Filter press type dewatering apparatus and its control method

Abstract

To appropriately manage a timing of ending deliquoring.SOLUTION: A filter press type deliquoring device 100 includes a filter chamber member 20 delimiting a filter chamber 10, a liquid concentrate pumping part 30 which pumps liquid concentrate to the filter chamber 10, a filter material 40 which is provided in the filter chamber member 20, and filters solid matters from the liquid concentrate pumped to the filter chamber 10, and a pressure measurement part 61 which measures the pressure of the liquid concentrate pumped by the liquid concentrate pumping part 30.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a filter press type liquid removal device and a control method for the filter press type liquid removal device.

Background Art

[0002] As a device for filtering a stock solution containing solids and liquid and extracting the liquid from the stock solution, a filter press type liquid removal device is known. Patent Document 1 discloses a filter press type dehydration device for filtering working wastewater containing sludge such as civil engineering wastewater and factory wastewater.

[0003] The filter press type dehydration device disclosed in Patent Document 1 includes an upper filter plate and a lower filter plate that form a filtration chamber, and filter cloths stretched on each of the upper filter plate and the lower filter plate. The working wastewater is pumped into the filtration chamber by a pump and filtered by the filter cloth. The filtered water extracted from the stock solution by filtration is collected in a tank. The sludge is filtered by the filter cloth and accumulates on the surface of the filter cloth to form a so-called dewatering cake. The dewatering cake is taken out from the filtration chamber after the pump stops and the pumping of the working wastewater ends.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In a filter press type liquid removal device, even after the solids fill the filtration chamber, the stock solution is continuously pumped, so that the solids filtered by the filter medium are squeezed by the stock solution further packed into the filtration chamber. Thereby, the liquid content rate of the dewatering cake formed from the solids can be reduced, and the amount of filtered liquid extracted from the stock solution can be increased.

[0006] On the other hand, the deliquid cake formed on the filter media acts as filtration resistance. The lower the liquid content of the deliquid cake, the greater the filtration resistance and the lower the flow rate of the filtrate. Therefore, if the pumping of the raw liquid continues when the liquid content of the deliquid cake in the filter chamber has decreased sufficiently and is almost solid, the flow rate of the filtrate will decrease significantly, and deliquidation will take an enormous amount of time.

[0007] For these reasons, it is necessary to properly manage the timing of the end of the dewatering process. Preferably, the timing of the end of dewatering should be determined by measuring the liquid content of the dewatered cake, but a method for directly measuring the liquid content of the dewatered cake has not been established. Currently, the worker visually checks the flow of the filtrate and ends the dewatering process when the worker judges that the flow rate of the filtrate has decreased to a certain extent. Therefore, it is difficult to properly manage the timing of the end of dewatering.

[0008] The present invention aims to appropriately control the timing of the completion of liquid removal. [Means for solving the problem]

[0009] The present invention comprises a filter chamber member that defines a filter chamber, a raw liquid pumping unit that pumps the raw liquid into the filter chamber, a filter material provided in the filter chamber member that filters out solid matter from the raw liquid pumped into the filter chamber, and a pressure measuring unit that measures the pressure of the raw liquid pumped by the raw liquid pumping unit. The liquid concentrate pumping unit is a diaphragm pump having a first fluid chamber divided into a first pump chamber and a first air chamber by a first diaphragm. The diaphragm pump expands and contracts the first pump chamber by deforming the first diaphragm through the supply and discharge of air to the first air chamber, thereby drawing in the liquid concentrate and pumping it to the filter chamber. The pressure measuring unit is provided in the first air chamber and measures the pressure of the liquid concentrate by measuring the air pressure in the first air chamber. ru.

[0010] Furthermore, the present invention comprises a filter chamber member that defines a filter chamber, a raw liquid pumping unit that pumps the raw liquid into the filter chamber, and a filter material provided in the filter chamber member that filters out solid matter from the raw liquid pumped into the filter chamber. The raw liquid pumping section is a diaphragm pump having a fluid chamber divided into a pump chamber and an air chamber by a diaphragm, and the diaphragm pump expands and contracts the pump chamber by deforming the diaphragm through the supply and discharge of air to the air chamber, thereby drawing in the raw liquid and pumping it to the filter chamber. A control method for a filter press type dewatering device, By measuring the air pressure in the air chamber using a pressure measuring unit installed in the air chamber, The pressure of the raw liquid pumped by the raw liquid pumping unit is measured. and measure fixed air When the pressure reaches a predetermined pressure threshold, the pumping of the raw liquid by the raw liquid pumping unit is stopped. ru. [Effects of the Invention]

[0011] According to the present invention, the timing of the completion of liquid removal can be appropriately controlled. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic diagram of a filter press type dewatering apparatus according to an embodiment of the present invention. [Figure 2] Figure 1 shows an enlarged view of part II, where (a) shows the filter chamber member closing the filter chamber, and (b) shows the filter chamber member opening the filter chamber. [Figure 3] Figure 1 is a schematic diagram showing the details of the raw liquid pumping section. [Figure 4] This is a block diagram of a filter press type deliquidation apparatus according to an embodiment of the present invention. [Figure 5] Figure 2 shows the upper filter plate and filter frame as viewed from the lower filter plate. [Figure 6] This is a perspective view of a deliquidated cake formed by a filter press type deliquidation apparatus according to an embodiment of the present invention. [Modes for carrying out the invention]

[0013] Embodiments of the present invention will be described below with reference to the drawings.

[0014] Figure 1 is a schematic diagram of the filter press type deliquidation device 100 according to this embodiment. The filter press type deliquidation device 100 is used, for example, in the operation of cutting slab concrete using a road cutter. In cutting operations using a road cutter, a liquid such as water is poured onto the cutter blade of the road cutter and the slab concrete to cool the cutter blade while cutting the slab concrete. After being poured onto the cutter blade and the slab concrete, solid matter such as cutting dust generated by cutting the slab concrete is mixed into the liquid. The filter press type deliquidation device 100 filters the stock solution (also called "slag water") containing solid matter and liquid to extract the liquid from the stock solution. The liquid extracted from the stock solution by the filter press type deliquidation device 100 is used again to cool the cutter blade in the road cutter.

[0015] Note that the filter press type liquid removal device 100 may also be used in construction work for drilling concrete etc. using wet core boring, construction work for cutting concrete etc. using a wet wall saw, and construction work for cutting concrete etc. using a wet wire saw. Similar to a road cutter, wet core boring, a wet wall saw, and a wet wire saw cut concrete etc. while applying liquid to a drilling bit, a cutting blade, and a cutting wire corresponding to the cutter blade of the road cutter.

[0016] As shown in FIG. 1, the filter press type liquid removal device 100 includes a filter chamber member 20 that defines a filter chamber 10, a stock solution pumping section 30 that pumps a stock solution into the filter chamber 10, and a filter medium 40 provided on the filter chamber member 20. The filter chamber member 20 is formed such that the filter chamber 10 can be opened. The filter medium 40 filters out solids from the stock solution pumped into the filter chamber 10.

[0017] The stock solution pumping section 30 is connected to a switching valve 11 through a stock solution suction pipeline 12 and is connected to the filter chamber 10 through a stock solution pumping pipeline 13. The switching valve 11 has a first position 11a that allows communication between a stock solution tank 16 that stores the stock solution and the stock solution suction pipeline 12, and a second position 11b that blocks communication between the stock solution tank 16 and the stock solution suction pipeline 12. FIG. 1 shows a state where the switching valve 11 is switched to the first position 11a. In the state shown in FIG. 1, the stock solution pumping section 30 sucks the stock solution in the stock solution tank 16 and pumps it into the filter chamber 10.

[0018] FIG. 2 is an enlarged view of a portion II shown in FIG. 1. FIG. 2(a) shows a state where the filter chamber member 20 closes the filter chamber 10, and FIG. 2(b) shows a state where the filter chamber member 20 opens the filter chamber 10. In FIG. 2(b), a so-called dewatering cake formed from the solids filtered by the filter medium 进行过滤。

[0019] As shown in FIG. 2, the filtration chamber member 20 includes a lower filter plate 21, an upper filter plate 22 provided above the lower filter plate 21, and a frame 23 that forms a filtration chamber 10 between the lower filter plate 21 and the upper filter plate 22. A stock solution supply port 22a is formed in the upper filter plate 22, and a stock solution pressure feed pipeline 13 is connected to the stock solution supply port 22a. The upper filter plate 22 is connected to a frame 25 via lifting means 24 and moves up and down with respect to the lower filter plate 21 by driving the lifting means 24. The lifting means 24 is, for example, a pantograph.

[0020] The filter frame 23 is fixed to the lower side of the upper filter plate 22. In a state where the upper filter plate 22 has moved to the lower limit by the lifting means 24 as shown in FIG. 2(a), the filter frame 23 is pressed against the lower filter plate 21, and the filtration chamber 10 is closed. When the upper filter plate 22 rises by the lifting means 24 as shown in FIG. 2(b), the filter frame 23 moves away from the lower filter plate 21, and the filtration chamber 10 is released.

[0021] The filter medium 40 includes a lower filter cloth 41 formed in a strip shape and an upper filter cloth 41 formed in a shallow bag shape and in a strip shape. The lower filter cloth 41 is attached to a fixing plate (not shown) provided across a pair of chains 51 formed in a ring shape. In FIG. 2, only one of the chains 51 is shown. The chains 51 are hung on a pair of drums 50 arranged at intervals in the horizontal direction. The drums 50 are rotatable, and the lower filter cloth 41 moves by the rotation of the drums 50. The lower filter plate 21 is arranged between the pair of drums 50, and the lower filter cloth 41 is movable on the lower filter plate 21. The lower filter cloth 41 is stretched on the upper surface of the lower filter plate 21 when it moves on the lower filter plate 21. The upper filter cloth 42 is stretched on the lower surface of the upper filter plate 22. The lower filter cloth 41 and the upper filter cloth 42 are accommodated in the filtration chamber 10.

[0022] In the examples shown in FIGS. 1 and 2, the lower filter cloth 41 is provided only on a part of the chain 51, but it may be provided on the entire circumference of the chain 51. That is, the lower filter cloth 41 may be formed in a ring shape.

[0023] As shown in Figures 1 and 2, if the lower cloth 41 is provided only on a part of the chain 51, the replacement of the lower cloth 41, which is a consumable item, becomes easier. If the lower cloth 41 is provided around the entire circumference of the chain 51, the operating mechanism of the lower cloth 41 becomes simpler.

[0024] The raw liquid is pumped between the lower filter cloth 41 and the upper filter cloth 42 and filtered by the lower filter cloth 41 and the upper filter cloth 42. The filtrate removed from the raw liquid by filtration is discharged from the filtration chamber 10 through pipes 21b and 22b connected to the lower filter plate 21 and the upper filter plate 22. Solid matter in the raw liquid is filtered out by the lower filter cloth 41 and the upper filter cloth 42 and accumulates on the surface of the lower filter cloth 41 and the surface of the upper filter cloth 42, forming a deliquidation cake.

[0025] The dewatered cake formed between the lower filter cloth 41 and the upper filter cloth 42 is removed from the filter chamber 10 after dewatering is complete. Specifically, after the pumping of the raw liquid by the raw liquid pumping unit 30 stops, the lifting mechanism 24 is driven to raise the upper filter plate 22, filter frame 23, and upper filter cloth 42, as shown in Figure 2(b). At this time, the dewatered cake remains on the lower filter cloth 41. Next, the lower filter cloth 41 moves due to the rotation of the drum 50, and the dewatered cake on the lower filter cloth 41 is carried to the right side in Figure 2(b) and falls through the chute 52 into the cake storage container 53 (see Figure 1). After that, when the drum 50 rotates in the reverse direction and the lower filter cloth 41 returns to its original position, the lifting mechanism 24 is driven to lower the upper filter plate 22, filter frame 23, and upper filter cloth 42. When the filter chamber 10 is closed, the filter press type dewatering device 100 becomes capable of dewatering again.

[0026] The solid material filtered by the lower filter cloth 41 and the upper filter cloth 42 is compressed by the stock liquid that is further packed into the filter chamber 10 by the stock liquid, even after the solid material has filled the filter chamber 10. This reduces the liquid content of the deliquidated cake formed from the solid material and increases the amount of filtrate extracted from the stock liquid.

[0027] On the other hand, the deliquid cake formed on the lower filter cloth 41 and the upper filter cloth 42 acts as filtration resistance. The lower the liquid content of the deliquid cake, the greater the filtration resistance and the lower the flow rate of the filtrate. Therefore, if the pumping of the raw liquid continues when the liquid content of the deliquid cake in the filter chamber 10 has decreased sufficiently and become almost solid, the flow rate of the filtrate will decrease significantly, and deliquidation will take an enormous amount of time.

[0028] In particular, when using a filter press type dewatering device 100 for cutting slab concrete with a road cutter, if the flow rate of the filtered liquid is low, there is a risk that the amount of liquid used during cutting the slab concrete cannot be supplied by the filtered liquid alone. In this case, it is necessary to prepare additional cutter blades for the road cutter and liquid to be applied to the slab concrete, resulting in additional liquid procurement costs and an increase in construction costs.

[0029] For these reasons, it is necessary to appropriately manage the timing of the end of dewatering so that the dewatering process is completed when the liquid content of the dewatered cake has sufficiently decreased and the dewatered cake has become almost solid, and the dewatered cake can be removed from the filter chamber 10. In the filter press type dewatering apparatus 100, it is possible to appropriately manage the timing of the end of dewatering by the configuration shown below.

[0030] Figure 3 is a schematic diagram showing the details of the raw liquid pumping unit 30. As shown in Figure 3, the raw liquid pumping unit 30 is a diaphragm pump having a fluid chamber 31a that is divided into a pump chamber 30a and an air chamber 33a by a diaphragm 32a. The pump chamber 30a is connected to the raw liquid tank 16 and also to the filter chamber 10. When compressed air is supplied to and discharged from the air chamber 33a, the diaphragm 32a deforms and the pump chamber 30a expands and contracts, causing the raw liquid pumping unit 30 to draw in the raw liquid from the raw liquid tank 16 and pump it into the filter chamber 10.

[0031] The filter press type deliquidation device 100 includes a pressure measuring unit 61 for measuring the pressure of the raw liquid pumped by the raw liquid pumping unit 30. Specifically, the pressure measuring unit 61 is located in the air chamber 33a of the raw liquid pumping unit 30 and measures the pressure in the air chamber 33a. The pressure in the air chamber 33a of the raw liquid pumping unit 30 is substantially the same as the pressure of the raw liquid pumped by the raw liquid pumping unit 30.

[0032] The pressure of the raw liquid pumped into the filter chamber 10 increases as the liquid content of the dewatered cake formed on the lower filter cloth 41 and upper filter cloth 42 decreases and the filtration resistance increases. Therefore, the liquid content of the dewatered cake can be determined by measuring the pressure of the pumped raw liquid. Consequently, dewatering can be terminated based on the liquid content of the dewatered cake, and the timing of termination can be appropriately controlled. This makes it possible to terminate dewatering and remove the dewatered cake from the filter chamber 10 when the liquid content of the dewatered cake has sufficiently decreased and the dewatered cake has become almost solid.

[0033] Alternatively, the pressure measuring unit 61 may be installed between the lower filter cloth 41 and the upper filter cloth 42 (see Figures 1 and 2) to directly measure the pressure between the lower filter cloth 41 and the upper filter cloth 42, or the pressure measuring unit 61 may be installed in the raw liquid pumping pipeline 13 to directly measure the pressure inside the raw liquid pumping pipeline 13. However, in these cases, the pressure measuring unit 61 may become clogged with solid matter in the raw water or stacked dewatering cake, making it impossible to accurately measure the pressure of the raw liquid pumped by the raw liquid pumping unit 30.

[0034] In this embodiment, the pressure measuring unit 61 is located in the air chamber 33a of the raw liquid pumping unit 30, so that the pressure measuring unit 61 is separated from the raw water. Therefore, it is possible to prevent the pressure measuring unit 61 from becoming clogged with solid matter in the raw water or the accumulated deliquidation cake, and to accurately measure the pressure of the raw liquid pumped by the raw liquid pumping unit 30. This allows for more appropriate control of the timing of the end of deliquidation.

[0035] Deliquor removal, i.e., pumping the stock solution into the filter chamber 10, is preferably started only after the stock solution tank 16 has accumulated a sufficient amount of stock solution. This is because if pumping the stock solution is started before the stock solution tank 16 has accumulated a sufficient amount of stock solution, the stock solution in the tank 16 will run out before the deliquor cake is compressed, preventing a reduction in the liquid content of the deliquor cake and resulting in a decrease in the amount of filtrate extracted from the stock solution.

[0036] As shown in Figure 1, the filter press type deliquidation device 100 is equipped with a liquid volume measuring unit 62 that measures the liquid volume of the raw material in the raw material tank 16. Therefore, the liquid volume of the raw material in the raw material tank 16 can be determined. Accordingly, deliquidation can be started based on the liquid volume of the raw material in the raw material tank 16, and the timing of the start of deliquidation can be appropriately managed. This prevents the raw material in the raw material tank 16 from running out before the deliquidation cake is compressed, and reduces the liquid content of the deliquidation cake formed from solid material, thereby increasing the amount of filtrate extracted from the raw material. The liquid volume measuring unit 62 is, for example, a laser distance meter that measures the position of the liquid level of the raw material.

[0037] Figure 4 is a block diagram of the filter press type deliquidation device 100. As shown in Figure 4, the filter press type deliquidation device 100 includes a controller 70 that controls the pumping of the raw liquid in the raw liquid pumping unit 30 based on the pressure measured by the pressure measuring unit 61.

[0038] The controller 70 is composed of a microcomputer that includes a CPU (Central Processing Unit) for performing calculations, a ROM (Read-Only Memory) for storing control programs executed by the CPU, and a RAM (Random Access Memory) for storing the results of calculations performed by the CPU. The controller 70 may consist of a single microcomputer or multiple microcomputers.

[0039] Functionally, the controller 70 comprises a pressure acquisition unit 71, a liquid volume acquisition unit 72, a dehydration start / end determination unit 73, and a signal output unit 74. The pressure acquisition unit 71, liquid volume acquisition unit 72, dehydration start / end determination unit 73, and signal output unit 74 are virtual units representing the functions of the controller 70.

[0040] The pressure acquisition unit 71 acquires the pressure measured by the pressure measuring unit 61. The liquid volume acquisition unit 72 acquires the liquid volume measured by the liquid volume measuring unit 62.

[0041] The dehydration start / end determination unit 73 determines whether it is time to end the dehydration process based on the pressure acquired by the pressure acquisition unit 71. Specifically, the dehydration start / end determination unit 73 compares the pressure acquired by the pressure acquisition unit 71 with a predetermined pressure threshold. If the pressure acquired by the pressure acquisition unit 71 is lower than the pressure threshold, the dehydration start / end determination unit 73 determines that it is not time to end the dehydration process. If the pressure acquired by the pressure acquisition unit 71 is equal to or greater than the pressure threshold, the dehydration start / end determination unit 73 determines that it is time to end the dehydration process. The pressure threshold is set, for example, to a pressure equivalent to or slightly lower than the set pumping pressure of the raw liquid pumping unit 30.

[0042] Furthermore, the deliquidation start / end determination unit 73 determines whether or not it is time to start deliquidation based on the liquid volume acquired by the liquid volume acquisition unit 72. Specifically, the deliquidation start / end determination unit 73 compares the liquid volume acquired by the liquid volume acquisition unit 72 with a predetermined liquid volume threshold. If the liquid volume acquired by the liquid volume acquisition unit 72 is lower than the liquid volume threshold, the deliquidation start / end determination unit 73 determines that it is not time to start deliquidation. If the liquid volume acquired by the liquid volume acquisition unit 72 is equal to or greater than the liquid volume threshold, the deliquidation start / end determination unit 73 determines that it is time to start deliquidation. The liquid volume threshold is set, for example, to 90% of the maximum storage capacity of the stock tank 16.

[0043] The signal output unit 74 outputs a control signal to control the drive of the raw liquid pumping unit 30 based on the result of the deliquidation start / end determination unit 73. Specifically, when the raw liquid pumping by the raw liquid pumping unit 30 has stopped, and the deliquidation start / end determination unit 73 determines that it is time to start deliquidation, the signal output unit 74 outputs a control signal to the raw liquid pumping unit 30 to start pumping the raw liquid. When the raw liquid pumping by the raw liquid pumping unit 30 is continuing, and the deliquidation start / end determination unit 73 determines that it is time to end deliquidation, the signal output unit 74 outputs a control signal to the raw liquid pumping unit 30 to stop pumping the raw liquid.

[0044] Thus, in the filter press type deliquidation apparatus 100, the controller 70 stops the raw liquid pumping by the raw liquid pumping unit 30 when the pressure measured by the pressure measuring unit 61 reaches a predetermined pressure threshold. Therefore, deliquidation is automatically terminated by the controller 70 when the liquid content of the deliquidated cake reaches a value corresponding to the pressure threshold. Consequently, the timing of the termination of deliquidation can be managed more appropriately.

[0045] Furthermore, the controller 70 starts pumping the raw liquid using the raw liquid pumping unit 30 when the liquid volume measured by the liquid volume measuring unit 62 reaches a predetermined liquid volume threshold. Therefore, deliquidation is automatically started by the controller 70 when the liquid volume in the raw liquid tank 16 reaches the liquid volume threshold. Thus, the timing of the start of deliquidation can be managed more appropriately.

[0046] In the filter press type deliquidation device 100, the controller 70 manages the timing of the start and end of deliquidation, but the timing of the start and end of deliquidation may also be managed by an operator. In this case, a display unit is provided that displays the pressure measured by the pressure measuring unit 61 and the liquid volume measured by the liquid volume measuring unit 62. The operator visually checks the display unit and starts and stops the raw liquid pumping.

[0047] As shown in Figure 4, when the controller 70 manages the timing of the start and end of the dewatering process, there is no need for an operator to manage the timing of the start and end of the dewatering process. Therefore, labor savings become possible.

[0048] The controller 70 may also control the raising and lowering of the upper filter plate 22 by the lifting mechanism 24 and the rotation of the drum 50. In this case, the process from the start of dewatering to the removal of the dewatered cake can be performed automatically, further reducing labor.

[0049] As shown in Figure 3, the raw liquid pumping section 30 has a fluid chamber 31b separate from the fluid chamber 31a. For convenience, in the following, configurations located relatively to the left in Figure 3 will be labeled "left side," and configurations located relatively to the right in Figure 3 will be labeled "right side." For example, fluid chamber 31a will be referred to as the "left side fluid chamber 31a," and fluid chamber 31b will be referred to as the "right side fluid chamber 31b."

[0050] The left fluid chamber 31a and the right fluid chamber 31b are formed by the body 31. The left fluid chamber 31a is divided into a left pump chamber 30a and a left air chamber 33a by the left diaphragm 32a, and the right fluid chamber 31b is divided into a right pump chamber 30b and a right air chamber 33b by the right diaphragm 32b. The left diaphragm 32a and the right diaphragm 32b are connected to each other using a pump rod 34.

[0051] The body 31 is provided with an air supply port 33c for selectively supplying compressed air to the left air chamber 33a and the right air chamber 33b, and an air outlet 33d for selectively discharging compressed air to the left air chamber 33a and the right air chamber 33b. The air supply port 33c is connected to an air supply source (not shown).

[0052] As shown in Figure 3, when compressed air is supplied to the right air chamber 33b while the flow of compressed air from the right air chamber 33b to the air outlet 33d is blocked, the right diaphragm 32b deforms in a direction that expands the right air chamber 33b and contracts the right pump chamber 30b. Since the right diaphragm 32b is connected to the left diaphragm 32a using the pump rod 34, the left diaphragm 32a deforms in a direction that contracts the left air chamber 33a and expands the left pump chamber 30a. At this time, the compressed air in the left air chamber 33a is discharged from the air outlet 33d.

[0053] Although not shown in the diagram, when compressed air is supplied to the left air chamber 33a while the flow of compressed air from the left air chamber 33a to the air outlet 33d is blocked, the left diaphragm 32a deforms in a direction that expands the left air chamber 33a and shrinks the left pump chamber 30a. The right diaphragm 32b deforms in a direction that shrinks the right air chamber 33b and expands the right pump chamber 30b.

[0054] Thus, in the raw liquid pumping section 30, the left pump chamber 30a and the right pump chamber 30b are expanded and contracted by a single air supply source.

[0055] The body 31 has a left-side suction port 30c and a left-side pressure outlet 30e that communicate with the left-side pump chamber 30a, and a right-side suction port 30d and a right-side pressure outlet 30f that communicate with the right-side pump chamber 30b. The left-side suction port 30c is connected to the stock tank 16 via the stock suction line 12, and the left-side pressure outlet 30e is connected to the filter chamber 10 via the stock pressure line 13. The right-side suction port 30d is connected to the lower filter plate 21 and the upper filter plate 22 via the filtrate suction line 14, and the right-side pressure outlet 30f is connected to the filtrate tank 17 via the filtrate pressure line 15.

[0056] The raw liquid pumping section 30 is equipped with check valves 35a, 35b, 35c, and 35d. Check valve 35a allows flow from the left intake port 30c to the left pump chamber 30a and blocks the flow in the reverse direction. Check valve 35c allows flow from the left pump chamber 30a to the left pumping port 30e and blocks the flow in the reverse direction. Therefore, when the left pump chamber 30a expands as shown in Figure 3, check valve 35a opens and check valve 35c closes, and the raw liquid is drawn from the raw liquid tank 16 into the left pump chamber 30a. When the left pump chamber 30a contracts, check valve 35a closes and check valve 35c opens, and the raw liquid is pumped from the left pump chamber 30a to the filter chamber 10.

[0057] The check valve 35b allows flow from the right intake port 30d to the right pump chamber 30b and blocks flow in the reverse direction. The check valve 35d allows flow from the right pump chamber 30b to the right pressure outlet 30f and blocks flow in the reverse direction. Therefore, when the right pump chamber 30b expands, the check valve 35b opens and the check valve 35d closes, and filtrate is drawn into the right pump chamber 30b from the lower filter plate 21 and the upper filter plate 22. When the right pump chamber 30b contracts as shown in Figure 3, the check valve 35b closes and the check valve 35d opens, and the raw liquid is pumped from the right pump chamber 30b to the filtrate tank 17.

[0058] In this manner, the raw liquid pumping section 30 expands and contracts the left pump chamber 30a to draw in the raw liquid from the raw liquid tank 16 and pump it to the filter chamber 10, and the right pump chamber 30b expands and contracts to draw in the raw liquid from the filter chamber 10 through the lower filter cloth 41 and the upper filter cloth 42 (see Figure 2) to extract the filtrate and pump it to the filtrate tank 17.

[0059] As shown in Figure 1, if the pumping pressure of the raw liquid by the raw liquid pumping unit 30 is PA, and the suction pressure of the filtrate by the raw liquid pumping unit 30 is PB, then the pressure PC between the lower filter cloth 41 and the upper filter cloth 42 is PA - PB. Therefore, compared to the case where the filtrate is removed by pumping the raw liquid only without suctioning the filtrate in the raw liquid pumping unit 30, the pressure inside the filter chamber 10 can be lowered. Consequently, the required rigidity of the lower filter plate 21, upper filter plate 22, and filter frame 23 (see Figure 2) can be reduced, and the lower filter plate 21, upper filter plate 22, and filter frame 23 can be made lighter and smaller. As a result, the filter press type filtrate removal device 100 can be made lighter and smaller.

[0060] As described above, in the raw liquid pumping section 30, the left pump chamber 30a and the right pump chamber 30b are expanded and contracted by a single air supply source. Therefore, the pumping of the raw liquid to the filter chamber 10 and the suction of the filtered liquid from the filter chamber 10 can be performed by a single air supply source, enabling efficient deliquidation and allowing the filter press type deliquidation device 100 to be made lighter and more compact.

[0061] The weight reduction and miniaturization of the filter press type deliquidation device 100 are particularly effective in new construction and demolition work of buildings. Specifically, the weight reduction and miniaturization of the filter press type deliquidation device 100 make it possible to install it in permanent elevators installed in buildings or temporary elevators installed during new construction and demolition work. Therefore, the filter press type deliquidation device 100 can be placed near the work where the raw liquid is generated, and the piping (piping for raw liquid recovery and piping for filtered liquid) can be shortened. This makes it possible to shorten the construction period and reduce costs in new construction and demolition work of buildings.

[0062] Figure 5 shows the upper filter plate 22 and filter frame 23 as seen from the lower filter plate 21. Note that the upper filter cloth 42 is not shown in Figure 5.

[0063] As shown in Figures 2 and 5, the upper filter plate 22 is provided with a jointing member 26 for creating joints in the deliquid cake. The jointing member 26 is, for example, an angle material.

[0064] Figure 6 is a perspective view of the dewatered cake formed from the solid material filtered by the lower filter cloth 41 and the upper filter cloth 42. As shown in Figure 6, joints are made in the dewatered cake at positions corresponding to the joint-filling members 26 (see Figures 2 and 5). Therefore, when the dewatered cake is subjected to impact, it breaks along the joints. Thus, the dewatered cake can be broken into desired sizes, making it easier to transport the dewatered cake. In addition, the volume of the dewatered cake is reduced when it is broken into smaller pieces, reducing wasted space and thus lowering the disposal costs of the dewatered cake.

[0065] Impact on the dehydrated cake occurs, for example, when the dehydrated cake falls into the cake storage container 53. An impact may also be applied to the dehydrated cake by an employee striking it with a hammer or the like.

[0066] As shown in Figures 1 and 2, the jointing member 26 is provided between the upper filter plate 22 and the upper filter cloth 42. Therefore, the upper filter cloth 42 rises along the jointing member 26 relative to the lower surface of the upper filter plate 22. Consequently, the surface area of ​​the upper filter cloth 42 can be increased compared to when the jointing member 26 is not present, and the filtration speed can be improved.

[0067] While the joint filling member 26 may be provided on the lower filter plate 21, in this case, it may become difficult to transport the dewatered cake by the rotation of the drum 50, or the lower filter cloth 41 may be damaged by the joint filling member 26 during transport of the dewatered cake. For these reasons, it is preferable to provide the joint filling member 26 only on the upper filter plate 22.

[0068] Even if the dewatered cake is removed from the filter chamber 10, residue from the dewatered cake may adhere to the lower filter cloth 41 and the upper filter cloth 42. If dewatering is performed again with residue from the dewatered cake still attached, the dewatering process will start from a clogged state on the lower filter cloth 41 and the upper filter cloth 42, which will prolong the dewatering process.

[0069] Therefore, the filter press type dewatering device 100 is provided with a mechanism to remove the residue of the dewatering cake adhering to the lower filter cloth 41 and the upper filter cloth 42. The mechanism for removing the residue of the dewatering cake from the lower filter cloth 41 and the upper filter cloth 42 will be described in detail below.

[0070] As shown in Figure 1, the rotation of the drum 50 causes the lower filter cloth 41 to be transported so that the side from which the solid matter has been filtered faces downward. In other words, the drum 50 functions as a transport means that transports the lower filter cloth 41 so that the side from which the solid matter has been filtered faces downward when the pumping of the raw liquid by the raw liquid pumping unit 30 is stopped.

[0071] The filter press type dewatering device 100 is equipped with a nozzle 80 that sprays cleaning liquid from below onto the lower filter cloth 41, which is conveyed by the drum 50. As a result, the cleaning liquid hits the lower filter cloth 41 from below, detaches the residue of the dewatered cake from the lower filter cloth 41, and then falls. Thus, the residue of the dewatered cake adhering to the lower filter cloth 41 can be removed. This reduces the time required for subsequent dewatering operations.

[0072] The filtrate stored in the filtrate tank 17 is pumped to the nozzle 80 using the cleaning liquid pumping unit 81. In other words, the cleaning liquid ejected from the nozzle 80 is the filtrate extracted from the raw liquid by the lower filter cloth 41 and the upper filter cloth 42. Therefore, there is no need to prepare a separate liquid for cleaning the lower filter cloth 41, and the cost of dewatering can be reduced. The cleaning liquid pumping unit 81 is, for example, a diaphragm pump. The cleaning liquid pumping unit 81 is driven by, for example, a controller 70.

[0073] Below the lower filter cloth 41, which is transported by the drum 50, is a collection member 82 for collecting the cleaning liquid (filter liquid) ejected from the nozzle 80. Specifically, the collection member 82 is a receiving plate. The collection member 82 has a collection hole 82a and is sloped to allow the cleaning liquid to collect in the collection hole 82a. Below the collection hole 82a is a used cleaning liquid tank 83. The cleaning liquid ejected from the nozzle 80 falls through the collection hole 82a and is collected in the used cleaning liquid tank 83.

[0074] The used cleaning fluid tank 83 is connected to the raw liquid pumping unit 30 via a switching valve 11. In the first position 11a, the switching valve 11 blocks communication between the used cleaning fluid tank 83 and the raw liquid suction line 12, and in the second position 11b, it allows communication between the used cleaning fluid tank 83 and the raw liquid suction line 12. When the switching valve 11 is switched to the second position 11b, the raw liquid pumping unit 30 pumps the cleaning fluid collected in the used cleaning fluid tank 83 to the filter chamber 10. As a result, solid matter contained in the used cleaning fluid is also filtered out by the lower filter cloth 41 and the upper filter cloth 42. Therefore, liquid can be extracted from the used cleaning fluid, and the extracted liquid (filtered liquid) can be reused for cooling the cutter blade in the road cutter or for cleaning the lower filter cloth 41.

[0075] As shown in Figures 1 and 2, a vibrator 90 is provided on the upper filter plate 22. The vibrator 90 vibrates the upper filter plate 22. By vibrating the upper filter plate 22 with the vibrator 90 after the dewatering is complete, the residue of the dewatered cake adhering to the upper filter cloth 42 is promoted, and the residue falls off. Therefore, the residue of the dewatered cake can be removed from the upper filter cloth 42. This shortens the time required for the dewatering process to be repeated. The driving and stopping of the vibrator 90 are automatically controlled, for example, by a controller 70 in conjunction with the raising and lowering of the upper filter plate 22.

[0076] Furthermore, the residue detached from the upper filter cloth 42 falls onto the lower filter cloth 41. However, the residue that falls onto the lower filter cloth 41 is then dropped via the chute 52 by the rotation of the drum 50 into the cake storage container 53 or the collection member 82, so none remains on the lower filter cloth 41.

[0077] The vibrator 90 may vibrate the upper filter plate 22 during deliquidation. In this case, solid-liquid separation of the raw liquid pumped into the filter chamber 10 is promoted. Therefore, the filtration rate can be improved and the deliquidation time can be shortened.

[0078] A vibrator 90 may be installed on the lower filter plate 21. In this case, vibrating the lower filter plate 21 after the dewatering is complete can promote the removal of the dewatering cake residue adhering to the lower filter cloth 41, and the dewatering cake residue can be removed more reliably from the lower filter cloth 41. In addition, vibrating the lower filter plate 21 during dewatering can also promote the solid-liquid separation of the raw liquid pumped into the filter chamber 10 from the lower filter plate 21, further improving the filtration speed and further shortening the dewatering time.

[0079] According to the above embodiments, the following effects and advantages are achieved.

[0080] The filter press type deliquidation device 100 is equipped with a pressure measuring unit 61 that measures the pressure of the raw liquid pumped by the raw liquid pumping unit 30. The pressure of the raw liquid pumped into the filter chamber 10 increases as the liquid content of the deliquidation cake formed on the lower filter cloth 41 and upper filter cloth 42 decreases and the filtration resistance increases, so the liquid content of the deliquidation cake can be determined. Therefore, deliquidation can be terminated based on the liquid content of the deliquidation cake, and the timing of termination of deliquidation can be appropriately managed. As a result, when the liquid content of the deliquidation cake has decreased sufficiently and the deliquidation cake has become almost solid, deliquidation can be terminated and the deliquidation cake can be removed from the filter chamber 10.

[0081] In the filter press type deliquidation apparatus 100, the controller 70 stops the pumping of the raw liquid by the raw liquid pumping unit 30 when the pressure measured by the pressure measuring unit 61 reaches a predetermined pressure threshold. Therefore, deliquidation is automatically terminated by the controller 70 when the liquid content of the deliquidated cake reaches a value corresponding to the pressure threshold. Thus, the timing of the termination of deliquidation can be managed more appropriately.

[0082] The filter press type deliquidation device 100 is equipped with a liquid volume measuring unit 62 that measures the liquid volume of the raw material in the raw material tank 16. Therefore, the liquid volume of the raw material in the raw material tank 16 can be determined. Consequently, deliquidation can be started based on the liquid volume of the raw material in the raw material tank 16, and the timing of the start of deliquidation can be appropriately managed. This prevents the raw material in the raw material tank 16 from running out before the deliquidation cake is compressed, and reduces the liquid content of the deliquidation cake formed from solid material, thereby increasing the amount of filtrate extracted from the raw material.

[0083] Furthermore, the controller 70 starts pumping the raw liquid using the raw liquid pumping unit 30 when the liquid volume measured by the liquid volume measuring unit 62 reaches a predetermined liquid volume threshold. Therefore, deliquidation is automatically started by the controller 70 when the liquid volume in the raw liquid tank 16 reaches the liquid volume threshold. Thus, the timing of the start of deliquidation can be managed more appropriately.

[0084] The raw liquid pumping unit 30 is a diaphragm pump having a pair of pump chambers 30a and 30b. One pump chamber 30a expands and contracts to draw in the raw liquid and pump it into the filter chamber 10, while the other pump chamber 30b expands and contracts to draw in the raw liquid from the filter chamber 10 via the lower filter cloth 41 and upper filter cloth 42, thereby extracting and pumping the filtrate. Therefore, compared to the case where the liquid is removed by pumping only the raw liquid without drawing in the filtrate in the raw liquid pumping unit 30, the pressure inside the filter chamber 10 can be lowered. Consequently, the rigidity required for the lower filter plate 21, upper filter plate 22, and filter frame 23 can be reduced, and the lower filter plate 21, upper filter plate 22, and filter frame 23 can be made lighter and smaller. As a result, the filter press type deliquidation device 100 can be made lighter and smaller.

[0085] The filter press type dewatering device 100 is equipped with a joint-filling member 26 provided on the upper filter plate 22. As a result, joints are formed in the dewatering cake at positions corresponding to the joint-filling member 26, and when the dewatering cake is subjected to impact, the dewatering cake breaks along the joints. Therefore, the dewatering cake can be broken into desired sizes, making it easier to transport the dewatering cake. In addition, since the volume of the dewatering cake is reduced by breaking it into smaller pieces, unnecessary gaps are reduced, thus reducing the volume of the dewatering cake and lowering the disposal costs of the dewatering cake.

[0086] The filter press type dewatering device 100 is equipped with a nozzle 80 that sprays cleaning liquid from below onto the lower filter cloth 41, which is conveyed by the drum 50. As a result, the cleaning liquid hits the lower filter cloth 41 from below, detaches the residue of the dewatered cake from the lower filter cloth 41, and then falls. Thus, the residue of the dewatered cake adhering to the lower filter cloth 41 can be removed. This reduces the time required for subsequent dewatering operations.

[0087] The cleaning liquid ejected from the nozzle 80 is the filtered liquid extracted from the raw liquid by the lower filter cloth 41 and the upper filter cloth 42. Therefore, there is no need to prepare a separate liquid for cleaning the lower filter cloth 41, and the cost of dewatering can be reduced.

[0088] The raw liquid pumping unit 30 pumps the cleaning liquid collected in the used cleaning liquid tank 83 into the filter chamber 10. As a result, solid matter contained in the used cleaning liquid is also filtered out by the lower filter cloth 41 and the upper filter cloth 42. Therefore, liquid can be extracted from the used cleaning liquid.

[0089] A vibrator 90 is provided on the upper filter plate 22. By vibrating the upper filter plate 22 with the vibrator 90 after the dewatering is complete, the residue of the dewatering cake adhering to the upper filter cloth 42 is promoted, and the residue falls off. Therefore, the residue of the dewatering cake can be removed from the upper filter cloth 42. This shortens the time required for the subsequent dewatering process. In addition, vibrating the upper filter plate 22 with the vibrator 90 during dewatering promotes the solid-liquid separation of the raw liquid pumped into the filter chamber 10. Therefore, the filtration speed can be improved, and the dewatering time can be shortened.

[0090] Although embodiments of the present invention have been described above, these embodiments only represent a part of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

[0091] The filter press type dewatering device 100 may be mounted on a trolley with caterpillar tracks, for example, and be remotely controllable. This enables unmanned or remote construction of work including dewatering.

[0092] It is preferable to provide a load cell in the chute 52. In this case, the weight of the dewatered cake passing through the chute 52 can be measured using the load cell, and the amount of dewatered cake discharged can be determined. The load cell is, for example, a belt scale.

[0093] The cake storage container 53 is preferably mounted on a trolley. The trolley facilitates the transport of the cake storage container 53, allowing the dehydrated cake stored in the container 53 to be easily transported within the construction site.

[0094] The cake storage container 53 is preferably a flexible container bag that can be loaded onto the bed of a truck. By using such a flexible container bag as the cake storage container 53, the flexible container bag containing the dehydrated cake can be lifted by a hoisting machine such as a crane and placed onto the bed of a truck, thus making it easy to transport the dehydrated cake from the construction site.

[0095] The filter chamber 10 may be formed by a pair of filter plates arranged horizontally and a filter frame 23 provided on at least one of the pair of filter plates, instead of the lower filter plate 21, upper filter plate 22, and filter frame 23. In this case, at least one of the pair of filter plates is configured to be horizontally movable. In addition, a jointing member 26 is provided on at least one of the pair of filter plates, and a vibration exciter 90 is provided on at least one of the pair of filter plates.

[0096] In the above embodiment, a lower filter cloth 41 is provided on the lower filter plate 21 and an upper filter cloth 42 is provided on the upper filter plate 22. However, it is also possible that only the lower filter cloth 41 is provided on the lower filter plate 21, and the upper filter cloth 42 is not provided on the upper filter plate 22. Alternatively, it is possible that only the upper filter cloth 42 is provided on the upper filter plate 22, and the lower filter cloth 41 is not provided on the lower filter plate 21. In other words, the filter material 40 may be provided on only one of the lower filter plate 21 and the upper filter plate 22.

[0097] If only the lower filter cloth 41 is provided on the lower filter plate 21 and the upper filter cloth 42 is not provided on the upper filter plate 22, then no piping 22b is formed on the upper filter plate 22, and the filtered liquid extracted from the raw liquid is discharged from the filter chamber 10 through the piping 21b formed on the lower filter plate 21. Also, if only the upper filter cloth 42 is provided on the upper filter plate 22 and the lower filter cloth 41 is not provided on the lower filter plate 21, then no piping 21b is formed on the lower filter plate 21, and the filtered liquid extracted from the raw liquid is discharged from the filter chamber 10 through the piping 22b formed on the upper filter plate 22.

[0098] In the above embodiment, there is one filter chamber 10, but multiple filter chambers 10 may be stacked on top of each other. [Explanation of symbols]

[0099] 100... Filter press type dewatering device 10. Filtration chamber 16. Concentrated liquid tank 20... filter chamber components 26. Joint filling materials 30.. Concentrated liquid pumping section 30a, 30b... Pump Room 40...filter media 50... Drum (conveying means) 61. Pressure measuring section 62... Liquid volume measurement section 70... Controller 80 nozzles 82...Collection materials 90... Vibration exciter

Claims

1. A filter chamber member that defines the filter chamber, A raw liquid pumping unit for pumping the raw liquid into the aforementioned filter chamber, A filter material is provided in the filter chamber member to filter out solid matter from the raw liquid that has been pumped into the filter chamber, The system includes a pressure measuring unit for measuring the pressure of the raw liquid pumped by the raw liquid pumping unit, The liquid pumping unit is a diaphragm pump having a first fluid chamber that is divided into a first pump chamber and a first air chamber by a first diaphragm. The diaphragm pump deforms the first diaphragm by supplying and discharging air to the first air chamber, thereby expanding and contracting the first pump chamber, to draw in the undiluted liquid and pump it under pressure to the filter chamber. The pressure measuring unit is provided in the first air chamber and measures the pressure of the undiluted liquid by measuring the air pressure in the first air chamber. Filter press type dewatering device.

2. The diaphragm pump further has a second fluid chamber partitioned into a second pump chamber and a second air chamber by a second diaphragm, and by expanding and contracting the second pump chamber, it draws the raw liquid from the filter chamber through the filter material, extracts the filtered liquid, and pumps it under pressure. The filter press type deliquidation apparatus according to claim 1.

3. The system further includes a controller that controls the pumping of the raw liquid by the raw liquid pumping unit based on the air pressure measured by the pressure measuring unit, The controller stops pumping the liquid by the liquid pumping unit when the air pressure reaches a predetermined pressure threshold. The filter press type deliquidation apparatus according to claim 1.

4. A stock liquid tank for storing the stock liquid pumped by the stock liquid pumping unit, The system further includes a liquid volume measuring unit for measuring the liquid volume of the stock solution in the stock solution tank. The filter press type deliquidation apparatus according to claim 1.

5. The system further includes a controller that controls the pumping of the raw liquid by the raw liquid pumping unit based on the liquid volume measured by the liquid volume measuring unit, The controller starts pumping the stock liquid by the stock liquid pumping unit when the liquid volume reaches a predetermined liquid volume threshold. The filter press type dewatering apparatus according to claim 4.

6. The filter chamber member is further provided with a joint-filling member for filling joints in the deliquid cake formed from the solid material filtered out by the filter material. The filter press type deliquidation apparatus according to claim 1.

7. When the pumping of the raw liquid by the raw liquid pumping unit is stopped, a conveying means for conveying the filter material so that the side from which the solid matter has been filtered faces downwards, A nozzle that sprays cleaning liquid from below toward the filter material conveyed by the conveying means, It also has, The filter press type deliquidation apparatus according to claim 1.

8. The cleaning liquid ejected from the nozzle is a filtered liquid extracted from the raw liquid by the filter material. The filter press type dewatering apparatus according to claim 7.

9. The collection member is provided below the filter material that has been transported by the transport means, and collects the cleaning liquid ejected from the nozzle toward the filter material, The raw liquid pumping unit pumps the cleaning liquid collected by the collection member to the filter chamber. The filter press type dewatering apparatus according to claim 7.

10. The system further includes a vibrator for vibrating the aforementioned filter chamber member. The filter press type deliquidation apparatus according to claim 1.

11. A control method for a filter press type deliquidation apparatus comprising: a filter chamber member defining a filter chamber; a raw liquid pumping unit for pumping raw liquid into the filter chamber; and a filter material provided on the filter chamber member for filtering solid matter from the raw liquid pumped into the filter chamber, wherein the raw liquid pumping unit is a diaphragm pump having a fluid chamber divided into a pump chamber and an air chamber by a diaphragm, and the diaphragm pump expands and contracts the pump chamber by deforming the diaphragm through the supply and discharge of air to the air chamber, thereby sucking in raw liquid and pumping it into the filter chamber, By measuring the air pressure in the air chamber using the pressure measuring unit provided in the air chamber, the pressure of the raw liquid pumped by the raw liquid pumping unit is measured. When the measured air pressure reaches a predetermined pressure threshold, the pumping of the raw liquid by the raw liquid pumping unit is stopped. A control method for a filter press type dewatering device.

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