JP2001224910A - Method for releasing stuck cake in filter press - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for releasing the sticking state of dehydrated cake to a filtration chamber and a filter medium with respect to a filter press suitable for dehydrating inorganic sludge of fine particles. SOLUTION: The filter press is constituted so that a metallic filter medium 6 is stretched and disposed on a filtration bed 5 of each of filtration plates 3 arranged in parallel with one another to be freely opened/closed on a rail 2, an undiluted solution is forcibly fed into the filtration chamber 7 formed by closing the adjacent plates 3 to carry out solid-liquid separation and the separated filtrate is discharged from a discharging hole 10. This method for releasing the stuck cake in the filter press comprises peeling off cake A from the plate 3a by supplying high pressure air Q or high pressure water Q' having the pressure higher than the forcibly feeding pressure P of sludge from the hole 10a of the plate 3a or making the high pressure air, which is used for generating a gap on the interface between the medium 6a and the cake A, pass through the outer peripheral part of the filtration surface of the plate 3a after sludge is fed forcibly and the solid-liquid separation is carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter press suitable for dewatering inorganic sludge having fine particles such as tap water sludge, dredged sludge, magnesium hydroxide and iron oxide, using a metal filter medium as a filter medium. In particular, the present invention relates to a method for releasing cake sticking to a filter chamber and a filter medium, which is a problem when discharging dewatered cake having a difficulty in air blow and cake washing effects.

[0002]

2. Description of the Related Art Conventionally, filter cloths have been used for filter presses. For example, when dewatering inorganic sludge such as water sludge, dredged sludge, calcium carbonate, magnesium hydroxide, iron oxide, etc., by applying a high pressure injection pressure or even a pressing pressure, a filter press capable of obtaining a low water content cake is obtained. Is often used, and filter cloth is mainly used as a filter medium. In a filter press having a filter plate with a diaphragm, the cake having the lowest water content can be obtained. Then, as a technology to further reduce the moisture of the cake pressed by the diaphragm, high-pressure air is used to remove moisture between cake particles, which is difficult to extrude with mechanical pressing pressure, by high-pressure air. The applicant of the present invention has proposed a so-called air blow device that supplies air to pass high-pressure air through a cake, for example, in Japanese Patent Publication No. 63-34766. At this time, it is necessary to seal the sealing surface of the filter cloth so that the high-pressure air does not leak from the filter frame sealing portion sandwiching the filter cloth. Next, as a conventional technique relating to a filter press using a metal filter medium and improving cake releasability, for example, a filter press cake peeling apparatus using a metal mesh such as a wire mesh coated with a fluororesin is disclosed in Japanese Patent Application Laid-Open No. H5-15707. In Japanese Patent Application Publication No. 2527922, a filter medium in which a metal mesh (wire mesh) is overlaid on a punching metal laid on a filtration floor of a filter plate and stretched is disclosed in Japanese Utility Model Registration No. 2527922.
Each is proposed by the applicant of the present invention.

[0003]

In the conventional filter press using a filter cloth, a thick filter cloth having a thickness of 1.0 to 2.0 mm which can withstand pressurization and squeezing pressure is used. As fine particles adhere to the cloth and the precipitation of crystals progresses, the filtration capacity decreases due to clogging, and the filter cloth cannot be used due to damage due to bending and abrasion. Need to be replaced. In addition, a so-called air blow device that supplies high-pressure air from a filtrate discharge port of a filter plate is an effective means in the case of an air blow in which air or water easily penetrates the inside of the cake and a cake in which the cake washing effect is extremely easy. However, as described above, it is necessary to seal the filter cloth seal portion, and furthermore, the filter cloth which is expensive due to the sealing processing and is difficult to recycle is consumed and discarded in a short time.

As a countermeasure, a metal filter medium having high rigidity, good wear resistance, long life, and easy material recycling is promising. However, even in a filter medium using a metal filter medium, when the target sludge is an organic sewage sludge, etc., the cake is relatively soft and has good peelability,
Inorganic sludge with fine particles (for example, a particle size of 0.04
The cake obtained by dewatering ６6 μ of precipitated calcium carbonate) has a low moisture content and is hard. Therefore, the cake was firmly fixed to the inner surface of the filtration chamber and the metal filter medium, and the cake did not separate under its own weight even when the front and rear filter plates were opened, and an excessive load was applied to a scraper or the like when the cake was discharged. Therefore, as a countermeasure against the cake sticking to the filter chamber and the filter medium, it has been necessary to devise measures such as coating the surface of the metal mesh with a fluorine resin as described above, or reinforcing the metal mesh by punching so as to withstand the peeling operation. The present invention provides a method of applying a high-pressure fluid to an interface between a cake, a filter frame inner surface, and an interface between the cake and a filter medium when a metal filter medium that is easily material-recycled is applied to a filter press or the like, and releases a problem of sticking of the cake. Is what you do.

[0005]

According to a first aspect of the present invention, a filter chamber is provided in which a metal filter medium is stretched on a filter bed of filter plates which are openably and closably arranged on rails, and front and rear filter plates are closed. To form
In a filter press in which the undiluted solution is pressed into this filtration chamber to perform solid-liquid separation, and the separated filtrate is discharged from a discharge hole communicating with a filtration bed of a filter plate, sludge is pressed into the filtration chamber to perform solid-liquid separation. After that, high pressure air higher than the press-fitting pressure of the sludge is supplied from the discharge hole of one of the filter plates, and the cake is squeezed with high-pressure air that has penetrated the metal filter medium, thereby reducing the water content of the cake and shrinking the metal. A gap is generated at the boundary between the filter medium and the cake, and this high-pressure air is passed over the boundary between the outer periphery of the cake and the inner peripheral surface of the filter frame portion of the filter plate. And a filter release method using a metal filter medium that discharges high-pressure air from a discharge hole of the filter plate through the filter press. This includes water sludge, dredged sludge, calcium carbonate, magnesium hydroxide,
The cake obtained by dewatering inorganic sludge with fine particles such as iron oxide has a low moisture content and is dense and hard, so high-pressure air cannot pass through the cake and is squeezed. This utilizes a phenomenon in which high-pressure air leaks on the boundary surface with the inner peripheral surface of the filter frame.

[0006] Further, in the filtration chamber where the solid-liquid separation is performed,
First, high-pressure air higher than the press-fitting pressure of the sludge is supplied from the discharge hole of one filter plate to generate a gap at the boundary surface between the metal filter medium and the cake, and then higher-pressure air is discharged from the discharge hole of the other filter plate. The high pressure air is passed through the inner peripheral surface of the filter frame portion of the filter plate, and then penetrates the outer peripheral portion of the filter surface of one of the opposing filter plates. Then, high-pressure air is discharged from the discharge hole of the filter plate, and the cake may be squeezed from both sides of the filtration chamber to peel the cake from the filter plate. Further, high-pressure water is used as a means for separating the cake from the filter plate, and high-pressure water higher than the press-in pressure of the sludge is supplied from the discharge hole of one of the filter plates to the filtration chamber in which the solid-liquid separation has been performed. A gap may be generated at the interface between the filter medium and the cake to separate the cake from the filter plate and the metal filter medium. This is based on the phenomenon that cake obtained by dewatering inorganic sludge with fine particles has a low moisture content and is dense and hard, so high-pressure water cannot pass through the cake and is squeezed. Is the same as However, in the case of high-pressure water, even after a lapse of time thereafter, there is no possibility of leaking on the boundary surface with the inner peripheral surface of the filter frame unlike the compressed air.

[0007] Further, in the filtration chamber where the solid-liquid separation is performed,
First, after supplying high-pressure water higher than the press-fitting pressure of the sludge from the discharge hole of one of the filter plates to generate a gap at the boundary surface between the metal filter medium and the cake, the pressurizing pressure of the sludge is calculated from the discharge hole of the other filter plate. Alternatively, the cake may be separated from the filter plate and the metal filter medium by supplying higher high-pressure air and discharging the cake through the discharge hole of one of the filter plates. Further, after the above-described solid-liquid separation was performed on the filtration chamber, first, high-pressure water higher than the press-fitting pressure of the sludge was supplied from the discharge hole of one of the filter plates to generate a gap at the interface between the metal filter medium and the cake. A gap may be generated at the interface between the metal filter medium and the cake by supplying high-pressure water higher than the press-fitting pressure of the sludge from the discharge hole of the other filter plate, or first, into the filtration chamber where the solid-liquid separation was performed, Then, high-pressure air higher than the press-fitting pressure of the sludge is supplied from the discharge hole of one filter plate to generate a gap at the boundary surface between the metal filter medium and the cake, and then the press-fitting pressure of the sludge from the discharge hole of the other filter plate is increased. High pressure water may be supplied to create a gap at the interface between the metal filter medium and the cake.

In another aspect of the method for releasing cake sticking according to the present invention, a diaphragm is provided in place of a metal filter medium on one filter plate forming a filtration chamber, and the other filter plate has a diaphragm. After the cake subjected to solid-liquid separation is squeezed and dewatered with a diaphragm, and the cake is attached to one of the metal filter media, the pressure is higher than the press-fitting pressure of the sludge from the discharge hole of the filter plate over which the metal filter material is stretched. By supplying high-pressure air, a gap is generated at the boundary surface between the metal filter medium and the cake, and the cake is separated from the filter plate. Since the diaphragm is an elastic body such as rubber, when the deformation at the time of squeezing is restored after squeezing, the sticking to the cake which is hardly deformed even when the squeezing force is released is eliminated. Further, the cake pressed and dewatered by the diaphragm may be supplied with high-pressure water higher than the press-fitting pressure of the sludge from a discharge hole of a filter plate in which a metal filter medium is stretched to generate a gap at a boundary surface between the metal filter medium and the cake. Things.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The apparatus according to the present invention is configured as described above. If sludge is pressed into a filtration chamber between closed filter plates, the filtrate is discharged to the back surface of the metal filter medium, The solid matter is captured by the metal filter medium and dehydrated while forming a cake layer. The filtrate flows down the filtration bed of the filter plate and is extracted from the discharge hole of the filtrate. Next, after the solid-liquid separation of the sludge injected into the filtration chamber is completed, high-pressure air or high-pressure water is supplied from the outlet of the filter plate at a pressure higher than the injection pressure of the sludge, and the cake is shrunk to form a metal filter medium and cake. A high-pressure air that has created a gap at the interface between the metal filter medium and the cake, passes over the interface with the filter frame inner peripheral surface of the filter plate, or a filtration chamber. And squeeze the cake from both sides of the filter plate. Alternatively, a diaphragm may be stretched on one of the filter plates, and the cake squeezed by the diaphragm may be attached to the metal filter medium, and then a high-pressure fluid may be supplied from the back surface of the metal filter medium. Next, by opening the front and rear filter plates, the cake in the filtration chamber can be dropped by its own weight. If necessary, a vertically movable scraper may be provided between the filter plates, and the remaining cake adhering to the metal filter medium may be separated by sliding the filter medium surface of the filter plate in contact with the filter plate. Alternatively, the filtering surface of the metal filter and the sealing surface of the filter plate may be cleaned.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A filter press using a metal filter medium according to the present invention will be described in detail with reference to the drawings. First, as shown in FIG. 1, the filter press is mounted on a rail 2 bridged between front and rear frames 1 and 1. Are supported by a hydraulic cylinder 4 mounted on one frame 1 to open and close the plurality of filter plates 3. As shown in FIG. 2, concave filter beds 5a and 5b are formed on the filter plates 3a and 3b, and metal filter media 6 such as punched metal and wedge wire are formed on the filter beds 5a and 5b.
a and 6b are stretched to form a filtration chamber 7 between the front and rear filter plates 3a and 3b. A press-fitting communication pipe 8 for sludge is provided at the upper part of the filter plate 3. Sludge is press-fitted into a filtration chamber 7 from a stock solution supply pipe 9 shown in FIG. 1 and solid-liquid is separated by metal filter media 6 a and 6 b. The filtrate obtained is filtered through the filtration bed 5 of the filter plates 3a and 3b.
a, 5b, and from the filtrate discharge holes 10a, 10b provided at the lower ends of the filter plates 3a, 3b.
a and 11b.

As shown in FIG. 2, the filtrate tubes 11a, 11b
Are high pressure air pipes 12a, 12b and high pressure water pipes 13a, 1
3b is branched, and high-pressure air or high-pressure water flows from the high-pressure air pipes 12a, 12b or the high-pressure water pipes 13a, 13b into the filtration beds of the filter plates 3a, 3b, and the metal filter medium 6a,
High-pressure air or high-pressure water is applied to the cake solid-liquid separated in the filtration chamber 7 from the back surface of 6b. In addition, the filter plate 3 of another embodiment shown in FIG.
A diaphragm 14 is provided in place of the metal filter medium 6b stretched on the filtration surface of the filter, and a squeezed water pipe 16 is connected to a supply port 15 of the filter plate 3b communicating with the back surface of the diaphragm 14, Is supplied to the back surface of the diaphragm 14, the diaphragm 14 is expanded, the cake in the filtration chamber 7 is squeezed, and the cake A is attached to the metal filter medium 6a of the one filter plate 3a facing the other.

An embodiment of a method for releasing the adhesion of cake based on a filter press using the above-mentioned metal filter medium will be described in detail. In FIG. 4, first, the filter plate 3a and the filter plate 3a are removed from the press-fitting communicating pipe 8 above the filter plates 3a and 3b. In the filtration chamber 7 formed between 3b, inorganic sludge in the range of 3 to 10 kg / cm 2, for example, 7 K in the embodiment for purified water sludge.
g / cm2 sludge press-fitting pressure P
a and 6b to perform solid-liquid separation.
b flows down and is discharged from the discharge holes 10a and 10b. FIG. 4 shows that the filtration chamber 7 is in the range of 0.5 to 48 hours,
For example, in the target purified water sludge, solid-liquid separation of the sludge press-fitted for 15 hours is completed, and cake A is placed in the filtration chamber 7.
Shows a state in which is full.

After the solid-liquid separation is completed, as shown in FIG. 5, a pressure of 4 to 12 K which is higher than the press-in pressure P of the sludge from the high-pressure air pipe 12a shown in FIG.
g / cm2, 8K for the target purified water sludge
g / cm 2 of high-pressure air Q is supplied, and the cake A is squeezed with the high-pressure air Q penetrating the metal filter medium 6a to reduce and shrink the water content of the cake A, thereby forming a gap at the interface between the metal filter medium 6a and the cake A. Generate. Then, the high-pressure air Q is passed on the boundary between the outer periphery of the cake A and the inner peripheral surface of the filter frame 3c of the filter plates 3a and 3b, and then penetrates the outer peripheral portion of the filter surface of the other opposing filter plate 3b. After the high-pressure air Q is exhausted from the discharge hole 10b of the filter plate 3b and the cake A fixed to the metal filter material 6a on one side is easily peeled off, the filter plates 3a and 3b are opened and the filtration chamber 7 is opened. The cake A can be dropped by its own weight. This is because cake A, which is made of dewatered inorganic sludge with fine particles such as water sludge, dredged sludge, calcium carbonate, magnesium hydroxide, and iron oxide, has a low water content and is dense and hard, so high-pressure air Q passes through cake A. It utilizes the phenomenon of being unable to squeeze. If necessary, a vertically movable scraper is provided between the filter plates 3a, 3b (not shown), and the remaining cake adhering to the metal filter media 6a, 6b is separated by sliding the filter media surfaces of the filter plates 3a, 3b. It may be.

Another embodiment of the cake releasing method shown in FIGS. 6 and 7 is as follows. First, in a filtration chamber 7 where solid-liquid separation has been performed, a pressure of 4 to 12 kg / cm 2 higher than the press-fitting pressure of sludge is applied. For example, in the target purified water sludge, 8 kg
/ Cm2 high-pressure air Q is discharged from one of the filter plates 3a to the discharge hole 10a.
And a gap is generated at the interface between the metal filter medium 6a and the cake A (FIG. 6), and then the discharge hole 10b of the other filter plate 3b is formed.
In the range of 5 to 14 Kg / cm 2, for example, for the target purified water sludge, 9 Kg / cm 2 high-pressure air R is supplied to generate a gap at the interface between the other metal filter medium 6 b and cake A, Filter the air R on the filter plates 3a, 3b
The filter plate 3c is passed over the boundary surface with the inner peripheral surface of the filter frame 3c.
The high-pressure air R may be discharged from the discharge hole 10a (FIG. 7), and the cake A squeezed from both sides of the filtration chamber 7 may be peeled from the filter plates 3a and 3b. This utilizes the phenomenon that high-pressure air leaks on the boundary surface with the inner peripheral surface of the filter frame portion having relatively low passage resistance as time passes.

FIG. 8 shows another embodiment of the cake releasing method using high-pressure water as a means for peeling the cake A from the filter plate 3a. First, high-pressure water Q ′ higher than the press-fitting pressure P of the sludge is supplied to the filtration chamber 7 from the discharge hole 10a of the one filter plate 3a to generate a gap at the boundary surface between the metal filter medium 6a and the cake A, and the cake A is formed. It may be peeled off from the metal filter 6a. This utilizes a phenomenon in which high pressure water cannot pass through the cake due to a low moisture content and is dense and hard, resulting in a state in which the cake is squeezed.

The cake releasing method shown in FIGS. 8 and 7 is another embodiment of the cake releasing method using high-pressure water and high-pressure air as a means for peeling the cake A from the filter plate 3. First, high-pressure water Q ', which is higher than the sludge press-in pressure P, is supplied from the discharge hole 10a of one filter plate 3a to the filtration chamber 7 where solid-liquid separation has been performed, so that a gap is formed at the boundary between the metal filter medium 6a and the cake A. After the generation (FIG. 8), a higher high-pressure air R is supplied from the discharge hole 10b of the other filter plate 3b to generate a gap at the interface between the other metal filter medium 6b and the cake A. The filter plates 3a and 3b are passed on the boundary surface with the inner peripheral surface of the filter frame portion 3c, and then passed through the outer peripheral portion of the filter surface of one filter plate 3a, and are discharged from the discharge hole 10a of the filter plate 3a with high-pressure air. R is discharged (FIG. 7) and cake A is squeezed from both sides of the filtration chamber 7 to form a cake. A may be separated from the filter plates 3a and 3b.

The cake release method shown in FIGS. 8 and 9 is another embodiment using high-pressure water. In the filtration chamber 7 in which solid-liquid separation has been performed, first, a pressure higher than the press-fitting pressure P of the sludge is applied. After high-pressure water Q 'is supplied from the discharge hole 10a of one filter plate 3a to generate a gap at the boundary surface between the metal filter medium 6a and the cake A (FIG. 8), sludge is discharged from the discharge hole 10b of the other filter plate 3b. High pressure water Q 'higher than the injection pressure of
A gap is generated at the interface between b and cake A (FIG. 9). The cake release method shown in FIGS. 6 and 9 is another embodiment using high-pressure air and high-pressure water. First, a sludge press-in pressure Q is applied to a filtration chamber 7 where solid-liquid separation has been performed. Higher pressure air P is supplied from the discharge hole 10a of one filter plate 3a to generate a gap at the interface between the metal filter medium 6a and the cake A (FIG. 6), and then the discharge hole 10b of the other filter plate 3b. , High pressure water Q ′ higher than the sludge press-in pressure P may be supplied to generate a gap at the boundary surface between the metal filter medium 6b and the cake A (FIG. 9).

Another embodiment in which the diaphragm 14 is disposed on one side of the filter plate 3b forming the filtration chamber 7 will be described in detail with reference to FIG. 3. The diaphragm 14 is disposed on the other filter plate 3b.
The cake A that has undergone solid-liquid separation is squeezed and dewatered by a diaphragm 14 to attach the cake A to the other metal filter medium 6, and then a high-pressure air pipe 12 To supply a high-pressure air Q from the filter medium to generate a gap at the boundary surface between the metal filter medium 6 and the cake A.
From the surface. The cake A pressed and dewatered by the diaphragm 14 is used as the filter plate 3 on which the metal filter medium 6 is stretched.
A high pressure water Q ′ higher than the press-fitting pressure of the sludge may be supplied from the high pressure water pipe 13 to the discharge hole 10 a to generate a gap at the boundary surface between the metal filter medium 6 and the cake A.

[0019]

As described above, the method for releasing the adhesion of cake in a filter press according to the present invention is as follows. The cake obtained by dewatering inorganic sludge having fine particles has a low moisture content and is dense and hard. Utilizing the phenomenon that the cake cannot be passed through the cake and is in a squeezed state, and furthermore, the phenomenon that high-pressure air leaks on the boundary surface with the inner peripheral surface of the filter frame portion, which has relatively little passage resistance over time, is used. Things. That is, the cake obtained by dewatering the inorganic sludge, squeezing the cake with high-pressure air or high-pressure water through a metal filter medium to generate a gap at the boundary between the metal filter medium and the cake, or the inner surface of the cake and filter frame portion The high pressure air acts on the boundary surface with the filter medium to release the sticking of the cake.

As a result, the cake is released under its own weight from the metal filter medium of the opened filter plate, and the scraper becomes unnecessary. Alternatively, no excessive load is applied to the scraper or the like when the cake is discharged. By the way, in the case of air and water which are extremely easy to penetrate the inside of the cake, that is, in the case of a conventional cake having a so-called air blow and cake washing effect which is extremely easy, the above-mentioned functions and effects are reduced. In other words, the effect of the present invention is greater for a cake having a more difficult air blowing and cake washing effect.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a filter press according to the present invention.

FIG. 2 is a partially cutaway perspective view of a filtration chamber similarly formed by filter plates before and after a metal filter medium is stretched.

FIG. 3 is a partially cutaway perspective view of a filtration chamber formed by a filter plate having a metal filter medium stretched and a filter plate with a diaphragm.

FIG. 4 is a conceptual diagram of an embodiment showing a state where solid-liquid separation is completed and cake is filled in a filtration chamber.

FIG. 5 is a conceptual diagram of an embodiment showing a state in which a gap is generated at a boundary surface between a metal filter medium and a cake by high-pressure air, and the high-pressure air is passed along an inner peripheral surface of a filter frame of a filter plate.

FIG. 6 is a conceptual diagram of an embodiment showing a state in which a gap is generated at a boundary surface between a metal filter medium and a cake by high-pressure air.

FIG. 7 is a diagram showing a state in which the action shown in FIGS. 6 to 8 is applied to one filter plate, and high pressure air is supplied from the other filter plate to generate a gap at the interface between the metal filter medium and the cake; It is a conceptual diagram of the Example which shows the state which let air pass along the inner peripheral surface of the filter frame part of a filter plate.

FIG. 8 is a conceptual diagram of an embodiment showing a state in which a gap is generated at a boundary surface between a metal filter medium and a cake with high-pressure water.

FIG. 9 is a diagram showing a state in which a high pressure air is supplied from the other filter plate opposing the filter plate in which the action of FIG. It is a conceptual diagram of an Example.

[Explanation of symbols]

 2 Rail 3, 3a, 3b Filter plate 3c Filter frame part 5, 5a, 5b Filter bed 6, 6a, 6b Metal filter material 7 Filtration chamber 10, 10a, 10b Discharge hole 14 Diaphragm A Cake P Sludge press-in pressure Q High-pressure air Q '' High-pressure water R High-pressure air

Claims (8)

[Claims] 1. A metal filter medium (6) is stretched on a filter bed (5) of a filter plate (3) which is openably and closably arranged on a rail (2), and the front and rear filter plates (3a, 3b) are closed. To form a filtration chamber (7). The undiluted solution is press-fitted into the filtration chamber (7) to perform solid-liquid separation, and the separated filtrate is filtered on a filtration bed (5a) of a filter plate (3a, 3b).
a, 5b), in a filter press discharged from the discharge holes (10a, 10b) communicating with the filter chamber (7), after performing a solid-liquid separation by pressing the sludge into the filtration chamber (7), the pressure is higher than the press-in pressure (P) of the sludge. High-pressure air (Q) is applied to one filter plate (3
a) through the discharge hole (10a) and the metal filter medium (6).
A gap is generated at the interface between the cake (A) and the cake (A) by high-pressure air (Q) penetrating the metal filter medium (6a), and the high-pressure air (Q) is further added to the outer periphery of the cake (A) and the filter plate (3a, 3
b) pass over the boundary surface with the inner peripheral surface of the filter frame portion (3c),
Next, the high-pressure air (Q) is discharged from the discharge hole (10b) of the filter plate (3b) by penetrating the outer peripheral portion of the filter surface of the other filter plate (3b) facing the other filter plate, and the cake (A) is removed from the metal filter medium. (6a)
A method for releasing the cake from the filter press, wherein the cake is released from the filter frame (3c). 2. A filtration chamber (7) in which the solid-liquid separation has been performed.
First, high-pressure air (Q) higher than the press-fitting pressure (P) of the sludge is supplied from the discharge hole (10a) of one of the filter plates (3a) to the boundary surface between the metal filter medium (6a) and the cake (A). After the formation of the gap, the discharge hole (10) of the other filter plate (3b) is formed.
b) to supply higher high pressure air (R) to generate a gap at the interface between the metal filter medium (6b) and the cake (A);
Further, the high-pressure air (R) is passed over the boundary between the outer periphery of the cake (A) and the inner peripheral surface of the filter frame (3c) of the filter plates (3a, 3b). 3a) through the perimeter of the filtration surface and the discharge holes (10) of the filter plate (3a).
2. A filter press according to claim 1, wherein high-pressure air (R) is discharged from a) to peel the cake (A) from the metal filter media (6a, 6b) and the filter frame (3c). Method. 3. A filtration chamber (7) in which the solid-liquid separation has been performed.
Then, high-pressure water (Q ′) higher than the press-fitting pressure (P) of the sludge is supplied from the discharge hole (10a) of one filter plate (3a),
A gap is generated at the interface between the metal filter medium (6a) and the cake (A) with high-pressure water (Q ′) penetrating the metal filter medium (6a), and the cake (A) is peeled from the metal filter medium (6a). The method for releasing cake sticking of a filter press according to claim 1, characterized in that: 4. A filtration chamber (7) in which the solid-liquid separation has been performed.
First, high-pressure water (Q ') higher than the press-fitting pressure (P) of sludge is supplied from the discharge hole (10a) of one of the filter plates (3a) to provide an interface between the metal filter medium (6a) and the cake (A). After a gap is formed in the other filter plate (3b), the discharge hole (10
b) to supply higher high pressure air (R) to generate a gap at the interface between the metal filter medium (6b) and the cake (A);
Further, the high-pressure air (R) is passed over the boundary between the outer periphery of the cake (A) and the inner peripheral surface of the filter frame (3c) of the filter plates (3a, 3b). 3a) through the perimeter of the filtration surface and the discharge holes (10
2. A filter press according to claim 1, wherein high-pressure air (R) is discharged from a) to peel the cake (A) from the metal filter media (6a, 6b) and the filter frame (3c). Method. 5. A filtration chamber (7) in which the solid-liquid separation has been performed.
First, high-pressure water (Q ') higher than the press-fitting pressure (P) of sludge is supplied from the discharge hole (10a) of one of the filter plates (3a) to provide an interface between the metal filter medium (6a) and the cake (A). After a gap is formed in the other filter plate (3b), the discharge hole (10
b) Supply high-pressure water (Q ′) higher than the sludge press-in pressure (P), and feed the metal filter medium (6b) and cake (A).
2. A method according to claim 1, wherein a gap is generated at the boundary surface of the filter press, and the cake (A) is separated from the metal filter medium (6a, 6b). 6. A filtration chamber (7) in which the solid-liquid separation has been performed.
First, high-pressure air (Q) higher than the press-fitting pressure (P) of the sludge is supplied from the discharge hole (10a) of one of the filter plates (3a) to the boundary surface between the metal filter medium (6a) and the cake (A). After the formation of the gap, the discharge hole (10) of the other filter plate (3b) is formed.
b) Supply high-pressure water (Q ′) higher than the sludge press-in pressure (P), and feed the metal filter medium (6b) and cake (A).
2. A method according to claim 1, wherein a gap is generated at the boundary surface of the filter press, and the cake (A) is separated from the metal filter medium (6a, 6b). 7. A diaphragm (14) is provided in place of the metal filter medium (6b) stretched on the other filter plate (3b),
The cake (A) subjected to the solid-liquid separation is put into the diaphragm (1).
After pressing and dewatering in 4) to attach the cake (A) to one metal filter medium (6a), press-fit sludge from the discharge hole (10a) of the filter plate (3a) on which the metal filter medium (6a) is stretched. Supply high pressure air (Q) higher than pressure (P)
2. The method according to claim 1, wherein a gap is formed at the boundary between the a) and the cake (A), and the cake (A) is separated from the filter plate (3a). 8. The cake (A) squeezed and dewatered by the diaphragm (14) is higher than the press-fitting pressure (P) of sludge from a discharge hole (10a) of a filter plate (3a) on which a metal filter medium (6a) is stretched. The high pressure water (Q ') is supplied to generate a gap at the interface between the metal filter medium (6) and the cake (A), and the cake (A) is peeled off from the filter plate (3a). The method of releasing cake from the filter press according to the above.