Filter press hydraulic system and filter press with same

Abstract

The application relates to the technical field of filter press equipment, and discloses a filter press hydraulic system and a filter press with the same. The filter press hydraulic system comprises a first driving oil cylinder assembly, a first push plate pushed by the first driving oil cylinder assembly, a locking mechanism used for locking the driving end of the first driving oil cylinder assembly, a second driving oil cylinder assembly, a second push plate pushed by the second driving oil cylinder assembly and a filter plate group. The filter press hydraulic system provided by the application can independently complete long-distance closing plate idle stroke and short-distance high-pressure pressing working stroke through the first driving oil cylinder assembly and the second driving oil cylinder assembly, the locking mechanism is used for locking the driving end of the first driving oil cylinder assembly, the first driving oil cylinder assembly is used for operating in the closing plate stage, the flow loss in the idle stroke stage is reduced, the second driving oil cylinder assembly is used for independently providing high-pressure thrust in the pressing operation, and the oil pressure of the second driving oil cylinder assembly needs to be maintained during pressure maintaining, and the whole machine hydraulic pump does not need to be frequently started and stopped for pressure supplementing.

Description

Technical Field

[0001] This invention relates to the field of filter press equipment technology, and more specifically to a hydraulic system for a filter press and a filter press having the same. Background Technology

[0002] A filter press is a filtration device that uses pressure to separate solids and liquids. It is widely used in solid-liquid separation operations in industries such as mining, chemical, pharmaceutical, and environmental protection. The filter press relies on a hydraulic system to complete the entire process of filter plate closure, pressing and pressure maintenance, and plate unloading. The performance of the hydraulic system directly determines the equipment's filtration sealing performance, circulation efficiency, and operating energy consumption.

[0003] Currently, filter presses in the industry generally use a single hydraulic cylinder to perform all stroke actions. A single hydraulic circuit synchronously completes the long-distance clamping movement of the filter plates and the short-distance high-pressure sealing and clamping. A supporting hydraulic station continuously maintains oil pressure to achieve filter plate clamping and pressure holding, which is the mainstream drive solution in the solid-liquid separation field. Existing single-cylinder hydraulic systems have a long idle stroke but require low thrust, and a short working stroke but require high thrust. However, a single large-diameter cylinder suffers from inefficient operation during the idle stroke due to high flow rate, long operation time, and high energy consumption. Furthermore, during the pressure holding stage, it relies on intermittent pressure replenishment by a hydraulic pump or a hydraulically controlled check valve, which also leads to frequent motor start-stop cycles, leakage pressure replenishment causing high energy consumption, and severe system overheating. Summary of the Invention

[0004] In view of this, the present invention provides a hydraulic system for a filter press and a filter press having the same, to solve the problems of high energy consumption during the idle stroke, long operating time, frequent motor start-stop during the pressure holding stage, high energy consumption for leakage compensation, and severe system overheating in the existing single-cylinder hydraulic system of the filter press.

[0005] In a first aspect, the present invention provides a hydraulic system for a filter press, comprising: The first drive cylinder assembly has its drive end extending in a first direction; The first push plate is disposed on the drive end of the first drive cylinder assembly and is pushed by the first drive cylinder assembly; A locking mechanism is provided between the first drive cylinder assembly and the first push plate for locking the drive end of the first drive cylinder assembly. The second drive cylinder assembly is disposed on the side of the first push plate away from the first drive cylinder assembly. The drive end of the second drive cylinder assembly extends out along the second direction, and the first direction is disposed opposite to the second direction. The second push plate is disposed on the drive end of the second drive cylinder assembly and is pushed by the second drive cylinder assembly; A filter plate assembly is disposed between the first push plate and the second push plate; The first drive cylinder assembly is used to push the first push plate to move in order to complete the closing of the filter plate assembly. After the locking mechanism locks the drive end of the first drive cylinder assembly, the second drive cylinder assembly is used to push the second push plate to move in order to complete the pressing of the filter plate assembly.

[0006] Beneficial effects The hydraulic system for a filter press provided by this invention features a first drive cylinder assembly and a second drive cylinder assembly that independently complete the long-distance plate-closing idle stroke and the short-distance high-pressure pressing stroke, respectively. A locking mechanism secures the drive end of the first drive cylinder assembly. During the plate-closing stage, only the first drive cylinder assembly, requiring minimal thrust, is used, eliminating the need for a large-diameter cylinder. This reduces flow loss during the idle stroke, shortens plate-closing time, and decreases operating energy consumption. The pressing operation is solely powered by the second drive cylinder assembly, providing high-pressure thrust. During pressure holding, only the oil pressure of the second drive cylinder assembly needs to be maintained, eliminating the need for frequent start-stop pressure replenishment by the main hydraulic pump. This effectively alleviates the high energy consumption and severe overheating problems caused by system leakage pressure replenishment, thereby improving the overall efficiency of the filter press's cyclic operation, reducing overall operating energy consumption, and ensuring a stable and reliable pressing and sealing effect for the filter plate assembly.

[0007] Optionally, the first drive cylinder assembly includes: First mounting plate; The first cylinder block is fixedly mounted on the first mounting plate; The first piston rod is telescopically disposed in the first cylinder, and the extended end of the first piston rod constitutes the drive end.

[0008] Optionally, the second drive cylinder assembly includes: A thrust plate is disposed on the side of the second push plate away from the first push plate; The central hydraulic cylinder assembly is located in the central region of the side of the thrust plate facing the second push plate; A perimeter hydraulic cylinder assembly is located on the side of the thrust plate facing the second push plate and around the central hydraulic cylinder assembly; A pressure transmission plate is disposed between the driving ends of the central cylinder group and the surrounding cylinder group and the second push plate. The driving ends of the central cylinder group and the surrounding cylinder group are respectively connected to the pressure transmission plate, and the pressure transmission plate abuts against the second push plate.

[0009] Optionally, both the central cylinder group and the surrounding cylinder group include multiple cylinders; Each cylinder of the central cylinder group is distributed around the central axis of the second drive cylinder assembly; The cylinders of the four-cylinder group are distributed around the outer periphery of the central cylinder group.

[0010] Optionally, the rated thrust of the central cylinder group is less than the total thrust of the surrounding cylinder groups.

[0011] Optionally, the locking mechanism includes: A push plate is disposed between the first drive cylinder assembly and the first push plate, and a slot is provided on the push plate; An opening and closing plate is disposed on the side of the push plate near the first push plate and is disposed opposite to the push plate. The opening and closing plate is adapted to be snapped into the slot. A cylinder, whose piston rod is connected to the opening and closing plate, is used to drive the opening and closing plate to move closer to or away from the propulsion plate.

[0012] Optionally, the locking mechanism further includes: A pressure-bearing push plate is disposed on the side of the push plate opposite to the first push plate, fixed on the drive end of the first drive cylinder assembly and in contact with the push plate.

[0013] Optionally, it also includes a hydraulic station, the hydraulic station comprising: The first oil pump has its outlet connected to the inlet of the first drive cylinder assembly; The second oil pump has its outlet connected to the inlet of the central oil cylinder group and the surrounding oil cylinder group, respectively.

[0014] Optionally, a one-way relief valve is provided on the return oil line of the central cylinder assembly; the oil inlet of the one-way relief valve is connected to the return oil port of the central cylinder assembly, and the oil outlet of the one-way relief valve is connected to the hydraulic station.

[0015] In a second aspect, the present invention also provides a filter press, comprising: The filter press hydraulic system described in any of the preceding descriptions; A frame is provided extending along the first direction; The first push plate and the second push plate are respectively disposed on the frame and can both slide along the frame; The cylinder body of the first drive cylinder assembly is fixed to one end of the frame; The filter plate assembly is disposed between the first push plate and the second push plate. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the hydraulic system of a filter press according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the first drive cylinder assembly according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of the first mounting plate and locking mechanism according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of the first push plate and the locking mechanism in an embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of the first mounting plate according to an embodiment of the present invention; Explanation of reference numerals in the attached figures: 1. First drive cylinder assembly; 11. First mounting plate; 12. First piston rod; 2. First push plate; 3. Locking mechanism; 31. Push plate; 32. Opening and closing plate; 33. Cylinder; 34. Pressure-bearing push plate; 4. Second drive cylinder assembly; 41. Thrust plate; 5. Second push plate; 6. Filter plate assembly. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] The following is combined Figures 1 to 5 The following describes embodiments of the present invention.

[0020] According to an embodiment of the present invention, in one aspect, a hydraulic system for a filter press is provided, comprising: The first drive cylinder assembly 1 has its drive end extending along a first direction; The first push plate 2 is disposed on the drive end of the first drive cylinder assembly 1 and is pushed by the first drive cylinder assembly 1. The locking mechanism 3 is located between the first drive cylinder assembly 1 and the first push plate 2, and is used to lock the drive end of the first drive cylinder assembly 1. The second drive cylinder assembly 4 is disposed on the side of the first push plate 2 away from the first drive cylinder assembly 1. The drive end of the second drive cylinder assembly 4 extends out along the second direction, and the first direction and the second direction are arranged opposite to each other. The second push plate 5 is disposed on the drive end of the second drive cylinder assembly 4 and is pushed by the second drive cylinder assembly 4. The filter plate assembly 6 is disposed between the first push plate 2 and the second push plate 5; The first drive cylinder assembly 1 is used to push the first push plate 2 to move, so as to complete the closing of the filter plate assembly 6. After the locking mechanism 3 locks the drive end of the first drive cylinder assembly 1, the second drive cylinder assembly 4 is used to push the second push plate 5 to move, so as to complete the pressing of the filter plate assembly 6.

[0021] The hydraulic system of the filter press provided in this embodiment has a first drive cylinder assembly 1 and a second drive cylinder assembly 4 that independently complete the long-distance plate-closing idle stroke and the short-distance high-pressure pressing stroke, respectively. With the locking mechanism 3, the drive end of the first drive cylinder assembly 1 is locked. During the plate-closing stage, only the first drive cylinder assembly 1 with small thrust requirements is used for operation, without the need to adapt to a large-diameter cylinder. This reduces flow loss during the idle stroke, shortens the plate-closing time, and reduces operating energy consumption. During the pressing operation, the second drive cylinder assembly 4 provides high-pressure thrust alone. During pressure holding, only the oil pressure of the second drive cylinder assembly 4 needs to be maintained, without the need for frequent start-stop pressure replenishment of the whole machine's hydraulic pump. This effectively alleviates the high energy consumption and serious heat generation problems caused by system leakage pressure replenishment, improves the overall cyclic operation efficiency of the filter press, reduces the overall operating energy consumption, and ensures a stable and reliable pressing and sealing effect of the filter plate group 6.

[0022] Specifically, the working pressure of the first drive cylinder assembly 1 is 6-10 MPa, and the working pressure of the second drive cylinder assembly 4 is 25-35 MPa.

[0023] Furthermore, the first drive cylinder assembly 1 includes: First mounting plate 11; The first cylinder block is fixedly mounted on the first mounting plate 11; The first piston rod 12 is telescopically disposed in the first cylinder, and the extended end of the first piston rod 12 constitutes the drive end.

[0024] Specifically, the first cylinder is securely mounted on the first mounting plate 11 to complete the overall positioning. The first piston rod 12 can freely extend and retract inside the first cylinder. The end of the piston rod that extends outward serves as the driving end that docks with the locking mechanism 3 and the first push plate 2. The piston rod is driven to reciprocate and extend by the oil pressure inside the first cylinder, thereby driving the first push plate 2 to complete the long-distance plate assembly movement of the filter plate group 6.

[0025] It is easy to understand that the first cylinder is stably fixed by the first mounting plate 11, ensuring that the cylinder does not deviate or shake during the plate-joining process. The first cylinder and the first piston rod 12 independently form a small thrust, long stroke drive unit, which is specially adapted to the plate-joining working condition during the idle stroke. There is no need to select a large-specification oil cylinder, which reduces the hydraulic flow consumption during the plate-joining process, shortens the plate-joining movement time, and effectively reduces the energy consumption of the equipment during the idle stroke stage.

[0026] Furthermore, the second drive cylinder assembly 4 includes: Thrust plate 41 is disposed on the side of the second push plate 5 away from the first push plate 2; The central cylinder assembly is located in the central area of ​​the thrust plate 41 on the side facing the second push plate 5; The surrounding hydraulic cylinder assembly is located on the side of the thrust plate 41 facing the second push plate 5 and around the central hydraulic cylinder assembly. A pressure transmission plate is located between the drive ends of the central cylinder group and the surrounding cylinder group and the second push plate 5. The drive ends of the central cylinder group and the surrounding cylinder group are respectively connected to the pressure transmission plate, and the pressure transmission plate abuts against the second push plate 5.

[0027] Specifically, the central cylinder group and the surrounding cylinder groups are arranged in a coordinated manner to output the pressing thrust synchronously. The thrust is evenly transmitted to the second push plate 5 through the pressure transmission plate, so that the filter plate group 6 is subjected to balanced force as a whole, avoiding leakage caused by insufficient local pressing force. The combination of multiple cylinders can distribute the high pressure load, eliminating the need for a single large-diameter high-pressure cylinder, reducing the difficulty of cylinder processing and manufacturing costs. During the pressure holding stage, only the oil pressure of multiple small cylinders needs to be maintained, resulting in less leakage, reducing the frequency of pressure replenishment, and further reducing energy consumption and system heat generation.

[0028] In this embodiment, the pressure transmission plate and the second push plate 5 are integrated, eliminating the assembly gap and connection structure between them. The clamping force output by the central cylinder group and the surrounding cylinder group can be directly transmitted to the filter plate group 6 without loss, effectively avoiding uneven force and local pressure leakage caused by the connection gap. At the same time, it reduces the number of parts, simplifies the assembly process, and reduces processing and assembly costs.

[0029] The circular arrangement of the four-sided hydraulic cylinder group can be eliminated, and only a single high-thrust central main hydraulic cylinder is used in conjunction with multiple auxiliary small hydraulic cylinders arranged symmetrically, which is suitable for the low-tonnage pressing requirements of small and medium-sized filter presses. In another alternative embodiment, it can be replaced with a full-circumference hydraulic cylinder structure with multiple hydraulic cylinders of the same specification evenly arranged in a ring around the thrust plate 41 without a central hydraulic cylinder, which relies on the synchronous pushing of multiple hydraulic cylinders to push the pressure transmission plate to achieve uniform pressure on the large plate surface.

[0030] Furthermore, both the central cylinder assembly and the surrounding cylinder assemblies include multiple cylinders; The cylinders of the central cylinder group are distributed around the central axis of the second drive cylinder assembly 4; The cylinders of the four cylinder groups are distributed around the outer perimeter of the central cylinder group.

[0031] In simple terms, the cylinders of the central cylinder group and the surrounding cylinder groups are arranged in a uniform ring around the central axis and the outer periphery of the central cylinder, respectively. The multiple cylinders output clamping force synchronously and distribute it evenly to the second push plate 5 through the pressure transmission plate, so that the filter plate group 6 is subjected to uniform force without eccentric load, and the leakage of filtrate caused by insufficient local clamping force is eliminated. The multiple cylinders disperse the high pressure load, which reduces the pressure load of a single cylinder compared with a single large cylinder, reduces the cylinder wall thickness and processing difficulty. At the same time, the distributed cylinder layout reduces single-point stress deformation, the leakage of a single cylinder is lower when holding pressure, reduces the number of times the hydraulic pump pressurizes, reduces energy consumption and system heat generation, and improves the sealing stability of the filter plate and the service life of the whole machine.

[0032] It is easy to understand that the specific number of cylinders in the central cylinder group and the surrounding cylinder groups is not limited here. It can be flexibly adjusted according to the size of the filter plate of the filter press, the required pressing tonnage, and the overall specifications of the equipment. Small models can reduce the number of two sets of cylinders to control costs, while heavy-duty filter presses with large processing capacity can increase the number of cylinders to improve the pressing force and the uniformity of force. As long as the arrangement logic of each set of cylinders is evenly arranged around the corresponding circumference is met, it can be adapted to different working conditions.

[0033] Specifically, the central cylinder group consists of 1-3 cylinders, and the surrounding cylinder group consists of 4-8 cylinders.

[0034] In simple terms, the central cylinder group has 1-3 cylinders, and the surrounding cylinder group has 4-8 cylinders on the first mounting plate. The number ratio is reasonable and they are evenly distributed along the circumference. A small number of central cylinders can complete the pre-fitting of the filter plate center, and multiple surrounding cylinders evenly distribute the frame clamping load, resulting in a balanced force distribution on the plate surface without eccentric load. The moderate number of cylinders avoids excessive stress at a single point and deformation and leakage of the plate surface due to too few cylinders, while also avoiding the increase in the complexity of the oil circuit and manufacturing cost due to too many cylinders. At the same time, the distributed pressure of multiple cylinders can reduce the load on a single cylinder, reduce the amount of pressure holding leakage, adapt to the adaptive pressure requirements of filter plates of different specifications, improve sealing stability, and control the overall processing and assembly cost.

[0035] Furthermore, the rated thrust of the central cylinder assembly is less than the total thrust of the surrounding cylinder assemblies.

[0036] In simple terms, the central cylinder assembly provides only the basic pre-tightening thrust, while the surrounding cylinder assemblies output a larger total clamping force. During the pre-tightening stage, the central cylinder assembly quickly adheres to the filter plate to eliminate gaps, and then the surrounding cylinder assemblies apply the main clamping load. The force levels are distinct, which ensures that the filter plate fits tightly in all areas and avoids pressure imbalance when a single cylinder applies pressure synchronously. The larger total thrust of the surrounding cylinders can share most of the high-pressure load, reducing the long-term pressure loss of the central cylinder. Under pressure holding conditions, the surrounding cylinders bear the main sealing pressure, resulting in less overall leakage, reducing the need for frequent hydraulic pump pressurization, effectively reducing energy consumption and alleviating system heat generation, and improving the sealing reliability of the filter plate.

[0037] Specifically, the rated thrust of the central cylinder group is 30%-50% of the total thrust of the four cylinder groups.

[0038] In a straightforward manner, the rated thrust of the central cylinder group is set to 30%-50% of the total thrust of the four cylinder groups. During the pre-pressing stage of the filter plate, the central cylinder outputs a moderate thrust to first adhere to the filter plate and eliminate gaps, while the four cylinders reserve a larger pressing force for subsequent sealing and pressure maintenance. When the feed into the filter chamber generates an inward counter-thrust, the central cylinder can slightly retract to relieve the impact load in the central area, while the four cylinders continuously output high pressure to concentrate and press the filter plate frame, achieving adaptive sealing. At the same time, the high and low thrusts are graded to distribute the load, reducing the long-term high-pressure loss of a single cylinder group, reducing the frequency of hydraulic pump pressure replenishment during the pressure maintenance stage, reducing system energy consumption and heat generation, and balancing the filter plate adhesion effect, equipment service life, and operating energy consumption.

[0039] Furthermore, the locking mechanism 3 includes: A push plate 31 is disposed between the first drive cylinder assembly 1 and the first push plate 2, and a slot is provided on the push plate 31. The opening and closing plate 32 is disposed on the side of the push plate 31 near the first push plate 2 and is disposed opposite to the push plate 31. The opening and closing plate 32 is adapted to be snapped into the slot. The cylinder 33, whose piston rod is connected to the opening and closing plate 32, is used to drive the opening and closing plate 32 to move closer to or away from the push plate 31.

[0040] Specifically, the locking mechanism 3 is located between the first drive cylinder assembly 1 and the first push plate 2, and mainly consists of a push plate 31 with a slot, a movable opening and closing plate 32, and a drive cylinder 33. During the plate-closing process, the first drive cylinder drives the push plate 31 and the first push plate 2 under no-load conditions to complete the long-distance plate-closing of the filter plate group 6; after the plates are closed, the cylinder 33 drives the opening and closing plate 32 to engage with the slot of the push plate 31, mechanically locking and fixing the stroke of the first drive cylinder. Then the first drive cylinder is depressurized, and the second drive cylinder independently completes the high-pressure clamping; when unloading, the cylinder 33 retracts to unlock, and all structures can be reset.

[0041] It should be noted that the first mounting plate 11 has a through hole through which the push plate 31 can pass. The diameter of the through hole matches the outer diameter of the push plate 31 and the gap is appropriate, which can ensure that the push plate 31 can pass smoothly without jamming or interference during the extension and retraction of the piston rod of the main oil cylinder. The push plate 31 is locked and fixed to the surface of the first push plate 2 by high-strength bolts. The two form a synchronous moving whole. The push plate 31 can pass through the through hole of the first mounting plate 11 and extend forward independently to complete the locking and alignment. This allows the locking mechanism 3 to be arranged independently and is not blocked or limited by the surface of the first mounting plate 11. This satisfies the axial limiting and locking requirements of the mechanical locking structure, and does not affect the overall sliding of the first push plate 2 and the first mounting plate 11 and the filter plate pressing action. This effectively avoids the problem of interference between the movement of various components and ensures that the assembly, locking and pressing processes of the whole machine are carried out stably and orderly.

[0042] It should be noted that the surface of the first mounting plate 11 facing the opening and closing plate 32 is equipped with an anti-collision structure, which can buffer the impact of the opening and closing plate 32 in place during the reciprocating motion of the opening and closing plate 32 being driven by the cylinder 33 to complete the insertion and withdrawal of the slot. This avoids the opening and closing plate 32 directly and rigidly impacting the first mounting plate 11 when moving at high speed, which would cause vibration, noise and wear on the plate surface. It also limits the extreme travel of the opening and closing plate 32 and prevents it from overtraveling and causing the slot to fail to align. Under long-term operation, it can protect the plates and cylinder 33 of the locking mechanism 3 from impact damage, and improve the smoothness of the locking mechanism 3 and the service life of the whole machine.

[0043] In simple terms, a purely mechanical locking structure replaces the traditional hydraulic pressure-holding lock. This provides strong locking rigidity, eliminates hydraulic leakage issues, and effectively resists the reverse thrust of high-pressure clamping, preventing the first drive cylinder from retracting or shifting. After locking, the first cylinder can be completely depressurized, eliminating the need for continuous pressure replenishment and holding, thus reducing system energy consumption and heat generation. Furthermore, the 33-cylinder drive action is stable and rapid, effectively improving the operational stability and cycle efficiency of the filter press.

[0044] In an easy-to-understand way, during the plate-assembly stage, the locking mechanism 3 is fully unlocked without resistance or interference, ensuring efficient and low-consumption operation during the no-load stroke. After the plate is in place, the plate is driven by cylinder 33 to engage and limit the plate. The mechanical rigidity constraint fully bears the high-pressure reaction force at the rear end, so that the first drive cylinder is completely unloaded. Structurally, this avoids high-pressure retreat and positional deviation, ensuring the accuracy of filter plate assembly and the stability of the pressing and sealing, and is suitable for high-pressure holding operation conditions.

[0045] In an alternative embodiment, the slot structure, the driving position of cylinder 33, and the installation form of cylinder 33 can be adapted and replaced. For example, trapezoidal or serrated slots can be used to improve the anti-disengagement capability, the driving angle of cylinder 33 can be changed to adapt to different installation spaces, and wear-resistant structures can be added to improve service life. The structural modifications are flexible and do not change the core locking function.

[0046] Furthermore, the locking mechanism 3 also includes: The pressure-bearing push plate 34 is disposed on the side of the push plate 31 away from the first push plate 2, fixed on the drive end of the first drive cylinder assembly 1 and in contact with the push plate 31.

[0047] In a straightforward manner, the addition of a pressure-bearing push plate 34, which is fitted together and fixed to the drive end of the first drive cylinder assembly 1, can bear and disperse the high-pressure reverse impact force borne by the locking mechanism 3 after locking. This avoids the problem of deformation and cracking caused by single-point stress on the push plate 31 and local stress concentration. At the same time, the pressure is evenly transmitted through the contact surface between the pressure-bearing push plate 34 and the push plate 31, thereby improving the structural strength and compressive rigidity of the overall locking structure. This ensures that the structure does not deform and the locking position does not shift under long-term high-pressure locking conditions, effectively extending the service life of the locking mechanism 3 and further ensuring the sealing stability and equipment operation reliability of the filter press pressing process.

[0048] Furthermore, it also includes a hydraulic station, which comprises: The first oil pump has its outlet connected to the inlet of the first drive cylinder assembly 1; The second oil pump has its outlet connected to the inlet of the central oil cylinder group and the surrounding oil cylinder groups.

[0049] In a straightforward manner, independent first and second oil pumps supply oil to the first drive cylinder assembly 1 for plate assembly, the central cylinder assembly for high-pressure clamping, and the surrounding cylinder assembly, respectively. During the plate assembly stage, only the first oil pump is activated, and a small flow rate is sufficient to meet the long-distance idle stroke movement requirements, eliminating the need for a large flow rate pump to operate under no-load, thus reducing idle stroke energy consumption. During the high-pressure clamping stage, the second oil pump is activated separately to output high-pressure oil. When maintaining pressure, only the pressure of the corresponding circuit of the second oil pump is maintained, and the first oil pump can be completely stopped. This avoids the frequent start-stop and overheating problems caused by continuous intermittent pressure replenishment of the entire pump assembly. The two oil circuits do not interfere with each other, and the pressure regulation does not affect each other. This not only improves the operating efficiency of the plate assembly and clamping processes but also reduces energy consumption and system temperature rise from the oil supply source.

[0050] Furthermore, a one-way relief valve is provided on the return oil line of the central cylinder assembly; the oil inlet of the one-way relief valve is connected to the return oil port of the central cylinder assembly, and the oil outlet of the one-way relief valve is connected to the hydraulic station.

[0051] As easily understood, when the material pressure inside the filter chamber increases and the central cylinder assembly experiences a reverse thrust exceeding the set value of the relief valve, the hydraulic oil in the central cylinder assembly can push open the one-way relief valve and flow back to the hydraulic station. This allows the central cylinder assembly to adaptively retract slightly to relieve the reaction force in the center, while the surrounding cylinder assemblies continue to maintain high-pressure output. This causes a slight deformation of the pressure transmission plate, concentrating the clamping force more on the filter plate frame, achieving adaptive pressure boosting and sealing of the filter plate frame. The one-way function prevents hydraulic oil from flowing back into the central cylinder assembly, ensuring that the central cylinder assembly can extend normally to establish pre-tightening pressure during the clamping oil supply phase. This achieves a zoned pressure application effect where the central cylinder retracts under load while the surrounding cylinders continuously maintain pressure. At the same time, it provides overload protection for the central cylinder, preventing high-pressure impact from damaging the cylinder and filter plate assembly in the filter chamber.

[0052] According to an embodiment of the present invention, in another aspect, a filter press is also provided, comprising: The hydraulic system of the filter press mentioned above; The frame extends along the first direction; The first push plate 2 and the second push plate 5 are respectively mounted on the frame and can both slide along the frame; The cylinder body of the first drive cylinder assembly 1 is fixed to one end of the frame; The filter plate assembly 6 is positioned between the first push plate 2 and the second push plate 5.

[0053] When the filter press is working, the first drive cylinder assembly 1, fixed to one end of the frame, extends by oil supplied by an independent first oil pump, driving the first push plate 2 to slide along the frame, quickly completing the long-distance idle stroke closing of the filter plate group 6; after the filter plate group 6 is fully in place, the cylinder 33 of the locking mechanism 3 drives the opening and closing plate 32 to engage with the slot of the push plate 31, fixing the extended position of the first drive cylinder assembly 1 by mechanical locking. After locking, the first oil pump is depressurized and the machine stops, and the first drive cylinder assembly 1 no longer bears axial load; then the second oil pump supplies oil separately, driving the central cylinder group on the thrust plate 41 and the surrounding cylinder groups to extend synchronously, through The pressure transmission plate evenly transmits the pressing force to the second push plate 5, which applies short-distance high-pressure pressing to the filter plate group 6 and maintains stable pressure to ensure that the filter plate group 6 is tightly sealed for solid-liquid separation. After the filtration operation is completed, the second oil pump is depressurized, the second drive cylinder assembly 4 is reset and the plate is loosened, the locking mechanism 3 cylinder 33 retracts and drives the opening and closing plate 32 to exit the slot and release the lock, and finally the first drive cylinder assembly 1 retracts and drives the first push plate 2 to reset, and the filter plate group 6 is completely released, completing the unloading operation. The overall cycle process has a clear division of labor and does not interfere with each other, which effectively reduces the energy consumption of the whole machine and the heat generation of the system, and improves the overall working efficiency and operational stability of the filter press.

[0054] It should be noted that this device uses a PLC control cabinet as the core of the whole machine control. It is connected to the main oil pump, high-pressure oil pump, locking drive cylinder / drive motor, various pressure sensors, and stroke position detection sensors. It can automatically execute the entire process of plate closing, locking, high-pressure pressing, filtration and pressure holding, plate loosening, and cake unloading according to the preset program. It can collect the filter chamber pressure, oil cylinder pressure, and locking mechanism three-position signals in real time. It automatically adjusts the oil pressure of the central oil cylinder and the surrounding oil cylinders according to the pressure changes inside the filter chamber to achieve adaptive zoned pressure application. It also has overload protection, pressure abnormality alarm, and fault shutdown functions. No manual operation is required throughout the process. It has a high degree of automation, ensures accurate matching of the timing of each process, stabilizes and reduces equipment energy consumption, and reduces material leakage failures.

[0055] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A hydraulic system for a filter press, characterized in that, include: The first drive cylinder assembly (1) has its drive end extending along a first direction; The first push plate (2) is disposed on the drive end of the first drive cylinder assembly (1) and is pushed by the first drive cylinder assembly (1); A locking mechanism (3) is disposed between the first drive cylinder assembly (1) and the first push plate (2) for locking the drive end of the first drive cylinder assembly (1); The second drive cylinder assembly (4) is disposed on the side of the first push plate (2) away from the first drive cylinder assembly (1), and the drive end of the second drive cylinder assembly (4) extends along the second direction, and the first direction is disposed opposite to the second direction; The second push plate (5) is disposed on the drive end of the second drive cylinder assembly (4) and is pushed by the second drive cylinder assembly (4); The filter plate assembly (6) is disposed between the first push plate (2) and the second push plate (5); The first drive cylinder assembly (1) is used to push the first push plate (2) to move in order to complete the closing of the filter plate group (6). After the locking mechanism (3) locks the drive end of the first drive cylinder assembly (1), the second drive cylinder assembly (4) is used to push the second push plate (5) to move in order to complete the pressing of the filter plate group (6). The second drive cylinder assembly (4) includes: A thrust plate (41) is disposed on the side of the second push plate (5) away from the first push plate (2); The central cylinder assembly is located in the central region of the thrust plate (41) on the side facing the second push plate (5); A four-sided hydraulic cylinder assembly is disposed on the side of the thrust plate (41) facing the second push plate (5) and located around the central hydraulic cylinder assembly; A pressure transmission plate is disposed between the driving ends of the central cylinder group and the surrounding cylinder group and the second push plate (5). The driving ends of the central cylinder group and the surrounding cylinder group are respectively connected to the pressure transmission plate, and the pressure transmission plate abuts against the second push plate (5). The rated thrust of the central cylinder group is less than the total thrust of the surrounding cylinder groups; The locking mechanism (3) includes: A push plate (31) is disposed between the first drive cylinder assembly (1) and the first push plate (2), and a slot is provided on the push plate (31); An opening and closing plate (32) is disposed on the side of the push plate (31) near the first push plate (2) and is disposed opposite to the push plate (31). The opening and closing plate (32) is adapted to be snapped into the slot. A cylinder (33) with its piston rod connected to the opening and closing plate (32) is used to drive the opening and closing plate (32) to move closer to or away from the push plate (31). It also includes a hydraulic power unit, which comprises: The first oil pump has its outlet connected to the inlet of the first drive cylinder assembly (1); The second oil pump has its outlet connected to the inlet of the central oil cylinder group and the surrounding oil cylinder group, respectively. A one-way relief valve is provided on the return oil line of the central cylinder assembly; the oil inlet of the one-way relief valve is connected to the return oil port of the central cylinder assembly, and the oil outlet of the one-way relief valve is connected to the hydraulic station.

2. The hydraulic system for a filter press according to claim 1, characterized in that, The first drive cylinder assembly (1) includes: First mounting plate (11); The first cylinder body is fixedly mounted on the first mounting plate (11); The first piston rod (12) is telescopically disposed in the first cylinder, and the extended end of the first piston rod (12) constitutes the drive end.

3. The hydraulic system for a filter press according to claim 1, characterized in that, Both the central cylinder group and the surrounding cylinder group include multiple cylinders; Each cylinder of the central cylinder group is distributed around the central axis of the second drive cylinder assembly (4); The cylinders of the four-cylinder group are distributed around the outer periphery of the central cylinder group.

4. The hydraulic system for a filter press according to claim 1, characterized in that, The locking mechanism (3) further includes: The pressure-bearing push plate (34) is disposed on the side of the push plate (31) away from the first push plate (2), fixed on the drive end of the first drive cylinder assembly (1) and in contact with the push plate (31).

5. A filter press, characterized in that, include: The filter press hydraulic system according to any one of claims 1 to 4; A frame is provided extending along the first direction; The first push plate (2) and the second push plate (5) are respectively disposed on the frame and can slide along the frame; The cylinder body of the first drive cylinder assembly (1) is fixed to one end of the frame; The filter plate assembly (6) is disposed between the first push plate (2) and the second push plate (5).

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