JP6484363B2 - Filter press dewatering device and operation method of filter press dewatering device - Google Patents

Description

  The present invention includes a filtration chamber in which a filter cloth is sandwiched between a filter plate and a diaphragm, a stock solution supply mechanism for introducing an object to be compressed into the filtration chamber, a squeezing fluid supply mechanism for supplying a squeezing fluid to the diaphragm, The filter press dehydration apparatus which squeezes the pressing target object thrown into the filtration chamber with a diaphragm, and the operating method of the filter press dehydration apparatus.

  Conventionally, a sludge treatment process that dehydrates sludge and other sludge generated at water purification plants and sewage treatment plants and separates it into filtered water and cake, or a solid-liquid separation process that is required in the production process of carbon products, titanium products, etc. In various fields, filter press dewatering devices are used for solid-liquid separation.

  Patent Document 1 discloses a filter press-type dewatering system for solving the problem that a cake produced in the initial stage of compression is tightly tightened to become resistance and hinder subsequent dewatering.

  The filter press-type dewatering system adjusts the flow rate of a filter press machine, a hydraulically driven pressure feed pump that compresses slurry introduced from a slurry supply source and drives the filter press machine, and a flow rate of pressure oil supplied to the pressure feed pump. According to a pressure control valve, a flow sensor for detecting the flow rate of filtered water discharged from the filter press machine, a pressure sensor for detecting the dehydration pressure in the filter press machine, and input signals from the flow sensor and the pressure sensor Control means for outputting a control signal for the pressure control valve.

  When the flow rate of the filtrate water per unit time detected by the flow rate sensor is higher than a preset flow rate, the control means reduces the flow rate of the pressure oil supplied to the pressure feed pump to reduce the pressure in the filter press machine. When the flow rate of filtered water per unit time detected by the flow rate sensor is lower than a preset flow rate, the flow rate of the pressure oil supplied to the pressure pump is increased and the filter is increased. The dewatering pressure in the press machine is increased, and thus the dewatering progress in the filter press machine is adjusted.

  Patent Document 2 discloses a filter press device for the purpose of further improving the dewatering performance without lowering the squeezing efficiency when the slurry is dehydrated by filtration, pressing and vacuum heating drying.

  The filter press apparatus is configured such that the squeezing process is started after a filtration process (hereinafter also referred to as “filling process”) in which slurry is supplied into the filter chamber by a slurry supply pump. More specifically, after squeezing at a dehydration pressure to a predetermined dehydration level in the squeezing step, the pressure in the filter chamber is detected by the pressure sensor until the end of squeezing, and the pressure in the filter chamber is equal to the squeezing pressure based on this detected pressure. It is comprised so that the opening degree of the fluid supply valve may be adjusted.

  In other words, when the pressing process is started, the pressure in the filter chamber detected by the pressure sensor is equal to the pressing pressure (fluid supply pressure or fluid chamber pressure) at the beginning of the pressing, whereas the phenomenon decreases with time. After being used and squeezed at a relatively high dehydration pressure to a predetermined dehydration level, the pressure of squeezing is gradually reduced to a non-squeezing pressure toward the end of squeezing.

JP 2002-292210 A JP-A-2005-270828

  However, in the filter press-type dewatering system disclosed in Patent Document 1, the filtration pressure is adjusted so that the flow rate of filtered water per unit time detected by the flow sensor becomes a preset flow rate. The pressure is gradually increased until the first half, and when the pressure reaches near the peak, the pressure is maintained, or pressurization control of the pump is performed so that the pressure rises as a whole while repeating the rise and fall of the pressure. However, since it does not have a squeezing mechanism that performs a squeezing step after the filtration step, further improvement in dewatering performance has not been expected.

  In a filter press apparatus equipped with a pressing mechanism that supplies a pressing fluid to a diaphragm having a pressing action after the filtration step and conventionally pressurizes, properties such as slurry concentration, particle size, specific gravity, viscosity, etc. have always fluctuated. A long squeezing time, that is, a target moisture content arrival time was set in accordance with the case where the property is poor.

  In such a filter press dewatering device, when the dewatering property is good, the pressing process can be completed in a short pressing time, but in view of the complexity of constantly monitoring the dewatering property, the dewatering property is adjusted accordingly. The pressing time is set. As a result, there has been a problem that wasteful time occurs.

  Therefore, a configuration in which dehydration is forcedly performed at a high pressing pressure depending on the ability of the pump for pressing regardless of properties such as the concentration, particle size, specific gravity, and viscosity of the slurry has been adopted. For example, it is a filter press apparatus which raises a compression side pressure stepwise whenever the input side pressure of a compression target object falls.

  As shown in FIG. 7 (a), when the compression side pressure is increased stepwise, it can be seen that, at the beginning of the increase, the input pressure of the object to be compressed temporarily increases, but decreases with time. It was necessary to repeat the work of increasing the compression side pressure stepwise each time the input side pressure of the compression object was lowered.

  However, if the water is forcibly dehydrated at a high pressing pressure, the dewatering efficiency changes depending on the properties of the slurry. That is, when a high squeezing pressure is applied to the filter, the density of the slurry in the vicinity of the filter becomes higher than the density of the slurry in a position away from the filter, and the water path of filtered water filtered in the vicinity of the filter is reduced. Filtration efficiency decreases. Furthermore, there is a problem that the filter life is shortened due to clogging of the filter and the like.

  Moreover, in the filter press apparatus disclosed by patent document 2, since it is comprised so that it may squeeze with a comparatively high pressing pressure to the predetermined dehydration level as shown in FIG.7 (b) at the initial stage of a pressing process, Depending on the properties of the slurry, there is a problem that the cake layer is consolidated and there are fewer voids through which filtered water leaks, and good filtration efficiency may not be obtained.

  An object of the present invention is to provide a filter press dewatering device and a method for operating the filter press dewatering device that can obtain good filtration efficiency regardless of whether the dehydrating property is good or not, in view of the conventional problems described above.

In order to achieve the above-mentioned object, the first feature of the filter press dewatering device according to the present invention is that the filter cloth is sandwiched between the filter plate and the diaphragm as described in claim 1 of the claims. A filtration chamber, an undiluted solution supply mechanism for introducing an object to be squeezed into the filtration chamber, and a fluid supply mechanism for squeezing to supply a squeezing fluid to the diaphragm. A filter press dewatering device that squeezes with the diaphragm, and supplies the diaphragm with the fluid supply mechanism for squeezing so that the input side pressure of the object to be squeezed into the filtration chamber is constant by the stock solution supply mechanism It exists in the point provided with the control part which performs the 1st expression control which controls the compression side pressure of the fluid for expression to be performed .

According to the above-described configuration, by adjusting the pressure on the squeezing side of the squeezing fluid so that the input side pressure of the squeezed object input to the filtration chamber is constant , It becomes possible to appropriately dehydrate while suppressing a decrease in dewatering performance due to a sudden change in the squeezed state. And, since the input side pressure is controlled to be constant, the filtered water can be efficiently drained from the compressed object without closing the gap through which the filtered water formed in the compressed object leaks. The In the first pressing control, the pressing side pressure is controlled so that the charging side pressure becomes constant. As a result, the pressing side pressure gradually increases as the filtrate is discharged. During this time, the filtered water is efficiently discharged in a state where the gap formed in the compressed object is not destroyed as much as possible.

In the second feature configuration, in addition to the first feature configuration described above, the control unit is configured such that the compression side pressure is set to a predetermined compression set value by the first compression control. If it reaches | attains, it exists in the point which performs the 2nd pressing control which controls the said fluid supply mechanism for pressing so that the said pressing side pressure may not exceed the said predetermined pressing pressure .

The slurry starts to harden by the first pressing control, and when the pressing side pressure reaches a predetermined pressing set value, the second pressing control is executed, and the pressing target pressure is not increased any more while maintaining the state of the pressing object. The filtered water comes to be squeezed from the object to be compressed. Thus, the compressed object formed by being squeezed as a whole has a constant moisture content and a low moisture content. Furthermore, clogging of the filter cloth is less likely to occur, leading to a longer service life of the filter cloth.

The first characteristic configuration of the operation method of the filter press dewatering device according to the present invention is, as described in claim 3, a filtration chamber in which a filter cloth is sandwiched between a filter plate and a diaphragm, and an object to be compressed in the filtration chamber. A filter press dewatering device comprising: a stock solution supply mechanism for supplying an object; and a squeezing fluid supply mechanism for supplying a squeezing fluid to the diaphragm. An operation method, wherein the pressure side of the squeezing fluid supplied to the diaphragm by the squeezing fluid supply mechanism is such that the input side pressure of the squeezed object to be squeezed into the filtration chamber by the stock solution supply mechanism is constant It exists in the point which performs the 1st expression control which adjusts a pressure.

  It becomes possible to appropriately dehydrate while suppressing a decrease in the dewatering performance due to a sudden change in the squeezed state in which the squeezed object is rapidly squeezed by a large squeezing side pressure.

In addition to the above-mentioned first characteristic configuration, the second characteristic configuration is the above-described first characteristic control, and when the compression side pressure reaches a predetermined compression set value by the first compression control, It exists in the point which performs the 2nd pressing control which controls the said fluid supply mechanism for pressing so that a side pressure does not exceed a predetermined pressing pressure .

The slurry starts to harden by the first pressing control, and when the pressing side pressure reaches a predetermined pressing set value, the second pressing control is executed, and the pressing target pressure is not increased any more while maintaining the state of the pressing object. The filtered water comes to be squeezed from the object to be compressed.

  As described above, according to the present invention, it is possible to provide a filter press dewatering device and a method for operating the filter press dewatering device that can obtain good filtration efficiency regardless of whether the dewaterability is good or not.

Schematic of filter press dewatering device according to the present invention Explanatory drawing showing the pressure contact state of multiple filtration units Explanatory drawing which shows the separation state of several filtration units Explanatory drawing which shows isolation state of filter plate, diaphragm and filter cloth Explanatory drawing which shows a press-contact state of a filter plate, a diaphragm, and a filter cloth Front view of filtration unit It is explanatory drawing of a compression side pressure and input side pressure, Comprising: (a) is explanatory drawing which raised the compression side pressure in the conventional step (b) is explanatory drawing (c) of patent document 2 of the compression pressure of FIG. An explanatory diagram (d) in which the input side pressure upper limit value is kept constant is an explanatory diagram (e) in which the compression side pressure upper limit value is increased by several steps in the second pressing control of the present invention. Explanatory drawing which lowered the pressure side pressure upper limit several steps Explanatory diagram showing the operating state of the diaphragm

  Below, an example of the filter press dehydration apparatus by this invention and its operating method is demonstrated.

  As shown in FIG. 1, the filter press dewatering device 1 includes a front frame 2, a rear frame 3, and a pair of side frames 4 that are installed between the front frame 2 and the rear frame 3.

  A plurality of filter plates 30 are slidably supported by the pair of side frames 4, and each filter plate 30 is in a pressure-contact state (also referred to as a closed plate state) and a separated state by the advance / retreat mechanism 5 installed in the front frame 2. It is also driven so as to be switched between.

  FIG. 2 shows a state where each filter plate 30 is switched to the pressure contact state, and FIG. 3 shows a state where each filter plate 30 is switched to the separated state.

  A driving roller 6 for feeding out the endless filter cloth 7 is disposed on the upper part of the front frame 2, and a cleaning mechanism 8 for cleaning the filter cloth 7 is disposed on the upper part of the rear frame 3.

  The filter cloth 7 fed out by the drive roller 6 is adjusted to a predetermined tension by a tension mechanism 9 similarly installed in the front frame 2, and then the filter surface is opposed by the support mechanisms 10 installed above and below each filter plate 30. Are arranged so as to be guided to the cleaning mechanism 8 after being drawn out from each filter plate 30.

  A pair of engagement pins 11 are provided on the left and right sides of each filter plate 30 so that the engagement pins 11 of a pair of adjacent filter plates 30 are formed in a connecting hole 12 as a link mechanism. Is engaged and connected. In FIG. 1, the left end filter plate 30 is connected to the rear frame 3, and the right end filter plate 30 is connected to the advance / retreat mechanism 5.

  The advance / retreat mechanism 5 is composed of a hydraulic cylinder 5c having a pressing member 5b at the tip of a rod 5a. When the rod 5a is moved forward by the hydraulic cylinder 5c, each filter plate 30 shifts to a pressure contact state pressed toward the rear frame 3 via the pressing member 5b, and when the rod 5a is retracted, the front frame 2 is moved. Each of the filter plates 30 moves toward it, and shifts to a separated state separated by a distance defined by a long hole formed in the connecting fitting 12.

  The filter press dewatering device 1 is subjected to a filtration process for filling each filtration chamber with a stock solution and a squeezing process for squeezing the filled stock solution in a pressure contact state in which the advance / retreat mechanism 5 is advanced.

  Then, in the separated state in which the advancing / retreating mechanism 5 is retreated after the squeezing step, a traveling process in which the filter cloth 7 is caused to travel a predetermined distance by the driving roller 6 so that the dewatered cake squeezed in each filtration chamber is separated from the filter cloth 7. Then, the advance / retreat mechanism 5 is advanced to repeat the same processing. The drive roller 6 is drivingly connected to a drive motor via a speed reduction mechanism, and the drive mechanism is constituted by the drive roller 6, the speed reduction mechanism, and the drive motor.

  The filter cloth 7 fed out from the filter plate 30 is washed by the washing mechanism 8 provided in the rear frame 3 and then passed over the drive roller 6 via the meander correcting mechanism 17.

  A meandering correction mechanism 17 provided between the cleaning mechanism 8 and the driving roller 6 is a mechanism for regulating the traveling position of the filter cloth 7 in the width direction, and is installed on a support frame 18 attached to the upper part of the front frame 2. Yes.

  The filter cloth 7 after being cleaned by the cleaning mechanism 8 is corrected to meander with high accuracy by the meander correction mechanism 17 and corrected to an appropriate transport posture, and then is driven downstream in a stable posture by the drive roller 6. It will be transported.

  The tension mechanism 9 applies a predetermined tension to the filter cloth 7. The predetermined tension refers to a tension at which the filter cloth 7 can stably travel by friction with the driving roller 6, and is appropriate so that the filter cloth 7 between the filter plates 30 does not bend in the separated state of the filter plates 30. Tension is preferred.

  As shown in FIG. 4, the diaphragm 20 is fixed to one surface of each filter plate 30 along the arrangement direction. The diaphragm 20 includes a thin portion 21 that can be expanded and contracted and a thick portion 22 that functions as a filter frame integrally formed around the thin portion 21, and is a space partitioned by a back surface of the filter plate 30 adjacent to the diaphragm 20. A chamber is formed.

  The support mechanism 10 includes an upper roller 10a and a lower roller 10b supported by brackets fixed to the filter plates 30, and the filter cloth 7 is stretched in the vertical direction between the adjacent filter plates 30 by both rollers 10a and 10b. ing.

  In the vicinity of the upper roller 10a, a guide roller 10c for guiding the filter cloth 7 so as not to contact the filter plate 30 and the diaphragm 20 when the filter plate 30 is separated is provided.

  As shown in FIG. 2, when each filter plate 30 shifts to the pressure contact state by the advance / retreat mechanism 5, a space partitioned by the filter cloth 7 in the filter chamber becomes a filtration chamber 31 (see FIG. 5).

  First, the filtration process of a compression target object is explained in full detail. As shown in each drawing of FIG. 1 to FIG. 4, between each filter plate 30, a filtration chamber 31 to which a stock solution that is an object to be compressed is supplied is provided in the filter chamber, and the object to be compressed is placed in each filtration chamber 31. In order to throw in, it is comprised so that the through-hole 32 formed in each filter plate 30 may communicate in the press-contact state.

  Then, as shown in FIG. 2, the stock solution is supplied to the through hole 32 from the stock solution supply path 51 provided in the rear frame 3 in the press contact state, and is formed in the base portion 14 that connects the through hole 32 and each filtration chamber 31. The stock solution is introduced into each filtration chamber 31 through the branched path. The input of the stock solution is detected by the input side pressure detection unit 50, and the input side pressure data is transferred to the control unit 62. The control unit 62 controls to supply the stock solution from the stock solution storage tank 53 to the filtration chamber 31 through the through-hole 32 and the cap unit 14 from the stock solution storage tank 53 using the stock solution feeding pump 54 based on the loading side pressure data. I do.

  After that, when the control unit detects that the predetermined time has elapsed or the input side pressure detection unit 50 has reached the predetermined pressure, the control unit regards that the stock solution of the predetermined pressure is also input in the filtration chamber 31, The input side valve 52 is closed and the stock solution input pump 54 is stopped to complete the filtration process.

  Next, the pressing process will be described in detail. As shown in FIG. 5, below each filter plate 30, a compression fluid path 33 that supplies a compression fluid for inflating the thin portion 21 of the diaphragm 20 attached to the filter plate 30 toward the filtration chamber 31. Is provided.

  The squeezing fluid introduced from the squeezing fluid passage 33 is supplied between the squeezing fluid supply hole 34 formed in the filter plate 30 and the thin portion 21 of the diaphragm 20 attached to the filter plate 30. Is done.

  By supplying pressurized water as a squeezing fluid to the squeezing fluid passage 33 by the squeezing fluid preparation pump 61, the thin wall portion 21 of the diaphragm 20 is expanded toward the filtration chamber 31 as shown in FIG. The stock solution supplied to is squeezed.

  That is, one filter unit is constituted by one filter plate 30 provided with the support mechanism 10 and the fluid passage 33 for compression and one diaphragm 20, and the filtration unit and the fluid generating pump 61 for compression are in a pressure contact state. A squeezing mechanism that squeezes the undiluted solution supplied to the opposing space of the filter surface formed between the filter plates 30 is configured.

  The plurality of filtration units are arranged in parallel so as to be movable between the pressure contact state and the separation state, and the filter plate 30 of one filtration unit becomes the one filter plate 30 and is adjacent to the diaphragm 20 of the one filtration unit. The filter plate 30 of the filtration unit is the other filter plate 30.

  As shown in FIG. 6, the filter plate 30 is formed with a liquid collecting part 35 for collecting the drained filtered water and flowing it along the surface of the filter plate 30, and a filter adjacent to the outside of the liquid collecting part 35. A rising portion 36 that contacts the plate 30 is formed.

  A drainage hole 37 penetrating in the thickness direction of the filter plate 30 is formed on the side of the lower end of the liquid collection part 35, and the filtered water collected in the liquid collection part 35 is discharged from the drainage hole 37 to FIG. Is passed through the filtered water discharge port 57 provided in the rear frame 2 and discharged to the outside of the filter press dewatering device 1.

  The squeezing fluid preparation pump 61 operates such that the pressure of the squeezing fluid supplied to the squeezing fluid path 33 is controlled by the control unit 62. In this case, the control unit 62 controls the pressure of the squeezing fluid while detecting the pressure of the input side pressure detection unit 50. Specifically, the control unit 62 holds the pressure controlled by the input side pressure detection unit 50 when it is input in the filtration process throughout the pressing process as a predetermined pressure or a target pressure set in advance by the control unit 62. Thus, the squeezing fluid creation pump 61 is controlled to control the squeezing side pressure of the squeezing fluid supplied to the diaphragm 20.

  By using the input side pressure as an index, the density of the object to be squeezed, which has been a problem of the prior art, is not constant in the filtration chamber 31, and the object to be squeezed is compacted in the vicinity of the filter cloth 7. The number of filtered water channels filtered in the vicinity of 7 is reduced, and the problem that the filtration efficiency is reduced does not occur.

  In this case, the control unit 62 controls the squeezing fluid creation pump 61 so that the input side pressure does not exceed a predetermined pressure according to the type of the stock solution to be squeezed. In general, the input side pressure may be set higher when the stock solution is an inorganic substance, but in the case of an organic substance, the input side pressure needs to be set lower than that of the inorganic substance. Therefore, the control unit 62 can also set the target pressure so that the charging side pressure has a predetermined value according to the type of the stock solution and has a predetermined value.

  By controlling in this way, the inside of the filtration chamber 31 is kept at a constant pressure, and the object to be squeezed in the filtration chamber 31 can always be continuously squeezed at an equal density. That is, filtered water can ooze out evenly from the object to be squeezed in the filtration chamber 31, and the object to be squeezed can be evenly squeezed. Since it can be secured in the chamber 31, the filtration efficiency can be maintained in a high state. As a result, with respect to the time required for filtration, since the filtration proceeds uniformly from all the objects to be squeezed, the squeezing is completed in a short time without delaying the filtration.

  For example, as shown in FIG. 7 (c), when the pressing process is advanced while maintaining the input side pressure when the object to be compressed is input into the filtration chamber 31 in the filtering process, Unlike the case of FIG. 7 (b), the object to be squeezed can always receive a constant pressure and continue to exist evenly in the filtration chamber 31. Further, the compressed object compressed in the vicinity of the filter cloth 7 does not accumulate and adhere to the filter cloth 7 as a solid content and the life of the filter cloth 7 is not shortened.

  In the embodiment described above, the compression side pressure is controlled by the control unit 62 so that the input side pressure becomes a predetermined pressure or a target pressure. In order to keep the input side pressure constant, it is necessary to control the squeezing fluid preparation pump 61 and continue to supply the squeezing fluid to the diaphragm 20. At that time, it is necessary to provide a compression-side pressure detection unit 56 that detects the compression-side pressure and to detect how much the compression-side pressure is.

  For this purpose, it is possible to adjust the inflow amount of the squeezed fluid by providing the squeezing side pressure detector 56 and controlling the squeezing fluid producing pump 61 according to the pressure. Also, if the pressure side pressure detector 56 shows an abnormally high pressure, or if the pressure suddenly drops, it is determined that there is a malfunction of the device, and the operation is performed by controlling the squeezing fluid preparation pump 61. It can also function as a safety device to stop.

  In the squeezing step, the pressure on the input side is increased in order to maintain the predetermined pressure or the target pressure, and the step of uniformly squeezing the object to be squeezed is executed as the first squeezing control. Go. And at the stage where the filtered water is generally discharged from the object to be compressed, the predetermined constant pressure of the pressing side pressure is maintained as the upper limit value, and the stage of discharging the filtered water from the object to be compressed is executed as the second expression control. To go.

  As shown in FIG. 7 (c), when switching from the first pressing control to the second pressing control at time t1, the input side pressure starts to naturally drop at time t2. For example, the controller 62 can determine that the squeezing process has been completed when the inlet pressure detected by the inlet pressure detector 50 falls below a preset constant pressure.

  Further, the discharged filtrate is discharged to the outside of the filter press dehydrator 1 through the filtrate outlet 57 (see FIG. 2). This drainage path is provided with a filtered water flow meter 59 and detects the flow rate of filtered water flowing through the filtered water discharge oral cavity 57. When the filtrate flow rate detected by the filtrate water flow meter 59 is equal to or less than a preset filtrate flow rate, the control unit 62 can also determine that the compression process has been completed by stopping the second compression control.

  Furthermore, as shown in FIG.7 (d) and FIG.7 (e), in 2nd squeezing control, in the said embodiment, the predetermined constant pressure was maintained as an upper limit, and filtered water was discharged | emitted from the pressing target object. However, in the second squeezing control, several squeezing pressure upper limit values can be provided and the control can be performed step by step. In this case, the input side pressure also decreases stepwise, and the filtered water of the compressed object can be efficiently discharged. Again, when switching from the first pressing control to the second pressing control at time t1, it naturally begins to drop at subsequent time t2.

  In this way, the compressed object formed by being compressed with an equal density is finished with a low moisture content because the moisture is discharged uniformly throughout. Furthermore, clogging of the filter cloth 7 is unlikely to occur, leading to a longer life of the filter cloth 7.

  In the filtration process, in order to continue to squeeze at a predetermined pressure or a preset target pressure when the squeezing process is started, the input side pressure is detected when the object to be compressed is introduced into the filter chamber. While being detected by the unit 50, the stock solution input pump 54 supplies the compressed object until the predetermined pressure or the target pressure set by the control unit 62 is reached. Thereby, squeezing can be started at a predetermined filtration pressure from the start of squeezing, and the squeezing process can be advanced efficiently.

  In order to keep the input side pressure at a constant value or a preset target pressure, it is necessary to continuously supply the object to be compressed and the fluid for pressing. In this embodiment, a squeezing fluid is supplied to the diaphragm using a multistage pump as a squeezing fluid production pump. In order to control the pressure, the pump's pumping motor is adjusted with high precision by adjusting the pump's pumping motor's pumping motor's pumping motor's pumping motor by adjusting the rotation speed of the pump's motor. To go. The control is not necessarily limited to inverter control, and can be controlled by other known pressure control techniques. The pump is not limited to a multistage pump, and other types of pumps can be used.

  Hereinafter, another embodiment of the filter press dewatering device according to the present invention will be described. In the above-described embodiment, the filter press dehydrator 1 controlled to keep the input side pressure constant has been described. However, for example, the input side pressure in the pressing step is not necessarily limited to a constant value. It is only necessary to secure a water channel for seeping out filtered water and to control the object to be compressed evenly. Depending on the nature of the compressed object, even if the input pressure in the compression process is somewhat higher than the final pressure in the filtration process, the compressed object can be filtered evenly, and a water channel that seeps out filtrated water can be secured. The squeezing can be advanced efficiently. That is, if the squeezing side pressure of the squeezing fluid supplied to the diaphragm 20 by the squeezing fluid mechanism is controlled using the input side pressure of the squeezing target to be put into the filtration chamber 31 as an index, the squeezing proceeds efficiently. Because.

  In embodiment mentioned above, although the input side pressure showed about the operation | movement which transfers to a pressing process, hold | maintaining the final pressure of a filtration process, when transferring to a pressing process, the pressure same as the final pressure of a filtration process is not necessarily hold | maintained. There is no need, for example, starting the squeezing process from a predetermined pressure equal to or lower than the final pressure of the filtration process in the squeezing process, and controlling the fluid supply mechanism for squeezing so as not to exceed the predetermined pressure It only has to be configured.

  In the above-described embodiment, the diaphragm 20 has been described with respect to the configuration including the thin-walled portion 21 that can be expanded and contracted and the thick-walled portion 22 that functions as a filter frame that is integrally formed around the thin-walled portion 21. A diaphragm can be used. For example, when using a diaphragm that does not include a thick part, a filter chamber may be configured with a thin part of the diaphragm, a filter plate, and a filter frame using a separately prepared filter frame.

  In the embodiment described above, the filter cloth 7 has a configuration in which two filter cloths are installed in one filter chamber by the support mechanism 10, but the structure of the filter cloth is not limited thereto. A configuration in which a filter cloth is suspended for each filter chamber may be used, or a configuration in which one filter cloth is arranged in the filter chamber and compressed by single-side filtration may be used.

  In the embodiment described above, the input side pressure is detected by the stock solution supply path 51 of FIG. 2, but a configuration in which a pressure detection unit is provided in the filter chamber to directly detect the pressure in the filtration chamber 31 may be employed.

  Each of the above-described embodiments is an example of the present invention, and the present invention is not limited by the description. The specific configuration of each part can be appropriately changed and designed within the range where the effects of the present invention are exhibited. Needless to say.

1: filter press dewatering device 2: front frame 3: rear frame 4: side frame 5: advance / retreat mechanism 5a: rod 5b: pressing member 5c: hydraulic cylinder 7: filter cloth 6: drive roller 8: cleaning mechanism 9: tension mechanism 10 : Support mechanism 10a: Upper roller 10b: Lower roller 10c: Guide roller 11: Engagement pin 12: Connecting bracket 14: Base part 17: Meandering correction mechanism 20: Diaphragm 21: Thin part 22: Thick part 22a: Discharge groove 30 : Filter plate 31: Filtration chamber 32: Through hole 33: Squeeze fluid path 34: Squeeze fluid supply hole 35: Liquid collection part 36: Rising part 37: Drainage hole 50: Input side pressure detection part 51: Stock solution supply path 52: Stock solution input side valve 53: Stock solution storage tank 54: Stock solution input pump 56: Pressure side pressure detection unit 57: Filtrated water discharge port 59: Filtrated water flow meter 61: Fluid production pump 62 for squeezing: Control unit

Claims (4)

A filtration chamber in which a filter cloth is sandwiched between a filter plate and a diaphragm; a stock solution supply mechanism for introducing an object to be compressed into the filtration chamber; and a squeezing fluid supply mechanism for supplying a squeezing fluid to the diaphragm. , A filter press dewatering device that squeezes the object to be squeezed into the filtration chamber with the diaphragm,
A first pressure for controlling the pressure on the squeezing fluid supplied to the diaphragm by the squeezing fluid supply mechanism so that the pressure on the squeezing target to be squeezed into the filtration chamber by the stock solution supply mechanism is constant . A filter press dewatering device provided with a control unit for executing compression control . The controller controls the fluid supply mechanism for pressing so that the pressing side pressure does not exceed the predetermined pressing pressure when the pressing side pressure reaches a predetermined pressing set value by the first pressing control. The filter press dewatering device according to claim 1, which performs two squeezing control. A filtration chamber in which a filter cloth is sandwiched between a filter plate and a diaphragm; a stock solution supply mechanism for introducing an object to be compressed into the filtration chamber; and a squeezing fluid supply mechanism for supplying a squeezing fluid to the diaphragm. The operation method of the filter press dewatering device that squeezes the object to be squeezed into the filtration chamber with the diaphragm,
A first pressure adjusting pressure of a squeezing fluid supplied to the diaphragm by the squeezing fluid supply mechanism so that a charging side pressure of an object to be squeezed into the filtration chamber by the stock solution supply mechanism is constant . The operation method of the filter press dehydrator which performs squeezing control. When the pressing side pressure reaches a predetermined pressing set value by the first pressing control, the second pressing control is performed to control the pressing fluid supply mechanism so that the pressing side pressure does not exceed the predetermined pressing pressure. The operation method of the filter press dehydrator according to claim 3.

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