JPS6057958B2 - Sludge dewatering equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sewage sludge dewatering device, and in particular, the sludge conveyed by a screening belt is compressed by a water-permeable pressing belt, and the sludge squeezed out by the pressing belt is This relates to a sludge dewatering device that uses suction means to suck out moisture inside.

Traditional methods of naturally dewatering sludge in sludge drying beds have been made impossible due to lack of space and labor.

Therefore, it is necessary to make the sludge into a form that can be artificially hoeed, dehydrated, and easily transported. Various devices have been proposed to achieve the above objectives. In conventional equipment, sludge treated with a relatively large amount of coagulation accelerator is squeezed between two endless belts. Among the endless belts, the belt passing below the sewage sludge is a belt screen.
However, with this type of device, the sludge is simply rubbed under pressure, and it is difficult to dewater the sludge in such a reliable manner.

The present invention has been made in view of the above points, and its purpose is to provide an apparatus that can relatively quickly and reliably remove water from sludge.

That is, the sludge dewatering apparatus of the present invention includes an endless screening belt that transports sludge and filters water in the sludge, a water-permeable press belt that presses the sludge on the screening belt, and a squeeze belt that squeezes the sludge. It is characterized by comprising a suction means for sucking water in the discharged sludge from the back side of the pressing belt through the pressing belt.

Another feature of the present invention is the process of artificially dewatering sewage sludge by using an endless screening belt and spreading the sludge on the screening belt, with or without the addition of coagulation accelerators. , the sludge spread out on the screening belt passes successively through a filtration zone and/or a slightly lower pressure suction zone, and finally through a squeezing zone.

A combination of filtration and/or suction and compression dewatering provides a high dehydration effect at low cost. At the same time, the shortcomings of current technology are solved. First, in the filtration zone, sludge from which a portion of the fluid has been removed is conveyed to the screening belt solely by the dripping action of gravity. It is preferable that the screening belt in this zone is placed slightly elevated in the direction of travel. Due to this upward slope and the filtration action, the sludge reaches the suction zone without being completely concentrated. Furthermore, in this filtration zone, the sludge is distributed onto the continuously advancing screening belt by means of devices arranged transversely to the direction of travel of the screening belt. The sludge is therefore distributed and spread to an even thickness and height over the entire surface of the screening belt. In a preferred embodiment, the device is a dispersing means or a rotating roll. The dispersion means can be arranged vertically or obliquely on the surface of the screening belt. The dispersion roll may be of a free-rotating type and may be equipped with a drive mechanism. In embodiments, it is possible for the drive mechanism to drive the dispersion roll against the direction of travel of the screening belt, or it is also possible for the drive mechanism to drive the dispersion roller in the direction of travel of the screening belt.
In the suction zone, which is preferably directly connected after the p-transmission zone,
The dewatering process can be continued economically without consuming large amounts of energy.

For this purpose, a screening belt, on which the sewage sludge is dispersed, is conveyed on a permeable planar support member.
A suction chamber is arranged below the member. Side seals are provided to prevent sludge conveyed to the screening belt from spilling from the support member. The suction chamber is connected to the suction device via a suitable conduit and has approximately 500 to
Since it is maintained at a low pressure of about 200 Aq, it functions as a holding tank and a low-pressure chamber. The conduit communicates the vacuum pump with the chamber in such a way that no water can be removed by suction. Water removed by suction is collected at the bottom of the chamber and then drained. In a preferred embodiment of the invention, the outflow vibrator is formed, for example, as a transparent vibrator, so that it can be used as a simple device for indicating low pressure within the suction chamber. The characteristics of the suction step are that this step uses only moderately low pressures, which can form a sludge cake on the screening belt, saving coagulation accelerators, and that the sludge cannot be screened in large enough quantities to cause clogging. Since it is not pushed into the belt, the degree of contamination of the liquid can be minimized. An important function of the suction zone is to plasticize the sludge material in order to achieve intense squeezing in the subsequent squeezing zone and to produce a relatively clean effluent. It is configured to generate suction in multiple stages and gradually increase the low pressure in each stage in the sludge transport direction. In this case, in the transition from the permeation zone to the suction zone, it is possible at first to provide a particularly careful suction effect to the sewage sludge, which, depending on its composition, becomes susceptible to reactions due to external influences. Furthermore, the screening belt will not become contaminated with such sewage sludge. The multi-stage configuration of the suction zone also ensures that, despite the initial careful suction, a high degree of plasticization is achieved in the final partial suction stage, resulting in a smooth transition to the squeezing zone. In the squeezing zone, a squeezing belt is preferably placed over the sludge material on the highly pre-dewatered screening belt to further crush and dewater the residue.

For this purpose, the squeezing belt is permeable and is preferably guided via several guide pulleys, so that the pressure on the screening belt presses against a watertight surface arranged below the belt. Residual moisture can thereby be squeezed out of the squeezing belt and sucked off via the suction means. In a preferred embodiment, the impermeable surface consists of the shell of a screening belt drive roller which is attached in some way to this area. In this case, the squeezing belt is guided by at least three guide rollers and presses against the screening belt under pressure. It has been found that it is more advantageous to operate an impermeable squeeze belt and drain the water through a permeable squeeze belt rather than to drain the water through a permeable cylinder. In fact, the surface of the cylinder is quite heavily contaminated and cannot be cleaned thoroughly since the free running distance for cleaning is short. Further, according to the present invention, the permeable squeeze belt can be effectively operated without being washed. Since the drive roller itself is impermeable, residual moisture can pass through the squeezing belt and be sucked onto the back side of the belt by the suction means, thereby ensuring reliable dewatering of the sludge. Preferably, the opening angle of the compression belt with respect to the screening belt and the pressure applied by the compression belt to the screening belt are configured to be adjustable.

For example, the opening angle can be selected such that the sludge layer conveyed on the screening belt is gradually subjected to a continuously increasing pressure during its entry into the squeezing zone. In the pressing zone, the sewage sludge can thus also be treated carefully and gradually, if this is required due to the particular sludge concentration. In addition to the above, the device for adjusting the opening angle and the tension of the compression belt can be made telescopic.

In the present invention, preferably, the sludge cake can be removed from the screening belt by the squeezing zone running vertically and/or by the squeezing belt separated from the screening belt continuing to move straight forward for a while.

The cake pressed between the two belts travels with the belt that continues straight ahead, ie the pressing belt, and leaves the screening belt in the simplest and cleanest way.

Since the diameter of the last press belt guide roller is very small, the pressed cake also eventually leaves the press belt naturally. Preferably, the squeezing belt leaves the guide roller following a smaller loop angle than the screening belt. While achieving the maximum possible dewatering effect, no or very little water is added to wash the return screening belt and press belt, respectively.

The sludge that is concentrated through the stages can be separated without any cleaning treatment. The belt is not contaminated, and even if it is contaminated, it is very minimal, and the bottom fluid remains clean. Further, water may be further removed from the sludge spread on the screening belt within the fourth drainage zone after the squeezing zone by the shear stress of the sludge mass.

Inside the zigzag zone, which can be formed as a fourth drainage zone after the squeezing zone for creating shear stresses inside the sludge mass, rollers which are horizontal to the conveying direction one after the other and which are mutually offset in the longitudinal direction are provided, one after the other, horizontal to the conveying direction. It is mounted with a transverse and horizontally positioned shaft. In particular, after compaction of the sludge mass, this shear stress can be used to decontaminate the residual water in a particularly effective manner. Can be highly removed from mud masses. In this case, the screening belt passing through the preceding two or three drainage zones is essentially not contaminated, and the additional screening belt that likewise runs between the rollers is also not contaminated. The effect of removing this residual water is as follows. This is further enhanced by draining in multiple steps in the four drainage zones under varying shear stresses, in particular increasing in the direction of conveyance. Fourth
During drainage under shear stress at specific intervals inside the drainage zone,
Doing this under pressure effects can increase the drainage effect.

In order to vary the degree of shear stress in an effective manner, the upper mouth roller and/or the lower roller may be movable across the direction of conveyance onto adjacent rollers.

Furthermore, all rollers that are continuous in the transport direction may be adjustable. It is then possible to continuously increase the shear stress if necessary. In order to make the overall structural dimensions of the sludge drainage device as short as possible even with the addition of the fourth drainage zone, it is possible to install the fourth drainage zone below the suction zone. Further features and advantages of the invention will become apparent from the description given in conjunction with the accompanying drawings, in which an exemplary embodiment is shown. FIG. 1, FIG. 1a, and FIG. 1b are schematic explanatory diagrams of preferred specific examples of a plant as a sludge dewatering apparatus of the present invention. The plant consists of three consecutive zone markings: a permeation zone 10, a suction zone 12 and a squeezing zone 14. Sewage sludge 16 is introduced via a stirring device 62 . Stirring device 6
2 is equipped with a stirring screw drive mechanism and mixes the introduced sludge 16 with a coagulation accelerator 68. It is noteworthy that the amount of coagulation accelerator required in this new plant is significantly less than that required in the conventional plant. The sludge 16 mixed with the coagulation accelerator 68 in the drinking zone 10 is transferred from the stirring device 62 to the endless screening belt 18.
distributed on top. In this zone, the screening belt 18 is arranged with a slight upward slope in the direction of travel. A dispersion device or roller 32 functions to distribute the sewage sludge onto the screening belt 18 to a uniform width and thickness. Due to this equalizing effect, at the same time the screening belt 18 is coated with an even layer of sludge before reaching the suction zone 12. The dispersing device or roller 32 may be an applicator knife 34 spaced apart from the screening belt 18. The applicator knife is arranged perpendicularly to the surface of the screening belt 18 according to FIG. 1a. However, it may also be arranged as in FIG. 1b, in which case the deformation distribution means 36 are inclined in the direction of travel of the screening belt 18. It is also possible to use a roller 32 as shown in FIG. 1 in place of the scraping knife. The rollers 32, which are likewise arranged at an adjustable spacing relative to the screening belt, may be of the free-rotating type or may be provided with a drive mechanism that rotates the rollers 32 in the direction of travel or opposite the screening belt 18. May be connected. Said rollers disperse and spread the sludge 16 more completely onto the screening belt 18. Either type of dispersion device is placed proximate the advancing end of the over-drinking zone 10. In the pass zone, the screening belt 18 functions as a door cloth.

That is, a portion of the water content of the sludge 16 falls through the free screening belt 18 solely by its own gravity.
Actuation takes place without applying pressure.

That is, there is no suction from below the screening belt 18, and no pressure is exerted on the sludge except for the pressure exerted by the dispersion device or rolls 32. However, the pressure applied by the dispersion device is very small. Falling moisture is collected in tank 76 and then drained into sump 56 via vibrator 78a. A tension roller 80 of the screening belt 18 is mounted within the pass-through zone 10 .

The suction zone 12 is directly connected to the rear of the permeation zone 10 in the direction of travel. The suction zone 12 essentially consists of a completely closed suction chamber 26. A permeable support member 22 is mounted on top of the suction chamber 26 over which a screening belt 18 slides to transport the sludge cake 16 spread onto the screening belt 18. The support member 24 may be a grid plate or a perforated plate or any other suitable flat transparent plate-like member with openings 24 of some shape. The sludge cake 16 is introduced into the chamber 26 from above the opening 24.
and sealing the passage of the screening belt 18. Elastic seals mounted on the side frames on both sides reliably function as side guides and seals. In order to establish a slight low pressure, the chamber 26 is provided with a side opening 52 that connects to a suction vibrator 54 .

The opening 52 is arranged at a considerable distance from the holding tank 42 arranged below, so that there is no risk of aspirated fluid flowing into the suction opening 52. The fluid may be collected within the tank. Vibrator 54 is collection vibe 85
The vibrator 85 is guided to the discharge trap 84. The moisture entrained in the discharge trap 84 is captured and conveyed to the drain sump 56 via the vibrator 86. A schematically illustrated vacuum pump 88 serves to establish a low pressure and is connected via a vibrator 87 . Sludge 1
The moisture sucked into the chamber 26 from the chamber 26 and collected in the holding tank 42 flows in an inclined direction and flows from the outlet 40 to the vibrator 43.
flows into.

The vibrator 43 extends to the lowest part of the water surface of the drainage basin 56, and low pressure prevails in the chamber 26, so that the offshore liquid constantly rises to a portion of the vibrator, which is formed as a vibrator made of transparent material, for example. There is. The degree of this increase can therefore be used as a measure of the underpressure present within chamber 26. Squeezing zone 1 directly connected to the rear of suction zone 12
4 details are shown in the left part of FIG.

In the squeezing zone 14 the screening belt 18 rotates along a relatively large diameter impermeable drive roller 20 .
The sludge 16 pre-dried in the drinking zone 10 and the suction zone 12 is squeezed by a squeezing belt 30 that is conveyed in the advancing direction from the introduction part of the squeezing zone 14 via a tension roller 28a.

The compression belts 30 are water permeable, and in this specific example, the total number of compression belts 30 is 3.
It is driven along the screening belt 18 via rollers 28 . In this embodiment, the roller 28b serving as the central drum controller is fixedly arranged, and the axis of the tension roller 28b is the tension roller 28b.
a support and pivot axis. For this purpose, the axis of the tension roller 28b carries a length-adjustable extension rod 94, so that the length can be adjusted, for example, by means of two opposing screws and a threaded sleeve surrounding these screws. can be adjusted. In this way, the distance between the axes of the rollers 28b and 28a is adjusted, and thereby the tension in the squeezing belt 30 is also adjusted, whereby the pressure exerted on the drive roller 20 and therefore on the screening belt 18 is adjusted. is adjusted, and the sludge cake 16 is formed between the screening belt 18 and the pressing belt 30.
The pressure applied to the can be adjusted. Furthermore, the axis of the tension roller or roller 28a may be loosely fixed in a position at an adjustable angle from the parallel line of the screening belt 18 in the direction of the arrow, so that the sludge cake 1
6 is gradually fed into the squeezing process. The squeezing is
This takes place between the screening belt 18 and the squeezing belt 30 in the area of the drive roller 20 .

Since the drive roller 20 is impermeable, the water remaining in the sludge cake 16 passes through the squeezing belt 30 and is sucked by a suction means disposed close to the back side of the squeezing belt 30, and is drained. It is discharged into a reservoir 56. The suction means consists of a slotted suction boat 60 which is connected to a suction collection vibrator 85 .

The vibrator is guided from the back into the area of the drive roller 20 and faces the squeeze belt 30 . The water sucked in by the suction boat 60 is captured by a conventional simple device (not shown) and then discharged to the drainage basin 56 via the holding tank 90 and partially via the suction collection vibrator 85 and the discharge trap 84. The water is discharged to a drainage basin 56. In many cases, a paper band 74 of sludge material is formed from the sludge cake 16 in the squeezing zone 14, which can be easily transported via a conveyor belt 75 and later removed from the plant in a suitable manner.

As is clear from the figure, the loop angle of the squeezing belt 30 around the drive roller 20 is smaller than the loop angle of the screening belt 18 around the same drive roller.

The paper-like band 74 of sludge material therefore easily separates from the two belts. The squeezing belt 30 on its way back inside the squeezing zone 14, ie the squeezing belt between the rollers 28c and 28b, can be cleaned of adhering sludge particles by a suitable cleaning device 73. In this case, the sludge, which has been gradually dewatered in stages, has no tendency to enter and adhere to the openings of the press belt 30 and the screening belt 18, and therefore cleaning for the purpose of complete cleaning of the press belt is not necessary. It should be pointed out that the amount of water required for the process is very small and that only occasional washing steps are required. Further, cleaning of the screening belt 18 on the way back is carried out by the freshwater utilization device 7 disposed between the drive roller 20 and another drum controller 79.
7 can be done in a simpler way.

Washing water is collected in a small tank and conveyed to a drainage basin 56 via a vibrator 91. Water necessary for the cleaning process is delivered via the vibrator 50.

Also, a relatively clean citrus liquid may be used. Finally, the screening belt 1 that has passed through the drum controller 79
8 is guided to a primary tension roll 80, after passing through which the screening belt 18 begins a new circulation necessary for continuous operation.

In the present invention, since a suction means for sucking the water in the sludge squeezed out by the water-permeable squeezing belt 30 is provided, the water in the sludge can be removed quickly and reliably.

FIG. 2 is an overall view showing another specific example of the present invention.

Although the slot-shaped suction boat 60 is omitted in FIG. 2, the suction boat 60 as a suction means is similar to FIG.
may be placed. In this example, Fig. 1, Fig. 1a and Fig. 1b
Components with the same reference numerals as those in the figures are the same members as in the above-described specific example and function in the same manner, so a detailed explanation of the invention will be omitted. The sludge 16 pre-dried by the filtration zone 10 and the suction zone 12 is led to the squeezing zone 14. A pressing belt 30 is placed on top of this sludge. This squeeze belt runs in the conveying direction at the entrance to the squeeze zone 14 before the tension roller 28 . The squeezing belt 30 is water permeable, and in this example has three rollers 28, 29, 3.
9, guided through all of the screening belts 1
8. In this embodiment, the intermediate steering roller 29 is stationary, and the axis of the tension roller 28 may be formed as a support and pivot axis for the roller 29. The axial distance between the rollers 28 and 29 is freely adjustable, thereby making it possible to adjust the tension of the pressing belt 30. By adjusting this tension, the pressing force on the sludge mass 16 between the screening belt 18 and the pressing belt 30 can also be adjusted at the same time as on the driving roller 20. Furthermore, the axis of the tension roller 28 can be fixed in a position slightly angled from the parallel of the screening belt 18 in the direction of the arrow. This is to slowly compress the sludge mass 16 little by little. Further, suction means may be arranged close to the back surface of the compression belt 30. Such a configuration is the same as that of the specific example described above. In the compression zone 14, a paper-like band or crushed sludge material is produced from the sludge mass 16.

This can be easily carried away via the screening belt 82 and conveyed in a suitable manner to the zigzag zone 15 formed as the fourth drainage zone. The zigzag zone 15 consists of a number of rollers 78 whose axes are transverse to the direction of conveyance of the screening belts 18, 82 and are mounted horizontally thereto.

The rollers 78 are horizontal in the conveying direction and are mounted longitudinally with respect to one another so that the screening belts 18, 82 guided between the rollers run in an undulating manner during operation. The screening belt 82 is guided around a deflection roller 84 before and after the zigzag zone. This screening belt is also formed as an endless belt. After the sludge mass passes through the squeezing zone 14 and falls onto the screening belt 82, the sludge mass is conveyed while being held between the two screening belts 18 and 82, and then conveyed in a wavy manner between the guide rollers 78. .

At this time, the sludge mass is sufficiently compressed and sheared by compressive stress and shear stress. This results in a further considerable drainage of the sludge mass. It is also possible to run the screening belt at different speeds to increase this crushing effect. The water removed in the zigzag zone 15 directly flows into the receiving water tank 76. Since this receiving water tank is an integrated component of the entire device, the entire device enclosed by the casing 86 can be installed as a tight structural unit anywhere in any desired location. After passing Zigzag Zone 15,
The sludge mass 16 floats up from the turning roller 84 and transfers to the conveying belt 8.
8. Five sludge masses, which have been drained very well, are carried away by means of this conveying belt. Because the degree of shear stress is adjustable, the guide rollers 78, particularly the upper rollers, are mounted movably transversely to the conveying direction.

In particular, the zigzag zone may be divided into two separate steps. In this case, the longitudinal offset of the rollers in the first step is smaller than in the second step. This results in greater shear stress in the second step than in the first step. The rollers may overlap directly at the ends of each step. As a result, the sludge mass is compressed again by the compressive stress due to the shear stress 4. Finally, the screening belt 18 is guided to a tension roller 80 behind which the screening belt 18 begins its circulation anew.

This circulation is necessary for continuous operation. The basic advantage of the present invention is that the sludge filtered and conveyed by the endless screening belt is squeezed by a water-permeable squeeze belt, and suction means are provided for sucking the water in the sludge squeezed out from the squeeze belt. Because of this, water in the sludge can be removed quickly and reliably, resulting in extremely excellent drainage effects. Some examples of embodiments of the invention are listed below.

3. Device according to claim 1, characterized in that: (1) the squeezing zone is arranged in the area of the guide roller of the screening belt. (2) The screening belt passing through the filtration zone is in the form of a cloth and passes very freely through the filtration zone, moves in the suction zone over the suction chamber covered by the supporting member, and in the squeezing zone at least two 3. A device according to claim 1, characterized in that it is subjected to the pressure of an endless squeeze belt guided by rollers.

(3) Claim 1, characterized in that in the squeezing zone the screening belt is guided over an impermeable surface;
2 and the device according to any one of the above items.

(4) Dehydration is performed without negative pressure in the filtration zone,
3. Device according to claim 1, characterized in that the subsequent suction zone takes place at a slightly lower pressure.

(5) The apparatus according to any one of claims 1 and 2 and each of the above items, characterized in that the final stage of the compression zone runs in the vertical direction.

(6) The device according to any one of claims 1 and 2 and each of the above items, characterized in that the compression belt spaced apart from the screening belt moves straight ahead by a certain distance.

(7) A fourth drainage zone is provided behind the squeezing zone, and in the fourth draining zone, shear stress is applied to the sludge mass formed in the squeezing zone. 2. The device according to 1 or 2.

(8) The device according to item (7), wherein the sludge mass is compressed within the fourth drainage zone as a certain shear stress progresses.

(9) The apparatus according to any one of (7) and (8) above, wherein the sludge mass is transported by performing wave-like motion in the transport direction.

(The device according to claim 1 or 2, wherein the screening belt is arranged with a slight upward slope in the direction of travel in the 10 offshore zone.

(11) The device according to claim 1 or 2, characterized in that the dispersion knife is arranged at a distance from the screening belt.

(12) The preceding item (11), characterized in that the dispersion knife is arranged perpendicularly to the surface of the screening belt.
The device described in.

(13) The device according to item (12) above, wherein the dispersion knife is inclined in the advancing direction of the screening belt.

(14) The apparatus according to claim 1 or 2, wherein the roller is arranged at a distance from the screening belt.

(15) The device according to item (14) above, wherein the roller is of a freely rotating type.

(16) The apparatus according to item (14), wherein the roller can be driven in a direction opposite to the traveling direction of the screening belt.

(17) The device according to item (14), wherein the roller can be driven in the same direction as the screening belt.

(18) The device according to claim 1 or 2, wherein the suction device is equipped with a suction pump, and a connecting pipe line of the pump opens into the suction chamber from the side above the holding tank.

(19) The device according to claims 1 and 2 or the preceding item (18), characterized in that the suction chamber is subdivided into several chambers having a low pressure that increases in the direction of travel of the screening belt. .

(20) A patent characterized in that the suction channel communicates with a water tank via a conduit, said conduit being immersed in said tank, thereby forming a pressure measuring device between the suction chambers. Claims 1 and 2 or the preceding paragraph (18)
The device described in.

(21) Device according to any of the preceding claims, characterized in that the impermeable surface is the surface area of the drive roller for the screening belt of the squeezing zone. (22) The device according to item (21), wherein the pressing belt presses a screening belt conveyed by a drive roller.

(23) The device according to any one of claims 1 and 2 and the preceding clause, characterized in that the squeezing belt does not have a self-driving mechanism and can be moved by a screening belt.

(20) The apparatus according to any one of claims 1 and 2 and the preceding claim, wherein the pressure in the compression zone is adjustable by changing the tension of the compression belt.

(25) The apparatus according to any one of claims 1 and 2 and the preceding clause, characterized in that the opening angle of the pressing belt with respect to the screening belt is adjustable.

(26) The device according to claims 1 and 2 or the preceding item (24) or (25), characterized in that a device is formed to freely adjust the tension or opening angle of the compression belt.

(27) The device according to any one of claims 1 and 2 and the preceding clause, characterized in that the residual water squeezed out of the squeezing belt is sucked by one or several suction devices.

(28) A device according to any one of claims 1 and 2 and the preceding clause, characterized in that the squeezing belt is spaced from the drive roller according to a smaller loop angle than the screening belt.

(29) The apparatus according to the preceding item (28), characterized in that the compression belt separated from the screening belt is conveyed a short distance in a tangential direction.

(31) The device according to item (28) above, characterized in that the loop angle is adjustable.

31. Device according to claim 1 or 2 or any of the preceding claims, characterized in that the final guide roller of the squeezing belt has a diameter essentially smaller than the drive roller of the screening belt.

(32) The device according to claim 1 or 2, having the following characteristics. (a) An endless screening belt is freely conveyed as a door cloth in a passing zone, moves in a suction zone over a suction chamber covered with a support member, and is supported by at least two rollers in a squeezing zone. Dewatering in the offshore zone (Aa), which is subjected to the pressure of the squeezing belt, is carried out because low pressure is not used.

(Ab) The screening belt in the abyss zone is arranged with a slight upward slope in the direction of travel, (Ac)
A device disposed in a direction transverse to the direction of movement of the screening belt in the permeation zone spreads and disperses the sewage sludge onto the screening belt with an even thickness and width.
Ad) said device is a dispersing means arranged perpendicularly or obliquely to the surface of the screening belt; (Ae)
(Bb) said device is a roller arranged at a distance from the screening belt and freely rotating in the direction of travel of the screening belt or in the opposite direction;
Dehydration of the suction zone takes place at slightly lower pressures (Bc)
The suction chamber consists of a closed chamber with a holding tank inclined towards the outlet and a supporting member arranged above, provided with side seals for the sewage sludge conveyed by the screening belt via the supporting member. (Bd) The suction chamber is subdivided into several chambers, the low pressure in each partial chamber increasing towards the advancement of the screening belt. are doing,
c(Be) The suction device is equipped with a suction pump, and the connecting pipe line thereof opens into the suction chamber from the upper side of the holding tank, (Bf) The suction chamber communicates with the drainage basin via a vibrator. (Cc) the squeezing zone is arranged in the area of the guide roller of the screening belt; (Cd) the squeezing zone The screening belt 4 of is guided to an impermeable surface, (Ce) the impermeable surface is the surface area of the roller that drives the screening belt in the squeezing zone, (Cf) the squeezing belt is conveyed by the drive roller The screening belt can be pressed.

(Cg) The pressure in the squeezing zone is increased by means of a device which is movable by the screening belt without any self-driving mechanism and is constructed such that the tension of the squeezing belt and the opening angle of the screening belt can be varied at will. is adjustable, (Ch) the residual water squeezed out of the pressing belt is sucked by one or several suction means, (Ci) separated from the vertically running screening belt in the final stage of the pressing zone. The squeeze belt is guided tangentially by a short distance, (Cj)
The squeeze belt is spaced apart from the drive roller according to an adjustable loop angle that is smaller than the loop angle of the screening belt (Ck). The final guide roller of the squeeze belt has a substantially smaller diameter than the drive roller of the screening belt.

(33) Items (7) and (8) above, characterized in that an additional screening belt around the screening belt and at least one end roller is guided between the rollers.
) or the device described in (9).

(34) The device according to (33) above, characterized in that the upper roller and/or the lower roller are movable in a direction above adjacent rollers across the conveying direction. 35) The device according to any one of (33) and (34) above, characterized in that at least two rollers are movable.

36) The preceding item (which is characterized in that the rollers are mounted so as to press against each other at the ends of each roller block)
35).

37) The device according to any one of (33) to (36) above, wherein the fourth drainage zone is installed below the suction zone.

38) Items (33) to (3) above, characterized in that the comprehensive receiving tank accommodates the water removed in all four drainage zones.
The device according to any one of 7).

39) The device according to item (38), characterized in that the water removed in the fourth drainage zone flows directly and the water removed in the filtration and suction zone flows into the receiving tank via a conduit.

(40) The device according to item (38), wherein the drain port of the receiving tank is installed at a high position so that a constant water level is maintained in the tank.

(41) characterized in that the conduit conveying the moisture removed in the suction zone extends into the water of the receiving tank, and the conduit guiding the moisture removed in the filtration zone leads above the water level of the receiving tank; The device according to any one of (33) to (40) above.

(42) Claims 1 and 2 and the preceding paragraph (33), characterized in that the entire device is formed as a unit that is transportable and can be installed anywhere, and a receiving water tank is incorporated therein. The device according to any one of -(41).

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of the device of the present invention, FIGS. 1a and 1b are explanatory diagrams showing detailed modifications of the filtration zone, and FIG.
FIG. 2 is a schematic explanatory diagram of an apparatus of the present invention having a configuration different from that of the apparatus shown in the figure. 10... Filtration zone, 12... Suction zone, 14... Squeezing zone, 16... Sludge,
Sludge cake, 18... Screening belt, 2
0...Roller, 22...Supporting member, 24
...Opening, 26...Suction chamber, 2
8...roller, 30...pressing belt,
32...Roller, 34...Applying knife,
36... Dispersion means, 40... Outlet, 42
... Tank, 52 ... Opening, 56.
...sump, 60...boat, 62...
- Stirring device, 68... Coagulation accelerator, 73...
...Cleaning device, 74...Paper band, 75.
... Conveyor belt, 76 ... Tank, 7
7... Freshwater utilization device, 79... Drum controller, 80... Tension roller, 84...
...Trap, 88...Vacuum pump, 90...
...Tank, 94...Rod.

Claims (1)

[Claims] 1. An endless screening belt that transports sludge and filters water in the sludge, a water permeable press belt that squeezes the sludge on the screening belt, and a water permeable press belt that squeezes the sludge on the screening belt, and a press belt that transfers the water in the sludge squeezed out by the press belt. A sludge dewatering device consisting of a suction means that suctions from the back side via a squeezing belt.