Vertical filter press and filtration method

Abstract

The present invention relates to a vertical filter press comprising a base plate disposed beneath a filter cloth within a filter press chamber and having a through-hole region formed of one or more through-holes. A cleaning liquid distributor is provided between the through-hole region and the filter cloth. The vertical filter press of the present invention effectively cleans solid matter, such as inorganic matter, that has deposited in the equipment from filtrate during normal production, significantly reducing blockages caused by deposition, which can even prevent filtrate discharge. Blockages can also be detected and effectively resolved in a timely manner.

Description

Technical Field

[0001] The present invention relates to the field of filter pressing, in particular to a vertical filter press and a filter pressing method using the filter press. Background Art

[0002] Vertical filter presses are suitable for filtering difficult-to-filter slurries (e.g., colloids or colloid-like slurries such as sludge and fruit pulp, especially activated biological sludge). In vertical filter presses, the components that come into contact with the filtrate often have some horizontally arranged sections. Solid matter, such as soil and inorganic matter, remaining in the filtrate can deposit on these sections, affecting the filtrate's discharge and even causing blockage, preventing the filtrate from being discharged and rendering the vertical filter press inoperable. Therefore, there remains a need for improved vertical filter presses to address these issues. Summary of the Invention

[0003] An object of the present invention is to provide a vertical filter press and a filtration method to solve the problems in the prior art. Specifically, the present invention provides the following technical solutions.

[0004] In one aspect, the present invention provides a vertical filter press, comprising a base plate arranged below a filter cloth of a filter press chamber and having a through-hole area consisting of one or more through holes, characterized in that a cleaning liquid distributor for spreading cleaning liquid on the upper surface of the through-hole area is provided between the through-hole area and the filter cloth, and the vertical filter press is arranged to allow filtrate from the filter press chamber and cleaning liquid from the cleaning liquid distributor to be discharged through the through-hole area.

[0005] In some cases, the vertical filter press comprises two or more filter press assemblies stacked in sequence from bottom to top, the filter press assembly comprising a base plate, a through hole area consisting of one or more through holes penetrating the base plate is provided in the middle of the base plate, a piston wall extending downwardly around the through hole area is provided on the bottom surface of the base plate, a piston top plate is provided at the bottom end of the piston wall, a channel plate having a groove surface on one side and a porous surface on the other side is provided on the piston top plate, the grooves on the groove surface are fluidically connected with the through holes on the porous surface, and mutually connected grooves are formed between the groove surface and the lower surface of the piston top plate to allow the fluid to flow everywhere on the lower surface of the piston top plate, a first filter cloth is provided on the porous surface, and a filter cloth for guiding the fluid into the grooves is provided on the piston top plate. A second tube for introducing fluid and a fourth tube for discharging fluid in the groove, a piston sleeve is sleeved around the outer surface of the piston wall to allow the piston composed of the piston wall, the piston top plate, the channel plate and the first filter cloth to move up and down in the piston sleeve, a filter press chamber is formed by the space defined by the lower surface of the first filter cloth and the inner surface of the piston sleeve, a first tube for introducing slurry to be filtered is provided in the filter press chamber, the filter press also includes a second filter cloth arranged between the adjacent upper filter press assembly and the lower filter press assembly, the lower surface of the second filter cloth is in close contact with and covers the through-hole area of ​​the lower filter press assembly, and when the upper surface of the second filter cloth is in close contact with and covers the lower end of the piston sleeve of the upper filter press assembly, it participates in defining the filter press chamber.

[0006] In some cases, two upper and lower adjacent filter press assemblies are connected to each other by a retractable connection portion.

[0007] In some cases, the porous surface is provided with a plurality of through holes penetrating the channel plate, and the groove surface is provided with a plurality of protrusions surrounding each through hole to form a plurality of grooves intersecting each other and in fluid communication on the groove surface.

[0008] In some cases, the space defined by the lower surface of the through-hole area, the inner surface of the piston wall and the upper surface of the piston top plate forms a liquid collecting chamber for collecting fluid entering from the through-hole area, and a third tube for discharging fluid is provided in the liquid collecting chamber.

[0009] In some cases, the piston sleeve is connected to the lower surface of the base plate via a retractable elastic pad.

[0010] Furthermore, a porous pad is provided between the cleaning liquid distributor and the filter cloth, which is in close contact with the filter cloth and allows the filtrate to pass through.

[0011] Furthermore, the cleaning liquid distributor is composed of one or more sections of cleaning liquid distribution pipes, and the cleaning liquid distribution pipes are arranged between the support columns.

[0012] Furthermore, one or more support columns are provided between the through-hole area and the filter cloth or porous pad, the lower end of the support column is supported on the upper surface of the through-hole area and the upper end is supported on the lower surface of the filter cloth or porous pad, thereby separating the through-hole area from the filter cloth or porous pad and forming a space defined by the upper surface of the through-hole area and the lower surface of the filter cloth or porous pad for accommodating the cleaning liquid distributor.

[0013] Furthermore, the plurality of support columns are interconnected by one or more porous connectors to form one or more detachable support column blocks, and the porous connectors are arranged above the cleaning liquid distributor and allow the filtrate to pass through.

[0014] Further, the porous connector is rigid and multiple porous connectors are independent of each other; or, the porous connector is flexible and multiple porous connectors are connected to each other.

[0015] Furthermore, a liquid collecting chamber for collecting filtrate or cleaning liquid from the through-hole area is provided below the through-hole area.

[0016] Furthermore, the cleaning liquid inlet pipe of the cleaning liquid distributor is provided with a first pump for supplying cleaning liquid to the cleaning liquid distributor, and a first flow meter and a first timer for measuring and recording the flow rate and time of the first pump when pumping the cleaning liquid, and the discharge pipe of the liquid collecting chamber is provided with a second pump for discharging the cleaning liquid, and a second flow meter and a second timer for measuring and recording the flow rate and time of the second pump when pumping out the cleaning liquid, wherein the actual maximum delivery flow rate of the second pump is greater than or equal to the actual maximum delivery flow rate of the first pump.

[0017] Another aspect of the present invention provides a filter press method comprising the following steps:

[0018] S000, providing any of the above vertical filter presses;

[0019] S100, during the filter pressing process or after each filter pressing, the cleaning liquid is spread on the through-hole area through the cleaning liquid distributor, and the cleaning liquid is discharged through the through-hole area.

[0020] Further, in step S100, after the filter press is completed, the first pump is started and maintained for a first time t1 so as to spread the cleaning liquid on the through-hole area through the cleaning liquid distributor, and a first total amount Q1 of the cleaning liquid pumped by the first pump within the first time t1 is measured, wherein t1 is 1 to 30 minutes;

[0021] Furthermore, the filter pressing method further comprises the following steps:

[0022] Step S200, simultaneously with starting the first pump in step S100, starting the second pump for a second time t2 to discharge the cleaning liquid entering the liquid collecting chamber, and measuring a second total amount Q2 of the cleaning liquid pumped out by the second pump within the second time t2, wherein t2 is 1.1 to 2 times t1 or the time required to achieve Q2 = Q1, whichever is smaller;

[0023] S300 , when the absolute value of the difference between the second time and the first time |t2-t1|<Δt and |Q1-Q2|<ΔQ, it is determined that the through-hole area is not blocked;

[0024] S400, when t2-t1≥Δt and Q1-Q2<ΔQ, it is determined that the through-hole area is partially blocked;

[0025] S500, when t2-t1≥Δt and Q1-Q2≥ΔQ, it is determined that the through-hole area is severely blocked;

[0026] Here, Δt is 1% to 20% of t1, and ΔQ is 1% to 20% of Q1.

[0027] Furthermore, step S400 also includes repeating steps S100 and S200.

[0028] Furthermore, step S500 also includes disassembling and cleaning the through-hole area of ​​the vertical filter press.

[0029] According to the filter press assembly, vertical filter press and filtration method of the present invention, the pressure-bearing components can be made of high-strength rigid materials and can be increased in size as needed to further increase the strength, avoiding the use of elastic diaphragm components with limited pressure resistance in the prior art, thereby achieving high-pressure and even ultra-high-pressure filtration.

[0030] Existing vertical filter presses are time-consuming and labor-intensive to disassemble and clean, significantly impacting production efficiency. Furthermore, they lack means to monitor, prevent, and address blockages. The inventors of the present invention unexpectedly discovered that the vertical filter press and filtration method of the present invention can effectively clean inorganic and other solid matter deposited in the equipment from the filtrate during normal production, significantly reducing filtrate blockage and even failures caused by deposition. Furthermore, potential blockages can be promptly detected and effectively addressed. Furthermore, the provision of detachable support columns makes the vertical filter press of the present invention particularly convenient for disassembly and cleaning.

[0031] The present invention therefore has the advantages of high operating pressure, fast filtration speed, low liquid content in the filter cake, reliable structure and convenient automated operation, and is particularly suitable for filtration of difficult-to-filter systems such as colloids or colloid-like systems (such as activated sludge, pectin, etc.).

[0032] The terms used herein have their commonly understood meanings in the art, but for the sake of clarity, the following definitions are given.

[0033] The terms "longitudinal", "transverse", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention. In addition, the terms "first", "second", "third" and the like are only used for descriptive purposes and should not be understood as indicating or implying relative importance. It should be noted that, unless otherwise expressly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be a communication between the internal parts of two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] "Substantially" or "essentially" does not exclude the meaning of "completely". For example, if a component "substantially does not contain" Y, it may also be completely free of Y. In the case of limiting a specific numerical value, it means that the specific numerical value has a floating range based on the specific numerical value, and the floating range can be + / -5%, + / -4%, + / -3%, + / -2%, + / -1%, + / -0.5%, + / -0.2%, + / -0.1%, + / -0.05%, + / -0.01% and so on of the specific numerical value. If necessary, "substantially" or "essentially" can be replaced by the above floating range or deleted from the definition of the present invention. "Contains" includes both the factors mentioned and allows the inclusion of additional, uncertain factors. "Approximately", "about" and "around" when limiting a specific numerical value mean that the specific numerical value has a range of fluctuation up and down based on the specific numerical value, and the fluctuation range can be + / -5%, + / -4%, + / -3%, + / -2%, + / -1%, + / -0.5%, + / -0.2%, + / -0.1%, + / -0.05%, + / -0.01% etc. of the specific numerical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A schematic cross-sectional view of the three-dimensional structure of a filter press assembly of a vertical filter press according to one embodiment of the present invention;

[0036] Figure 2 Based on Figure 1A perspective structural diagram of the filter press assembly is shown, wherein the porous pad and three of the four support column blocks are removed to expose the structure therein;

[0037] Figure 3 Based on Figure 2 A three-dimensional structural diagram of the support column block in FIG;

[0038] Figure 4 Based on Figure 1 An exploded view of the three-dimensional structure of the filter press assembly shown;

[0039] Figure 5 To include Figure 1 A schematic diagram of the three-dimensional structure of the filter press of the filter press assembly shown;

[0040] The meanings of the marks in the figure are as follows: 1-bottom unit, 2-middle unit; 21-base plate, 22-through hole area, 220-through hole; 221-porous pad, 222-cleaning liquid distributor, 223-support column; 2231-connecting piece; 2232-protrusion; 2233-opening; 23-piston wall, 231-sealing ring, 24-piston top plate, 241-channel plate, 242-first filter cloth; 25-elastic pad, 26-piston sleeve, 261-sealing pad, 271-first tube, 272-second tube, 273-third tube, 274-fourth tube, 275-fifth tube, 281-first pin hole; 282-second pin hole; 291-liquid collecting chamber, 292-filter pressure chamber; 5-second filter cloth; 7-top unit; 81-first connecting pin, 82-second connecting pin. DETAILED DESCRIPTION

[0041] Some embodiments of the present invention are further described below with reference to the accompanying drawings, but are not intended to limit the scope of protection of the present invention.

[0042] The present invention will be further described below with reference to the accompanying drawings and examples, wherein the examples are based on the contents disclosed in Chinese patent application CN113797614A, the entire contents of which are incorporated herein by reference.

[0043] Example 1

[0044] like Figure 1-5 As shown, the vertical filter press of the present invention includes a bottom unit 1, one or more filter press assemblies as middle units 2, a top unit 7 and a second filter cloth 5 arranged between the above units, which are stacked in sequence from bottom to top.

[0045] The filter press assembly includes a base plate 21, a through-hole area 22 consisting of one or more through-holes penetrating the base plate 21 is provided in the middle of the base plate 21, a piston wall 23 extending downward and surrounding the through-hole area 22 is provided on the bottom surface of the base plate 21, a piston top plate 24 is provided at the bottom end of the piston wall 23, a channel plate 241 is provided on the piston top plate 24 to allow fluid to flow everywhere on the lower surface of the piston top plate 24, and a first filter cloth 242 is provided on the lower surface of the channel plate 241.

[0046] A second tube 272 and a fourth tube 274 are provided on the piston top plate 24. One end of the second tube 272 is fluidically connected to the channel plate 241, and the other end extends upward through the piston wall 23 to introduce fluid from the outside into the channel plate 241. One end of the fourth tube 274 is fluidically connected to the channel plate 241, and the other end extends upward through the piston wall 23 to discharge the fluid in the channel plate 241 to the outside.

[0047] A piston sleeve 26 is sleeved around the outer surface of the piston wall 23 so that the piston composed of the piston wall 23 , the piston top plate 24 , the channel plate 241 and the first filter cloth 242 can move up and down in the piston sleeve 26 .

[0048] The space defined by the lower surface of the through-hole area 22, the inner surface of the piston wall 23 and the upper surface of the piston top plate 24 forms a liquid collecting chamber 291 for collecting fluid (such as filtrate, cleaning fluid, gas, etc.) entering therefrom from the through-hole 220 of the through-hole area 22. A third tube 273 is provided in the liquid collecting chamber 291. One end of the third tube 272 is fluidically connected to the liquid collecting chamber 291, and the other end passes through the piston wall 23 for discharging the fluid in the liquid collecting chamber 291 to the outside.

[0049] A filter press chamber 292 is formed by the space defined by the lower surface of the first filter cloth 242 of the upper filter press assembly, the inner surface of the piston sleeve 26 and the second filter cloth 5 on the through-hole area 22 of the adjacent lower filter press assembly. A first tube 271 is provided in the filter press chamber 292. One end of the first tube 271 is fluidically connected to the filter press chamber 292, while the other end extends upward and passes through the first filter cloth 242, the channel plate 241, the piston top plate 24 and the piston wall 23 in sequence to introduce the slurry to be filtered into the filter press chamber 292 from the outside.

[0050] A cleaning liquid distributor 222 for spreading cleaning liquid on the upper surface of the through-hole area 22 is provided in the space defined by the upper surface of the through-hole area 22 and the lower surface of the second filter cloth 5 between the through-hole area 22 and the second filter cloth 5. The cleaning liquid distributor 222 is composed of one or more sections of cleaning liquid distribution pipes, which are basically evenly laid on the upper surface of the through-hole area 22. Liquid spray ports are provided on the side and bottom surfaces of the cleaning liquid distribution pipes for spraying cleaning liquid on the upper surface of the through-hole area 22. The filtrate that enters the space from the filter press chamber 292 through the second filter cloth 5 and the cleaning liquid from the cleaning liquid distributor 222 can be discharged through the through holes 220 of the through-hole area 22 and enter the liquid collecting chamber 292.

[0051] The cleaning liquid inlet of the cleaning liquid distributor 222 extends downward to form a fifth tube 275 that passes through the through-hole area 22 and out of the piston wall 23 from the liquid collecting chamber 292 for supplying cleaning liquid to the cleaning liquid distributor 222 .

[0052] In this embodiment, the slurry to be filtered is, for example, activated sludge produced in sewage treatment, and the cleaning liquid may be water.

[0053] A porous pad 221 is provided between the cleaning liquid distributor 222 and the second filter cloth 5, which is close to the second filter cloth 5 and allows the filtrate to pass through, for supporting the second filter cloth 5. The porous pad 221 can be a porous plate or a wire mesh pad.

[0054] A plurality of support columns 223 are provided between the through-hole area 22 and the porous pad 221. One end of the support column 223 abuts against the upper surface of the through-hole area 222, and the other end abuts against the lower surface of the porous pad 221, thereby providing further support for the second filter cloth 5 to prevent the second filter cloth 5 from collapsing or being damaged.

[0055] In some cases, the multiple support columns 223 are interconnected by four porous connectors 2231 to form four detachable support column blocks. The porous connectors 2231 can be sheet-like or mesh-like consisting of ropes, chains or rods. The porous connector 2231 is arranged above the cleaning liquid distributor 222 and has multiple openings 2233 to allow filtrate to pass through. The cleaning liquid distribution pipe is arranged between the support columns 223. The support column 223 passes upward through the connector 2231 to form a protrusion 2232, and the upper surface of the protrusion 2232 rests on the lower surface of the porous pad 221, thereby preventing the porous pad 221 from directly pressing or even damaging the connector 2231. The support column 223 and the connector 2231 can be made of metal such as stainless steel or engineering plastics such as high-density polyethylene. Connecting the plurality of support columns 223 with the connector 2231 and dividing them into a plurality of blocks facilitates quick assembly and disassembly of the plurality of support columns 223 , and makes it quicker and easier to remove the support columns 223 for thorough cleaning of the through-hole area 222 .

[0056] In some cases, the piston sleeve 26 is connected to the lower surface of the base plate 21 via a retractable elastic pad 25, so that when the base plate 21 moves upward, the piston sleeve 26 can be pulled upward, and when the base plate 21 moves downward, the piston can be allowed to move downward in the piston sleeve 26. The elastic pad 25 can be any suitable form, such as a rubber pad, a spring, a hydraulic rod, etc.

[0057] In some cases, a sealing gasket 261 is provided on the lower surface of the piston sleeve 26 , and when the piston sleeve 26 falls on the second filter cloth 5 , a seal is formed between the piston sleeve 26 and the second filter cloth 5 to prevent the slurry in the filter press chamber 292 from leaking.

[0058] In some cases, a sealing ring 231 is provided on the outer surface of the lower end of the piston wall 23 to form a seal between the piston wall 23 and the piston sleeve 26, thereby preventing the slurry in the filter press chamber 292 from leaking.

[0059] In some cases, the bottom unit 1 has a substantially identical structure to the middle unit 2, except that the piston top plate 24 is replaced by a bottom plate and the piston sleeve 26, the filter press chamber 291, the first tube 271, the second tube 272, and the fourth tube 274 are not provided. The top unit 7 has a substantially identical structure to the middle unit 2, except that the base plate 21, which does not have the through-hole area 22, is replaced by a top 71. The lower surface of the second filter cloth 5 is in close contact with and covers the through-hole area 22 of the lower unit (preferably the upper surface of the porous pad 221), and when the upper surface of the second filter cloth 5 is in close contact with and covers the lower end of the piston sleeve 26 of the upper unit (preferably the lower surface of the sealing gasket 261), it helps define the filter press chamber 292.

[0060] In some cases, two adjacent units are connected to each other in a vertically retractable manner using a connecting portion. During the contraction process, the piston is allowed to move relative to the piston sleeve 26 to compress the filter press chamber 292, thereby performing a filter press operation on the slurry to be filtered in the filter press chamber 292. During the extension process, the piston sleeve 26 in the upper unit is allowed to separate from the second filter cloth 5, allowing the second filter cloth 5 to move horizontally to remove the filter cake 9 formed on the second filter cloth 5 during the filter press operation from the filter press section, for example, to a filter cake collection tank (not shown). The connecting portion can be any suitable form, such as a hinge, a connecting pin, a chain, a lever, a rack, a hanging rope, etc. For example, the connecting portion may be a first connecting pin 81 and a second connecting pin 82 respectively provided in the first pin hole 281 and the second pin hole 282 at the four corners of the base plate 21 of the intermediate unit 2, wherein when the unit above the unit moves upward, the first connecting pin 81 simultaneously moves upward until the lower end of the first connecting pin 81 hooks the unit and drives the unit to move upward, and when the unit moves upward, the second connecting pin 82 simultaneously moves upward until the unit below the unit is hooked by the lower end of the second connecting pin 82 and moves upward accordingly.

[0061] The vertical filter press according to the present invention includes the above-mentioned filter press section and a pressurizing mechanism (not shown) for applying pressure thereto, wherein the upper and lower press plates of the pressurizing mechanism are connected to the top and bottom plates, respectively. When the upper and lower press plates move separately or simultaneously and approach each other, they drive the top and / or bottom plates to move, causing the pistons of each unit to move relative to the piston sleeve 26 and compress the filter press chamber 292, thereby performing a filter press operation on the slurry to be filtered in the filter press chamber 292. When the upper and lower press plates move separately or simultaneously and away from each other, they drive the top and / or bottom plates to move, causing the piston sleeve 26 of the upper unit to move away from the second filter cloth 5, thereby enabling the second filter cloth 5 to translate and remove the filter cake formed on the second filter cloth 5 during the filtration operation from the filter press section, for example, to a filter cake collection tank (not shown). The pressurizing mechanism can be a hydraulic press, for example, a hydraulic press capable of generating 80 tons, 100 tons, 300 tons, 1000 tons, or even greater pressure, or a pressurizing mechanism such as a screw.

[0062] According to the present invention, the filtration method using the vertical filter press comprises the following steps:

[0063] S010, one or both of the two adjacent units in the filter press section are moved so that the piston sleeve 26 of the upper unit contacts the second filter cloth 5 covering the through-hole area 22 of the lower unit in a sealed manner, thereby sealing the filter press cavity 292 of the upper unit, that is, the filter press section is in the first state of waiting for or performing the slurry introduction operation;

[0064] S020, in the first state, the slurry to be filtered is introduced into the filter press chamber 292 through the first pipe 271 of the upper unit, and then the first pipe 271 is closed;

[0065] S030, after step S020 is completed, one or both of the upper unit and the lower unit are moved, so that the piston of the upper unit moves relative to the piston sleeve 26 to compress the filter press chamber 292 of the upper unit, thereby allowing the liquid in the slurry to pass through the second filter cloth 5 and the through-hole area 22 of the lower unit and enter the liquid collecting chamber 291 of the lower unit and / or pass through the first filter cloth 242 of the upper unit and enter the groove between the channel plate 241 and the piston top plate 24 of the upper unit, and form a filter cake 9 between the second filter cloth 5 and the first filter cloth 242 of the upper unit (i.e., in the filter press chamber 292), that is, the filter press section is in the second state of performing or completing the filter press operation;

[0066] S040, after step S030 is completed, one or both of the upper unit and the lower unit are moved so that the piston sleeve 26 of the upper unit leaves the second filter cloth 5, that is, the filter press is in a third state of waiting or performing a discharge operation;

[0067] S100, during the filter pressing process or after each filter pressing, the cleaning liquid is spread on the through-hole area through the cleaning liquid distributor, and the cleaning liquid is discharged through the through-hole area.

[0068] In some cases, the fifth tube 275 is further provided with a first pump for supplying cleaning liquid to the cleaning liquid distributor 222, as well as a first flowmeter and a first timer for measuring and recording the flow rate and time of the first pump when pumping the cleaning liquid. The third tube 273 is provided with a second pump for discharging the cleaning liquid from the liquid collecting chamber 292, as well as a second flowmeter and a second timer for measuring and recording the flow rate and time of the second pump when pumping the cleaning liquid, wherein the actual maximum delivery flow rate of the second pump is greater than or equal to the actual maximum delivery flow rate of the first pump, thereby ensuring that the cleaning liquid entering the liquid collecting chamber 292 can be discharged in a timely manner, that is, it will not be retained in the liquid collecting chamber 292. For example, when the first pump and the second pump are centrifugal pumps of the same specifications, the speed of the second pump can be set to be greater than or equal to the speed of the first pump.

[0069] When the through-hole area 22 is unobstructed, the cleaning liquid pumped by the first pump in the first time will quickly pass through the cleaning liquid distributor 22 and the through-hole 220 of the through-hole area 22 into the liquid collecting chamber 292, and then the second pump discharges the cleaning liquid from the liquid collecting chamber 292 in the second time. Since the actual maximum delivery flow rate of the second pump is greater than or equal to the actual maximum delivery flow rate of the first pump, the second time will be approximately equal to or slightly greater than the first time, and the first total amount of cleaning liquid supplied by the first pump in the first time will be approximately equal to the second total amount of cleaning liquid discharged by the second pump in the second time.

[0070] When the through-hole area 22 is partially blocked, the first total amount of cleaning liquid pumped by the first pump in the first time will stay in the through-hole area 22 for a long time or even partially accumulate in the through-hole area 22, thereby causing the second pump to have to wait for the cleaning liquid to enter the liquid collecting chamber 292. The second time required for the second pump to discharge the first total amount of cleaning liquid will be significantly longer than the first time, or when it is impossible to wait for the first total amount of cleaning liquid to enter the liquid collecting chamber 292, the second total amount of cleaning liquid discharged by the second pump within the specified second time will be significantly less than the first total amount.

[0071] Therefore, the clogging condition of the through-hole area 22 can be monitored using the first time and the first total amount of the first pump and the second time and the second total amount of the second pump.

[0072] In some cases, in step S100, after the filter press is completed, the first pump is started and maintained for a first time t1 to spread the cleaning liquid on the through-hole area through the cleaning liquid distributor, and a first total amount Q1 of the cleaning liquid pumped by the first pump within the first time t1 is measured, where t1 is 1 to 30 minutes;

[0073] Furthermore, the filter pressing method further comprises the following steps:

[0074] Step S200, simultaneously with starting the first pump in step S100, starting the second pump for a second time t2 to discharge the cleaning liquid entering the liquid collecting chamber, and measuring a second total amount Q2 of the cleaning liquid pumped out by the second pump within the second time t2, wherein t2 is 1.1 to 2 times t1 or the time required to achieve Q2 = Q1, whichever is smaller;

[0075] S300 , when the absolute value of the difference between the second time and the first time |t2-t1|<Δt and |Q1-Q2|<ΔQ, it is determined that the through-hole area is not blocked;

[0076] S400, when t2-t1≥Δt and Q1-Q2<ΔQ, it is determined that the through-hole area is partially blocked, and steps S100 and S200 are repeated. In this way, the blockage problem can be effectively solved by intermittent repeated cleaning;

[0077] S500, when t2-t1≥Δt and Q1-Q2≥ΔQ, it is determined that the through-hole area is severely blocked, and the vertical filter press is disassembled and cleaned;

[0078] Wherein, Δt is any appropriate set threshold value, which may be 1% to 20% of t1, for example, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 14%, 16%, 18%, or 20%; ΔQ is any appropriate set threshold value, which may be 1% to 20% of Q1, for example, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 14%, 16%, 18%, or 20%.

[0079] In some cases, the first total amount Q1 = f1 × t1, and the second total amount Q2 = f2 × t2, where the first flow rate f1 of the first pump and the second flow rate f2 of the second pump can be measured using any suitable liquid flow meter, such as a rotor flowmeter, a throttling flowmeter, a slit flowmeter, a volumetric flowmeter, an electromagnetic flowmeter, an ultrasonic flowmeter, etc.

[0080] In some cases, the cleaning solution may be water, an organic solvent such as alcohol or ketone, or any combination thereof, and may optionally contain additives such as a surfactant and a pH adjuster.

[0081] By using the vertical filter press and filtration method of the present invention, solid substances such as inorganic matter deposited in the equipment from the filtrate can be effectively cleaned during normal production, significantly reducing blockages caused by deposition and even failures such as inability to discharge the filtrate. It is also possible to timely monitor and discover possible blockage problems and effectively resolve them.

[0082] The present invention therefore has the advantages of high operating pressure, fast filtration speed, low liquid content in the filter cake, reliable structure and convenient automated operation, and is particularly suitable for filtration of difficult-to-filter systems such as colloids or colloid-like systems (such as activated sludge, pectin, etc.).

[0083] The above embodiments are merely preferred technical solutions of the present invention and should not be construed as limiting the present invention. The embodiments and features in the embodiments of this application may be arbitrarily combined with each other unless they conflict. The scope of protection of the present invention shall be the technical solutions described in the claims, including equivalent alternatives to the technical features of the technical solutions described in the claims. Equivalent alternatives and improvements within this scope are also within the scope of protection of the present invention.

[0084] The present invention has been described above by way of example. However, it should be understood that the present invention is by no means limited to these specific embodiments. A person skilled in the art may make various modifications or variations to the present invention, and such modifications and variations fall within the scope of protection of the present invention.

Claims

1. A filter press method comprising the following steps: S000 provides a vertical filter press, comprising a substrate disposed below a filter cloth in a filter press chamber and having a through-hole area consisting of one or more through-holes, a cleaning liquid distributor for spreading cleaning liquid on the upper surface of the through-hole area being provided between the through-hole area and the filter cloth, the vertical filter press being configured to allow filtrate from the filter press chamber and cleaning liquid from the cleaning liquid distributor to be discharged through the through-holes in the through-hole area, a porous pad closely adhering to the filter cloth and allowing the filtrate to pass therethrough being provided between the cleaning liquid distributor and the filter cloth, and one or more support columns being provided between the through-hole area and the filter cloth or the porous pad, the through-hole area A liquid collecting chamber for collecting filtrate or cleaning liquid from the through-hole area is provided below the liquid collecting chamber; wherein, a first pump for supplying cleaning liquid to the cleaning liquid distributor and a first flow meter and a first timer for measuring and recording the flow rate and time of the first pump when pumping the cleaning liquid are provided on the cleaning liquid inlet pipe of the cleaning liquid distributor, and a second pump for discharging the cleaning liquid and a second flow meter and a second timer for measuring and recording the flow rate and time of the second pump when pumping out the cleaning liquid are provided on the discharge pipe of the liquid collecting chamber, wherein the actual maximum delivery flow rate of the second pump is greater than or equal to the actual maximum delivery flow rate of the first pump; S100, during the filter pressing process or after each filter pressing, the cleaning liquid is spread on the through-hole area through the cleaning liquid distributor, and the cleaning liquid is discharged through the through-hole area; wherein, after the filter pressing is completed, the first pump is started and continued for a first time In order to spread the cleaning liquid on the through-hole area through the cleaning liquid distributor, and at the same time measure the first pump at the first time The first total amount of cleaning fluid pumped in ,in 1~30 minutes; Step S200: simultaneously with starting the first pump in step S100, start the second pump and continue for a second time. In order to discharge the cleaning liquid into the liquid collecting chamber, the second pump is measured at the second time. The second total amount of cleaning fluid pumped out ,in for 1.1~2 times or reach = the shorter of the time required for S300, when the absolute value of the difference between the second time and the first time and When , it is judged that there is no blockage in the through hole area; S400, when and When , it is judged that the through hole area is partially blocked; S500, when and When , it is judged that the through hole area is seriously blocked; in, for 1%~20%, for 1%~20% of the total.

2. The filter press method according to claim 1, wherein Step S400 further includes repeating steps S100 and S200.

3. The filter press method according to claim 1 or 2, wherein: The cleaning liquid distributor is composed of one or more cleaning liquid distribution pipes laid flat on the upper surface of the through-hole area.

4. The filter press method according to claim 1 or 2, wherein The lower end of the support column is supported on the upper surface of the through-hole area and the upper end is supported on the lower surface of the filter cloth or porous pad, thereby separating the through-hole area from the filter cloth or porous pad and forming a space defined by the upper surface of the through-hole area and the lower surface of the filter cloth or porous pad for accommodating the cleaning liquid distributor.

5. The filter press method according to claim 1 or 2, wherein: The plurality of support columns are interconnected by one or more porous connectors to form one or more detachable support column blocks. The porous connectors are arranged above the cleaning liquid distributor and allow the filtrate to pass through.

6. The filter press method according to claim 5, wherein: The porous connector is rigid and multiple porous connectors are independent of each other; or, the porous connector is flexible and multiple porous connectors are connected to each other.

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