JP2016073933A - Method for dewatering belt press and belt press - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a belt press in which side leak does not occur by folding two endless filter cloths thereby forming a filtration space.SOLUTION: A belt press 1 in which two endless filter cloths 3 are so wound around plural rollers 2 as to be capable of freely travelling and which performs dewatering of sludge supplied between an upper filter cloth 3a and a lower filter cloth 3b. In the belt press, the lower filter cloth 3b is folded from both lateral sides to a sludge supply side in a width direction of the lower filter cloth 3b to which sludge is supplied, and the folded filter cloth 3b and the upper filter cloth 3a are overlapped with each other thereby forming a filtration space 5, and after dewatering of sludge is performed in the filtration space 5, the folded lower filter cloth 3b is developed and a dewatered cake is removed. Thus, dewatering of sludge can performed in such a manner that the sludge is wrapped by the filter cloth, and therefore, side leak does not occur.SELECTED DRAWING: Figure 3

Description

The present invention relates to a belt press including two endless filter cloths that are freely run around and forming a filtration space by folding the filter cloths in the width direction.

Conventionally, a belt press that dewaters sludge sandwiched between two filter cloths by using two endless filter cloths by multiple rollers and dewatering them by the tension of the filter cloths and the pressing force of the pressure roller. It is used.
In addition, in Patent Document 1, a single endless filter cloth is held in a double fold shape perpendicular to the traveling direction of the filter cloth, and sludge is supplied to the double fold and dehydrated by a pressure roller. A belt press is disclosed.

Further, Patent Document 2 discloses a moromi frying tank method that squeezes moromi in a tri-fold filter cloth using an apparatus for squeezing moromi.
Similarly, Patent Document 3 discloses an apparatus that wraps and squeezes moromi with a trifolded filter cloth and folds the filter cloth into three folds.

JP 58-50197 A Japanese Examined Sho 46-28152 Japanese Patent Publication No. 46-22557

In the belt press using two conventional filter cloths, or in the dewatering part of the belt press disclosed in Patent Document 1, the moisture content of sludge is high or the supply amount is large. For example, part of the sludge escapes in the vertical and horizontal directions. Here, the longitudinal direction indicates the traveling direction of the filter cloth, and the lateral direction indicates a direction perpendicular to the traveling direction (width direction) on the filtration surface of the filter cloth.

In a conventional belt press using an endless filter cloth, two filter cloths are stacked one above the other, or one filter cloth is folded in two to form a filtration space between the filter cloths. When the filtration space is formed in this way, the filter cloth forming the filtration space is always torn and discontinuous at both ends or one end in the longitudinal direction of the filtration space deformed by external pressure. Therefore, the mating surface of the filter cloth is easily opened by the pressure from the inside.
Therefore, when pressure is applied from the outside during dehydration and sludge in the filtration space escapes in the lateral direction, there is a possibility that side leakage occurs and the sludge protrudes from the end of the filter cloth.
For these reasons, the belt press is often limited to the pressure of pressing, and is often inferior to other dehydrators in terms of moisture content of the dehydrated cake.

Moreover, although patent document 2 and patent document 3 disclose the technology of wrapping and squeezing moromi in a tri-fold filter cloth, the tri-fold filter cloth is further folded, stacked, and pressed. It is a device that does not squeeze continuously.

In a belt press that dewaters the sludge supplied between the upper and lower filter cloths by running two endless filter cloths on multiple rollers to run freely, both sides in the width direction of the lower filter cloth supplied with sludge The filter cloth is folded back to the sludge supply side and the folded filter cloth and the upper filter cloth are overlapped to form a filtration space. After the sludge is dehydrated in the filtration space, the folded filter cloth is expanded and the dehydrated cake is spread. By discharging, the sludge can be dehydrated by wrapping it with a filter cloth, so that side leakage does not occur.

In a belt press that hangs two endless filter cloths on multiple rollers so that they can run freely, and dewaters the sludge supplied between the upper and lower filter cloths, a hopper that supplies the sludge onto the lower filter cloth, and the lower filter cloth A folding device that folds the lower filter cloth from both sides in the width direction to the sludge supply side and overlays the upper filter cloth on the folded lower filter cloth to form a filtration space, and a shear roll that wraps the filter cloth that forms the filtration space By providing a developing roller for developing the folded down filter cloth, sludge can be wrapped with the filter cloth, dehydrated without causing side leak, and the dehydrated cake discharged.

The folding device includes: a pressing roller that presses the lower filter cloth downward to form a U-shaped bottom; a guide roller that folds both sides of the lower filter cloth on both sides of the pressing roller to form both sides of the U-shaped; The filter cloth can be smoothly folded back by including a plurality of guide bars that bend inward both side surfaces of the lower filter cloth bent into the mold.

The dehydrated cake is peeled off by unfolding the folded down filter cloth and winding it around a developing roller, and the dehydrated cake can be discharged from the filtration space.

By forming both ends of the filtration space in the longitudinal direction with folded portions of the lower filter cloth, sludge does not leak out from both ends of the filtration space in the longitudinal direction, and dehydration can be performed by applying a higher pressure.

The folding surface of the lower filter cloth is folded to form a filtration space by pinching the upper filter cloth, or a filtration space is formed by overlapping the folded upper surface of the lower filter cloth. The filter cloth and the lower filter cloth can form a filtration space by overlapping both ends and folding back from the fold.

The sealing effect of filtration space increases more by making into a folding part the location below 1/4 width from the both sides of the width direction of the said lower filter cloth.

Since both ends of the filtration space form a filtration space by folding the lower filter cloth, side leaks do not occur. The folded down filter cloth is overlapped with the upper filter cloth to form a filtration space and serve as a seal. Therefore, the seal of the overlapped filter cloth becomes stronger by applying external pressure.
If the width of the lower filter cloth is reduced, the effective area of the filter cloth is increased, and the processing amount can be increased.
Since side leakage does not occur, it becomes possible to increase the amount of sludge supplied and to dehydrate at a higher pressure.
Also, no special equipment is required to seal the filtration chamber. Furthermore, since dehydration is performed while running an endless filter cloth, dehydration can be performed continuously.

1 is a schematic side view of a belt press according to the present invention. Similarly, it is an expanded view of the filter cloth folded by the folding apparatus. Similarly, it is sectional drawing of the filter cloth folded with the folding apparatus. Similarly, it is a top view of the folding device of a filter cloth. Similarly, it is a side view of a filter cloth folding device. Similarly, it is a top view of the filter cloth wound around the developing roller.

The present invention is a belt press in which a filtration space is formed between two endless filter cloths that are freely run around and dewatered by supplying sludge to the filtration space.
FIG. 1 is a schematic side view of a belt press according to the present invention.
The belt press 1 of the present invention includes a plurality of rollers 2 and two endless filter cloths 3 (an upper filter cloth 3a and a lower filter cloth 3b) that are hung around the plurality of rollers 2 to be able to travel. The hopper 4 that supplies sludge onto the lower filter cloth 3b, and the lower filter cloth 3b is folded from the both sides in the width direction of the lower filter cloth 3b to the sludge supply side, and the folded lower filter cloth 3b and upper filter cloth 3a are overlapped to form a filtration space 5 A folding device 6, a shearing roll 7 around which the filter cloth 3 forming the filtration space 5 is wound, and a developing roller 8 that unfolds the folded down filter cloth 3b.

One endless lower filter cloth 3b wound around the plurality of rollers 2 is folded back at both ends in the width direction by the folding device 6. The folding device 6 supplies the sludge from the hopper 4 while folding both ends of the lower filter cloth 3b in the traveling direction (vertical direction) so that the endless lower cloth 3b receives the sludge. Accordingly, in the process of turning back, both ends of the lower filter cloth 3b are folded, and sludge is supplied onto the lower filter cloth 3b when the cross section of the lower filter cloth 3b becomes U-shaped. After supplying the sludge, the upper filter cloth 3a is guided by the guide roller 36 so as to cover the sludge supplied to the lower filter cloth 3b, and is run.
The filter cloth 3 forms a filtration space 5 by folding back both ends in the width direction with a folding device 6. The upper and lower filter cloths 3 a and 3 b supplied with sludge in the filtration space 5 are wound around the shear roll 7 to dehydrate the sludge. After dehydration, the lower filter cloth 3b folded by the developing roller 8 is developed, and the dehydrated cake is discharged by a peeling device.

FIG. 2 is a development view of the filter cloth folded by the folding device according to the present invention.
FIG. 3 is a cross-sectional view of the filter cloth folded by the folding device according to the present invention.
The lower cloth 3b shown in FIGS. 2 and 3 has folds 9a and 9b that fold back to the sludge supply side at a quarter width from both sides in the width direction. The width | variety of the upper filter cloth 3a has a width | variety equivalent to between the folding parts 9a and 9b of the lower filter cloth 3b.
As shown in FIG. 3A, after the sludge is supplied, the upper filter cloth 3a having the same width as that between the two folded portions 9a and 9b is guided above the sludge. Then, one end of the lower filter cloth 3b is folded inward from the folding part 9a so as to hold the upper filter cloth 3a, and then the other end of the lower filter cloth 3b is also turned inward from the folding part 9b so as to hold the upper filter cloth 3a. Wrap around.
Since the folding portions 9a and 9b of the lower filter cloth 3b are folded at ¼ width portions from both sides, the folded surfaces 10a and 10b of the lower filter cloth 3b overlap with the upper filter cloth 3a and serve as a seal when folded. And the filtration space 5 is formed between the filter cloths 3a and 3b.

By folding the lower filter cloth 3b, both ends in the longitudinal direction of the filtration space 5 deformed by pressure are formed by the folded portions 9a and 9b of the lower filter cloth 3b, and both ends of the filtration space 5 are not torn. Does not occur.
Further, the folded surfaces 10 a and 10 b of the folded lower filter cloth 3 b overlap with the upper filter cloth 3 a to seal the filtration space 5. By applying pressure from the outside, the strength of the seal at the overlapping portions of the folding surfaces 10a and 10b is increased, so that sludge does not leak from the overlapping portions of the folding surfaces 10a and 10b.

As described above, the endless lower cloth 3b forms the filtration space 5 by folding the folding surfaces 10a and 10b at both ends in the width direction at the quarter width from both ends. The same effect can be obtained by folding back a portion having a width of 4 or less. By reducing the area where the folded surfaces 10a and 10b of the folded down filter cloth 3b overlap, the effective filtration area can be increased.

Moreover, as shown in FIG.3 (b), it is also possible to form the filtration space 5 by guiding the upper filter cloth 3a on the upper surface of the folding surfaces 10a and 10b of the folded lower filter cloth 3b. In that case, after supplying sludge to the lower filter cloth 3b, one end of the lower filter cloth 3b is folded back from the folding part 9a, and then the other end of the lower filter cloth 3b is folded back from the folding part 9b. Then, the upper filter cloth 3a is guided above the folding surfaces 10a and 10b of the folded lower filter cloth 3b, and the filtration space 5 is formed between the upper and lower filter cloths 3a and 3b by covering the folded surfaces 10a and 10b.

In addition, as shown in FIG. 3 (c), two endless upper and lower filter cloths 3a and 3b having the same width and length are connected to both ends of the upper and lower filter cloths 3a and 3b at the folding portions 9a and 9b. The filtration space 5 can also be formed between the upper and lower filter cloths 3a and 3b by being folded back.

As described above, there are various ways of folding the two filter cloths 3 according to the present invention. In any case, the folding surfaces 10a and 10b of the lower filter cloth 3b are folded back to the sludge supply side, and the lower filter cloth 3 is folded. The filtration space 5 is formed by overlapping the surfaces 10a, 10b and the upper filter cloth 3a. The endless lower filter cloth 3b prevents the occurrence of side leaks by forming both ends in the longitudinal direction of the filtration space 5 that is deformed by external pressure by the folded portions 9a and 9b of the lower filter cloth 3b. The folded surfaces 10a and 10b of the folded endless lower cloth 3b serve as a seal for the filtration space 5 by overlapping with the upper filter cloth 3a. In order to increase the sealing performance, the overlapping area of the folding surfaces 10a and 10b of the upper filter cloth 3a and the lower filter cloth 3b may be increased. Further, the sealing performance can be improved by further folding back the overlapping portions of the folding surfaces 10a and 10b of the upper filter cloth 3a and the lower filter cloth 3b.

The folding device 6 for the filter cloth 3 according to the present invention bends the traveling lower filter cloth 3b by arranging a plurality of guides. In this embodiment, a folding device 6 is used that folds the folding surfaces 10a and 10b of the lower filter cloth 3b and forms the filtration space 5 by holding the upper filter cloth 3a.

FIG. 4 is a plan view of the filter cloth folding device according to the present invention.
FIG. 5 is a side view of the filter cloth folding device according to the present invention.
The folding device 6 of the present invention includes a pressure roller 11 and a guide roller 12 that fold the lower cloth 3b into a U shape, guide bars 13a and 13b that horizontally guide the folded surfaces 10a and 10b of the folded lower cloth 3b, and an upper filter cloth 3a. It is comprised with the guide roller 36 which guides to the upper part of the lower cloth 3b. Moreover, the hopper 4 is arrange | positioned in the position which can supply sludge in the filter cloth 3 bent in the U shape.

The lower filter cloth 3b folded by the folding device 6 is formed in a U shape by the pressing roller 11 so that sludge does not leak out. The width of the pressure roller 11 is equal to the folded width of the lower filter cloth 3b, and the lower roller cloth 3b is pressed downward at the center of the upper surface of the lower filter cloth 3b with the pressure roller 11 to form the lower filter cloth 3b in a U shape. Accordingly, the pressing roller 11 forms a U-shaped bottom. At the same time, both ends of the lower filter cloth 3b are bent by the guide rollers 12 arranged perpendicularly to both side surfaces of the pressing roller 11 to form U-shaped side surfaces. On the downstream side of the pressing roller 11, a hopper 4 for supplying sludge is suspended toward the lower filter cloth 3b, and continuously supplies sludge. On the downstream side of the hopper 4, the upper filter cloth 3 a is guided above the sludge by the guide roller 36, and the sludge is held between the upper filter cloth 3 a and the lower filter cloth 3 b.

The lower cloth 3b whose both side surfaces are vertical along the guide roller 12 is bent inward by a plurality of horizontally fixed guide rods 13a and 13b downstream from the arrangement position of the hopper 4 and the guide roller 36. It is done.
At this time, the upper filter cloth 3a is guided in the recess of the U-shaped lower filter cloth 3b, and when the lower filter cloth 3b is folded, both ends of the lower filter cloth 3b are held so as to sandwich the upper filter cloth 3a. Wrap.
One vertical lower cloth 3b side end is guided to be bent horizontally at the bottom of the guide bar 13a, and the other vertical lower cloth 3b side end is also horizontal at the bottom of the guide bar 13b. Guide them to bend. Since both sides of the lower filter cloth 3b that is vertical are folded inward and become horizontal, the lower filter cloth 3b is folded back while traveling and encloses the upper filter cloth 3a guided above the sludge and the sludge.
When the auxiliary bar 14 is horizontally disposed at the bottom of the filter cloth 3 in contact with the guide bars 13a and 13b, the filter cloth 3 is not bent by the pressing of the guide bars 13a and 13b, and the filter cloth 3 is folded in three. Misalignment does not occur. The guide rod 13 and the auxiliary rod 14 are rod-shaped, plate-shaped, or the like.

The folding device 6 described above can cope with various ways of folding the filter cloth 3 by appropriately arranging a plurality of guides as well as how to fold the filter cloth 3 of the embodiment.

As shown in FIG. 1, the upper and lower filter cloths 3 a and 3 b wrapped with sludge by the folding device 6 are wound around a shear roll 7 to dehydrate sludge. The shear roll 7 travels around the upper and lower filter cloths 3a and 3b, thereby applying surface pressure to the sludge in the filtration space 5, and further traveling the filter cloth 3 traveling inside and the filter cloth 3 traveling outside. Dehydrating by applying shear force from the difference in speed. Dehydration is possible not only by the shear roll 7 but also by applying a high pressure from the outside with a pressure belt or a pressure roll. Since the side filter cloth 3b is folded back to prevent side leaks, no side leak occurs even when the pressure is increased.

FIG. 6 is a plan view of a filter cloth wound around a developing roller according to the present invention.
The lower filter cloth 3b wound around the plurality of shear rolls 7 is developed by being wound around the developing roller 8, and the dewatered cake is discharged by the peeling device. The lower filter cloth 3 b is unfolded, wound around the developing roller 8, and traveled, so that the lower filter cloth 3 b naturally develops between the shear roll 7 and the developing roller 8.
Moreover, the upper filter cloth 3a held between the lower filter cloths 3b is wound around the peeling roller 37 after the lower filter cloth 3b is unfolded as shown in FIG.
Since the dewatered cake dehydrated at high pressure has good peelability, the dewatered cake can be easily peeled by wrapping the filter cloth 3 around the peeling roller 37 disposed as a peeling device. In this embodiment, the developing roller 8 wound around the lower filter cloth 3 b is used as the peeling roller 37.

In the belt press according to the present invention, when the filtration space is formed by the upper and lower endless filter cloths, both ends in the width direction of the lower filter cloth are folded to form the filtration spaces, and therefore no side leak occurs. Therefore, it is possible to perform high-pressure dehydration that cannot be performed conventionally due to side leakage.

DESCRIPTION OF SYMBOLS 1 Belt press 2 Roller 3a Upper filter cloth 3b Lower filter cloth 4 Hopper 5 Filtration space 6 Folding device 7 Shear roll 8 Unfolding roller 9a, 9b Folding part 10a, 10b Folding surface 11 Pressing roller 12 Guide roller 13a, 13b Guide bar

Claims (9)

A belt press (1 that hangs two endless filter cloths (3) around a plurality of rollers (2) so as to run freely and dewaters the sludge supplied between the upper filter cloth (3a) and the lower filter cloth (3b). )
Fold the lower filter cloth (3b) from the both sides in the width direction of the lower filter cloth (3b) supplied with sludge to the sludge supply side,
The folded down filter cloth (3b) and upper filter cloth (3a) are overlapped to form a filtration space (5),
After dewatering the sludge in the filtration space (5),
A belt press dewatering method characterized by unfolding the folded down cloth (3b) and discharging the dewatered cake.
A belt press (1 that hangs two endless filter cloths (3) around a plurality of rollers (2) so as to run freely and dewaters the sludge supplied between the upper filter cloth (3a) and the lower filter cloth (3b). )
A hopper (4) for supplying sludge onto the lower filter cloth (3b);
The lower filter cloth (3b) is folded from both sides in the width direction of the lower filter cloth (3b) to the sludge supply side, and the upper filter cloth (3a) is superimposed on the folded lower filter cloth (3b) to form a filtration space (5). A folding device (6);
A shear roll (7) around which a filter cloth (3) forming a filtration space (5) is wound;
A belt press comprising: a developing roller (8) for developing the folded down cloth (3b). The folding device (6)
A pressure roller (11) for pressing the lower filter cloth (3b) downward to form a U-shaped bottom,
A guide roller (12) that bends both sides of the lower cloth (3b) on both sides of the pressure roller (11) to form both sides of the U-shape;
The belt press according to claim 2, further comprising: a plurality of guide bars (13a, 13b) that bend inward both side surfaces of the lower cloth (3b) bent in a U shape. The belt press according to any one of claims 2 and 3, wherein the dehydrated cake is peeled off by unfolding the folded down filter cloth (3b) and winding it around a developing roller (8).
The belt press according to any one of claims 2 to 4, wherein both ends in the longitudinal direction of the filtration space (5) are formed by folded portions (9a, 9b) of the lower filter cloth (3b). The belt press according to claim 5, wherein the folding surface (10a, 10b) of the lower filter cloth (3b) is folded back so as to sandwich the upper filter cloth (3a). The belt press according to claim 5, wherein the upper filter cloth (3a) is overlapped with the upper surface of the folded surface (10a, 10b) of the folded lower filter cloth (3b). 6. The belt press according to claim 5, wherein the upper filter cloth (3 a) and the lower filter cloth (3 b) are folded from the folding portions (9 a, 9 b) with both ends overlapped.
9. The portion according to claim 5, wherein a portion having a width of ¼ or less from both sides in the width direction of the lower filter cloth (3 b) is defined as a folded portion (9 a, 9 b). Belt press.

Images