JP2006247465A - Filter press apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology for removing quickly, easily and inexpensively even solid retained in fibers of a filter cloth. <P>SOLUTION: An filter press apparatus is provided with a filter cloth regeneration means constituted so that one filter cloth 9B of a pair of filter clothes 9A, 9B is fixed to one filter plate 4 facing the filter cloth 9B to form the fixed filter cloth 9B, the other filter cloth 9A is set to freely travel in relation to the other filter plate 4 facing the other filter cloth 9A to form the traveling filter cloth 9A, and the filter clothes 9A, 9B are forcedly dried, and an external force is applied to dried cake attached to the filter clothes 9A, 9B to drop the dried cake C1 from the filter cloth. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a technique for removing cake adhering to a filter cloth in dehydration using the filter cloth.

  In the filter press apparatus, a pair of filter cloths are arranged between a plurality of filter plates arranged side by side, and the filter plates are fastened and brought into close contact with each other to form a filter chamber between the filter plates and supply slurry between the filter cloths. The liquid is discharged through the filter cloth to form a cake between the filter cloths, and then the filter plates and the filter cloth are separated from each other, and the cake formed between the filter cloths is dropped and discharged. .

  2. Description of the Related Art A filter press apparatus includes a squeeze type apparatus that includes a diaphragm that can be expanded and contracted on a surface of a filter plate that faces a filter cloth. In this squeezing type apparatus, the diaphragm is expanded during filtration, and the cake is squeezed through a filter cloth. The squeezing type apparatus is widely used because it can reduce the moisture content of the cake as compared with the non-squeezing type.

  In addition to the filter cloth fixing type in which the filter cloth is fixed to the filter plate, the filter press device includes a filter cloth traveling type device in which the filter cloth is configured to run freely with respect to the filter plate. In the filter cloth fixing type device, the filter plates are separated from each other (open frame), and the cake is peeled off and discharged from the filter cloth by the weight of the cake, whereas in the filter cloth traveling type, the filter plates are separated from each other, The filter cloth is wound on the lower side of the filter plate, the filter cloth is lowered, and the cake is peeled off from the filter cloth and discharged. Further, in the filter cloth fixing type device, for example, after the cake is peeled off, the filter cloth cleaning is performed by moving the cleaning device up and down between the filter cloths with the filter plate open, while the filter cloth traveling type device is used. Then, for example, after the cake is peeled off, when the filter cloth is fed out, the cleaning cloth is sprayed on the surface of the filter cloth that travels and moves to clean the filter cloth.

  As is apparent from this comparison, the cake is difficult to peel and remains in the filter cloth fixing type device, whereas the filter cloth running type device has excellent cake peelability, but the filter cloth running mechanism and washing It is necessary to equip the mechanism, and there is a problem that the device cost increases.

  For this reason, of the pair of filter cloths arranged between the filter plates, the filter cloth on the one filter plate side having the diaphragm is fixed to the one filter plate (fixed filter cloth), and the other filter cloth is provided. Has been proposed to be able to travel (running filter cloth) with respect to the other filter plate having no diaphragm (see Patent Document 1). Hereinafter, such a configuration is referred to as a filter cloth one-side fixed / one-side traveling type regardless of the presence or absence of a diaphragm.

  In such a filter cloth single side fixed / single side traveling type, the squeezing force by the diaphragm acts only from one side of the filter chamber, or the diaphragm contracts prior to discharging the cake and the fixed filter cloth on the diaphragm side becomes free. , As well as depending on the apparatus, due to the compressed air being blown between the filter cloths prior to cake discharge, the cake formed between the filter cloths peels from the fixed filter cloth on the diaphragm side during cake discharge, There is a tendency to be discharged while being held by the running filter cloth on the opposite side. Therefore, the cake can be discharged even if the traveling mechanism is provided only on the side having no diaphragm. In this case, the traveling mechanism can be omitted in half compared to the conventional filter cloth traveling type, and the apparatus cost can be greatly reduced.

  However, in the above prior art, although the cake peels off from the filter cloth on the diaphragm side, this is a secondary effect of mounting the diaphragm only on one side, and the certainty is not high. Therefore, in the above prior art, cake pieces or the like remain on the fixed filter cloth, and there is a high risk of causing problems such as shortening the life of the filter cloth due to clogging.

In order to solve this problem, the filter cloth can be washed by raising and lowering the cleaning device between the filter cloths in a state where the filter plate is opened as in the conventional filter cloth fixing type. In this case, both the filter cloth traveling mechanism and the lifting / lowering type cleaning device are provided, and the cost of the device increases, and the maintainability deteriorates.
JP-A 61-46211

  Therefore, a main problem of the present invention is to prevent the filter cloth from being short-lived and deteriorated in maintainability in the filter cloth one-side fixed / one-side traveling type.

The present invention that has solved the above problems is as follows.
<Invention of Claim 1>
A plurality of juxtaposed filter plates;
A pair of filter cloths disposed between a pair of opposed filter plates;
Tightening means for bringing the filter plates into close contact with each other;
A filtration means for supplying a slurry between the filter cloths and discharging a liquid component through the filter cloths to form a cake between the filter cloths;
An open discharge means for separating the filter plates and the filter cloths from each other and dropping and discharging the cake formed between the filter cloths,
One filter cloth of the pair of filter cloths is a fixed filter cloth formed by fixing the filter cloth to one filter plate facing the one filter cloth, and the other filter cloth is the other filter cloth. A traveling filter cloth configured to be able to travel with respect to the other opposite filter plate, and after forcibly drying the filter cloth, an external force is applied to the filter cloth and the residue attached to the filter cloth, Provided with a filter cloth regeneration means for removing the residue from the filter cloth,
The filter press apparatus characterized by the above-mentioned.

(Function and effect)
The inventors of the present invention have made extensive research from the general idea of washing away with a liquid, and as a result, by applying external force such as vibration and bending after forced drying of the filter cloth, not only the filter cloth surface but also the filter cloth is filtered. It has been found that even solids retained between the fibers of the fabric can be effectively removed. Moreover, in this method, as will be understood from the examples to be described later, the cost is less than that provided by the conventional lifting type cleaning device, and even the cleaning device in the filter cloth traveling mechanism can be omitted as necessary. . The present invention has been made on the basis of such knowledge, and by applying filter cloth regeneration by forced drying to a filter cloth one-side fixed / one-side traveling type apparatus, a significant increase in the apparatus cost can be avoided. The filter cloth can be reliably regenerated while maintaining the advantages of the cloth side fixed / single side running type.

<Invention of Claim 2>
The filter press apparatus according to claim 1, wherein the filter cloth regeneration unit includes a forced drying unit that performs the forced drying by bringing dry air, heated air, or heated dry air into contact with the filter cloth. .

(Function and effect)
As the forced drying method of the present invention, a method of bringing dry air, heated air, or heated dry air into contact with the filter cloth is particularly preferable from the viewpoint of ease of incorporation into an existing apparatus and utility cost.

<Invention of Claim 3>
The said forced drying means is comprised so that the said forced drying may be performed in the state which clamped the said filter plate and formed a filter chamber between filter plates, and has arrange | positioned the filter cloth oppositely in the filter chamber. Filter press equipment.

(Function and effect)
If dry air or the like is used with the filter plate open, heat will escape to the outside and the energy efficiency will decrease, so as described in this section, the filter plate will be closed for forced drying. It is preferable to adopt a form in which dry air or the like is supplied to the filter cloth.

<Invention of Claim 4>
The filter press apparatus according to claim 2 or 3, wherein the forced drying means is configured such that the temperature of the air brought into contact with the filter cloth is 15 to 90 ° C.

(Function and effect)
The temperature of the air to be brought into contact with the filter cloth may be appropriately selected. However, if it is less than 15 ° C., it is not preferable because it is almost the same as natural drying and the drying efficiency is low. Moreover, since it may damage a filter cloth when it exceeds 90 degreeC, it is unpreferable.

<Invention of Claim 5>
The said filter cloth reproduction | regeneration means is provided with the residue removal means to drop a residue from a filter cloth by giving a vibration with respect to a filter cloth, or bending a filter cloth. The filter press apparatus described in 1.

(Function and effect)
Residue adhering to the filter cloth can be removed by bringing a scraper or brush into contact with the filter cloth, but the filter cloth hanging type filter press device is designed to promote the removal of the residue from the filter cloth. A vibration mechanism is provided, and a filter cloth traveling type is equipped with a mechanism for winding the filter cloth with a roll. By using these, the filter cloth can be applied to the filter cloth without requiring a new equipment configuration. The residue can be removed by applying vibration or bending the filter cloth.

<Invention of Claim 6>
The dewatering operation excluding the step by the filter cloth regenerating unit is repeatedly performed, and the process by the filter cloth regenerating unit is automatically interrupted after a predetermined time has elapsed to regenerate the filter cloth. The filter press apparatus of any one of -5.

(Function and effect)
In this way, by interposing the filter cloth regeneration process by forced drying of the present invention for a predetermined period, for example, once a day, the progress of clogging can be reliably suppressed with a minimum maintenance time.

  As described above, according to the present invention, even with a filter cloth one-side fixed / one-side traveling type filter press apparatus, the filter cloth can be easily regenerated, and the filter cloth can be prevented from shortening its life and deterioration of maintainability. It becomes like this.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
1 to 3 show an embodiment of a filter cloth traveling type filter press device with a pressing mechanism. First, the apparatus configuration will be described. FIG. 1 shows a filter mechanism section 1, in which a filter plate 4 is positioned along a vertical direction between a fixed frame 2 and a loose head 3 that are spaced apart in the lateral direction. A plurality are arranged in the horizontal direction. These filter plates 4 are interconnected by connecting members (not shown) provided on both sides, and are supported by a main beam 6 arranged on both sides so as to be movable in the juxtaposed direction. Thus, the filter plates 4 can be brought into contact with and separated from each other (open frame). In addition, when the loose head 3 is tightened by a tightening cylinder 8 (not shown) in the contact state between the filter plates 4 after the movement, the filter plates 4 are brought into close contact with each other and are closed.

  As shown in FIG. 3, as the filter plate 4, a filter plate 4 having a diaphragm 4D (hereinafter also referred to as a pressed filter plate) and a filter plate 4 not having the diaphragm 4D (hereinafter also referred to as a receiving filter plate) are alternately arranged. Is arranged. In any of the filter plates 4, a frame portion 4 </ b> A that forms a thick portion at the periphery and a central recess 4 </ b> B surrounded by the frame portion 4 are formed on both sides. A plate-like diaphragm 4D is affixed to the surface. When the frame is closed, a filter chamber 4C is formed by the recess 4B of the receiving filter plate 4 and the diaphragm 4D of the compressed filter plate 4.

  Filtrate grooves d are respectively formed on the side of the filter chamber 4C of the recess 4B of the receiving filter plate 4 and the diaphragm 4D of the pressing filter plate. The filtrate groove d communicates with a filtrate outlet 12A formed outside via a filtrate outlet 4F formed in the lower frame portion of the filter plate 4 during filtration.

  In a more preferred form, as shown in FIGS. 4 and 5, a net plate N is provided over the whole (or a part of) the recess 4 </ b> B of the receiving filter plate 4. A method of fixing the mesh plate N can be determined as appropriate, but a technique of providing a boss x on the surface of the mesh plate N as shown in the drawing and screwing the fixing screw y through the boss x to the filter plate 4 is suitable. The net plate N may be configured so as to cover the entire installation portion with a single sheet, but a plurality of mesh plates N may be arranged side by side as shown in the example in accordance with the size of the installation portion.

  Although the net plate N can be selected as appropriate, as shown in FIGS. 6 and 7, at least one of the front surface forming the filter cloth side and the back surface forming the receiving filter plate side, from one end to the opposite end The thing provided with two or more continuous protrusion N1 is suitable. In general, the ridges N1 are preferably formed in parallel at equal intervals over the entire surface of the mesh plate N, but may be formed only on a part of the mesh plate N. Moreover, it is preferable that this protruding item | line N1 is extended along the direction which cross | intersects a horizontal direction, ie, a vertical direction, or the diagonal direction. Further, when the ridge N1 is formed on the surface of the mesh plate N, at least the ridge N1 on the surface of the mesh plate is preferably extended along an oblique direction intersecting both the horizontal direction and the vertical direction.

  Although not shown, the mesh plate N can also be provided on the side surface of the filter chamber 4C of the diaphragm 4D. Further, when the mesh plate N is provided, the filtrate groove d on the surface of the filter plate 4 or the surface of the diaphragm 4D can be omitted.

  On the other hand, a pressure water supply / discharge passage 4G communicating with the diaphragm 4D and the surface of the filter plate 4 opposite to the diaphragm 4D is formed in the lower frame portion of the compressed filter plate 4. It communicates with a pressure water inlet 15A and an outlet 15B provided outside. Furthermore, a slurry supply path 4i is opened on the side surface of the receiving filter plate 4 in the upper frame portion of the compressed filter plate 4, and the slurry supply path 4i is provided outside via a slurry supply header H. The slurry inlet 10 and the compressed air inlet 16 are communicated with each other. In addition, a header cleaning water inlet 17 and an outlet 18 are communicated with the slurry supply header H, respectively. Valves 10V, V5, V4, and 16V to 18V for switching paths are interposed in the inlets and outlets 10 and 16 to 18 of the supply header H, respectively. A cake discharge conveyor 13 is provided below the filter plate 4.

  A pair of filter cloths 9A and 9B are disposed between the filter plates 4, and one of the filter cloths 9B is fixed to the one filter plate 4 facing the one filter cloth 9B. (Fixed filter cloth). The fixed filter cloth 9B is preferably a filter cloth 9B on the diaphragm 4D side. The fixing method is not particularly limited, but when the fixed filter cloth 9B can be disposed on both sides of the filter plate 4 as shown in the figure, the peripheral portions of both filter cloths 9B are arranged around the filter plate 4, for example, the upper surface and the lower surface. The two filter cloths 9B can be fixed to the filter plate 4 by wrapping around and connecting the peripheral portions of the two filter cloths 9B facing each other by connecting means such as a binding band. Further, as shown in the figure, a filter cloth supply port 9i that communicates with the slurry supply path 4i in the upper frame portion of the compressed filter plate 4 is formed at the upper part of the fixed filter cloth 9B.

  The other filter cloth 9A is configured to be able to travel with respect to the other filter plate 4 facing the other filter cloth 9A (traveling filter cloth). The traveling filter cloth 9A is preferably a filter cloth 9A on the side not having the diaphragm 4D. More specifically, the filter cloth driving device 70 is provided on the upper portion of the filter plate 4, and the upper end portion of the traveling filter cloth 9 </ b> A is supported by being suspended by the filter cloth driving device 70 so as to be lifted and lowered. The lower end portion of the filter cloth 9 is configured to be wound around a take-up roll 81 provided above the return roll 80 via a return roll 80 provided below the filter plate. Therefore, when the filter cloth 9 is wound up by the take-up roll 81, the filter cloth 9 is wound while being gradually lowered.

  In the case of the filter cloth single side fixed / single side traveling type apparatus, it is preferable that the cake peelability of the cake contact surface of the fixed filter cloth 9B is higher than the cake peelability of the cake contact surface of the travel filter cloth 9A. . Such a configuration specifically includes elements that affect the cake peelability between the fixed filter cloth 9B and the traveling filter cloth 9A, such as the material, the form of the yarn, the type of woven structure, and the surface treatment. This can be achieved by making at least one different.

  As a material of the filter cloths 9A and 9B, polypropylene, polyester, nylon, vinylidene chloride, Conex, Teflon, acrylic, cotton, or the like can be selected. Nylon, polyester, and vinylidene chloride are suitable for the fixed filter cloth 9B because they have excellent cake peelability compared to other materials. Polypropylene is inferior in cake peelability compared to nylon or the like, but is excellent in chemical resistance and tough fiber, and is therefore suitable for the running filter cloth 9A.

  As the form of the yarns of the filter cloths 9A and 9B, a monofilament yarn (single fiber), a multifilament yarn (long fiber), a spun yarn (spun yarn), a twisted yarn, a processed yarn and the like can be selected. In general, the monofilament yarn is suitable for the fixed filter cloth 9B because of its high cake peelability, and the multifilament yarn is suitable for the traveling filter cloth 9A because it is inferior in cake peelability compared to the monofilament yarn.

  Plain weave, twill weave, satin weave and the like can be selected as the type of weave structure of the filter cloths 9A and 9B. In general, satin weave is smooth with a lot of warp on the surface and is excellent in cake peelability, so it is suitable for fixed filter cloth 9B. Compared to this, plain weave and twill weave are suitable for running filter cloth because of poor cake peelability. ing. Compared with plain weave and twill weave, twill weave is preferred because it is excellent not only in cake peelability but also in various properties such as filtration amount, clarity, clogging, and recovery of washing.

  The filter cloth 9A, 9B can be subjected to a surface treatment for improving or reducing cake peelability. Silicon processing, fluorine processing, or the like can be used as the former example, and surface roughening, fluffing, or the like can be used as the latter example.

  It should be noted that just because the cake peelability is high, the material is not limited to the fixed filter cloth 9B, such as nylon or the like, the monofilament or the satin weave. As long as the fixed filter cloth 9B has higher cake peelability as the filter cloth than the traveling filter cloth 9A, elements that affect the cake peelability can be appropriately selected. As a preferred combination, at least a fixed filter cloth 9B in which warp yarn is made of nylon or polyester monofilament yarn, and multifilament yarn of nylon, polyester, or polypropylene are plain weave, twill weave, cedar weave, or satin weave. A combination with the filter cloth 9A can be mentioned. A particularly preferred combination is a combination of a fixed filter cloth 9B formed by satin weaving nylon or polyester monofilament yarns and a traveling filter cloth 9A formed by plain or twill weave polypropylene multifilament yarns.

  On the other hand, as shown in FIG. 2, slurry supply means, pressure water supply means, cleaning liquid (water, etc.) supply means, compressed air supply means and drying means are connected to the apparatus mechanism described above. . Specifically, a slurry tank 20 for temporarily storing the slurry is installed, and the stored slurry is supplied to the slurry inlet 10 by the slurry pump 21. The slurry inlet 10 is piped so that it can be switched to a direct connection to the slurry tank 20. In addition, a pressure water tank 60 is installed, and the water stored therein is piped so as to be supplied to the pressure water inlet 15 </ b> A by the pressure water pump 61. The pressure water tank 60 is also communicated with the pressure water outlet 15B. In addition, a cleaning liquid tank 90 is provided, and the cleaning liquid stored therein is piped so as to be supplied to the header cleaning liquid inlet 17 via the cleaning pump 91, and the header cleaning liquid outlet 18 is communicated with the slurry tank 20. . Furthermore, an air compressor 30 and a compressed air tank 31 for temporarily storing compressed air supplied from the air compressor 30 are installed, and the outlet side of the compressed air tank 31 communicates with the compressed air inlet 16.

  The slurry supply header H is provided with an inlet 19 such as dry air having a valve 19 </ b> V, and a forced drying means 40 is connected through the inlet 19. As the forced drying means 40, an air suction device such as a vacuum pump or a dehumidifying device can be used in addition to a device that supplies dry air, heated air, or dry heated air. FIG. 8 shows an example of a supply device such as dry air, which temporarily stores air from the air supply means 200 such as an air compressor or a blower fan in the compressed air tank 201 and then supplies it to the user. is there. When supplying pre-dried or heated air, the compressed air tank 201 can be omitted and supplied directly. When supplying dry air, the dehumidifier 202 can be used. The dehumidifier 202 is interposed between the air supply means 200 and the compressed air tank 201 in the illustrated embodiment. Moreover, when supplying heated air, the heating means 203 can be provided in the compressed air tank 201, and the air in the tank 201 can also be heated continuously. As the heating means 203, for example, a heat exchanger using a heating medium such as steam or hot water or a heater using fuel or electricity can be used. Even a type provided in the tank is a jacket type provided on the outer peripheral surface of the tank. Things can also be used.

  As the dry air used for the forced drying means 40, those dried to a humidity of 50% or less can be suitably used. As the heated air, air heated to a temperature of about 15 to 90 ° C., particularly about 30 to 90 ° C. by a heat source such as steam can be suitably used. As the dry heated air, those having a humidity range and a temperature range can be suitably used.

  Dry air or the like from the forced drying means 40 can be supplied through a supply / discharge path other than the slurry supply path, or can be supplied via a separate supply path such as dedicated dry air.

  Next, a dehydration method using the above apparatus will be described with reference to FIG. First, with the traveling filter cloth 9A raised and positioned between the filter plates 4 and 4, the filter plates 4 and 4 are brought into contact with each other, the tightening cylinder is operated, and the filter plates 4 and 4 are brought into close contact with each other. A filter chamber 4C is formed between the four and four. In this state, the slurry supply port 9i of the filter cloth 9A communicates with the slurry supply path 4i of the filter plate frame portion. Next, the slurry inlet valve 10V is opened, and the slurry pump 21 is operated with the header cleaning liquid inlet valve 17V, the outlet valve 18V, and the compressed air inlet valve 16V closed, and the slurry is placed between the filter cloths 9A and 9B in each filter chamber 4C. Supply. The slurry supplied between the filter cloths 9A and 9B receives pressure due to the supply pressure of the slurry supplied later, and the liquid component is discharged out of the filter cloths 9A and 9B through the filter cloths 9A and 9B. This filtrate passes through the filtrate groove d, and is discharged to the outside from the filtrate outlet 12A via the filtrate outlet 4F.

  In particular, when the mesh plate N having the ridges N1 is provided on the front surface or the back surface, the gap formed between the ridges N1, N1 of the mesh plate N is from the one side end surface of the mesh plate N to the other side. The end surface is communicated and the filtrate is discharged through this gap. Therefore, compared with a simple net plate in which such a gap is not formed, the filtrate discharge efficiency is remarkably improved, and the filtration efficiency can be further improved. In addition, it is particularly preferable that the ridges N1 are formed on at least the back surface of the mesh plate N because a drainage passage is more reliably formed between the mesh plate N and the surface of the filter plate 4. Further, it is preferable that the protrusion N1 of the mesh plate N extends along the direction intersecting the horizontal direction because the filtrate discharging performance is enhanced.

  When a predetermined time has elapsed from the start of slurry supply, the slurry supply pump 21 is stopped, the pressure water pump 61 is operated, and the pressure water inlet valve V5 is opened to supply pressure water into the diaphragm 4D. Bulge. Thereby, the filter cake between the filter cloths 9A and 9B is further squeezed into a low moisture cake.

  If filtration and pressing are completed, the pressure water supply pump 61 is stopped and the pressure water outlet valve V4 is opened to return the pressure water to the pressure water tank 60. Further, while the slurry inlet valve 10V is kept open, the connection of the slurry inlet valve 10V is switched to the slurry tank 20, the cleaning liquid inlet valve 17V, the cleaning liquid outlet valve 18V and the compressed air inlet valve 16V are opened, and the cleaning liquid supply pump 91 is operated. Cleaning liquid and compressed air are supplied into the slurry supply header H, and the slurry remaining in the header H is returned to the slurry tank 20 via the slurry supply path. When the cleaning of the header H is completed, the cleaning liquid supply pump 91 is stopped and the cleaning liquid outlet valve 18V is closed, and compressed air is supplied into the filter chamber 4C through the slurry supply path, and the slurry remaining in the filtrate groove d is removed. Drain through the filtrate outlet 4F.

  When the blow process is completed, the compressed air inlet valve 16V is closed to stop the supply of compressed air, and the frame is opened. That is, after the tightening cylinder is released, the filter plate 4 is moved away by the filter plate driving device 7 to be in an open frame state. Thereafter, the take-up roll 81 is driven to lower the filter cloth, and it is folded back and wound up via the return roll 80. By this folding (bending of the filter cloth), the cake C is peeled from the filter cloth 9 and discharged onto the conveyor 13 below.

  In particular, when the mesh plate N is provided, as shown in FIG. 10, both the filter cloth 9A and the cake C are pushed into the holes of the mesh plate N at the time of filtration. The cloth 9A comes out of the hole of the mesh plate N and becomes flat, whereas the cake C does not become flat, and a convex portion remains in a portion corresponding to the hole of the mesh plate N. As a result, the filter cloth 9 </ b> A acts to push up the convex portion of the cake C and peel off, and the peeling of the cake C is promoted. With respect to this point, when the ridge N1 on the surface of the mesh plate extends along an oblique direction intersecting both the horizontal and vertical directions, the peeling force acting on the cake C from the filter cloth 9A is oblique. Acts along the direction. In this case, the peeling force in the oblique direction has a vertical component and a horizontal component. Therefore, the peeling force easily acts on the entire surface of the filter cloth 9A, and the cake C hardly remains on the filter cloth 9A.

  Thus, the dehydration operation is repeated with each of the above steps as one cycle. A filter cloth regeneration process by forced drying is performed between each cake discharge process and the tightening process in the next dewatering operation every cycle or every multiple cycles (for example, once a week, once a week or once a month). Is called. That is, as shown in FIG. 11, once the cake discharge is completed, after the filter plate 4 is closed, the valves 10V, 16V to 18V are closed, the valve 19V is opened, and dry air or the like is passed through the slurry supply header H. And supplied between the filter cloths 9A and 9B. By supplying the dry air or the like, the filter cloth and the residue attached and held on the filter cloth are forcibly dried. The filter plate does not have to be closed, but in that case, it is better to close the filter plate because heat escapes to the outside and energy efficiency decreases.

  When the drying is completed after a predetermined time, supply of dry air or the like is stopped. The dry residue adhering to the traveling filter cloth 9A and the fixed filter cloth 9B drops off from the filter cloths 9A and 9B when the slurry is supplied in the next cycle. That is, since the filter cloths 9A and 9B are deformed when the slurry is supplied, an external force is applied to the residue by the deformation, and the adhesion structure of the residue to the surface and the inside of the filter cloth 9A and 9B is destroyed, and the residue pieces Falls off. The dropped residue is taken into the cake for the next discharge and discharged.

  Further, in order to discharge the residue adhered to the traveling filter cloth 9A, as shown in FIG. 12, after opening the filter plate 4 in the same manner as the cake discharging step, the winding roll 81 is driven and the filter cloth is driven. Can be lowered and folded back and wound up via the return roll 80. By folding back (bending of the filter cloth) by the return roll, the adhesion structure of the residue on the surface and inside of the filter cloth 9A can be destroyed, and the residue piece C1 can be dropped and discharged. Although not shown, it is possible to drop the residue by applying an external force mechanically and directly to the fixed filter cloth by a method such as running while pressing a roller against the surface.

  Further, instead of or together with such forced drying, between the cake discharging step and the tightening step in the next dewatering operation (prior to this when forced drying), as shown in FIG. Conventional cleaning using cleaning water can also be performed. For this reason, in the illustrated embodiment, a cleaning liquid injection pipe 100 for injecting a cleaning liquid onto the traveling filter cloth 9 </ b> A passing through the return roll 80 is provided. The cleaning liquid injection pipe 100 communicates with a cleaning liquid supply pump 91 provided outside.

  A pair of chutes 110 and 110 are provided below the filter plate 4 so as to be movable between a position where the cylinder 111 covers the filter plate 4 below and a retreat position on both sides thereof. The discharge conveyor 13 is provided. These chutes 110 and 110 function as a pan for receiving the cleaning liquid at a position covering the lower side of the filter plate 4, and a cleaning liquid outlet 112 is provided at the lower part for this function. Further, the chute 110 functions as a chute for guiding the discharged cake C onto the conveyor 13 in the retracted position.

  At the time of washing, in the process in which the traveling filter cloth 9A that has descended as the cake is discharged is raised by the filter cloth driving device 70, the cleaning liquid is sprayed on the surface of the traveling filter cloth 9A that passes through the return rolls 80 and 80. The cake adhering to 9A is washed away. When using such cleaning with a cleaning solution, for example, a cleaning process with cleaning water is performed for each cycle, and the forced drying is performed as necessary or periodically (for example, once a day, a week, or a month). It can be performed.

  However, since this cleaning mode is intended only for the traveling filter cloth 9A, the fixed filter cloth 9B cannot be cleaned. Therefore, it is preferable to adopt a method conventionally used in a fixed filter cloth type filter press apparatus as the cleaning mechanism. That is, as shown in FIG. 14, a washing carriage 50 is provided below the filter plate 4, and the washing carriage 50 is configured to be movable in the direction in which the filter plate 4 is juxtaposed by the carriage driving device 52. A vertically extending cleaning pipe 51 is mounted, and the cleaning liquid is sprayed onto the filter cloths 9A and 9B on both sides from a spray nozzle provided in the cleaning pipe 51. When washing, in the open frame state after the cake is discharged, the washing carriage 50 is moved downward between the filter plates 4 and 4, the washing pipe 51 is extended and inserted between the filter plates 4 and 4, and the traveling filter cloth 9A. The cleaning liquid is sprayed on the surface of the fixed filter cloth 9B.

<Others>
Although the said form is an example of the pressing type filter press apparatus provided with the diaphragm, this invention is applicable also to the non-pressing type filter press apparatus which does not have a diaphragm.

  The present invention can be applied without particular limitation as long as it is a filter press device of a filter cloth one-side fixed and one-side traveling type.

It is explanatory drawing which shows the filter mechanism part of embodiment. It is explanatory drawing which shows the slurry supply means etc. of embodiment. It is a longitudinal cross-sectional view which shows the filter plate part of embodiment. It is a longitudinal cross-sectional view which shows the other example of a filter plate. It is a side view which shows the other example of a filter plate. It is a front view of a net board. It is XX sectional drawing of FIG. It is a flowchart which shows an example of supply apparatuses, such as dry air. It is explanatory drawing which shows the spin-drying | dehydration operation point of embodiment. It is principal part sectional drawing for demonstrating the effect of a mesh board. It is explanatory drawing which shows a drying process. It is explanatory drawing which shows a dry cake discharge process. It is explanatory drawing which shows a washing | cleaning process. It is explanatory drawing which shows another washing | cleaning process.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Filter mechanism part, 4 ... Filter plate, 9 ... Filter cloth, 40 ... Supply apparatus, such as dry air.

Claims (6)

A plurality of juxtaposed filter plates;
A pair of filter cloths disposed between a pair of opposed filter plates;
Tightening means for bringing the filter plates into close contact with each other;
A filtration means for supplying a slurry between the filter cloths and discharging a liquid component through the filter cloths to form a cake between the filter cloths;
An open discharge means for separating the filter plates and the filter cloths from each other and dropping and discharging the cake formed between the filter cloths,
One filter cloth of the pair of filter cloths is a fixed filter cloth formed by fixing the filter cloth to one filter plate facing the one filter cloth, and the other filter cloth is the other filter cloth. A traveling filter cloth configured to be able to travel with respect to the other opposite filter plate, and after forcibly drying the filter cloth, an external force is applied to the filter cloth and the residue attached to the filter cloth, Provided with a filter cloth regeneration means for removing the residue from the filter cloth,
The filter press apparatus characterized by the above-mentioned.   The filter press apparatus according to claim 1, wherein the filter cloth regeneration unit includes a forced drying unit that performs the forced drying by bringing dry air, heated air, or heated dry air into contact with the filter cloth. .   The said forced drying means is comprised so that the said forced drying may be performed in the state which clamped the said filter plate and formed a filter chamber between filter plates, and has arrange | positioned the filter cloth oppositely in the filter chamber. Filter press equipment.   The filter press apparatus according to claim 2 or 3, wherein the forced drying means is configured such that the temperature of the air brought into contact with the filter cloth is 15 to 90 ° C.   The said filter cloth reproduction | regeneration means is provided with the residue removal means to drop a residue from a filter cloth by giving a vibration with respect to a filter cloth, or bending a filter cloth. The filter press apparatus described in 1.   The dewatering operation excluding the step by the filter cloth regenerating unit is repeatedly performed, and the process by the filter cloth regenerating unit is automatically interrupted after a predetermined time has elapsed to regenerate the filter cloth. The filter press apparatus of any one of -5.

Images