JP3773164B2 - Filter press device, filter plate for filter press device, and sludge dewatering method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention mainly relates to a filter including a pressure type filter press that performs pressure filtration and pressure dewatering of sludge, which is mainly used for dewatering sludge of sewage and sewage treatment plants, industrial waste water, or general chemical and food-related sludge. The present invention relates to a sludge dewatering method using a press device, a filter plate for a filter press device, and a squeeze type filter press.
[0002]
[Prior art]
Conventionally, water sludge and the like have been dehydrated using a filter press. Particularly in recent years, the processing capacity of facilities has been insufficient due to deterioration of water quality and the like, and as a solution, the processing capacity has been improved by heating sludge supplied to the filter press.
[0003]
[Problems to be solved by the invention]
However, although this conventional technology can improve the processing capacity to a certain extent, it is difficult to further reduce the moisture content of the dehydrated cake and the peelability of the thin dehydrated cake, and shorten the filtration and pressing time. At present, there is no effective means for conversion.
[0004]
Therefore, the main problem of the present invention is to reduce the moisture content of the dehydrated cake and improve the peelability of the dehydrated cake while improving the processing capacity, and to shorten the filtration and pressing time.
[0005]
[Means for Solving the Problems]
The present invention that has solved the above problems is as follows.
[0006]
[0007]
[0008]
<Invention of Claim 1 >
In a filter press apparatus in which a filter cloth is provided opposite to each other in a filter chamber between opposing filter plates, and sludge is supplied between the filter cloths for filtration.
A diaphragm provided between one filter plate and the facing filter cloth;
A fluid chamber formed between the diaphragm and the one filter plate;
A hollow heat conduction panel is disposed between the other filter plate and the filter cloth directly facing, and a supply sludge is added to heat the sludge supplied between the filter cloths by passing a heating fluid through the hollow heat conduction panel. Temperature means;
Sludge heating means for heating the sludge before supplying it between the filter cloths;
In the filtration step in which the heated warm sludge is pressure-fed to the inner surface of the filter cloth and filtered through the filter cloth, the heated fluid is supplied into the fluid chamber and the diaphragm is expanded by the pressure. And means for alternately repeating a squeezing operation for squeezing the dewatered sludge in the filter chamber through the filter cloth, and an opening operation for discharging the fluid in the fluid chamber;
A filter press apparatus characterized by comprising:
[0009]
<Invention of Claim 2 >
Means for supplying a heated fluid into the fluid chamber after the filtration step, expanding the diaphragm by the pressure, and pressing the dewatered sludge in the filter chamber through the filter cloth to squeeze; equipped with claim 1 Symbol placement of filter press apparatus.
[0010]
<Invention of Claim 3 >
The filter press device according to claim 1 or 2 , wherein a filtrate groove is formed on the filter cloth facing surface of the hollow heat conductive panel, and the filtrate passes through the filtrate groove.
[0011]
<Invention of Claim 4 >
The filter press apparatus according to any one of claims 1 to 3 , wherein a filtrate groove is formed on the diaphragm facing surface of the diaphragm, and the filtrate passes through the filtrate groove.
[0012]
[0013]
<Invention of Claim 5 >
The filter press device according to any one of claims 1 to 4 , wherein the hollow heat conductive panel is a metal panel.
[0014]
<Invention of Claim 6 >
The filter press device according to any one of claims 1 to 5 , wherein the filter plate is formed of a resin material.
[0015]
<Invention of Claim 7 >
The filter press apparatus according to claim 3 or 4 , wherein a negative pressure generating means for negative pressure in the filter chamber is connected to the filtrate groove.
[0016]
[0017]
[0018]
[0019]
[0020]
<Invention of Claim 8 >
A filter cloth is provided opposite to each other in a filter chamber between opposing filter plates, and sludge is supplied between the filter cloths for filtration. A diaphragm is provided between one filter plate and the filter cloth facing the filter cloth. Using a filter press device in which a fluid chamber is provided between the diaphragm and the one filter plate, and a hollow heat conductive panel is disposed between the filter plate and the other filter plate .
The heated sludge is heated and supplied to the inner surface of the filter cloth and filtered through the filter cloth, and the heated fluid is supplied into the fluid chamber. A method for dewatering sludge, comprising performing a filtration step of alternately repeating a squeezing operation for squeezing indoor dewatered sludge through the filter cloth and an opening operation for discharging the fluid in the fluid chamber .
[0021]
<Invention of Claim 9 >
After the filtration step, a squeezing step is performed in which a heated fluid is supplied into the fluid chamber, the diaphragm is expanded by the pressure, and the dewatered sludge in the filter chamber is pressed through the filter cloth to squeeze. The method for dewatering sludge according to claim 8, which is performed.
[0022]
<Action>
Upon filtration and supplying pressurized hot sludge, the filtering capacity is increased has been known conventionally, even you adopt the means in the present invention.
[0023]
However, even if the heated sludge is supplied, the temperature is lowered within the time until the filtration and dewatering is completed, and the dewaterability is lowered with time. Further, even if the sludge supplied into the filter chamber is heated, part of the heat is released to the outside of the apparatus through a heat transfer path such as a filter plate, and the heat transfer efficiency to the sludge is not good.
[0024]
Therefore, in the present invention, heating of sludge in the filter chamber and high-efficiency heat transfer to the sludge are possible. As a result, it is possible to prevent a decrease in filtration dehydration accompanying a temperature decrease in the filtration step.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 shows a front view of one example of a filter press apparatus according to the present invention, FIG. 2 shows a II-II cross-sectional view thereof, and FIG. 3 shows a filter plate arrangement form thereof. As shown in FIG. 3, the present apparatus 1 includes a filter plate 2 (hereinafter also referred to as a pressed filter plate) provided with a diaphragm 2E on each side of each filter cloth 4, and a filter plate 3 provided with no diaphragm (hereinafter referred to as a diaphragm). , Also referred to as warm filter plates) are alternately arranged in the horizontal direction, and belong to the horizontal type from the arrangement form of the filter plates. This warming filter plate 3 is also shown in FIGS.
[0026]
Further, one example of the present apparatus belongs to a so-called intaglio type filter plate, and each filter plate 2, 3 is formed with recesses 2a, 3a on the surface facing the adjacent filter plates 3, 2, respectively. A pair of filter cloths 4, 4... Are suspended between the matching filter plates 2 and 3.
[0027]
These filter plates 2, 3... Are connected to adjacent filter plates via connecting members 109, 109, and the mutual interval is adjusted by a cylinder 5 that expands and contracts in the horizontal direction. A shaft 103 is supported on the filter plates 2 and 3 in the horizontal direction, and can be rotated forward and backward by a filter cloth driving device 102, and can be wound up by pulleys 104 and 104 attached to the shaft 103. The filter cloths 4 and 4 are supported in a suspended state via the wire rope 105 and a support bar 108 connected to the lower end of the wire rope. And after raising the support bar 108 which suspends a filter cloth to an upper limit, as shown in FIG. A filter chamber 6 surrounded by a pair of filter cloths 4, 4 is formed between the three. An external sludge supply path 7F, which will be described later, communicates with the filter chamber 6 via an internal sludge supply path 31 (see also FIG. 2) of the warm filter plate 3. The lower structure of the filter plate will be described later.
[0028]
In particular, in this example, each compression filter plate 2 is made of resin, and made of resin with filtrate grooves 2e, 2e ... formed on the surface so as to cover the recesses 2a, 2a facing the outer surfaces of the filter cloths 4, 4. Diaphragms 2E and 2E are arranged, respectively, and fluid chambers 2D and 2D are formed between the diaphragms 2E and 2E and the outer surface of the compression filter plate 2, respectively. An internal fluid supply / discharge passage 2F communicates with each fluid chamber 2D, 2D. Therefore, the fluid F can be supplied to and discharged from the fluid chambers 2D and 2D. Further, the gap SP1 (including the filtrate grooves 2e, 2e,...) Between the filtrate grooves 2e, 2e,... Of the diaphragms 2E, 2E and the outer surface of the filter cloth 4 facing the diaphragm grooves 2E, 2E. 2H communicates with each other, and the internal pressurized air supply path 2J communicates with each other at the upper end.
[0029]
On the other hand, the heating filter plate 3 is also made of resin, and the hollow heat conductive panel 30 (for example, in which the groove 3e, 3e ... is formed on the surface in the recesses 3a, 3a facing the outer surfaces of the filter cloths 4, 4) : A metal panel) and a warming chamber 3s in which a warming fluid circulates in the hollow space of the heat conduction panel 30 is formed, and an internal fluid is formed at the lower end and the upper end of the warming chamber 3s. The supply path 3F and the internal fluid discharge path 3G are communicated with each other. Therefore, the diaphragm 3 is not arranged between the heating filter plate 3 and the outer surface of the facing filter cloth 4 like the compressed filter plate 2. Furthermore, in the gap SP2 (including the filtrate grooves 3e, 3e, ...) between the filtrate grooves 3e, 3e ... and the outer surface of the filter cloth 4 facing this, the internal filtrate discharge passage 3H is connected to the lower end portion thereof, respectively. The internal pressurized air supply path 3J communicates with the upper end portion.
[0030]
Thus, in the present apparatus 1, the main members facing the outside of the apparatus 1 such as the warming filter plate 3, the compressed filter plate 2 and the diaphragm 2E are made of resin, so that the filter chamber 6 surrounded by them is removed from the filter chamber 6 outside the apparatus. Heat conduction and heat conduction panel 30 (which correspond to the heating portion of the supply sludge heating means) are suppressed from heat conduction and heat dissipation to the outside of the apparatus, respectively, and the heat retention of the sludge in the filter chamber 6 is suppressed. Highly efficient heat transfer to the sludge in the filter chamber 6 is possible.
[0031]
Moreover, in this apparatus 1, the diaphragm 2E which squeezes the sludge supplied to 4S between a pair of filter cloth 4 and 4 is arranged between the pressing filter board 2 and the filter cloth 4 which opposes this, and this diaphragm 2E and A fluid chamber 2D is formed between the compressed filter plate 2 and a diaphragm is not disposed between the heated filter plate 3 and the filter cloth 4 opposed to the heated filter plate 3, and the heated filter plate 3 is supplied with a fluid. The heating means for heating the sludge that has been heated (the heating chamber 3s constitutes the heating means) is provided.
[0032]
On the other hand, referring to the system flow diagram of FIG. 4, the present apparatus 1 is an example of a sludge supply means 7 for supplying heated sludge, a sludge storage tank 7A, and a sludge for heating sludge S in the sludge storage tank 7A. A heating means 7B (for example, a steam blowing device) and a sludge pump 7P that pressurizes and supplies the heated sludge S in the sludge storage tank 7A to the filter cloth 4, 4S through the external sludge supply passage 7F. ing. A cleaning liquid supply path 8F having a cleaning valve 8Vf communicates with the external sludge supply path 7F, and a sludge blow path 8B having a sludge blow valve 8Vb is branched from the external sludge supply path 7F, and the sludge blow path 8B is sludge. It leads to the storage tank 7A. 7Vf of illustration has shown the sludge supply valve arrange | positioned between the communicating part of the washing | cleaning liquid supply path 8F in the external sludge supply path 7F, and the sludge pump 7P exit side.
[0033]
Further, as means 9 for supplying a heated fluid (hot water, steam, etc.) F to the warming room 3s in the heat conduction panel 30 in order to heat the supplied sludge, a fluid storage tank 9A and this fluid storage tank Fluid heating means 9B (for example, a steam blowing device) that heats the fluid F in 9A, and the warming fluid F in the fluid storage tank 9A are heated through the external fluid supply path 9F and the internal fluid supply path 3F. And a heated fluid supply pump 9P for supplying 3 s. 9Vf indicates a heated fluid supply valve disposed in the fluid supply path 9F. Further, an internal fluid discharge path 3G communicates with the upper part of the heating chamber 3s, and the heated fluid supplied into the heating chamber 3s passes through the internal fluid discharge path 3G and the fluid return path 12 to the fluid storage tank 9A. To be sent back to.
[0034]
Further, in this example, the heated fluid F is supplied into the fluid chamber 2D and used for the expansion of the diaphragm 2E. Specifically, a press-fitting pump 10P that pressurizes and supplies the heated fluid F in the fluid storage tank 9A into the fluid chambers 2D and 2D via the external fluid supply path 10F and the internal fluid supply path 2F is provided. 10Vf indicates a fluid inlet valve disposed in the external fluid supply path 10F. With such a configuration, even when a resin diaphragm is used, some heat conduction can be expected through the diaphragm 2E, so that the diaphragm 2E with respect to the supplied sludge can be heated. Further, a return path 10R is branched from the portion of the external fluid supply path 10F between the fluid inlet valve 10Vf and the internal fluid supply path 2F, and communicates with the fluid storage tank 9A. A relief valve 10Vr is provided in the return path 10R. By doing so, the supply pressure of the heated fluid to the fluid chambers 2D, 2D is also kept below the set pressure of the relief valve.
[0035]
Further, in this example of the apparatus, the internal filtrate discharge passages 2H and 3H of the filter plates 2 and 3 are joined to the filtrate tank 11A through the external filtrate discharge passage 11H having the filtrate outlet valve 11Ve. The filtrate in the filtrate tank 11A is supplied to the filtrate storage tank 11C by the filtrate pump 11B in accordance with the amount of stored filtrate. A filtrate blow passage 11J having a filtrate blow valve 11Vb is branched from the external filtrate discharge passage 11H, and the filtrate blow passage 11J communicates with the filtrate storage tank 11C. Preferably, as shown in the figure, a vacuum pump 11D is connected to the filtrate tank 11A, and by this vacuum pump 11D, the filtrate grooves 2e and 3e and the filter cloth are passed through the filtrate tank 11A and the filtrate discharge paths 2H and 3H. The gaps SP1 and SP2 with respect to 4 and 4 are configured to be a negative pressure. Further, as in the illustrated example, the gaps SP1 and SP2 between the filtrate grooves 2e and 3e and the outer surface of the filter cloth 2B can be sucked from the upper part of the gap via the pressurized air supply paths 2J and 3J and the upper suction path 14 so that negative pressure can be obtained. As a result, highly efficient and uniform dehydration of the material to be dehydrated becomes possible.
[0036]
Further, in this example of the apparatus, the internal pressurized air supply paths 2J and 3J are supplied with pressurized air (for example, compressed air) from the compressor 13C via the external pressurized air supply path 13J and the pressurized air tank 13A.
[0037]
<Example of dehydration method>
Next, an example of the sludge dewatering method of the present invention using the above-described dewatering device 1 will be described. This example of the dehydration method mainly includes a filtration step and a subsequent pressing step.
[0038]
In the filtration step, first, the filter plates 2, 3... Are fastened and closed by extension of the cylinder 5 (only shown in FIG. 1) to form the filter chamber 6 as shown in FIG. Also, keep all valves closed. Thereafter, the heated fluid supply pump 9P is operated and the fluid inlet valve 9Vf is opened. As a result, the warming fluid F (warm water or steam) heated by the heating means 9B enters the heating chamber 3s of the heat conduction panel 30 from the fluid storage tank 9A via the external fluid supply path 9F and the internal fluid supply path 3F. Supplied. In this example, the warming fluid F supplied to the warming chamber 3s is returned to the fluid storage tank 9A via the upper fluid discharge path 3G and the fluid return path 12, heated by the warming means 9B, and then again. It is sent to the greenhouse 3s. By performing the circulation in this way, the warming fluid F that is always newly warmed is present in the warming chamber 3s.
[0039]
At the same time or subsequently, the sludge pump 7P is operated, the sludge supply valve 7Vf is opened, and the heated sludge S previously heated by the heating means 7B and stored in the sludge storage tank 7A is Pressure is supplied between the filter cloths 4 and 4 of the filter chamber 6 through the internal sludge supply paths 7F and 31. This state is shown in FIG. In the sludge S1 in the filter chamber 6, only the filtrate passes through the filter cloths 4 and 4 due to the supply pressure of the sludge sent sequentially, and the filtration proceeds. At this time, the heat of the heating fluid F passing through the heating chamber 3s is transmitted to the sludge between the filter cloths 4 and 4 through the heat conduction panel 30, and the filtration proceeds while the sludge is heated. Become.
[0040]
At this time, either one of the filtrate outlet valve 11Ve and the filtrate blow valve 11Vb is kept open, and in any case, the filtrate is filtered into the filtrate groove 2e of the diaphragm 2E,..., The filtrate groove 3e of the heat conduction panel,. The filtrate is discharged into the filtrate storage tank 11C through the discharge paths 2H and 3H and the external filtrate discharge path 11H (details will be described later).
[0041]
After the predetermined time has elapsed, for example, the sludge pump 7P is stopped and the sludge supply valve 7P is closed to finish the filtration step, and then the operation proceeds to the pressing step (the pressing step can also be performed while the sludge is being supplied).
[0042]
In the squeezing step, the heating fluid F is supplied to the heating chamber 3s in the heat conduction panel 30 of the heating filter plate 3 (preferably continuously supplied from the filtering step), and is supplied to the fluid chamber 2D. It is preferable to press-fit the fluid. That is, in the illustrated example, the warming fluid supply valve 10Vf is opened and the warming fluid press-fitting pump 10P is operated, so that the warming fluid F stored in the warming fluid storage tank 9A is supplied to the warming fluid press-in passage 10F and the internal supply. It is press-fitted and supplied into the fluid chamber 2D through the passage 2F. The supply pressure at this time is kept below the set pressure by the action of the relief valve 10Vr as described above. As a result, as shown in FIG. 6, when the internal pressure of the fluid chambers 2D and 2D becomes higher than the internal pressure of the filter chamber 6, the differential pressure causes the diaphragm 2E to move from the compressed filter plate 2 to the heated filter plate 3. The dewatered sludge S1 in the filter chamber 6 is sandwiched through the filter cloths 4 and 4 and pressed by the swelled diaphragm 2E.
[0043]
Thus, even during squeezing, the heating fluid F passing through the heating chamber 3s mainly passes through the heat conduction panel 30, and the heating fluid in the fluid chamber 2D is supplementarily passed through the diaphragm 2E to filter the cloth 4 , 4 effectively heats sludge. Thereby, the sludge between the filter cloths 4 and 4 is at least kept warm. By this heating, highly efficient squeeze filtration is performed.
[0044]
Further, after a predetermined time has elapsed, the warming fluid supply valve 10Vf is closed, the warming fluid press-fitting pump 10P is stopped, and the fluid return valve 4Vb is opened. Thus the fluid in the fluid chamber 2D is returned to the fluid reservoir 9A through the fluid return path 4C.
[0045]
In the present invention, it intends repeated line alternately such pressing operation and opening operation during the filtration process (repeated usually several times). Thereby, sludge is masticated and the promotion of the filtration action by pressing can be aimed at.
[0046]
Furthermore, a series of cycles of filtration operation, squeezing operation, and opening operation can be repeated. In this case, since the volume of the dehydrated material after squeezing is reduced, further heating between the filter cloths 4 and 4 is performed. Sludge can be press-fitted (in this case, the diaphragm 2E is pushed back to return to the state shown in FIG. 5), and not only the filtration action is promoted by squeezing but also the sludge S supply (injection) amount accompanying it is dramatically increased. be able to.
[0047]
If a pressing process is complete | finished, the press injection pump 10P will be stopped and the valve which is open will be closed.
[0048]
Here, the discharge form of the filtrate in these filtration steps and pressing steps can be selected mainly from the following methods, respectively. That is, the first method is a method of opening the filtrate outlet valve 11Ve and closing the filtrate blow valve 11Vb and operating the vacuum pump 11D. Thus, the filtrate tank 11A, the external filtrate discharge path 11H, the internal filtrate discharge paths 2H and 3H, the filtrate grooves 2e of the diaphragm 2E, and the filtrate grooves 3e of the heat conduction panel 30 constituting the filtrate discharge path are negative pressure. Therefore, the discharge of the filtrate during filtration or pressing can be promoted, and the moisture content of the dehydrated cake can be lowered. In this case, the filtrate passes through the filtrate grooves 2e, 2e ... of the diaphragm 2E and the filtrate grooves 3e, ... of the heat conduction panel 30, and passes through the internal filtrate discharge paths 2H, 3H and the external filtrate discharge path 11H to the filtrate tank 11A. And is temporarily stored in the filtrate tank 11A. Then, the filtrate in the filtrate tank 11A is pumped out by the filtrate pump 11B that automatically operates according to the filtrate storage amount in the filtrate tank 11A, and is discharged into the filtrate storage tank 11C.
[0049]
The second method is a method in which the filtrate blow valve 11Vb is opened, the filtrate outlet valve 11Ve is closed, and the vacuum pump 11D is not operated. In this case, the filtrate passes through the filtrate grooves 2e, 2e ... of the diaphragm 2E and the filtrate grooves 3e, ... of the heat conduction panel 30, and passes through the internal filtrate discharge paths 2H, 3H, the external filtrate discharge path 11H, and the filtrate blow path 11J. Is discharged directly to the filtrate storage tank 11C.
[0050]
The most effective method is that the filtrate blow valve 11Vb is opened and the filtrate outlet valve 11Ve is closed during the filtration step, the filtrate is allowed to flow down naturally, and the same amount of time is passed after entering the squeezing step. In this method, the filtrate outlet valve 11Ve is opened and the filtrate blow valve 11Vb is closed, and the vacuum pump 11D is operated at the same time to make the filtrate discharge path 11H have a negative pressure. In this method, while the filtrate is naturally discharged, the filtrate discharge path 11H is not set to a negative pressure, and the filtrate discharge path 11H is set to a negative pressure when it is difficult to discharge the filtrate naturally. While reducing the moisture content of the cake, there is an advantage that the energy consumed by the vacuum pump 11D can be reduced as compared with the case where the filtrate discharge path 11H is always set to a negative pressure in the filtration step or the squeezing step.
[0051]
On the other hand, if the above-mentioned pressing process and filtration process are completed, it is recommended to perform a blow process subsequently. In this blow process, the cleaning valve 8Vf and the sludge blow valve 8Vb are opened, and the sludge in the sludge supply path including the external sludge supply path 7F is blown to the sludge storage tank 7A by the cleaning water.
[0052]
Next, the cleaning valve 8Vf is closed and the pressurized air inlet valve 13Vf is opened. As shown in FIG. 7, the external pressurized air supply path 13J and the internal pressurized air supply paths 2J, 3J are caused by the pressure air stored in the pressurized gas tank 13A by the compressor 13C. , And blow through the filtrate grooves 2e, 2e of the diaphragms 2E, 2E and the filtrate grooves 3e,... Of the heat conduction panel 30, and the washing water remaining in the sludge supply path including the external sludge supply path 7F is blown into the sludge storage tank 7A. To do. Preferably, the pressure air blow is performed before and after the washing water blow.
[0053]
More preferably, after this predetermined time has elapsed, the sludge blow valve 8Vb is closed, the fluid blow valve 4Vb and the filtrate blow valve 11Vb are opened, and the supplied pressurized air is supplied into the filter chamber 6 this time. The heated fluid in the fluid chamber 2D is returned to the fluid storage tank 9A through the fluid blow passage 4C by the action of the supply air into the filter chamber 6, and the filtrate grooves 2e,. The filtrate remaining in the filtrate grooves 3e of the panel 30 is blown to the filtrate storage tank 11C through the internal filtrate discharge paths 2H and 3H, the external filtrate discharge path 11H, and the filtrate blow valve 11Vb.
[0054]
The filtration, squeezing, and blowing processes are completed as described above, and the dewatering cake K is formed in the filter chamber 6, so that the discharging process is started. In the discharging process, as can be understood from the comparison between FIG. 8 and FIG. 1, first, the cylinder 5 is contracted to open the loose head 101, and the filter plates 2, 3. The frames are sequentially pulled, and the frames 2 and 3 are opened so as to have a constant interval. Subsequently, the filter cloth driving device 102 rotates the drive shaft 103 so that the wire rope 105 wound around the pulley 104 can be fed out and each filter cloth is opened so that the lower ends of the bonded filter cloths 4 and 4 are opened. 4 is wound around each take-up roll 107 through each return roll 106. This winding is performed according to the amount of filter cloth descending as the wire rope 105 is unwound, and the filter cloths 4 and 4 are always pulled between the support bar 108 and the respective return rolls 106 so as to be substantially flat. The
[0055]
Thus, the dehydrated cake K formed between the filter cloths 4 and 4 is peeled off and discharged from the filter cloths 4 and 4 by the action of the sharp turns of the filter cloths 4 and 4 on the return rolls 106 and 106 and the own weight. Normally, the dewatered cake K can be peeled only by driving the filter cloth. However, if the peelability is poor, the cake from the filter cloth 4 is placed on the opposite side of the return rolls 106 and 106 with the filter cloths 4 and 4 interposed therebetween. The scraper (not shown) which scrapes off can be provided, and it can comprise so that the dewatering cake adhering to the filter cloth 4 and 4 may be peeled positively.
[0056]
<Others>
The diaphragm 2E of the present invention can be formed of a resin such as a rubber material, but at least a portion corresponding to the filter chamber through the filter cloth in the diaphragm 2E is a material having high heat conductivity, for example, flexibility. It is preferable to form a thin steel plate (especially a stainless steel plate is preferable from the viewpoint of rust prevention). For example, although not shown, the outer edge portion of the diaphragm that does not substantially contribute to the heat retaining effect is formed of a flexible material having low thermal conductivity such as a rubber material, and the central portion that substantially contributes to the heat retaining effect is made of metal. It can also be formed of a hard material with high thermal conductivity.
[0057]
In the above description, the application example to the filter cloth traveling type is shown, but the present invention can also be applied to a filter cloth hanging type dehydrator. Further, in the present invention, as in the above example, in addition to the upper feed for supplying the sludge from the upper part of the filter plate, the center feed for supplying the heated sludge from the central part of the filter plate, or the under feed for supplying the sludge from the lower part of the filter plate It can also be done.
[0058]
Further, in the present invention, the opening / closing of the valve, the start / stop of the pump, the closing / opening of the frame by the cylinder, etc. in the above-mentioned specific example can be performed automatically by an appropriate control device.
[0059]
【The invention's effect】
As described above, according to the present invention, it is possible to increase the sludge injection amount, shorten the filtration and pressing time, significantly reduce the moisture content of the dewatered cake, improve the peelability of the dewatered cake, Dehydration ability can be increased.
[Brief description of the drawings]
FIG. 1 is a front view of an example of a filter press apparatus according to the present invention.
FIG. 2 is a longitudinal sectional view showing a II-II section in FIG. 1;
FIG. 3 is a longitudinal sectional view of a main part showing an arrangement form of filter plates.
FIG. 4 is a flowchart showing an example of a filter press apparatus according to the present invention.
FIG. 5 is a longitudinal sectional view of a main part showing a filtration step.
FIG. 6 is a longitudinal sectional view of a main part showing a pressing process.
FIG. 7 is a longitudinal sectional view of a main part showing a blowing process.
FIG. 8 is a longitudinal sectional view of a main part showing a cake discharging step.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Filter press apparatus, 2 ... Pressing filter board, 3 ... Heating filter board, 4 ... Filter cloth, 2E ... Diaphragm, 2D ... Fluid chamber.

Claims (9)

In a filter press apparatus in which a filter cloth is provided oppositely in a filter chamber between opposing filter plates, and sludge is supplied between the filter cloths for filtration.
A diaphragm provided between one filter plate and the facing filter cloth;
A fluid chamber formed between the diaphragm and the one filter plate;
A hollow heat conduction panel is disposed between the other filter plate and the filter cloth directly facing, and a supply sludge is added to heat the sludge supplied between the filter cloths by passing a heating fluid through the hollow heat conduction panel. Temperature means;
Sludge heating means for heating the sludge before supplying it between the filter cloths;
In the filtration step in which the heated warm sludge is pressure-fed to the inner surface of the filter cloth and filtered through the filter cloth, the heated fluid is supplied into the fluid chamber and the diaphragm is expanded by the pressure. And means for alternately repeating a squeezing operation for squeezing the dewatered sludge in the filter chamber through the filter cloth, and an opening operation for discharging the fluid in the fluid chamber;
A filter press apparatus characterized by comprising: Means for supplying a heated fluid into the fluid chamber after the filtration step, expanding the diaphragm by the pressure, and pressing the dewatered sludge in the filter chamber through the filter cloth to squeeze; equipped with claim 1 Symbol placement of filter press apparatus. The filter press apparatus according to claim 1 or 2 , wherein a filtrate groove is formed on the filter cloth facing surface of the hollow heat conductive panel, and the filtrate passes through the filtrate groove. The filter press apparatus according to any one of claims 1 to 3 , wherein a filtrate groove is formed on the diaphragm facing surface of the diaphragm, and the filtrate passes through the filtrate groove. The filter press device according to any one of claims 1 to 4 , wherein the hollow heat conductive panel is a metal panel. The filter press device according to any one of claims 1 to 5 , wherein the filter plate is formed of a resin material. The filter press apparatus according to claim 3 or 4 , wherein a negative pressure means for negative pressure in the filtration chamber is connected to the filtrate groove. A filter cloth is provided opposite to each other in a filter chamber between opposing filter plates, and sludge is supplied between the filter cloths for filtration. A diaphragm is provided between one filter plate and the filter cloth facing the filter cloth. Using a filter press device in which a fluid chamber is provided between the diaphragm and the one filter plate, and a hollow heat conductive panel is disposed between the filter plate and the other filter plate ;
The heated sludge is heated and supplied to the inner surface of the filter cloth and filtered through the filter cloth, and the heated fluid is supplied into the fluid chamber. A method for dewatering sludge, comprising performing a filtration step of alternately repeating a squeezing operation for squeezing indoor dewatered sludge through the filter cloth and an opening operation for discharging the fluid in the fluid chamber . After the filtration step, a pressing step is performed in which a heated fluid is supplied into the fluid chamber, the diaphragm is expanded by the pressure, and the dewatered sludge in the filter chamber is pressed through the filter cloth to squeeze. The method for dewatering sludge according to claim 8, which is performed.

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