JP2006223946A - Filter press apparatus and slurry pressing method of slurry in the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance dehydration ratio of a cake by removing a moisture layer remaining on the surface of filter cloth during a pressing process. <P>SOLUTION: This filter press apparatus 10 has a pressing mechanism with filter cloths 700 provided facing one another in a filtering chamber 300 between facing filter plates 100, and two or more passing ports 500 for leading pressed-out filtrate to the outside of the filtering chamber. To a first passing port 500A, a line 210 sending compressed air into the filtering chamber during the cake pressing process is connected, and the compressed air sent into the filter chamber is discharged from a second passing port 500C entraining filtrate attached to the filter cloth surface. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a filter press device and a method for squeezing slurry in the filter press device.

  In recent years, there has been a filter press apparatus having a pressing mechanism in which a pair of diaphragms and a filter cloth are provided between opposed filter plates, and a slurry accommodated in the filter cloth is pressed and dehydrated by pressure.

  In such a filter press apparatus, a slurry containing solid matter is press-fitted into a filter chamber formed through a filter cloth, and then the slurry press-fitting system is closed, and the diaphragm attached to the filter plate is compressed with water or Compressed air is injected to expand. As a result, the filter chamber is reduced and the slurry is compressed, and the filtrate passes through the filter cloth and is discharged out of the filter chamber.

  However, in the filter press apparatus, at the end of the slurry pressing process, the filtrate is present in the form of a membrane on the surface of the filter cloth. When the diaphragm is contracted in a state where such a membrane-like filtrate is present on the filter cloth surface, there is a problem that the filtrate on the filter cloth surface returns to the cake again. The presence of the filtrate on the surface of the filter cloth at the end of the pressing process causes a decrease in the dewatering rate of the cake. If the filtrate layer remaining on the filter cloth surface can be removed, the dewatering rate of the cake is reduced. Improvement is expected.

  Accordingly, an object of the present invention is to provide a new and improved filter press apparatus capable of removing the filtrate layer remaining on the filter cloth surface during the pressing step and improving the dewatering rate of the cake, and the filter press. It is to provide a squeezing method in the apparatus.

  In order to solve the above problems, in the first aspect of the present invention, a filter chamber is formed between a pair of opposing filter plates via a pair of diaphragms and a filter cloth, and the slurry press-fitted into the filter chamber expands the diaphragm. The filter plate is provided with two or more filtrate outlets for discharging the filtrate of the slurry squeezed from the surface of the filter cloth. In the filter press apparatus, the first filtrate discharge line communicating with the first filtrate discharge port is connected with a compressed air supply line for pumping compressed air into the filter chamber, and the compressed air is After the slurry pressing step is performed for a predetermined time, the slurry is pumped into the filter chamber and discharged to the outside through the second filtrate discharge port along with the filtrate adhering to the filter cloth surface. , That Filter press apparatus is provided to symptoms.

  In the above-described invention, before ending the pressing process, compressed air is pumped from one filtrate outlet and blown onto the surface of the filter cloth, so that the exuding filtrate is entrained and the other filtrate outlet is Discharged. As a result, even if the squeezing process is completed and the diaphragm is contracted, the filtrate on the filter cloth surface does not return into the cake, so that the dehydration rate of the cake can be improved.

  Further, if the first filtrate discharge port is arranged above the second filtrate discharge port, the compressed air is blown from the upper side to the lower side, so that it is separated from the filter cloth surface. The flow of the filtrate can be promoted to flow downward according to gravity.

  Further, the first filtrate outlet and the second filtrate outlet are arranged on a substantially diagonal line on the filter plate, so that compressed air passes through the entire filter cloth surface. Therefore, the filtrate on the filter cloth surface can be effectively removed.

  In order to solve the above-mentioned problems, in the second aspect of the present invention, a filter chamber is formed between the opposing filter plates via a filter cloth, and the slurry press-fitted into the filter chamber is compressed by expanding the diaphragm. A filter press having a squeezing mechanism for pressurizing and dewatering, and the filter plate having two or more filtrate outlets for discharging the filtrate of the slurry squeezed from the surface of the filter cloth In the apparatus, after the slurry pressing step is performed for a predetermined time, compressed air is pumped into the filter chamber through the first filtrate outlet, and the compressed air pumped into the filter chamber is There is provided a method for squeezing a slurry, characterized in that the filtrate adhering to the water is discharged to the outside through a second filtrate discharge port.

  In the above-described invention, before ending the pressing process, compressed air is pumped from one filtrate outlet and blown onto the surface of the filter cloth, so that the exuding filtrate is entrained and the other filtrate outlet is Discharged. As a result, even if the squeezing process is completed and the diaphragm is contracted, the filtrate on the filter cloth surface does not return into the cake, so that the dehydration rate of the cake can be improved.

  Even if the squeezing process is finished and the diaphragm is contracted, the filtrate on the surface of the filter cloth does not return into the cake, so that the dehydration rate of the cake can be improved.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

  First, based on FIG.1 and FIG.2, the structure of the filter press apparatus concerning this embodiment is demonstrated. FIG. 1 is a side sectional view showing the configuration of the filter press apparatus according to the present embodiment. FIG. 2 is a perspective view showing a main configuration of the filter press apparatus according to the present embodiment.

  In the filter press device according to the present embodiment, the configuration is the same as that of the prior art except that the compressed air supply line is provided in the filtrate discharge line. .

  First, as shown in FIG. 1, in the filter press device 10 according to the present embodiment, a filter chamber 300 surrounded by a filter cloth 700 for dewatering slurry is formed between adjacent filter plates 100. Has been. The slurry is supplied to the filter press apparatus 10 from the stock solution (slurry) supply port 400 by a slurry supply pump (not shown) and filtered, and then the filtrate is discharged from the filtrate discharge port 500.

  As shown in FIG. 2, a stock solution supply line 410 for supplying slurry (stock solution) is connected to the stock solution supply port 400 of the filter press device 10. The stock solution supply line 410 is provided with a valve 420 for operating the supply and stop of the stock solution.

  Further, filtrate discharge ports 500A to 500D are provided at four corners of the filter press device, and filtrate discharge lines 510A to 510D are connected to the corners, respectively. Further, the filtrate discharge lines 510A to 510D are provided with valves 520A to 520D for operating the filtrate discharge and the filtrate discharge stop, respectively, to select the filtrate discharge line for the filtrate discharged from the filter press device. be able to.

  Unlike the conventional case, a compressed air supply line 210 is connected to the filtrate discharge line 510A according to the present embodiment. Although details will be described later, by compressing compressed air from the compressed air supply line 210 into the filter press apparatus during the pressing process and blowing the compressed air onto the surface of the filter cloth, the filtrate oozed from the filter cloth is entrained, The filtrate can be discharged from the filtrate discharge line (for example, the filtrate discharge line 510C) selected by operating the valves 520A to 520D.

  Further, a compressed liquid supply line 800 for inflating the diaphragm 600 is connected to the lower side of the filter plate 100 of the filter press device 10, and the compressed liquid is applied to each filter plate 100 through the branch lines 800 a. 600.

  In the present embodiment, unlike the prior art, a compressed air supply line 210 for pumping compressed air into the filtration chamber is connected to, for example, the filtrate discharge line 500A. The compressed air is pumped from the compressed air supply line 210 into the filter chamber via the filtrate discharge line 500A before the slurry pressing step is finished. At this time, since the compressed air is blown onto the surface of the filter cloth, it is discharged to the outside along with the filtrate oozing out on the surface of the filter cloth. Thereby, the dehydration rate of the cake can be improved. The compressed air supply line 210 is provided with a valve 220 for operating the supply and stop of the supply of compressed air.

  Next, based on FIG. 3, the structure of the filter plate concerning this embodiment is demonstrated. FIG. 3A is a front view showing the structure of the filter plate according to the present embodiment. FIG.3 (b) is sectional drawing which shows the internal structure which cut | disconnected the filter plate concerning this embodiment by the GG line.

  As shown in FIG. 3, the filter plate 100 according to the present embodiment includes a diaphragm (squeezed membrane) 600 stretched on both side surfaces thereof. Note that the filter plate 100 and the diaphragm 600 may be integrally formed, and the plate itself may have a diaphragm function. Such a diaphragm can use a crosslinked rubber containing chlorinated polyethylene as a main component in order to enhance heat transfer. Also, a polyethylene material capable of forming a crosslinked rubber such as chlorosulfonated polyethylene can be used.

  A pressurizing liquid supply port 160 for expanding the diaphragm 600 is formed in the lower side portion of the filter plate 100, and the pressurizing liquid supplied to the pressurizing liquid supply port 160 is compressed liquid supply paths 160a, b, The diaphragm 600 can be expanded by being supplied to the diaphragm 600 through c.

  The filter chamber 300 is disposed as an internal space with the filter cloth 700 supported by the diaphragm 600 of the adjacent filter plate 100. The filter plate 100 is formed with holes 140 at locations corresponding to the stock solution supply port 400, and the slurry is passed through the holes 140 and supplied to the filter chambers 300.

  Further, a filtrate guide groove 110 that guides the discharge of the filtrate filtered through the filter cloth is formed in the inner periphery of the filter plate 100, and is provided at two places above and below the filtrate guide groove 110 (four places in total). The filtrate discharge small holes 110a, b, c and d are formed. The filtrate filtered through the filter cloth is guided to the filtrate discharge small holes 110a, b, c, d through the filtrate guide groove 110. The filtrate guided to the filtrate discharge small holes 110a, b, c, d is collected at the filtrate collecting port 112 formed inside the filter plate, and is connected to the apparatus through the filtrate discharge ports 150A, B, C, D. It is discharged outside. Thus, the filtrate passes through the filter cloth 700 and is discharged out of the filter chamber, and the filtrate discharged from each filter chamber 300 is discharged from the filter press main body through the filtrate discharge port 150 to the outside of the filter chamber.

  In the pressing process of the slurry, by operating the valve 420, the press-fitting system of the stock solution supply line 410 is closed, and the compressed water is put into the diaphragm 600 provided between the filter plates 100 via the compressed water supply line 800. To inflate by pumping. As a result, the volume of the filter chamber 300 is reduced, and the filtrate passes through the filter cloth 700 and is discharged to the outside of the filter chamber.

  In the present embodiment, unlike the conventional case, the compressed air can be blown onto the filter cloth surface by pumping the compressed air from the compressed air supply line 210 via the filtrate discharge line 500A. That is, for example, the valves 520A, 520B, and 520D of the filtrate discharge lines 510A, 510B, and 510D are closed, and only the valve 520C of the filtrate discharge line 510C is opened.

  When the valve 220 of the compressed air supply line 210 is opened in such a state, the compressed air is pumped from the filtrate discharge line 510A into the filter press device via the compressed air supply line 210. Further, the compressed air is blown along the recess of the diaphragm 600 in the filter chamber, for example, from the filtrate discharge small hole 110a toward the filtrate discharge small hole 110c as shown by a dotted arrow in FIG.

  That is, in the slurry squeezing step, the slurry with a large amount of moisture is initially squeezed, but the slurry moisture decreases as the slurry squeezes. For this reason, at the end of the squeezing process, the filtrate is present in a membrane-like state on the surface of the filter cloth. As described above, the filtrate layer remaining on the surface of the filter cloth is sprayed with compressed air sent from one filtrate outlet, so that the oozing filtrate is accompanied by the other filtrate outlet. Can be discharged. Therefore, even if the diaphragm is contracted, the filtrate on the surface of the filter cloth does not return to the cake again, so that the dewatering rate of the cake can be improved at the end of the pressing process.

  This is similar to the principle experienced when squeezing wet rags, for example. That is, when a wet rag is squeezed, it initially drops as a drop, but when the moisture gradually decreases, it does not become a water drop even when the rag is squeezed, but a water film is formed on the surface of the rag. it can. At this time, if the hand that squeezes the rag is loosened, the water film will enter the rag. If such a water film is cut off from the surface and discharged to the outside, the water film formed on the surface of the rag will not return into the rag. In the present invention, such a principle is applied to the squeezing process of the filter press device, and the compressed air is blown onto the surface of the filter cloth before the squeezing process is completed. Separate. This improves the dehydration effect of the cake.

  Next, based on FIG. 4, the slurry processing process in the filter press apparatus 10 concerning this embodiment is demonstrated. In addition, FIG. 4 is explanatory drawing for demonstrating the slurry processing process of the filter press apparatus concerning this embodiment.

  The slurry processing method of the filter press apparatus according to the present embodiment includes a filtration process, a pressing process, a compressed air pressure entering process (squeezing process), a frame opening process, and the like.

  First, as shown in FIG. 4A, in the filtration step, slurry (raw solution) is supplied into the filter chamber 300 through the raw solution supply port 400. The filter chamber 300 is disposed as an internal space with the filter cloth 700 supported by the diaphragm 600 of the adjacent filter plate 100, and the slurry is passed through the hole 140 formed at a position corresponding to the slurry injection hole 400. , Slurry is supplied to each filter chamber 300.

  Further, the filtrate passes through the filter cloth 700 and is discharged out of the filter chamber. The filtrate discharged from each filter chamber 300 is discharged from the filter press main body via the filtrate discharge port 150 to the outside of the filter chamber.

  Next, as shown in FIG. 4 (b), in the pressing process, the press-fitting system composed of the stock solution supply line 410 is closed by the valve 420, and compressed water is pumped into the diaphragms 600 provided between the filter plates 100. And inflate. As a result, the volume of the filter chamber is reduced, and the filtrate is discharged outside the filter chamber through the filter cloth.

  Furthermore, in this embodiment, unlike the prior art, as shown in FIG. 4C, a compressed air pressure entering step (squeezing step) is performed.

  That is, in the compressed air pressure input process (squeezing process) in the present embodiment, compressed air can be pumped from the compressed air supply line 210 through the filtrate discharge line 500A and sprayed onto the filter cloth surface. At this time, since the compressed air is discharged together with the filtrate oozing out on the filter cloth surface, the cake after pressing can be more effectively dehydrated. As a result, even if the diaphragm is contracted, the filtrate on the surface of the filter cloth does not return into the cake, so that the dewatering rate of the cake is improved.

  Finally, as shown in FIG. 4 (d), the filter press device is released and the cake is discharged. Since the moisture content of the cake is less than that of the conventional one, the peelability is good, and there is almost no cake remaining in the filter cloth as particles.

  In addition, after performing a compressed air pressure process (squeezing process) and performing a cake drying process, the frame opening process of a filter press apparatus can be performed. In this case, for example, hot water is put into the diaphragm 600 after sucking with a vacuum pump and lowering the evaporation temperature of the cake with respect to the cake that has become a solid lump through the compressed air pressure entering step (pressing step). Pump to inflate. As a result, the cake in the filter chamber is heated after the evaporation temperature of the water is lowered, and the cake itself is dehydrated more than before, so that the drying efficiency of the cake is improved. At this time, the lower the pressure outside the filter chamber, the better. Further, if, for example, surplus hot water in the factory is used as the hot water, the cost for drying the cake can be reduced. After the cake has been dried, the cake is released and a cake discharging process is performed to discharge the cake. Since the cake is in a dry state, the peelability is good, and there is almost no cake that is separated into particles and remains on the filter cloth.

  In this embodiment, before the end of the pressing process, compressed air is sent from one passage port, and the compressed air is blown onto the surface of the filter cloth. More drain. As a result, even if the diaphragm is contracted, the filtrate on the surface of the filter cloth does not return into the cake, so that the dehydration rate of the cake can be improved.

Example 1
Since the slurry was squeezed based on the above embodiment, it will be described in comparison with a conventional example. In the conventional example, the squeezing process was completed without injecting compressed air, and the other conditions were completely the same.

Slurry used: Human waste surplus sludge Compression time: 60 minutes Compressed air pressure entry time: 10 minutes

(Implementation results)
The water | moisture content of the cake after the pressing process by a present Example was 67%. The moisture content in the conventional example was 70%. Thus, the moisture content of the cake was reduced by 3%. Furthermore, the peelability of the cake after the pressing process was even better than before.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the example which concerns. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are of course within the technical scope of the present invention. Understood.

  For example, in the above embodiment, the configuration in which the filtrate discharge line 510A is a compressed air supply port and the filtrate discharge line 510C is a compressed air discharge port is described as an example, but the present invention is not limited to this example. The air flow direction can be changed by opening and closing the valve of the filtrate discharge line as appropriate.

  Moreover, in the said embodiment, although demonstrated taking the example of the structure which pumps compressed air before the completion | finish of the pressing process of a slurry, it is not limited to this example. For example, compressed air can be continuously and intermittently fed during the slurry pressing step. In this case, it is preferable to lengthen the blow time with compressed air immediately before the end of the pressing step.

  Moreover, it is preferable that the filtrate discharge port which pumps compressed air is arrange | positioned above the filtrate discharge port which discharges compressed air. With such a configuration, the compressed air is blown downward from above, so that the filtrate separated from the surface of the filter cloth can be promoted to flow downward according to gravity.

  Further, it is preferable that the filtrate outlet for pumping compressed air and the filtrate outlet for discharging compressed air are arranged on a substantially diagonal line on the filter plate. As a result, the compressed air can be passed over the entire filter cloth surface, so that the filtrate on the filter cloth surface can be effectively removed.

  The present invention can be applied to a filter press device, and particularly has a squeezing mechanism in which filter cloths are provided facing each other in filter chambers between opposed filter plates, and is provided with two or more filtrate passage ports. It is applicable to a press device.

It is a perspective view which shows the structure of the filter press apparatus concerning 1st Embodiment. It is a perspective view which shows the structure of the filter press apparatus concerning 1st Embodiment. FIG. 3A is a front view showing a configuration of a filter plate used in the filter press device according to the first embodiment. FIG. 3B is a cross-sectional view showing the internal configuration of the filter plate used in the filter press device according to the first embodiment. It is explanatory drawing which shows the processing method of the slurry in the filter press apparatus concerning 1st Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Filter press apparatus 100 Filter plate 140 Slurry supply port 150 Filtrate discharge port 160 Pressurized water supply port 210 Pressed air supply line 220 Valve 300 Filtration chamber 400 Stock solution supply port 410 Stock solution supply line 420 Valve 500 Filtrate discharge port 510 Filtrate discharge line 520 Valve 600 Diaphragm 700 Filter cloth 810 Pressed water supply line
820 valve

Claims (4)

A filter chamber is formed between the opposing filter plates via a pair of diaphragms and a filter cloth, and has a pressing mechanism that pressurizes and dewaters the slurry press-fitted into the filter chamber by expanding the diaphragm; and In the filter press apparatus provided with two or more filtrate discharge ports for discharging the filtrate of the slurry squeezed from the surface of the filter cloth in the filter plate,
The first filtrate discharge line communicating with the first filtrate discharge port is connected with a compressed air supply line for pumping compressed air into the filter chamber,
The compressed air is pumped into the filter chamber after the slurry pressing step is performed for a predetermined time, and is accompanied by the filtrate adhering to the filter cloth surface through the second filtrate discharge port. Discharged into,
The filter press apparatus characterized by the above-mentioned.   3. The filter press device according to claim 1, wherein the first filtrate discharge port is arranged above the second filtrate discharge port. 4.   2. The filter press device according to claim 1, wherein the first filtrate discharge port and the second filtrate discharge port are disposed substantially diagonally on the filter plate. A filter chamber is formed between the opposing filter plates via a filter cloth. The filter chamber has a pressing mechanism for pressing and dewatering the slurry press-fitted into the filter chamber by expanding a diaphragm. Is a filter press device provided with two or more filtrate outlets for discharging the filtrate of the slurry squeezed from the surface of the filter cloth,
After the slurry pressing step is performed for a predetermined time, compressed air is pumped into the filter chamber through the first filtrate outlet,
The compressed air pumped into the filter chamber is discharged to the outside through the second filtrate discharge port along with the filtrate adhering to the filter cloth surface.
A method for squeezing slurry.

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