WO2010113822A1 - Suction filtration/concentration method and suction filtration/concentration device - Google Patents

Abstract

A suction filtration/concentration method which comprises a sludge supply stage in which sludge is supplied to a filtration/concentration tank, a filtration/concentration stage in which the supplied sludge is concentrated by filtration within the filtration/concentration tank, a thick-sludge separation stage in which the thick sludge obtained by the filtration/concentration is separated from the outer surface of the filter cloth, and a thick-sludge discharge stage in which the separated thick sludge is discharged outside the filtration/concentration tank, wherein the filtration/concentration stage involves a step in which the thick sludge is adhered to the outer surface of the filter cloth by continuously performing suction at a given suction pressure that enables the thick sludge to retain the shape thereof even when separated in unconcentrated sludge, and the thick-sludge separation stage involves a step in which water is continuously and forcedly sent to the filter cloth via the filtration chamber over a given period to thereby separate, in the supplied unconcentrated sludge, the thick sludge (filter cake) adherent to the outer surface of the filter cloth. A suction filtration/concentration device is provided.

Description

Suction filtration concentration method and suction filtration concentration apparatus

The present invention relates to a suction filtration concentration method and a suction filtration concentration device, and more particularly to a suction filtration concentration method and a suction filtration concentration device that can be efficiently discharged to the outside without re-dissolving concentrated sludge.

Conventionally, a suction filtration concentration apparatus using a siphon principle or a suction pump has been used in a concentration stage of sludge generated when filtering water. Since this suction filtration concentrator includes a bag-like filter cloth that forms a filtration chamber inside, the suction sludge (sludge before concentration) is separated into moisture and concentrated sludge. That is, the moisture contained in the sludge is guided into the filtration chamber and collected as a filtrate by passing through countless pores of the filter cloth. In addition, the sludge from which moisture has been removed and concentrated is attached to the outer surface of the filter cloth, and then is subjected to a peeling treatment and discharged to the outside of the suction filtration concentration device (see Patent Document 1).

Incidentally, when the concentrated sludge adhering to the outer surface of the filter cloth is peeled off from the filter cloth, the following processes (S1) to (S4) have been conventionally performed. First, unconcentrated sludge in the filtration and concentration tank is discharged to the outside and temporarily stored (S1). This is to prevent the concentrated sludge from being reduced in concentration by dissolving the concentrated sludge into the unconcentrated sludge. Next, air of a predetermined pressure (air) is pumped from the inside of the filter cloth to the outside through the filtration chamber (S2). Concentrated sludge adheres to the entire outer surface of the filter cloth, and countless pores of the filter cloth are blocked. Therefore, by sending air, the filter cloth bulges outward and deforms, and when the air passes through numerous pores, the concentrated sludge can be forcibly peeled outward. It becomes. Next, the concentrated sludge is discharged to the outside (S3). From (S2) described above, the peeled concentrated sludge accumulates at the bottom of the filtration concentration tank. Therefore, it is performed to remove concentrated sludge from the filtration concentration tank. Next, the stored unconcentrated sludge is returned to the filtration concentration tank (S4).

Thus, according to the conventional suction filtration concentration apparatus, the concentrated sludge is peeled off from the filter cloth by air in the atmosphere. Thereby, it is possible to peel the concentrated sludge from the filter cloth without reducing the concentration of the sludge. The air pressure is adjusted according to the degree of adhesion of the concentrated sludge to the filter cloth.

However, there are the following technical problems in such concentrated sludge stripping technology.

First, due to the compressibility of air as a stripping medium, it is difficult to achieve desired stripping characteristics for concentrated sludge. For example, if the concentrated sludge adheres to the entire outer surface of the filter cloth, the countless pores of the filter cloth are blocked by the concentrated sludge. For this reason, if the concentrated sludge adhering to the entire outer surface is not sufficiently shape-retaining and the adhesion between the filter cloth and the concentrated sludge is not uniform, if air is pumped to the filter cloth, some pores in the filter cloth Therefore, it becomes easy for air to leak out. Further, once air leaks from a part of the pores of the filter cloth, the air easily flows out from the part. That is, since it becomes difficult for air to flow out from the other part of the filter cloth, it is difficult to peel the concentrated sludge adhering to the other part. Therefore, nonuniformity of peeling is caused in the circumferential direction of the bag-shaped filter cloth, and the concentrated sludge that cannot be peeled remains on the filter cloth. If the concentrated sludge remains on the filter cloth, it is necessary to take another means, for example, scraping the residual concentrated sludge manually, thereby reducing the processing efficiency of the concentrated sludge.

Also, if the concentrated sludge is peeled off in the non-concentrated sludge without discharging the non-concentrated sludge from the filtration and concentration tank, the concentrated sludge is re-dissolved, so that the concentrated sludge cannot be efficiently discharged to the outside. Therefore, as described above, conventionally, the concentrated sludge has been peeled off from the filter cloth by air in the atmosphere. However, in such a peeling process, a large noise is generated when the concentrated sludge is peeled from the filter cloth. Therefore, there exists a problem that the installation place of a suction type sludge concentration apparatus is restricted. This is the second problem. The generation of such a large noise is caused by, for example, an ejection sound caused when air is ejected from countless pores of the filter cloth when air is pumped from the inside of the filter cloth. Another cause is the impact sound and the like when the peeled concentrated sludge falls to the bottom of the filtration and concentration tank. That is, this collision sound is generated when the concentrated sludge falls in the atmosphere and collides with the bottom of the filtration and concentration tank in the sludge concentration tank where the unconcentrated sludge is discharged to the outside. Since the ejection sound and the collision sound using the inside of the filtration and concentration tank as a sound source resonate in the filtration and concentration tank, they easily become excessive noise.

Third, the concentrated sludge that accumulates at the bottom of the filtration and concentration tank is in a form with no shape retention, and it is difficult to discharge the concentrated sludge to the outside. This is because the concentrated sludge was peeled off from the filter cloth by air in the atmosphere. That is, the concentrated sludge is peeled off from the filter cloth by air, and falls in the air with low resistance toward the bottom of the filtration concentration tank and collides. Due to this collision, the concentrated sludge loses its shape and accumulates at the bottom as a precipitate having no shape retention. Here, “shape retention” refers to the degree to which the concentrated sludge adhered to the filter cloth maintains the plate-like form (size, thickness, etc.) at the time of attachment. For example, if the concentrated sludge at the time of peeling peels off as a large lump (a lump with a longest dimension of 100 mm or more, preferably 150 mm or more) and the shape does not collapse much at a later stage, It can be judged good. On the other hand, if it becomes a small lump at the time of peeling, or the lump after peeling breaks down into a small lump, or if it breaks and becomes extremely small, it can be said that the shape retention is poor.

In connection with such technical problems, Patent Document 2 discloses a method and an apparatus for concentrating clean water sludge. In the method and apparatus described in Patent Document 2, a flat membrane module is disposed in a sludge concentration tank (corresponding to the above-described filtration concentration tank), and is sucked intermittently by a suction pump, thereby flowing into the sludge concentration tank. The water sludge is filtered and concentrated. More specifically, the water in the water sludge that has flowed into the sludge concentration tank passes through the pores of the flat membrane module and is collected as a filtrate. On the other hand, clean water sludge that cannot pass through the pores adheres to the outer surface of the flat membrane module, thereby forming a concentrated sludge having a concentrated concentration of about 25%. Next, air or water is intermittently pumped into the flat membrane module by a blower. With this intermittently pumped air or water, the concentrated sludge adhering to the outer surface of the flat membrane module is peeled off in unconcentrated clean water sludge. The peeled concentrated sludge settles in unconcentrated clean water sludge and accumulates at the bottom of the sludge concentration tank. Next, the concentrated sludge is captured by the concentrated sludge separation screen provided at the bottom of the sludge concentration tank, and the unconcentrated sludge is discharged to the outside. In this way, concentrated sludge and unconcentrated sludge are separated in the sludge concentration tank. Next, the water sludge accumulated at the bottom of the sludge concentration tank is discharged to the outside using a screw conveyor.

Thus, in patent document 2, the peeling technique of the concentrated sludge by the air or water in a liquid (clean water sludge) is disclosed, and it can solve the said 1st thru | or 3rd technical problem. Is possible. However, in the filtration and concentration apparatus of Patent Document 2, the cake (lumps or layers) of the concentrated sludge adhering to the outer surface of the flat membrane module is peeled off in the form of a relatively large lump from the cake piece (filter cloth or membrane surface). Even if the concentrated sludge can be peeled off from the outer surface of the flat membrane module, the cake piece of the peeled concentrated sludge is stratified and fragile under the influence of the bubbling caused by the bubbles ejected from the air diffuser. .

That is, in the apparatus of Patent Document 2, the sludge is filtered and concentrated using a flat membrane module by a suction pump. In other words, when sludge is adhered to the outer surface of the flat membrane module, the concentration of sludge is as high as 20% or more. On the other hand, in order to facilitate the separation of the concentrated sludge, suction by a suction pump is performed “intermittently”. For this reason, it is essential that the sludge adhering to the outer surface of the flat membrane module is intentionally made dense. In other words, the concentrated sludge cake (lumps or layers) adhering to the filter cloth in such a state has a shape-retaining property that does not re-dissolve before the stripping process, but after stripping, it is soft and small (small pieces) ), Or inevitable to have a shape. Furthermore, according to Patent Document 2, air or water is supplied “intermittently” in order to facilitate separation of the concentrated sludge, and the filtration membrane is repeatedly expanded and contracted. At the same time, the outside of the flat membrane module is aerated (ie, “bubbling”). Further, when the unconcentrated sludge is discharged, the unconcentrated sludge flows between the concentrated sludge of the cake pieces. Therefore, the concentrated sludge of soft small and coarse cake pieces collected at the bottom of the sludge concentration tank after peeling is strongly affected by these effects, and the cake pieces are broken into layers. Therefore, in the filtration concentration apparatus of Patent Document 2, the cake pieces are re-dissolved before discharging the concentrated sludge, and the concentrated sludge cannot be taken out efficiently.

In addition, it is difficult to peel the concentrated sludge in the unconcentrated sludge using the siphon type filtration concentration apparatus of Patent Document 1. This is because if the concentrated sludge is peeled off in the unconcentrated sludge, the concentrated sludge adhering to the outer surface of the filter cloth is dissolved in the unconcentrated sludge. In addition, the concentrated sludge cannot be peeled in a cake-like state (a lump or layer state when the sludge adheres to the filter cloth). Furthermore, the concentrated sludge accumulated at the bottom of the sludge concentration tank cannot be discharged to the outside while maintaining its shape retention.

That is, the siphon type filtration concentration apparatus using the filter cloth which is the filtration system disclosed in Patent Document 1 is different from the case of using the filter membrane as in Patent Document 2, in the first place, the solid content having a particle size smaller than the mesh of the filter cloth. To capture. Therefore, a condensed and dense membrane layer of solids is formed on the surface of the filter cloth, and the solid content smaller than the mesh of the filter cloth is filtered (so-called dynamic filtration). A siphon type filtration concentrator using a filter cloth can be filtered even if the suction force is not so strong, so that the solid content is not concentrated on the membrane surface and the filtration is not hindered. Intermittent operation (that is, interruption of the filtration and concentration operation by backwashing) is unnecessary. Moreover, because of the low pressure suction, in addition to the concentrated concentration of the attached concentrated sludge being low, the adhesion strength between the attached solids is weak. Therefore, when there is no suction force, solids cannot adhere to each other, and when sludge is concentrated and filtered with a filter cloth using a siphon, the outside of the filter cloth is removed in the unconcentrated sludge in the filtration and concentration tank. Technology in the industry predicts that when the concentrated sludge adhered to the surface is peeled off with compressed air, etc., the concentrated sludge (solid content) is weakly adhering, so it diffuses and dissolves in the unconcentrated sludge, reducing the concentration. It was common sense.

JP 2006-218455 A JP 2000-325998 A

Therefore, in view of such conventional technical problems, an object of the present invention is to provide a suction filtration concentration method and a suction filtration concentration device that can be efficiently discharged to the outside without re-dissolving the concentrated sludge. is there. That is, the cake of concentrated sludge adhering to the filter cloth by continuous suction under a predetermined suction pressure is hardened and enlarged, and water can be continuously pumped at the time of peeling, so that the hardness, size and shape retention not to be re-dissolved. An object of the present invention is to provide a suction filtration and concentration method and a suction filtration and concentration device capable of peeling concentrated sludge in a state having the properties. In particular, an object of the present invention is to provide a suction filtration concentration method and a suction filtration concentration device that can reduce re-dissolution even if concentrated sludge is moved in water.
In order to achieve the above object, the present invention provides the following suction filtration concentration method and suction filtration concentration apparatus.

[1] A suction filtration concentration method in which sludge is suction filtered through a filter cloth in a filtration and concentration tank, and the filtrate is collected through a filtration chamber inside the filter cloth, and the sludge is adhered to the outer surface of the filter cloth as concentrated sludge. A sludge supply stage for supplying sludge into the filtration and concentration tank, a filtration and concentration stage for filtering and concentrating the supplied sludge in the filtration and concentration tank, and separating the filtered and concentrated sludge from the outer surface of the filter cloth. It has a concentrated sludge stripping stage and a concentrated sludge discharge stage that discharges the stripped concentrated sludge to the outside of the filtration and concentration tank, and the filtration and concentration stage retains shape even if the concentrated sludge is stripped in unconcentrated sludge. The concentrated sludge is adhered to the outer surface of the filter cloth by continuously sucking under a predetermined suction pressure that can maintain the concentration, and the concentrated sludge stripping stage includes the supplied unconcentrated sludge. Filter through the filtration chamber in the sludge Towards by pumping over a continuous predetermined time water, comprising the step of separating the concentrated sludge (filter cake) adhering to the filter cloth of the outer surface, suction filtered and concentrated way.

[2] The suction filtration concentration method according to [1], wherein the concentrated sludge discharge step includes a step of scooping out the concentrated sludge of cake pieces accumulated at the bottom of the filtration concentration tank in the unconcentrated sludge.

[3] The concentrated sludge discharge stage is performed after repeating the cycle consisting of the filtration concentration stage and the concentrated sludge stripping stage a predetermined number of times, and is filtered by the sludge supply stage before the filtration concentration stage in each cycle. The suction filtration concentration method according to [1] or [2], including a step of supplying sludge to the concentration tank.

[4] The concentrated sludge discharging step is performed in parallel with the filtration and concentration step, and has a step of supplying sludge into the filtration and concentration tank by the sludge supply step before the filtration and concentration step [1] ] Or the suction filtration concentration method according to [2].

[5] The suction filtration concentration method according to any one of [1] to [4], in which the water pumped into the filtration chamber uses the filtrate collected in the filtration chamber in the concentrated sludge peeling step.

[6] A suction filtration and concentration device that collects sludge through a filter chamber by filtering the sludge through a filter cloth and deposits the sludge as a concentrated sludge on the outer surface of the filter cloth. Sludge supply means for supplying sludge into the concentration tank, filtration and concentration means for filtering and concentrating the supplied sludge in the filtration and concentration tank, and concentrated sludge removing means for separating the filtered and concentrated concentrated sludge from the outer surface of the filter cloth And concentrated sludge discharge means for discharging the peeled concentrated sludge to the outside of the filtration and concentration tank, and the filtration and concentration means can maintain the shape retention even if the concentrated sludge is peeled off in the unconcentrated sludge. Having a means for adhering the concentrated sludge to the outer surface of the filter cloth by continuously sucking under a predetermined suction pressure of about a degree, and the concentrated sludge removing means is filtered in the supplied unconcentrated sludge. Water towards the filter cloth through the chamber By continuously pumping for a predetermined time, and means for separating the thickened sludge (filter cake) adhering to the filter cloth of the outer surface, suction filtration concentrator.

[7] The suction filtration and concentration apparatus according to [6], wherein the concentrated sludge discharging means has means for scooping out the concentrated sludge of cake pieces accumulated at the bottom of the filtration and concentration tank in the unconcentrated sludge.

[8] The concentrated sludge discharging means is a mesh-shaped saucer with a handle that is disposed at the bottom of the filtration and concentration tank and has a length that extends upward from the upper opening of the filtration and concentration tank. [6] The suction filtration concentration apparatus according to 1.

[9] The concentrated sludge discharging means is a bucket conveyor that extends from the bottom of the filtration and concentration tank to the outside through the upper opening of the filtration and concentration tank, and has a conveyor surface that moves outward from the bottom of the filtration and concentration tank. The suction filtration concentration apparatus according to [6], which is disposed upward.

[10] In the means capable of continuously pumping water toward the filter cloth through the filter chamber, a plurality of water supply pipes communicate with the filter chamber at different levels in the height direction of the filter cloth. The suction filtration concentration apparatus according to [6], which is provided as described above.

According to the suction filtration concentration method and the suction filtration concentration device according to the present invention, it is possible to achieve an excellent effect that the concentrated sludge can be efficiently discharged to the outside without re-dissolving the concentrated sludge before discharging. . That is, the concentrated sludge cake is hardened and enlarged by continuous suction under a predetermined suction pressure, and the water is continuously pumped at the time of peeling, so that it is concentrated in a state with hardness, size and shape retention that does not re-dissolve. There is an effect that the sludge can be peeled off. In particular, according to the method and apparatus of the present invention, re-dissolution can be prevented even when concentrated sludge is moved in water.

It is a flowchart of the suction filtration concentration method of this invention. It is a schematic diagram which shows one Embodiment of the suction filtration concentration apparatus of this invention. It is a schematic diagram which shows another embodiment of the suction filtration concentration apparatus of this invention. It is a schematic diagram which shows another embodiment of the suction filtration concentration apparatus of this invention. It is a schematic diagram which shows another embodiment of the suction filtration concentration apparatus of this invention. It is a schematic diagram which shows another embodiment of the suction filtration concentration apparatus of this invention. It is a schematic diagram which shows another embodiment of the suction filtration concentration apparatus of this invention. It is a schematic diagram which shows another embodiment of the suction filtration concentration apparatus of this invention. It is a schematic diagram of the side surface which shows the filter plate in the suction filtration concentration apparatus of this invention. In the suction filtration concentration apparatus of this invention, it is a schematic diagram which is a partial top view which shows the state by which the several filtration board is suspended and supported by the filtration concentration tank. In the suction filtration concentration apparatus of the present invention, it is a perspective view showing a state where a plurality of filtration plates are arranged adjacent to each other. It is the schematic which shows the state in the bulging about the filter cloth of the suction filtration concentration apparatus of this invention. It is the schematic which shows the state in filtration about the filter cloth of the suction filtration concentration apparatus of this invention. It is a schematic diagram which shows the processing flow in one Embodiment of the suction filtration concentration apparatus of this invention. It is a schematic diagram which shows the processing flow in another embodiment of the suction filtration concentration apparatus of this invention. It is a flowchart of the suction filtration concentration method of this invention. It is a flowchart of the suction filtration concentration method of this invention. It is a schematic diagram which shows the suction filtration concentration apparatus which concerns on another embodiment of this invention. It is a schematic diagram which shows the peeling effect | action in the suction filtration concentration apparatus of this invention. It is a schematic diagram which shows the peeling effect | action in the suction filtration concentration apparatus of this invention. It is a schematic block diagram of the suction filtration concentration apparatus which concerns on the Example of this invention. It is a graph which shows the relationship between peeling time and a peeling rate by using peeling pressure as a parameter regarding the test result in the test apparatus of FIG.

Embodiments of the suction filtration concentration method and apparatus according to the present invention will be described in detail below with reference to the drawings, but the present invention is not limited to these embodiments. In addition, below, it demonstrates as an example the case where sludge generated in a water purification plant, a sewage plant, etc. is made into the object of filtration concentration.

[1] Configuration in the suction filtration concentration method of the present invention:
In the suction filtration concentration method of the present invention, as shown in FIG. 1, the sludge is filtered through suction through a filter cloth in a filtration and concentration tank, whereby the filtrate is recovered through the filtration chamber inside the filter cloth, and the sludge is used as the concentrated sludge. A suction filtration concentration method for adhering to the outer surface of a filter cloth, comprising a sludge supply stage (T1) for supplying sludge into a filtration concentration tank, and a filtration concentration stage for filtering and concentrating the supplied sludge in a filtration concentration tank ( T2), a concentrated sludge stripping stage (T3) for stripping the filtered and concentrated concentrated sludge from the outer surface of the filter cloth, and a concentrated sludge discharge stage (T4) for discharging the stripped concentrated sludge to the outside of the filtration and concentration tank. In the filtration and concentration step (T2), continuous suction is performed under a predetermined suction pressure that can maintain shape retention even if the concentrated sludge is peeled in unconcentrated sludge. To attach the concentrated sludge to the outer surface of the filter cloth In the concentrated sludge peeling step (T3), in the supplied unconcentrated sludge, water is continuously pumped through the filtration chamber toward the filter cloth for a predetermined time. And a step of peeling off the filter cake adhering to the outer surface of the filter cloth.

According to the method of the present invention, the cake of concentrated sludge adhering to the filter cloth is not formed in layers, and the cake can be hardened and further peeled as concentrated sludge of large cake pieces. Therefore, the concentrated sludge of the cake piece is less likely to be re-dissolved even in the unconcentrated sludge, and the concentrated sludge can be taken out efficiently. That is, the liquid to be treated containing the object to be filtered and concentrated is suctioned continuously under a predetermined suction pressure, not intermittently, and passed through the filter cloth, so that the liquid to be treated is filtered and provided on the filter cloth. Pass through innumerable pores. In this way, the filtrate is recovered. On the other hand, an object to be filtered and concentrated cannot pass through innumerable pores and adheres to the outer surface of the filter cloth, thereby being concentrated and ensuring adhesion with the filter cloth. In other words, a concentrated concentrated sludge cake is formed on the outer surface of the filter cloth by sucking continuously instead of intermittently.

Further, after completion of filtration and concentration, water is continuously pumped from the surface opposite to the surface to which the concentrated sludge is adhered in the liquid to be treated after filtration and concentration toward the filter cloth for a predetermined time. At that time, the pressure-fed water (hereinafter also referred to as “pressure-fed water” as appropriate) tends to flow into the liquid to be treated through the countless pores of the filter cloth. However, the concentrated sludge adheres to the entire outer surface of the filter cloth and blocks countless pores of the filter cloth. Therefore, the liquid pressure of the liquid to be treated is uniformly applied to the outer surface to which the concentrated sludge has adhered. That is, the concentrated sludge adhering to the outer surface of the filter cloth is pressed into the liquid to be treated until the water pressure of the water fed into the filtration chamber overcomes at least the liquid pressure of the liquid to be treated. Therefore, the concentrated sludge does not peel from the surface of the filter cloth until the water pressure of the water pumped into the filtration chamber overcomes at least the liquid pressure of the liquid to be treated. Thereby, the pressure of the pumping water in the filtration chamber rises, and the filter cloth swells with it.

Here, since the pumped water is liquid water, it has an incompressible property compared to a gas such as air. Therefore, it is possible to prevent a situation caused by the conventional separation by air in the atmosphere. That is, in the case of conventional pneumatic feeding, the concentrated sludge adhering to the surface of the filter cloth from the filter cloth close to that part is partially directed into the liquid to be treated due to a local pressure increase in the filtration chamber. Pressed. It is possible to prevent the situation where the pressed concentrated sludge is peeled off from the surface of the filter cloth and the air continues to flow out only from the open pores. In other words, in the present invention, when the water pressure of the pumped water reaches a predetermined pressure uniformly in the filtration chamber, the concentrated sludge adhering to the surface of the filter cloth is covered all over the filter cloth. It becomes possible to press into the processing liquid. Therefore, it becomes possible to peel the concentrated sludge (filter cake) uniformly from the surface of the filter cloth in the circumferential direction.

Furthermore, in the present invention, since sludge is continuously sucked under a predetermined suction pressure, a densified hard concentrated sludge is formed on the surface of the filter cloth, and adhesion with the filter cloth is also increased. Therefore, even if the suction is stopped and pressed toward the liquid to be treated at the same time, the concentrated sludge becomes a layer and does not peel off while being broken. That is, when the cake of concentrated sludge adhering to the filter cloth in a densified and hard state is peeled off, it is accumulated in the unconcentrated sludge of the filtration and concentration tank as a cake piece of large concentrated sludge. Therefore, since the cake piece of the concentrated sludge is small broken or difficult to re-dissolve when discharged from the filtration and concentration tank, the concentrated sludge can be discharged efficiently and easily outside the filtration and concentration tank.

In the present invention, a siphon type suction filtration method or a suction filtration method using a suction pump can be adopted as the suction filtration method.
Next, the suction filtration concentration method of the present invention will be described together with the suction filtration concentration device of the present invention. Here, the siphon type suction filtration concentration device and method will be described.

[2] Configuration of the suction filtration concentration apparatus of the present invention:
As shown in FIGS. 2A to 2G, the suction filtration concentration apparatus of the present invention collects the filtrate through a filtration chamber inside the filter cloth and concentrates the sludge by performing siphon suction filtration through the filter cloth. A siphon-type suction filtration and concentration device that adheres to the outer surface of the filter cloth as sludge (filter cake). The sludge supply means supplies sludge into the filtration and concentration tank, and the supplied sludge is filtered and concentrated in the filtration and concentration tank. Filtration concentration means, concentrated sludge peeling means for peeling the filtered and concentrated concentrated sludge from the outer surface of the filter cloth, and concentrated sludge discharge means for discharging the peeled concentrated sludge to the outside of the filtration and concentration tank, The filtration and concentration means filters the concentrated sludge (filter cake) by continuously sucking it under a predetermined suction pressure that can maintain the shape retention even if the filter cake is peeled off in the unconcentrated sludge. Means to adhere to the outer surface of the fabric The concentrated sludge stripping means has an outer surface of the filter cloth by continuously pumping water through the filtration chamber toward the filter cloth over a predetermined time in the supplied unconcentrated sludge. It is comprised as the siphon type suction filtration concentration apparatus 10 which has a means to peel the filter cake adhering to.

Specifically, as shown in FIGS. 2A to 2E, the siphon type suction filtration and concentration apparatus 10 is disposed in the filtration and concentration tank 12 for storing the sludge to be filtered and concentrated, and the filtration and concentration tank 12. Filter plate 14, suction unit 16 for sucking sludge, concentrated sludge stripping unit 20 for stripping concentrated sludge adhering to the outer surface of filter cloth 18 provided on filter plate 14 by suction unit 16, and concentrated sludge stripping unit A concentrated sludge scooping portion 23 for discharging the concentrated sludge of cake pieces separated by 20 and accumulated at the bottom of the filtration and concentration tank 12 is constituted. Moreover, it has the concentrated sludge discharge pipe 30 and the concentrated sludge discharge valve 32 for discharging | emitting the cake piece and liquid concentrated sludge as needed. By opening the concentrated sludge discharge valve 32, cake pieces and liquid concentrated sludge accumulated at the bottom of the filtration and concentration tank 12 are discharged to the outside through the concentrated sludge discharge pipe 30 due to gravity drop. The concentrated sludge discharge pipe 30 and the concentrated sludge discharge valve 32 preferably have a large diameter that can discharge small pieces of concentrated sludge, for example, a nominal diameter of 200 A or more (200 mmφ or more).

(Sludge supply stage / sludge supply means)
The sludge supply stage (means) is a stage (means) for supplying sludge into the filtration concentration tank 12 which is a filtration concentration tank. That is, the sludge supply means is generally constituted by the sludge supply / discharge pipe 24, the sludge supply / discharge valve 26, the sludge supply / discharge pump 28, etc. as shown in FIGS. 2A to 2F. The sludge supply process in the sludge supply stage (T1) shown in FIG. 1 is realized by the sludge supply / discharge pipe 24, the sludge supply / discharge valve 26, the sludge supply / discharge pump 28, and the like. However, it is not limited to this. In addition, a sludge supply pump and a discharge pump may be provided separately as separate systems.

More specifically, the filtration concentration tank 12 is a container having a bottomed rectangular cross section, and has a volume capable of installing a filter plate 14 to be described later. One end of a sludge supply / discharge pipe 24 for supplying sludge into the filtration concentration tank 12 communicates with the side wall 22 of the filtration concentration tank 12. Further, a sludge supply / discharge pump 28 capable of forward / reverse operation is connected via a sludge supply / discharge valve 26 provided in the middle of the sludge supply / discharge pipe 24. Thus, the sludge can be supplied into the filtration and concentration tank 12 by opening the sludge supply / discharge valve 26 and operating the sludge supply / discharge pump 28. Further, by operating the sludge supply / discharge pump 28 in reverse, the unconcentrated sludge in the filtration and concentration tank 12 can be discharged from the filtration and concentration tank 12.

2A to 2F, the sludge is supplied into the filtration and concentration tank 12 through the sludge supply / discharge pipe 24. As shown in FIG. 2G, the water purification tank 2 is disposed upstream of the filtration and concentration tank 12. The raw water R can be separated into purified water C and sludge X in advance, and the sludge X can be supplied to the filtration and concentration tank 12. Sludge X is supplied to the filtration and concentration tank 12 through the sludge supply pipe 4 by opening the sludge supply valve 8 and operating the sludge supply pump 6. The separated purified water C is further processed on the downstream side and used as, for example, drinking water. In addition, the water purification tank 2 may be a conventionally well-known thing, and receives raw | natural water, for example, a raw material water is isolate | separated into purified water and sludge by adding a flocculant in a tank.

(Filtration concentration stage / filtration concentration means)
The filtration concentration stage (means) is a stage (means) for further filtering and concentrating the sludge supplied in the sludge supply stage (means) in a filtration concentration tank. That is, the filtration concentration step (T2) shown in FIG. 1 is continuously performed under a predetermined suction pressure that can maintain the shape retaining property even if the concentrated sludge (filter cake) is peeled in the unconcentrated sludge. This is the stage of suction. Furthermore, the concentrated sludge (filter cake) is attached to the outer surface of the filter cloth by such continuous suction. The filtration concentration process in the filtration concentration step (T2) is performed, for example, by a filtration concentration means including the filter plate 14, the suction pipe 31, the suction valve 33, the distribution pipe 34, the vacuum pump 35, etc. shown in FIGS. 2A to 2G. Realized. However, it is not limited to this.

Specifically, the filter plate 14 is connected to a filtrate storage tank 36 via a distribution pipe 34 at the upper part thereof. The filtrate storage tank 36 is installed outside the filtration concentration tank 12, and one end of the filtrate discharge pipe 38 is connected to and connected to the filtrate storage tank 36. The filtrate discharge pipe 38 extends vertically downward, and a filtrate discharge valve 40 is provided on the way.

Further, the distribution pipe 34 and the filtrate discharge pipe 38 are connected in an inverted U shape through the filtrate storage tank 36. Thereby, the filtrate filtered in the filtration concentration tank 12 is discharged out of the filtration concentration tank 12 using the principle of siphon. Further, the suction pipe 31 is branched and connected to a distribution pipe 34 and is connected to a vacuum pump 35 via a suction valve 33 provided in the middle. Accordingly, when the vacuum pump 35 is operated with the suction valve 33 opened, the liquid to be processed in the filtration and concentration tank 12 is sucked into the distribution pipe 34. In this manner, the filtrate can be discharged to the outside through the filtrate discharge pipe 38 using the principle of siphon.

Here, the siphon suction pressure is determined in accordance with the level difference between the end portion and the top portion of the inverted U-shaped tube constituted by the distribution pipe 34 and the filtrate discharge pipe 38. However, the suction pressure for practical use of the suction filtration concentration device 10 is preferably 0.02 MPa to 0.08 MPa. Under such a relatively low suction pressure, the sludge in the filtration and concentration tank 12 is continuously sucked, so that the concentrated sludge can be adhered to the outer surface of the filter cloth 18. In particular, even if the concentrated sludge is peeled off from the filter cloth 18 by the concentrated sludge peeling unit 20 by being continuously sucked, the shape of the cake pieces as the concentrated sludge in the unconcentrated sludge in the filtration concentration tank 12 is preserved. Therefore, the adhesion strength and hardness of the concentrated sludge to the outer surface of the filter cloth 18 can be obtained so that the property can be maintained. The standard of continuous suction is continuous suction until the thickness of the concentrated sludge adhering to the filter cloth is about 5 mm to 20 mm, preferably about 8 mm to 15 mm. The suction duration time at that time is about 30 minutes to 4 hours. Further, the suction method in the present application is not limited to the siphon type, and the suction pressure may be generated by a suction pump such as a vacuum pump.

As shown in FIG. 5, a plurality of the filtration plates 14 are arranged in the filtration concentration tank 12 with the flat portion 13 extending in the vertical direction. That is, the plurality of filter plates 14 (14A to 14E) are arranged adjacent to each other with a predetermined interval D therebetween. As the distance D between adjacent filter plates 14 is reduced, the number of filter plates 14 that can be installed in the filter concentration tank 12 can be increased, thereby increasing the total filtration area. However, it is preferable to determine the interval between the adjacent filter plates 14 from the viewpoint of ensuring the maximum filtration area while preventing the adjacent filter plates 14 from contacting each other. This is to swell the filter cloth 18 in order to peel the concentrated sludge adhering to the filter cloth 18 of the filter plate 14. That is, since the filter cloth 18 protrudes toward the adjacent filter plate 14 due to the bulging of the filter cloth 18, the filter cloth 18 comes into contact with the adjacent filter plate 14 and the filtration area is reduced. This is because there is a possibility that it cannot be filtered.

(Concentrated sludge stripping stage / Concentrated sludge stripping means)
The concentrated sludge stripping stage (means) is a stage (means) for stripping the concentrated sludge filtered and concentrated in the filtration concentration stage (means) from the outer surface of the filter cloth. This concentrated sludge stripping step (means) is to suck continuously in a non-concentrated sludge under a predetermined suction pressure that can maintain shape retention even if stripped sludge (filter cake) is stripped. Thus, a step (means) for attaching the concentrated sludge (filter cake) to the outer surface of the filter cloth is provided. As this concentrated sludge stripping means (concentrated sludge stripping section 20), for example, a means provided with a water inflow pipe 42, a water inflow valve 44, a liquid feed pump 46, etc. as shown in FIGS. 2A to 2G can be cited. it can. Furthermore, it can be said that the filter plate 14 also constitutes the concentrated sludge stripping means. 1 is realized by the concentrated sludge removing means such as the water inflow pipe 42, the water inflow valve 44, and the liquid feed pump 46, as shown in FIG. However, it is not limited to this.

Specifically, one end of a water inflow pipe 42 is connected to the filtrate storage tank 36, and a water inflow valve 44 and a liquid feed pump 46 are connected in the middle thereof. As a result, when the liquid feed pump 46 is operated with the water inflow valve 44 open, water (pressure feed water) is formed inside the filter plate 14 through the water inflow pipe 42 and the distribution pipe 34. (Supplied later). In the present embodiment, the filtrate in the filtrate storage tank 36 is used as the pressure feed water, and a switching valve 47 is provided for this purpose. In this way, when the concentrated sludge is peeled from the filter cloth 18, the filter cloth 18 is expanded. In this case, the peeling pressure and / or the peeling time may be adjusted by using the liquid feed pump 46 and the water inflow valve 44 so that the attached concentrated sludge is peeled off from the filter cloth 18 as cake pieces.

Here, in the concentrated sludge stripping step (means), when sludge is to be filtered and concentrated, it is important to continuously pump water as a stripping medium over a predetermined time, not intermittently. That is, by continuously pumping water as a stripping medium over a predetermined time, the concentrated sludge dissolves in the unconcentrated sludge even if the concentrated sludge adhered to the filter cloth is stripped in the unconcentrated sludge. The shape retention can be maintained as a cake piece. Note that, as described above, it is preferable to use the filtrate collected in the filtration chamber 76 as the water to be pumped into the filtration chamber 76 in the concentrated sludge peeling step. That is, it is preferable to use a filtrate that is recovered in the filtration chamber 76 by filtering the sludge with the filter cloth 18 as the water as the stripping medium for the concentrated sludge.

Further, as shown in FIGS. 2A to 2G and 3, the filter plate 14 accommodates the filter frame 48, the support plate 50 disposed inside the filter frame 48, and the support plate 50 therein. The filter cloth 18 having a bag shape and a plurality of coil springs 54 provided between the filter frame 48 and the support plate 50 are schematically configured. The filter frame 48 has a hollow rectangular shape, and has an upper side 56, a lower side 58, and both side sides 60 and 62 between the upper and lower sides. The filter plate 14 is suspended and supported from the inner surface of the filtration concentration tank 12 by both end portions of the upper side 56. More specifically, as shown in FIGS. 3 and 4, extension portions 64 are provided at both ends of the upper side 56. On the other hand, a pair of guide plates 70 (70A) and 72 (72A) projecting inward are provided on the inner surface 68 of the filtration concentration tank 12. Moreover, the edge part of the extension part 64 (64A, 64B, 64C) is arrange | positioned between a pair of guide plates 70 (70A) and 72 (72A). Furthermore, an engagement plate 66A fixed to the upper surface of the extension portion 64 (64A, 64B, 64C) is placed on the upper surface of the pair of guide plates 70 (70A), 72 (72A). Thereby, each filter plate 14 is suspended and supported by the filtration concentration tank 12. The interval between adjacent filter plates 14 is determined by selecting a pair of guide plates 70 (70A) and 72 (72A) that support the filter plates 14 in a suspended manner. However, the interval D between the adjacent filter plates 14 may be changed as appropriate. In such a case, for example, the filter plate 14 is suspended and supported in accordance with the amount of concentrated sludge adhering to the filter cloth 18, the magnitude of the negative pressure due to suction, the lateral section length of the filter cloth 18, and the like. A case where a pair of guide plates 70 (70A) and 72 (72A) is selected is mentioned.

The support plate 50 is composed of a net or a mesh net and is formed in a rectangular shape. The support plate 50 is provided with innumerable small openings. Further, the surface of the support plate 50 is provided with an uneven portion (not shown) extending in the vertical direction. Between the recess of the support plate 50 and the inner surface of the filter cloth 18, a plurality of filtrate flow paths extending in the vertical direction of the support plate 50 are formed. Such a support plate 50 does not substantially cause deformation in the plane of the support plate 50 due to the filter cloth 18 being immersed in sludge, or deformation that impairs the flatness of the support plate 50. It is preferably formed from a hard material. Furthermore, it is formed of a hard material so that the shrinkage in the plane of the support plate 50 accompanying the swelling of the filter cloth 18 or the deformation that impairs the flatness of the support plate 50 does not occur substantially. It is preferable. For example, resin is more preferable. Specifically, for example, polyethylene or EVA resin is preferable. By adopting such a material, when the filter cloth 18 is immersed in sludge for a long period of time or when the filter cloth 18 is bulged, the filter plate 14 (support plate 50) is used by the coil spring 54 described later. It is possible to make the tension acting on the lens constant at all times.

The filter cloth 18 is preferably made of chemical fiber or metal, and in the case of chemical fiber, nylon, polypropylene, and polyester are particularly preferable. For example, it is preferable to use monofilament yarns that have a high cleaning effect and are less likely to be clogged with respect to the type of fiber. A multifilament formed by twisting a plurality of fibers may be employed if importance is attached to strength and fine particle capturing ability. The diameter of the yarn to be employed may be determined appropriately for each of the warp and the weft in consideration of the required strength of the filter cloth 18 and the elongation rate. Regarding the weaving method of the fabric, it is preferable to use a satin weave which has a high cleaning effect and hardly clogs. A plain weave or twill weave may be used if emphasis is placed on the roughness of the eyes or the ability to capture fine particles. Further, regarding the density of the woven yarn, the warp and the weft may be appropriately determined in consideration of the required strength of the filter cloth 18 and the elongation rate. For example, the filter cloth 18 is preferably formed in a bag shape in which a pair of rectangular cloth bodies are overlapped and the peripheral edges are sewn. Alternatively, a single rectangular cloth body may be bent so that opposing edges overlap with each other, and formed into a bag shape in which peripheral edges are sewn. A plurality of eyelets 78 are provided around the filter cloth 18, and one end of the coil spring 54 is hooked to the eyelets 78.

2A to 2G and FIG. 3, the filter cloth 18 is provided with a plurality of seams 74 extending in the vertical direction of the filtration concentration tank 12, and the seams 74 allow the filter cloth 18 to be placed therein. The support plate 50 to be accommodated is sewn together. As a result, as shown in FIGS. 6A and 6B, a filtration chamber 76 partitioned by adjacent seams 74 is formed inside the filter cloth 18. The horizontal pipe 15 provided in the upper part in the filter cloth 18 is connected to the front-end | tip of the branch pipe 34 (refer FIG. 3). The horizontal pipe 15 is provided with an outflow hole (not shown) that communicates with each filtration chamber 76 downward. Then, water as a peeling medium is pumped into each filtration chamber 76 through an outflow hole provided in the branch pipe 34 and the horizontal pipe 15. 6A is a schematic diagram showing a state during bulging, and FIG. 6B is a schematic diagram showing a state during filtration.

Furthermore, when the length in the vertical direction of the filter cloth 18 is long and the difference in the hydraulic pressure due to the sludge in the filtration and concentration tank 12 is large, the water supply pipes at different levels in the height direction of the filter cloth 18, You may provide so that it may connect with a filtration chamber. For example, when stripping the concentrated sludge adhering to the filter cloth 18 with water as a stripping medium, the fluid pressure due to the sludge in the filtration and concentration tank 12 loaded on the filter cloth 18 may fluctuate in the height direction. . In such a case, if a plurality of water supply pipes are provided at the same level in the height direction of the filter cloth, the concentrated sludge cannot be uniformly peeled in the height direction of the filter cloth, and peels as cake pieces. It becomes difficult to cause adverse effects. However, by providing a plurality of water supply pipes at different levels in the height direction of the filter cloth 18 as water pumping means capable of continuously pumping water toward the filter cloth through the filtration chamber, this problem can be prevented. Can be prevented. As another example, for example, water having a relatively low water pressure is sent to the upper part of the filter cloth 18 having a low hydraulic pressure, and water having a relatively high water pressure is supplied to the lower part of the filter cloth 18 having a high hydraulic pressure. May be sent. However, compared to the pressure during water pumping (0.1 to 1.0 MPa), the difference in the hydraulic pressure in the vertical direction is small and can be ignored if it does not cause a problem.

Here, the coil spring 54 is a member for adjusting the tension acting on the filter plate (specifically, the support plate 50) so that it is always substantially constant. Specifically, as shown in FIG. 3, the plurality of coil springs 54 are provided between the side 60 of the filter frame 48 and the side 61 of the filter cloth 18, and the side 62 of the filter frame 48 and the filter cloth 18. Are disposed between the lower side 58 of the filter frame 48 and the lower side 59 of the filter cloth 18 and between the upper side 56 of the filter frame 48 and the upper side 57 of the filter cloth 18. What is necessary is just to set suitably the space | interval of the adjacent coil springs 54 installed in the both sides and upper and lower sides of the filter frame 48 according to the size of the filter cloth 18 and the amount of concentrated sludge adhering. Specifically, one end of each coil spring 54 is hooked to the eyelet 78 of the filter cloth 18, and the other end is fixed to the side sides 60 and 62, the upper side 56 and the lower side 58 of the filter frame 48. Yes. The plurality of coil springs 54 are preferably made of SUS from the viewpoint of corrosion resistance. In addition, several tens of coil springs 54 are usually arranged around the periphery of the filter plate 14, and the number of filter plates 14 is, for example, several tens. For this reason, a standard product is used instead of a custom-made product. Good.

When the filter plate 14 (14A, 14B, 14C, 14D, 14E) and the filter cloth 18 are large and have a weight exceeding a predetermined value, the upper side 56 of the filter frame 48 is shown in FIGS. Instead of the coil spring 54, a highly rigid support member 65 that fixes the heavy filter cloth 18 and the support plate 50 and does not expand and contract is provided between the filter cloth 18 and the upper side 57 of the filter cloth 18. When the weight of the filter cloth 18 and the support plate 50 becomes larger than a predetermined value, the coil spring 54 on the upper side of the filter cloth 18 extends, and the coil spring 54 on the lower side of the filter cloth 18 contracts, the filter cloth 18 and the support plate 50 are supported. The tension acting on the plate 50 is not constant, and the filter cloth 18 and the support plate 50 are moved by a slight external force. This adversely affects the attachment of the concentrated sludge to the filter cloth 18 by suction and the separation of the concentrated sludge by water pumping. Because.

(Concentrated sludge discharge stage / concentrated sludge discharge means)
The concentrated sludge discharging step (means) is a step (means) for discharging the peeled concentrated sludge to the outside of the filtration concentration tank. In the present embodiment, the concentrated sludge discharging step (means) is performed without discharging the unconcentrated sludge in the filtration concentration tank 12. Concentrated sludge discharge means include sludge supply / discharge valve 26, sludge supply / discharge pump 28, sludge supply / discharge pipe 24, and concentrated sludge scooping section 23 (mesh-shaped tray 82) as shown in FIGS. 2A to 2G. Etc. By such concentrated sludge discharge means, the concentrated sludge discharge process in the concentrated sludge discharge stage (T4) shown in FIG. 1 is realized.

The concentrated sludge discharge stage (means) includes a stage (means) for scooping out the concentrated sludge of cake pieces accumulated in the bottom of the filtration and concentration tank in the unconcentrated sludge. By being configured in this manner, it is possible to scoop out the concentrated sludge of cake pieces collected at the bottom of the filtration and concentration tank in the unconcentrated sludge without discharging the unconcentrated sludge from the filtration and concentration tank as in the prior art. it can. That is, continuous treatment of concentrated sludge can be performed. Moreover, the peeled concentrated sludge (concentrated sludge of cake pieces) can be discharged in a state that does not re-dissolve even if it is moved in water in a state that has hardness, size, and shape retention that does not re-dissolve. Therefore, the concentrated sludge can be discharged from the filtration and concentration tank to the outside simply and efficiently without reducing the concentration of the concentrated sludge. This completes the sludge filtration and concentration operation. The concentrated sludge discharged to the outside of the filtration concentration tank 12 is further concentrated by a separate dehydrator, formed again into a cake, and subjected to incineration or landfill disposal.

In addition, in the concentrated sludge discharge stage, if necessary, a small piece of cake or liquid concentrated sludge accumulated at the bottom of the filtration concentration tank 12 is separated from the cake concentration tank 12 in a separate process from the cake piece concentration sludge discharge stage. These are discharged through the concentrated sludge discharge pipe 30 for discharge to the outside. In that case, you may discharge | emit the unconcentrated sludge in the filtration concentration tank 12 previously, or you may discharge | emit from the concentrated sludge discharge pipe 30 with those concentrated sludges.

Examples of such concentrated sludge discharging means include the concentrated sludge scooping portion 23, mesh tray 82, bucket conveyor 84 (84a, 84b, 84c) and the like as shown in FIGS. 2A to 2G and FIG. it can. And the concentrated sludge discharge process of a concentrated sludge discharge stage is implement | achieved by such a concentrated sludge discharge means. Specifically, the concentrated sludge scooping section 23 is disposed at the bottom of the filtration and concentration tank 12, and is stripped by the concentrated sludge stripping section 20 to scoop out the concentrated sludge of cake pieces that have accumulated on the bottom of the filtration and concentration tank 12. Has the role of The concentrated sludge scooping portion 23 in the present embodiment has a mesh-shaped tray 82 with a handle 80 having a length that extends upward from the upper opening of the filtration concentration tank 12.

Here, it is preferable that the size of the mesh tray 82 covers the entire bottom of the filtration and concentration tank 12 in order to scoop out the concentrated sludge accumulated at the bottom of the filtration and concentration tank 12 without leakage. The mesh size may be determined as appropriate in relation to the size of the cake piece of concentrated sludge. However, when lifting the mesh tray 82 using the handle 80, the mesh size is selected so that the moisture in the concentrated sludge is removed through the mesh and the concentrated sludge is retained on the mesh. It is preferred that

In addition, in order to draw out the mesh-shaped saucer 82 to the upper part, the filtration concentration tank 12 is provided with a part (for example, a part where D in FIG. 5 is widened) in which a large interval between the filter plates 14 is secured. Is installed. Below the filter plate 14, a wire mesh belt conveyor is installed at the bottom of the filtration concentration tank 12, and by this wire mesh belt conveyor, the concentrated sludge of the peeled cake pieces is received and transferred horizontally to the mesh tray 82. By providing a scraper instead of the conveyor, the peeled cake-like concentrated sludge can be transferred to the mesh-like receiving tray 82. When there is a sufficient space in the filtration and concentration tank 12, the mesh-shaped tray 82 is provided directly below the filtration plate 14, and the mesh-shaped tray 82 itself is laid horizontally at the bottom of the filtration and concentration tank 12 using the handle 80. Move. Thereafter, the mesh tray 82 may be lifted upward and the mesh tray 82 may be taken out.

As another embodiment, as shown in FIG. 10, bucket conveyor 84 (84 a, 84 b, 84 c) is used to discharge concentrated sludge W in the form of cake pieces collected at the bottom of filtration concentration tank 12 to the outside. May be adopted. For example, a bucket conveyor 84 that extends from the bottom of the filtration concentration tank 12 to the outside through the top opening of the filtration concentration tank 12 and is disposed with the conveyor surface moving upward from the bottom of the filtration concentration tank 12 as an example. Can be mentioned.

For example, when there is a space limitation due to the arrangement of the filtration plate 14 in the filtration and concentration tank 12, three sets of bucket conveyors 84a, 84b, and 84c are adopted as shown in FIG. Is preferred.

Specifically, in the first set of bucket conveyors 84 a, one is configured as a drive roller 86, and the conveyor is stretched between both rollers 86 and 88 disposed at the bottom of the filtration concentration tank 12. Further, a plurality of buckets 89 a are attached to the stretched conveyor, and the conveyor is configured to move along the bottom surface of the filtration concentration tank 12. In the second set of bucket conveyors 84 b, one roller 90 is disposed above the filtration concentration tank 12. Further, a plurality of buckets 89 b are attached to a conveyor stretched between both rollers 88 and 90, and the conveyor moves along the side wall of the filtration and concentration tank 12. Further, in the third set of bucket conveyors 84c, both rollers 90 and 92 are disposed above the filtration and concentration tank 12 (above the sludge stored in the filtration and concentration tank 12), and the conveyor is between the rollers 90 and 92. Is stretched. In addition, a plurality of buckets 89c are attached to the conveyor. In this way, when three sets of bucket conveyors 84a, 84b, and 84c are employed, for example, the concentrated sludge can be discharged in parallel with the filtration and concentration of unconcentrated sludge. That is, using the three sets of bucket conveyors 84a, 84b, and 84c, the concentrated sludge squeezed out by each bucket of the first set is transferred to the second and third sets of bucket conveyors, and finally filtered. It can be discharged to the outside of the concentration tank 12.

Note that the bucket conveyor is not limited to the above example. For example, a bucket conveyor may be used which can change the route by providing a roller in the middle.

As an alternative to such a bucket conveyor, a wire mesh belt conveyor extending from the bottom of the filtration and concentration tank 12 to the outside through the upper opening of the filtration and concentration tank 12 may be used. In this case, the belt conveyor is similarly arranged with the conveyor surface moving from the bottom of the filtration concentration tank 12 to the outside facing upward.

As another embodiment, in the concentrated sludge discharging stage shown in FIG. 7 and FIG. 8, a wire mesh belt conveyor is installed at the bottom of the filtration concentration tank 12 below the filter plate 14. It is also preferable to employ a structure in which the belt conveyor extends to the bottom portion of the filtration concentration tank 12 where the filter plate 14 is not located above and is connected to the bucket there. In the case of this embodiment, the concentrated sludge W of cake pieces falling from the filter plate 14 is placed on a wire mesh belt conveyor, carried to a bucket, and can be taken out of the filter concentration tank 12. .

As an unconcentrated sludge discharge means, an unconcentrated sludge discharge pipe 67 is provided to discharge unconcentrated sludge. The unconcentrated sludge discharge pipe 67 is preferably connected to the filtration concentration tank at a predetermined level above the bottom of the filtration concentration tank so as not to discharge the concentrated sludge accumulated at the bottom of the filtration concentration tank.

Specifically, one end of an unconcentrated sludge discharge pipe 67 for discharging unconcentrated sludge in the filtration and concentration tank 12 communicates with a predetermined level H above the bottom of the filtration and concentration tank 12. In the middle of the unconcentrated sludge discharge pipe 67, an unconcentrated sludge discharge valve 68 is provided. This predetermined level H is set above the height of the concentrated sludge of the cake pieces collected at the bottom of the filtration and concentration tank 12. For example, it is installed above the upper end of the mesh tray 82. By setting the predetermined level H in this manner, the concentrated sludge that is peeled off from the filter cloth 18 and accumulated at the bottom of the filtration concentration tank 12 is prevented from being discharged to the outside together with the unconcentrated sludge discharge pipe 67. be able to. Further, as shown in FIG. 2B, one end of a concentrated sludge discharge pipe 30 that discharges a small piece of cake or liquid concentrated sludge accumulated on the bottom of the filtration concentration tank 12 communicates with the bottom of the filtration concentration tank 12. Yes. A concentrated sludge discharge valve 32 is provided in the middle of the concentrated sludge discharge pipe 30. By opening the concentrated sludge discharge valve 32, the concentrated sludge accumulated at the bottom of the filtration concentration tank 12 is discharged to the outside through the concentrated sludge discharge pipe 30 due to gravity drop.

That is, in the lower part of the filtration and concentration tank 12, cake-like concentrated sludge is precipitated in the unconcentrated sludge, and it is necessary to separate the unconcentrated sludge and the concentrated sludge and discharge them to the outside. In this case, if the unconcentrated sludge is discharged from the unconcentrated sludge discharge pipe connected to the bottom of the filtration and concentration tank 12, the concentrated sludge is mixed in the unconcentrated sludge, and it is difficult to recover only the unconcentrated sludge. Become. Or the discharge port connected to the non-concentrated sludge discharge pipe may be blocked by the concentrated sludge of cake pieces having shape retention, and it may be difficult to recover the non-concentrated sludge. Therefore, according to the suction filtration and concentration device having the above-described configuration, when discharging the non-concentrated sludge through the non-concentrated sludge discharge pipe, the non-concentrated liquid does not discharge the concentrated sludge of the cake pieces accumulated at the bottom. Only sludge can be efficiently discharged outside. In this embodiment, the unconcentrated sludge discharged to the outside is circulated and supplied again to the filtration and concentration tank 12 by the sludge supply valve 26, the sludge supply pump 28, etc. (pipe lines are not shown). .

As another example, a second unconcentrated sludge discharge pipe (not shown) may be provided between the bottom of the filtration and concentration tank 12 and the non-concentrated sludge discharge pipe 67. That is, when discharging the unconcentrated sludge to the outside, first, the unconcentrated sludge is discharged from the unconcentrated sludge discharge pipe 67 to the outside. Next, unconcentrated sludge remaining from the bottom of the filtration and concentration tank 12 to a predetermined level H is discharged to the outside from the second unconcentrated sludge discharge pipe. When the second unconcentrated sludge discharge pipe is provided as described above, the unconcentrated sludge is not discharged from the beginning through the second unconcentrated sludge discharge pipe, and first the unconcentrated sludge is discharged from the unconcentrated sludge discharge pipe 67 to the outside. The unconcentrated sludge level in the filtration and concentration tank 12 is once lowered to lower the water pressure. For this reason, it becomes possible to discharge the unconcentrated sludge remaining from the bottom of the filtration concentration tank 12 to the predetermined level H while limiting the amount of the concentrated sludge discharged together with the unconcentrated sludge. In particular, when the concentrated sludge of cake pieces accumulated at the bottom of the filtration and concentration tank 12 is large, the discharge port provided at the bottom of the filtration and concentration tank 12 leading to the second unconcentrated sludge discharge pipe is blocked by this concentrated sludge. May be. Therefore, it is possible to discharge the unconcentrated sludge remaining up to the predetermined level H to some extent while preventing the concentrated sludge from being discharged outside.

As another example of the unconcentrated sludge discharge pipe, it has a plurality of branch pipes connected to the unconcentrated sludge discharge pipe in parallel with each other, and each branch pipe is at a different level above the bottom of the filtration concentration tank. Further, it may be connected to the filtration and concentration tank through a discharge valve. For example, as shown in FIG. 2C, the unconcentrated sludge discharge pipe 67 is configured to have three branch pipes 108a, 108b, and 108c connected to the unconcentrated sludge discharge pipe 67 in parallel with each other. And each branch pipe 108a, 108b, 108c is connected to the filtration concentration tank 12 through the discharge valves 112a, 112b, 112c at different levels above the bottom of the filtration concentration tank 12. The unconcentrated sludge discharge pipe 67 is provided with a suction pump 120. According to the apparatus having the above configuration, the unconcentrated sludge from any of the three branch pipes 108a, 108b, and 108c, depending on the sedimentation height of the concentrated sludge that accumulates at the bottom of the filtration and concentration tank 12, It is possible to select whether to discharge through the unconcentrated sludge discharge pipe 67. For example, when the sedimentation height of the concentrated sludge is closest to the lowest-level branch pipe 108c from the bottom of the filtration and concentration tank 12, the discharge valve 112c of the lowest-level branch pipe is closed. On the other hand, by opening the discharge valves 112a and 112b of the second and third level branch pipes and operating the suction pump 120, the concentrated sludge accumulated at the bottom of the filtration and concentration tank 12 is removed from the unconcentrated sludge discharge pipe 67. Only the unconcentrated sludge can be discharged to the outside without being discharged to the outside. Furthermore, when the amount of concentrated sludge generated varies due to fluctuations in the raw water quality, the discharge valves 112a, 112b and 112c may be switched. Thereby, it becomes possible to discharge | emit only unconcentrated sludge outside irrespective of the fluctuation | variation of the sedimentation height in the filtration concentration tank 12 of concentrated sludge. For example, when the sedimentation height of the concentrated sludge increases and is closest to the second height level branch pipe 108b from the bottom of the filtration and concentration tank 1, the discharge of the first and second height level branch pipes is performed. Valves 112c and 112b are closed. On the other hand, the discharge valve 112a of the third-level branch pipe may be opened. In this embodiment, the installation level of the lowest level branch pipe 108c is positioned above the upper end of the mesh tray 82.

Furthermore, the following embodiment can be given as another example. 2D, as the unconcentrated sludge drain pipe 67, the upper part of the filtration and concentration tank 12 so that the lower end portion of the unconcentrated sludge drain pipe 67 is at a predetermined level H above the bottom of the filtration and concentration tank 12. The apparatus (falling pipe) provided so that it may extend toward the downward direction in the filtration concentration tank 12 from opening can be illustrated. A plurality of falling pipes may be provided, and the same function as that of the branch pipes 108a, 108b, and 108c may be provided by changing the level position of each falling pipe end in the filtration and concentration tank 12. Further, the unconcentrated sludge drain pipe 67 is provided with a suction pump 113. According to such an apparatus, only the unconcentrated sludge is discharged to the outside by the suction pump 113 without discharging the concentrated sludge accumulated at the bottom of the filtration concentration tank 12 to the outside from the unconcentrated sludge drain pipe 67. Is possible. Furthermore, the unconcentrated sludge drain pipe having such a falling pipe structure can be easily replaced according to the case where the amount of concentrated sludge generated varies due to fluctuations in the quality of raw water. As a result, regardless of fluctuations in the sedimentation height of the concentrated sludge, only the unconcentrated sludge is discharged to the outside without discharging the concentrated sludge accumulated at the bottom of the filtration and concentration tank 12 from the unconcentrated sludge discharge pipe 67 to the outside. It becomes possible.

Furthermore, as another example, a flexible hose or the like may be provided. For example, as shown in FIG. 2E, the flexible hose 114 is connected to the lower end portion of the unconcentrated sludge discharge pipe 67 so as to be able to communicate therewith. The length of the flexible hose 114 in the vertical direction can be adjusted so that the lower end portion of the unconcentrated sludge discharge pipe 67 reaches a predetermined level H above the bottom of the filtration concentration tank 12. More specifically, since the flexible hose 114 has a flexible meandering part, the meandering part is extended and contracted in the vertical direction. Thereby, it is possible to adjust the length of the flexible hose 114 in the vertical direction. The unconcentrated sludge drain pipe 67 is provided with a suction pump 113. According to the apparatus having the above configuration, only the unconcentrated sludge can be obtained by operating the suction pump 113 without discharging the concentrated sludge accumulated in the bottom of the filtration and concentration tank 12 from the unconcentrated sludge discharge pipe 67 to the outside. Can be discharged to the outside. Furthermore, when the amount of concentrated sludge generated varies due to fluctuations in the quality of the raw water, the length of the flexible hose 114 provided at the lower end of the falling pipe is expanded and contracted in the vertical direction. Can be used while. Accordingly, it is possible to discharge only the unconcentrated sludge to the outside without the need to replace the unconcentrated sludge discharge pipe 67 itself, regardless of fluctuations in the sedimentation height of the concentrated sludge.

(Operation method and operation of suction filtration concentrator)
About the suction filtration concentration apparatus 10 which has the above structure, the effect | action including a driving | operation method is demonstrated below. In FIG. 7, in the treatment stage (A), first, the sludge X is supplied into the filtration and concentration tank 12. Specifically, as shown in FIGS. 2A to 2F, the sludge supply / discharge valve 26 is opened and the sludge supply / discharge pump 28 is operated. Then, the sludge to be filtered and concentrated is supplied into the filtration and concentration tank 12 through the sludge supply / discharge pipe 24 to the top level of the filter plate 14. Subsequently, the sludge in the filtration concentration tank 12 is prepared to be filtered and concentrated by a siphon method. Specifically, the suction valve 33 is opened and the vacuum pump 35 is operated. Thereby, the liquid in the filter cloth 18 is sucked into the filtrate storage tank 36 through the distribution pipe 34. Further, according to the level difference between the end of the distribution pipe 34 on the filtration plate 14 side and the filtrate storage tank 36, the filtrate guided into the filtration chamber 76 by siphon action as shown in FIG. It becomes possible to discharge outside through the sludge discharge pipe 38.

Next, in the treatment stage (B) shown in FIG. 7, the sludge in the filtration and concentration tank 12 is filtered and concentrated. More specifically, as shown in FIGS. 2A to 2G, the sludge in the filtration concentration tank 12 is sucked toward the outer surface of the filter cloth 18 by the siphon principle. At that time, the water in the sludge passes through the filter cloth 18 and is guided as a filtrate into the filtration chamber 76 (see FIG. 6B) in the filter cloth 18 to dehydrate the sludge. The dewatered and concentrated sludge W adheres to the outer surface of the filter cloth 18. At that time, sludge can be adhered to the outer surface of the filter cloth 18 with a desired adhesion force even by continuous suction at a relatively low pressure by a siphon type. That is, even if the cake W of the concentrated sludge adhering to the outer surface of the filter cloth 18 is peeled in the non-concentrated sludge, it adheres with the hardness and adhesion that can maintain the shape retention as the concentrated sludge of the cake piece. it can.

The support plate 50 of the filter plate 14 is always tensioned by a coil spring 54 from the periphery. Therefore, the support plate 50 of the filter plate 14 is maintained in an immobile stationary state. Thereby, it can prevent that the filter plate 14 (support plate 50) flutters or wobbles. Therefore, a situation in which the concentrated sludge W adhering to the outer surface of the filter cloth 18 is peeled off from the outer surface of the filter cloth 18 before the concentrated sludge peeling step (or before being peeled off by the concentrated sludge peeling means). It is possible to prevent.

Next, in the processing step (C) shown in FIG. 7, the concentrated sludge W adhering to the filter cloth 18 is peeled off by swelling the filter cloth 18. Even when this treatment is performed, the unconcentrated sludge in the filtration and concentration tank 12 remains. Specifically, as shown in FIGS. 2A to 2G and FIG. 3, the water inflow valve 44 is opened, and water is supplied from the liquid feed pump 46 through the water inflow pipe 42, the distribution pipe 34 and the horizontal pipe 15 to the filter plate 14. It pumps in the filtration chamber 76 (refer FIG. 6A). That is, in the non-concentrated sludge that has been filtered and concentrated, water is continuously pumped from the side opposite to the surface to which the concentrated sludge is adhered toward the filter cloth 18 for a predetermined time. At that time, the pumped water tends to flow into the unconcentrated sludge through the countless pores of the filter cloth 18. On the other hand, the concentrated sludge adheres to the entire outer surface of the filter cloth 18 and closes countless pores of the filter cloth 18. Further, the liquid pressure of the unconcentrated sludge is uniformly applied to the outer surface of the filter cloth 18 to which the concentrated sludge has adhered. For this reason, at least until the hydraulic pressure of the unconcentrated sludge is overcome, the water pressure of the water fed into the filtration chamber 76 presses the concentrated sludge adhering to the outer surface of the filter cloth 18 toward the unconcentrated sludge. become. That is, the concentrated sludge is not separated from the surface of the filter cloth 18 at least until the liquid pressure of the unconcentrated sludge is overcome. Therefore, the pressure of the pumped water in the filtration chamber 76 increases, and the filter cloth 18 swells with it.

In other words, when the concentrated sludge adheres to the entire outer surface of the filter cloth 18 and closes the countless pores of the filter cloth 18, the swelling of the filter cloth 18 is caused by the hydraulic pressure of the pumped water. Until the predetermined pressure is uniformly reached in the filtration chamber 76. Then, when the water pressure of the pumped water uniformly reaches a predetermined pressure in the filtration chamber 76, the swelling of the filter cloth 18 is completed. That is, the pumped water can press the concentrated sludge adhering to the outer surface of the filter cloth 18 together into the unconcentrated sludge over the entire filter cloth 18.

In this way, the concentrated sludge W can be uniformly peeled in the circumferential direction from the outer surface of the filter cloth 18, as shown in FIG. 11A. Moreover, as shown in FIG. 11B, the concentrated sludge W can be uniformly peeled from the outer surface of the filter cloth 18 in the height direction.

Further, when the concentrated sludge adhering to the outer surface of the filter cloth 18 is peeled off from the filter cloth 18, the noise accompanying the peeling can be reduced by peeling with water in the unconcentrated sludge, and the suction filtration concentration apparatus can be installed at a place where It is possible to remove the restrictions.

Furthermore, since the concentrated sludge can be peeled in a state of having hardness, size and shape retaining property so as not to be re-dissolved, the concentrated sludge of the cake piece is buoyant toward the bottom of the filtration concentration tank 12 through the unconcentrated sludge. It will fall while receiving the action. Thereby, it is possible to relieve the impact when colliding with the bottom. In addition, since the cake-like concentrated sludge can be hardened, it is possible to prevent the concentrated sludge from being reduced by dissolving the concentrated sludge into the unconcentrated sludge. Furthermore, since the cake-like concentrated sludge has shape retaining properties, the cake is not layered and broken. Therefore, it is easily and efficiently discharged from the inside of the mesh-shaped tray 82 positioned at the bottom of the filtration and concentration tank 12 while maintaining the cake-like form as cake cake concentrated sludge or as easily drained. It becomes possible to do.

Next, in the processing step (D) shown in FIG. 7, the separated concentrated sludge W is discharged to the outside of the filtration concentration tank 12. For example, when the concentrated sludge discharging means is the concentrated sludge scooping section 23, the mesh-shaped tray 82, the bucket conveyor 84, etc. as shown in FIG. 2F and FIG. Take out from the outside. Even at this stage, the unconcentrated sludge in the filtration and concentration tank 12 remains. Thereafter, the operator grasps the handle, lifts the mesh-shaped tray 82, scoops out the concentrated sludge of cake pieces accumulated in the mesh-shaped tray 82, and discharges it to the outside. Since the concentrated sludge has hardness, size and shape retention that does not re-dissolve, the shape retention can be maintained as cake pieces in the unconcentrated sludge until it is taken out after peeling. Therefore, according to such a configuration, it is not necessary to discharge unconcentrated sludge to the outside before discharging concentrated sludge, and solid-liquid separation can be easily performed in unconcentrated sludge. That is, continuous processing is possible. This completes the sludge filtration and concentration operation. The concentrated sludge discharged to the outside of the filtration and concentration tank 12 is further concentrated separately by a dehydrator, formed into a cake again, and subjected to incineration or landfill disposal.

In the present invention, preferably, the concentrated sludge discharge stage is performed after repeating the cycle consisting of the filtration concentration stage and the concentrated sludge separation stage a predetermined number of times, and the sludge supply stage before the filtration concentration stage in each cycle. The step of supplying sludge to the filtration concentration tank 12 is provided. In order to realize such a concentrated sludge discharging step, for example, as shown in FIG. 9A, a step of supplying (supplying) new sludge into the filtration and concentration tank 12 may be included. Specifically, as shown in FIG. 9A, unconcentrated sludge is supplied into the filtration and concentration tank 12, filtered and concentrated in the filtration and concentration tank 12, and the concentrated sludge is peeled off. Furthermore, after the peeled concentrated sludge is discharged to the outside and the concentrated sludge is discharged to the outside, new sludge may be supplied (supplemented) into the filtration and concentration tank 12. Alternatively, as shown in FIG. 9A, a cycle including a filtration concentration stage and a concentrated sludge separation stage is repeated a predetermined number of times. Then, before the filtration concentration stage in each cycle, new sludge may be supplied into the filtration concentration tank 12 by the sludge supply stage. In addition, what is necessary is just to determine the frequency | count of a cycle suitably in consideration of the filtration capacity by the filter plate 14, the amount of sludge to be processed, and the like. Thereby, it is possible to perform the sludge filtration concentration process more efficiently.

Further, the concentrated sludge discharging step is performed in parallel with the filtration concentration step, and the step of supplying sludge into the filtration concentration tank 12 by the sludge supply step before the filtration concentration step may be included. preferable. In order to realize such a concentrated sludge discharge stage, for example, as shown in FIGS. 8 and 9B, while discharging the concentrated sludge of the peeled cake pieces to the outside, new sludge is filtered in the concentration tank 12. Filtration concentration may be performed while having a step of replenishing (supplying). Specifically, it can be applied when there is a sufficient space in the filtration and concentration tank 12 and it is not necessary to take out the filter plate 14 once to discharge the concentrated sludge to the outside. Further, the present invention can be applied when a plurality of sets of bucket conveyors or belt conveyors are arranged along the bottom and side walls of the filtration concentration tank 12 and used. Thereby, it is possible to perform the sludge filtration concentration process more efficiently.

The embodiment of the present invention has been described in detail above, but various modifications or variations can be made by those skilled in the art without departing from the scope of the present invention. For example, in this embodiment, although the case where the object of filtration concentration was sludge was demonstrated, it is not limited to this. For example, examples of the target for filtration concentration include incinerated ash contained in an alkaline solution, foreign matter contained in a beverage such as milk and juice, and suspended matter in turbid water. As long as the conditions such as the type of filter cloth 18, the size of the pore diameter, and the suction force are appropriately set according to the target of the filtration and concentration, the suction filtration and concentration method and the suction type filtration and concentration device according to the present invention are It is applicable to these.

In order to confirm the effect of the present invention, the present inventor conducted a siphon-type suction filtration concentration test using a filter cloth with sludge from a water purification plant as a filtration and concentration target, and measured the separation pressure due to water as a separation medium as a parameter. Further, the relationship between the peeling time and the peeling rate was examined.

The whole test equipment is shown in FIG. The basic configuration is the same as that shown in FIG. 2A except for the concentrated sludge scooping portion 23 (mesh-shaped tray 82), and a detailed description thereof will be omitted, but one end communicates with an inverted U-shape communicating with the filtration chamber 76. The water pressure and supply time were adjusted by providing a peeling pressure adjusting valve 150 in the water inflow pipe 42 connected in the middle of the pipe and adjusting the opening of the peeling pressure adjusting valve 150. Specifically, the washing water was supplied from the washing water tank 162 to the filtration chamber 76 formed inside the filter plate 14 through the water inflow pipe 42 and the distribution pipe 34 by the washing water pump 160. In addition, the undiluted | stock solution which is the sludge of a water purification plant is supplied to the filtration concentration tank 12 by the undiluted | stock solution tank 152 by the undiluted | stock solution pump 154. The sludge is continuously sucked by the suction pipe 31, the filtrate F is discharged to the external filtrate tank 36 through the filtrate discharge pipe 38, and the concentrated sludge W is attached to the outer surface of the filter cloth 18. The concentrated sludge accumulated at the bottom of the filtration concentration tank 12 is discharged to the external filtration concentration tank 158 by the concentrated sludge discharge pump 156. Reference numeral 164 denotes a washing water pressure adjusting valve, 166 denotes a compressor, and 168 denotes a stock solution discharge pump. Moreover, the specification of the filter plate 14 is shown below.

(1) Material: Filter cloth 18 ..Nylon, support plate 50 ..Resin (2) Number of sheets: 1 sheet (3) Dimensions: 1900 mm × 2500 mm, filtration area: 9.5 m ²
(4) Manufacturing method: Filter cloth 18 and support plate 50 are integrally sewn (5) Filter plate volume: 0.07 m ³ (15 mm thickness)
(6) Sludge composition: Ig. _{loss: 36.4%, SiO 2:} 34.2%, Al 2 O 3: 18.7%, Fe 2 O 3: 4.1%, CaO: 1.4%, SO 4: 1.8%, Others: 3.4% (% indicates mass%)
(7) Filtration time: 90 minutes

FIG. 13 shows the relationship between the peeling time and the peeling rate. As shown in FIG. 13, if the peeling pressure is constant, the peeling rate increases as the peeling time increases. In order to ensure 95% or more as a practical peeling rate, it was found that a continuous peeling time of at least 30 seconds was required regardless of the peeling pressure.

The suction filtration concentration method and the suction filtration concentration apparatus according to the present invention are not limited to water treatment technical fields including clean water, middle water, and sewage, but to a wide range of technical fields such as food-related fields and chemical industry fields. Among them, the present invention is particularly useful for a suction filtration concentration apparatus applied in a concentration stage of sludge generated in a water treatment stage such as a water purification plant.

2: water purification tank, 4: sludge supply pipe, 6: sludge supply pump, 8: sludge supply valve, 10, 10A, 10B, 10C, 10D, 10E: suction filtration concentration apparatus, 12: filtration concentration tank, 13: plane part 14, 14A, 14B, 14C, 14D, 14E: filter plate, 15: horizontal pipe, 16: suction part, 18: filter cloth, 20: concentrated sludge stripping part, 22: side wall, 24: sludge supply / discharge pipe, 26: sludge supply / discharge valve, 28: sludge supply / discharge pump, 30: concentrated sludge discharge pipe, 31: suction pipe, 32: concentrated sludge discharge valve, 33: suction valve, 34, 34A, 34B, 34C, 34D, 34E ,: distribution pipe, 35: vacuum pump, 36: filtrate storage tank, 38: filtrate discharge pipe, 40: filtrate discharge valve, 42: water inlet pipe, 44: water inlet valve, 46: liquid feed pump, 47: switching valve 48: Filtration frame, 50: Support plate, 54 Coil spring, 56, 57: Upper side, 58, 59: Lower side, 60, 61, 62, 63: Side, 64: Extension, 65: Support member, 66A: Engagement plate, 67: Unconcentrated sludge discharge pipe, 68 : Unconcentrated sludge discharge valve, 69: Inner side surface, 70, 70A, 72, 72A: Guide plate, 74: Seam, 76: Filtration chamber, 78: Eyelet, 80: Handle, 82: Receptacle, 84a, 84b, 84c: Bucket conveyor, 86: roller (drive roller), 88, 90, 92: roller, 89a, 89b, 89c: bucket, 108a, 108b, 108c: branch pipe, 112a, 112b, 112c: discharge valve, 113: suction pump, 114: Flexible hose, 120: Suction pump, 150: Peeling pressure adjusting valve, 152: Stock solution tank, 154: Stock solution pump, 156: Concentrated sludge discharge pump 158: Filtration concentration tank, 160: Wash water pump, 162: Wash water tank, 164: Wash water pressure adjusting valve, 166: Compressor, 168: Stock solution discharge pump, C: Clean water, D: Interval, F: Filtrate, H: Predetermined Level, P: Overhang amount, R: Raw water, S: Transfer amount, W: Concentrated sludge, X: Sludge, T1: Sludge supply stage, T2: Filtration concentration stage, T3: Concentrated sludge stripping stage, T4: Concentrated sludge discharge stage .

Claims (10)

1. A suction filtration concentration method in which sludge is suction filtered through a filter cloth in a filtration concentration tank to collect the filtrate through a filter chamber inside the filter cloth and attach the sludge to the outer surface of the filter cloth as a concentrated sludge,
   A sludge supply stage for supplying sludge into the filtration concentration tank;
   A filtration concentration stage for filtering and concentrating the supplied sludge in a filtration concentration tank;
   A concentrated sludge stripping step for stripping the filtered concentrated sludge from the outer surface of the filter cloth;
   A concentrated sludge discharging stage for discharging the peeled concentrated sludge to the outside of the filtration concentration tank;
   The filtration and concentration step continuously sucks the concentrated sludge on the outer surface of the filter cloth by sucking continuously under a predetermined suction pressure that can maintain the shape retaining property even if the concentrated sludge is peeled off in the unconcentrated sludge. Having a step of attaching,
   In the concentrated sludge peeling step, water is continuously fed to the filter cloth through the filtration chamber for a predetermined time in the supplied non-concentrated sludge, thereby adhering to the outer surface of the filter cloth. A suction filtration concentration method comprising a step of peeling concentrated sludge (filter cake).
2. The suction filtration concentration method according to claim 1, wherein the concentrated sludge discharging step includes a step of scooping out cake-like pieces of concentrated sludge accumulated at the bottom of the filtration concentration tank in the unconcentrated sludge.
3. The concentrated sludge discharge stage is performed after repeating the cycle consisting of the filtration concentration stage and the concentrated sludge stripping stage a predetermined number of times, and before the filtration concentration stage in each cycle, by the sludge supply stage, The suction filtration concentration method according to claim 1, further comprising a step of replenishing sludge.
4. The concentrated sludge discharging step is performed in parallel with the filtration and concentration step, and has a step of supplying sludge into the filtration and concentration tank by the sludge supply step before the filtration and concentration step. The suction filtration concentration method according to 1.
5. The suction filtration concentration method according to any one of claims 1 to 4, wherein in the concentrated sludge peeling step, the water pumped into the filtration chamber uses a filtrate collected in the filtration chamber.
6. A suction filtration and concentration device for collecting sludge through a filtration chamber inside the filter cloth by suction filtration of the sludge and attaching the sludge to the outer surface of the filter cloth as a concentrated sludge,
   Sludge supply means for supplying sludge into the filtration concentration tank;
   Filtration concentration means for filtering and concentrating the supplied sludge in a filtration concentration tank;
   Concentrated sludge stripping means for stripping the filtered and concentrated concentrated sludge from the outer surface of the filter cloth,
   Concentrated sludge discharge means for discharging the peeled concentrated sludge to the outside of the filtration concentration tank,
   The filtration and concentration means continuously sucks the concentrated sludge on the outer surface of the filter cloth by sucking continuously under a predetermined suction pressure that can maintain the shape retaining property even if the concentrated sludge is peeled off in the unconcentrated sludge. Having means to adhere,
   The concentrated sludge stripping means adheres to the outer surface of the filter cloth by continuously pumping water through the filtration chamber toward the filter cloth over a predetermined time in the supplied unconcentrated sludge. A suction filtration concentrator having means for stripping concentrated sludge (filter cake).
7. The suction filtration concentration apparatus according to claim 6, wherein the concentrated sludge discharging means has means for scooping out the concentrated sludge of cake pieces accumulated at the bottom of the filtration concentration tank in the unconcentrated sludge.
8. The suction filtration according to claim 6, wherein the concentrated sludge discharging means is a mesh-shaped tray with a handle that is disposed at the bottom of the filtration concentration tank and has a length extending upward from an upper opening of the filtration concentration tank. Concentrator.
9. The concentrated sludge discharging means is a bucket conveyor that extends from the bottom of the filtration and concentration tank to the outside through the upper opening of the filtration and concentration tank, with the conveyor surface moving upward from the bottom of the filtration and concentration tank facing upward The suction filtration concentration apparatus according to claim 6, which is arranged.
10. The suction filtration concentration apparatus according to claim 6, wherein a plurality of water supply pipes are provided so as to communicate with the filtration chamber at different levels in the height direction of the filter cloth.

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