both ends in the width direction of the first filter cloth and extending in the longitudinal direction of the filter cloth and having a predetermined cross-sectional shape in the extension direction, and positioned at both ends in the width direction of the second filter cloth and in the longitudinal direction of the filter cloth. It extends and has a predetermined cross-sectional shape in the extending direction, and comprises a second side dam coupled to the first side dam to form a closed space between the first and second filter cloth sheet.

In addition, the first side dam and the second side dam is formed with grooves and protrusions that are fitted to each other.

In addition, the second filter cloth is provided with a plurality of cross dams extending in the width direction of the second filter cloth and preventing sludge from moving in the longitudinal direction of the second filter cloth.

In addition, the first and second side dams and cross dams are made of a material which is elastically deformable by a force applied from the pressure roller.

In addition, the sludge dewatering apparatus of the present invention, the frame for providing a support force; A plurality of press rollers and idle rollers disposed in parallel to the frame, and sludges that are in close contact with each other while passing through the press roller while circulating along the respective paths while being supported by the press rollers and idle rollers Compression and dewatering, the first and second filter cloth sheet having a predetermined width and thickness, and the first and second filter cloth sheets are provided at both ends in the width direction of the first and second blocking means for blocking the outflow of the sludge outward in the width direction A belt press having first and second filtration cloths; A cake discharge part which receives the cake separated from the first and second filtration cloths which pass through the pressing roller and guides the outside to the outside; And a washing unit for supporting the frame and washing the first and second filtration cloths that are circulating.

The belt press provided with the closed circulation filter cloth of the present invention made as described above stably maintains the sludge introduced between the two layers of the filter cloth inside the filter cloth, so that the amount of flocculant can be limited to the minimum, and thus the treatment efficiency is excellent and the treatment is performed. It also reduces costs.

1 is a side view showing the configuration of a sludge dewatering apparatus according to an embodiment of the present invention.
Figure 2 is a side view showing a modification of the sludge dewatering apparatus according to an embodiment of the present invention.
Figure 3 is a block diagram showing a separate belt press with a closed circular filter according to an embodiment of the present invention.
4 is a cross-sectional view taken along the line IV-IV of FIG. 3.
5A to 5C are cross-sectional views for explaining the action of the circulatory filter shown in FIG.
FIG. 6 is a longitudinal cross-sectional view of the circulation filter shown in FIG. 3. FIG.
7 is a cross-sectional view showing a modified example of the belt press shown in FIG.
8 and 9 are partial cross-sectional views showing a modified example of the circulating filter cloth shown in FIG.

Hereinafter, one embodiment according to the present invention will be described in detail with reference to the accompanying drawings.

Basically, the sludge dewatering apparatus 10 which will be described later is the dewatering of the sludge continuously introduced from the outside using the belt press 30. The sludge dewatering device 10 includes a frame 12, a belt press 30, a cake discharge unit 20, a plurality of washing units (18a, 18b) and will be described in detail with reference to FIG. do.

1 is a side view showing a sludge dewatering apparatus according to an embodiment of the present invention.

As shown, the sludge dewatering device 10 according to the present embodiment, the frame 12 for providing the support force, the stirring portion 14 and the sludge wide supply portion 15 provided at one end of the frame 12, The belt press 30 for conveying the sludge introduced from the sludge wide supply unit 15 and compressing the cake press 20 for washing the cake discharge unit 20 and the belt press 30 for receiving the cake discharged from the belt press 30 and discharging it to the outside The upper and lower washing parts 18a and 18b are included.

First, the frame 12 is a structure that provides a supporting force and has a stirring portion 14 and a sludge wide supply portion 15 at one end thereof. The stirring unit 14 serves to mix the sludge to be treated with the coagulant, and includes a sealed chamber 14a for receiving the sludge and the coagulant introduced from the outside therein, and stirring the sludge and the coagulant inside the sealed chamber 14a. The stirring blade 14b and the stirring motor 14c which drive the stirring blade 14b are provided.

The proportion of flocculant mixed in the sludge varies depending on the state of the sludge, but may or may not be used in a minimum amount. By minimum amount is meant the minimum amount within the flocculant input range, known in the sludge treatment art. As such, the reason why the minimum flocculant may or may not be used is due to the structural features of the belt press 30 to be described later.

3 to 9 will be described first with respect to the belt press 30.

Figure 3 is a block diagram showing a separate belt press with a closed circular filter according to an embodiment of the present invention. 4 is a cross-sectional view taken along the line IV-IV of FIG. 3.

As shown, the belt press 30 having the closed circulation filter in the present embodiment includes a plurality of pressure rollers 31 and idle rollers 32a and 32b, and the pressure rollers 31 and idle rollers. The first filter cloth 35 and the second filter cloth 37 which circulate in the state supported by 32a, 32b are included.

The pressure roller 31 is supported so as to be axially rotatable to the frame 12 and axially rotates in a state parallel to each other, and the size may be different as necessary. Axial rotation of the pressure roller 31 may be changed in various ways. For example, it may be operated as a driving roller by transmitting a rotational torque to one of the plurality of pressure rollers. Reference numeral 41 shown in Fig. 1 and Fig. 2 is a drive unit for transmitting the rotational torque to any pressure roller. As the driving unit 41, a motor and a speed reducer can be applied.

In particular, the support shaft (31d) of the pressure roller 31 is capable of position adjustment in a state supported by the frame (12). For example, in order to adjust the tension of the first and second filtration cloths 35 and 37 passing through the pressure roller 31 as necessary, the distance between the pressure rollers 31 may be adjusted. The configuration for moving the position of the pressure roller 31 follows a general manner.

In addition, in order to properly maintain the tension of the first and second filtration cloths 35 and 37 itself, as shown in FIG. 2, a tension control cylinder 24 may be added. The power of the tension control cylinder 24 may be variously applied, such as oil pressure.

The pressure roller 31 includes a roller body 31a, a support shaft 31d, and a roller circumferential pressure part 33. As shown in Fig. 4, the roller body 31a has a cylindrical shape with a constant diameter, and has a plurality of guide holes 31c at its periphery and side drains 31b at both ends thereof. A plurality of roller bodies 31a having such a structure are installed to be parallel to the frame 12 via the support shaft 31d.

In addition, the roller circumferential pressure unit 33 tightly wraps the outer circumferential surface of the roller body 31a as an elastic member made of elastic synthetic resin or rubber. The roller circumferential pressing portion 33 is adhesively fixed to the roller body 31a. The thickness of the roller circumferential pressing portion 33 may be changed as necessary in consideration of the elasticity of the roller circumferential pressing portion 33. In addition, a plurality of through holes 33a are also formed in the roller circumferential pressing portion 33. The through holes 33a correspond one-to-one with the guide holes 31c formed in the roller body 31a and communicate with each other.

Therefore, the water discharged from the sludge Z compressed through the pressure roller 31 may pass through the through hole 33a and the guide hole 31c in order to flow into the roller body 31a. The water flowing into the roller body 31a flows out through the side drain holes 31b on both sides.

Meanwhile, the idle rollers 32a and 32b include a first idler roller 32a and a second idler roller 32b.

A plurality of first idler rollers 32a are horizontally supported with respect to the frame 12 and are parallel to each other. The first idler roller 32a together with the pressure roller 31 provides a circulation path of the first filter cloth 35. The first filter cloth 35 is circulated in the direction of the arrow m while being supported by the pressure roller 31 and the first idler roller 32a.

The second idler roller 32b is likewise mounted horizontally to the frame 12 and together with the pressure roller 31 provides a circulation path of the second filter cloth 37. The second filter cloth 37 is circulated along the direction of the arrow m in a state supported by the pressure roller 31 and the second idle roller 32b.

The first filter cloth 35 and the second filter cloth 37 circulates at the same speed and transports the sludge introduced therebetween, and constitutes a circulation filter cloth 39 that compresses and squeezes water. That is, the circular rollers are circulated along their respective paths while being supported by the pressure roller 31 and the first and second idle rollers 32a and 32b. It is.

Reference numeral 30a denotes an inlet portion. The inlet portion 30a is a portion into which sludge introduced from the outside is introduced. The sludge dropped into the inlet portion 30a is drawn between the first filter cloth 35 and the second filter cloth 37 and trapped between the first and second filter cloths 35 and 37, and the plurality of pressure rollers 31 are pressed. Pass through). The first and second filter cloths 35 and 37 pass through the pressure roller 31 and are pressed in the thickness direction to compress the sludge contained therein. Water contained in the sludge is squeezed out through the pressing process and discharged to the outside.

Reference numeral 30b denotes an outlet portion. The outlet part 30b is a part where the 1st filter cloth 35 and the 2nd filter cloth 37 open | release. As the first filter cloth 35 and the second filter cloth 37 are opened, the cake sludge compressed between the first and second filter cloth is separated and falls down. That is, it falls to the cake discharge part 20 shown in FIG. 1 by self weight.

5A to 5C are cross-sectional views for explaining the detailed configuration and operation of the circulation filter cloth 39 shown in FIG. 3, and FIG. 6 is a longitudinal cross-sectional view of the circulation filter cloth 39. FIG. In the present description, the circulating filter cloth 39 is a term encompassing the first filter cloth 35 and the second filter cloth 37.

First, as shown in FIG. 5A, the first filter cloth 35 has a first filter cloth 35a having a predetermined width and thickness, and a first side as blocking means fixed to both ends of the filter cloth sheet 35a in the width direction. It has a dam 35b.

The first filter cloth 35a is a sheet-like member that can pass water. Naturally, the sludge cannot escape through the first filter cloth 35a. In some cases, a rigid mesh or wire mesh may be embedded in the first filter cloth 35a.

The first side dam 35b is a member extending along the longitudinal direction of the first filter cloth 35a and is elastically deformable by an external force. The first side dam 35b is bonded and fixed to the first filter cloth 35a. The first side dam 35b can be made of stretchable synthetic resin or rubber. In addition, the protrusion 35c is integrally formed on the bottom surface of the first side dam 35b. The protruding portion 35c is a portion fitted into the groove portion 37c of the second side dam 37b to be described later.

Moreover, the 2nd filter cloth 37 has the 2nd filter cloth 37a which has a fixed width and thickness, and the 2nd side dam 37b fixed to the width direction both ends of the 2nd filter cloth 37a. The size and mechanical properties of the second filter cloth 37a are the same as those of the first filter cloth 35a. The second side dam 37b is bonded and fixed to the second filter cloth 37a.

In addition, the second side dam 37b is an elastic member made of stretchable synthetic resin or rubber and extends along the length direction of the second filter cloth 37a. In particular, as shown in FIG. 5A, the second side dam 37b traps the sludge Z introduced from the outside to prevent the sludge Z from being lost to the outside in the width direction of the second filter cloth 37a. do. By applying the second side dam 37b having such a function, the amount of flocculant mixed in the sludge Z can be reduced to a minimum, and in some cases, the flocculant itself may not be used.

In addition, a groove 37c is formed on the upper surface of the second side dam 37b. The groove part 37c is a groove which accommodates the protrusion part 35c of the 1st side dam 35b. There are two reasons for providing the groove 37c and the protrusion 35c and inserting the protrusion 35c into the groove 37c.

The first reason is that the space between the first filtration cloth 35 and the second filtration cloth 37 is more completely sealed, so that the first filtration cloth 35 and the second filtration cloth 37 are strongly applied to each other as shown in FIG. 5C. The sludge Z is prevented from passing through the first and second side dams 35b and 37b even when pressed. The second reason is to prevent the misalignment of the first and second filtration cloths 35 and 37 which are repeatedly separated and overlapped by the continuous circulation movement. In other words, the separated first and second filter cloths 35 and 37 are guided so as to accurately fit without passing against each other while passing through the inlet portion 30a.

As long as this function can be implemented, the configuration of the first and second side dams 35b and 37b may be variously changed. For example, it may have a structure shown in Figs.

8 and 9 are partial cross-sectional views showing modified examples of the circulating filter cloth 39 shown in FIG.

Referring to FIG. 8, a protrusion 35c having a semicircular cross section is formed on a bottom of the first side dam 35b provided in the first filter cloth 35a, and a semicircular shape is formed on an upper surface of the second side dam 37b. Groove 37c is provided. By applying the semicircular cross-sectional shape of the protrusions 35c and the grooves 37c as described above, the coupling of the first side dams 35b to the second side dams 37b is more smoothly realized.

In addition, the protrusion part 35c of the 1st side dam 35b shown in FIG. 9 takes the form of a sawtooth. On the upper surface of the second side dam 37b, a groove portion 37c in the form of a V-shaped cutting groove capable of accommodating the sawtooth protrusion 35c is applied.

Meanwhile, a plurality of cross dams 37e are further provided on the upper surface of the second filter cloth 37. The cross dam 37e is an elastic member extending in the width direction of the second filter cloth 37, and both ends thereof contact the second side dam 37b. The cross dam 37e and the second side dam 37b may be perpendicular to each other.

The cross dam 37e prevents the fluid sludge Z filled between the circulation filter cloth 39 from being pushed backward in the transport direction during the transfer of the circulation filter cloth 39. For example, the sludge that is introduced into the inlet portion 30a shown in FIG. 3 and moved to the pressure roller 31 while being loaded on the second filter cloth 37 is prevented from being pushed backward.

As the first and second filter cloths 35 and 37, which are opened, are transferred to the first pressure roller 31, the first and second filter cloths 35 and 37 gradually become closer, and finally, the pressing force in the thickness direction is exerted. As a result, the volume between the first and second filtration cloths 35 and 37 is reduced. When the volume is small, pressure is transmitted to the sludge Z interposed between the first and second filtration cloths 35 and 37, and the sludge is pushed in the direction opposite to the conveying direction. This is because sludge has fluidity. If the sludge is repeatedly moved back without moving to the pressure roller 31 side, it is natural that a stable and effective compression can not be made.

In the present embodiment, the cross dam 37e serves to support the sludge Z. That is, the transfer force is transmitted to the sludge Z approaching the pressure roller 31 so that the sludge receives the pressure of the pressure roller 31 as it is. The distance between the cross dams 37e depends on the size of the belt press 30.

7 is a cross-sectional view showing a modified example of the belt press shown in FIG.

As mentioned above, the dewatering device 10 according to the present embodiment strongly compresses the first and second filter cloths 35a and 37a in the thickness direction, as necessary, and the first and second filter cloths 35a. In order to adjust the tension of, 37a, it is possible to adjust the interval between the pressure rollers 31.

FIG. 7 is a view showing that the space between the pressure rollers 31 adjacent to each other is narrowed, so that the circulating filter cloth 39 passing therebetween can be pressed more strongly. The reason for compressing the circulation filter cloth 39 is, of course, for more complete dewatering of the sludge.

As shown in the figure, as the pressure roller 31 presses the circulating filter cloth 39 in the thickness direction, the roller circumferential pressing portion 33 and the first and second side dams 35b and 37b are elastically deformed at the same time. The elastic deformation portion is restored to the initial state after passing through the pressure roller (31). The cross dam 37e is also compressed only while passing through the pressure roller 31, and is restored to its original state after passing.

Returning to FIG. 1 again, the description will be continued.

As shown in FIG. 1, a plurality of pressure rollers 31 and first and second idle rollers 32a and 32b constituting the belt press 30 are supported by the frame 12 in a rotatable and horizontal manner. It is. The pressure roller 31 is rotated by receiving a rotational force from a driving means such as a motor and a controller (not shown). Naturally, the rotation speed can be adjusted through the control unit.

On the other hand, the flocculant and the stirred sludge in the stirring unit 14 is transmitted to the gravity dewatering unit 16 through the sludge wide supply unit 15. The sludge wide supply part 15 includes an input pump 15a and an induction pipe 15b. The induction pipe 15b is a pipe that guides the sludge of the stirring portion 14 toward the gravity dewatering portion 16 side. In addition, the input pump 15a serves to pump the sludge in the hermetic chamber 14a to move toward the gravity dewatering unit 16.

The gravity dewatering unit 16 passes the sludge supplied through the sludge wide supply unit 15 and induces the water in the sludge to be drained by the action of gravity. The water is first drained before the sludge is pressed. Water drained from the gravity dewatering unit 16 is discharged to the outside through a suitable drain passage.

The upper washing unit 18a serves to wash the inner and outer surfaces of the second filter cloth 37. The washing manner of the upper washing unit 18a may be variously changed. For example, it may be a method of spraying high pressure water.

The lower washing part 18b is positioned below the belt press 30. The lower washing portion 18b washes the inner and outer surfaces of the first filter cloth 35. The washing method of the lower washing unit 18b may also be variously changed, and like the upper washing unit 18a, it may be a high pressure spraying method.

In addition, the vibration generating portion 22 is located on the side of the lower washing portion (18b). The vibration generating unit 22 transmits vibration to the first filter cloth 35 during transfer, and shakes off the sludge attached to the first filter cloth 35. Of course, the vibration generating unit for transmitting vibration to the second filter cloth 37 is also installed.

Figure 2 is a side view showing a modification of the sludge dewatering apparatus according to an embodiment of the present invention.

As shown in the drawing, the stirring section 14 and the sludge wide supply section 15 may be disposed above the inlet section 30a of the belt press 30. In this case, the gravity dehydration unit 16 is omitted. When the sludge drainability is low, there is no meaning of gravity dehydration, it has a configuration as shown in FIG. 2.

Operation of the sludge dewatering device 10 according to the present embodiment made as described above is made as follows.

First, in the state in which the belt press 30 is operated, sludge and flocculant are continuously injected into the stirring unit 14 and stirred, and the inlet pump 15a of the sludge wide supply unit 15 is operated. After the stirring, the sludge is sent to the inlet portion 30a of the belt press 30. In the case where the gravity dewatering unit 16 is applied, the sludge pumped through the sludge wide supply unit 15 moves to the inlet 30a via the gravity dewatering unit 16.

The sludge introduced into the inlet portion 30a is compressed between the first and second filtration cloths 35 and 37 in a state interposed therebetween, and the water is squeezed out. Passed through the two filter cloth sheets (35a, 37a) is discharged to the outside. Inside the first and second filter cloths 35 and 37, only cake-like sludge remains.

The sludge which continuously passes through the belt press 30 through the above process is discharged through the outlet portion 30b as a state of the cake and then dropped into the cake valley portion 20 and then carried out.

As mentioned above, although this invention was demonstrated in detail through the specific Example, this invention is not limited to the said Example, A various deformation | transformation is possible for a person with ordinary knowledge within the scope of the technical idea of this invention.

10: sludge dewatering device 12: frame 14: stirring part
14a: airtight chamber 14b: stirring blade 14c: stirring motor
15: sludge wide supply part 15a: inlet pump 15b: induction pipe
16: Gravity Dewatering 18a: Upper Wash 18b: Lower Wash
20: cake discharge part 22: vibration generating part 24: tension adjustment cylinder
30: Belt press 30a: Inlet part 30b: Outlet part
31: Pressing roller 31a: Roller body 31b: Side drain
31c: guide hole 31d: support shaft 32a: first idler roller
32b: second idler roller 33: roller circumferential pressing portion 33a: through hole
35: 1st filter cloth 35a: 1st filter cloth 35b: 1st side dam
35c: protrusion 37: second filtration cloth 37a: second filtration cloth
37b: 2nd side dam 37c: groove 37e: cross dam
39: circulating filtration cloth 41: driving part

Claims (10)

A plurality of pressure rollers and idle rollers disposed in parallel to each other;
The first filter cloth and the first filter cloth having a predetermined width and thickness to press and dewater the sludge that is in close contact with each other while passing through the pressure roller while circulating along the path while being supported by the pressure roller and the idle roller And a closed circulating filter cloth including two filtration cloths and first and second filtration cloths positioned at both ends in the width direction of the first and second filter cloth sheets and having blocking means for preventing the sludge from flowing outward in the width direction. ,
The blocking means;
First side dams positioned at both ends in the width direction of the first filter cloth and extending in a length direction of the filter cloth and having a predetermined cross-sectional shape in an extension direction;
Located in the width direction both ends of the second filter cloth and extending in the longitudinal direction of the filter cloth and has a predetermined cross-sectional shape in the extension direction, in combination with the first side dam to form a closed space between the first and second filter cloth sheet A second side dam,
The second press fabric has a belt press having a closed circulation filter cloth which extends in the width direction of the second filter cloth and is provided with a plurality of cross dams for preventing the sludge from moving in the longitudinal direction of the second filter cloth. delete The method of claim 1,
The first press and the second side dam is a belt press having a closed circulation filter cloth formed with grooves and protrusions to be fitted to each other. delete The method of claim 1,
The first and second side dams and cross dams, the belt press having a closed circulation filter cloth made of a material that is elastically deformable by the force applied from the pressure roller. A frame providing support;
Supported by the frame, any one of the belt press selected from claim 1, 3 and 5;
A cake discharge part which receives the cake separated from the first and second filtration cloths which pass through the pressing roller and guides the outside to the outside;
Sludge dewatering apparatus comprising a washing unit for supporting the frame and washing the first and second filtration cloth to circulate. The method of claim 6,
The blocking means;
First side dams positioned at both ends in the width direction of the first filter cloth and extending in a length direction of the filter cloth and having a predetermined cross-sectional shape in an extension direction;
Located in the width direction both ends of the second filter cloth and extending in the longitudinal direction of the filter cloth and has a predetermined cross-sectional shape in the extension direction, in combination with the first side dam to form a closed space between the first and second filter cloth sheet A sludge dewatering device having a closed circulation filter cloth including a second side dam. The method of claim 7, wherein
Sludge dewatering device having a closed circulation filter cloth formed in the first side dam and the second side dam is formed with grooves and protrusions to be fitted to each other. The method of claim 7, wherein
The sludge dewatering apparatus having a closed circulation filter cloth, which has a plurality of cross dams extending in the width direction of the second filter cloth and preventing the sludge from moving in the longitudinal direction of the second filter cloth. The method of claim 9,
The first and second side dams and cross dams, the sludge dewatering device having a closed circulation filter cloth made of a material that is elastically deformable by the force applied from the pressure roller.

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