Solid-liquid separation system and solid-liquid separation method

Abstract

The present application relates to the technical field of solid-liquid separation, and more particularly to a solid-liquid separation system and a solid-liquid separation method.The present application utilizes compressed air for backwashing, is stable in filtration yield, simple and efficient in operation process, and can greatly reduce the cost.Furthermore, the filtration is realized by using low pressure, cross-flow filtration and compressed air backwashing.In addition, the filter material of the present application is not easy to be blocked, does not need high-cost backwashing liquid, does not produce backwashing thick slurry liquid, and the filter material does not need external regeneration treatment, so that the investment and operation cost can be greatly reduced.Furthermore, the present application can basically realize the automation of operation.

Description

Technical Field

[0001] This invention relates to the technical field of solid-liquid separation, and more specifically, to a solid-liquid separation system and a solid-liquid separation method. Background Technology

[0002] Liquids with high viscosity, high density, fine and irregularly shaped solid particles containing high-hardness solid particles are generally referred to as special liquids. These fine, irregularly shaped, and very hard solid particles are simply called "clogging particles." Under filtration pressure, these clogging particles can severely clog the filter pores; the higher the filtration pressure, the more severe the clogging, to the point that backwashing is unlikely to restore the filter pores to their original state. It's like hammering a nail into a board—easy to drive in, but difficult to pull out. This condition is simply called "impact."

[0003] Common methods typically employ filter media with pore sizes smaller than the solid particles to intercept solid particles in the raw liquid as they pass through, resulting in filtered liquid. During this process, solids gradually clog the filter media pores, forming a filter cake. This causes a gradual decrease in the filter media's filtration capacity. At a certain point, backwashing is necessary to remove the solid filter cake clogging the pores, restoring pore patency and thus restoring the filter media's capacity. This continuous cycle of filtration-backwashing-filtration completes the solid-liquid separation of the raw liquid. Backwashing requires a much more expensive backwash liquid than the raw liquid. The backwash liquid reacts with the filter cake to form a concentrated backwash slurry, which cannot be recycled, and its reprocessing is extremely difficult.

[0004] In practice, increasing filtration flow rate and extending backwashing cycles are common methods to achieve higher output. Increasing filtration pressure, typically above 0.5 MPa, usually solves these problems. However, the higher the filtration pressure, the more severe the clogging of the filter pores by clogging particles becomes; the more difficult the backwashing process, the lower the regeneration rate, and the more severe the problem becomes, causing significant physical damage to the filter media. Each backwash reduces the filtration capacity of the media, and after a certain period of operation, the media will lose its filtration function. At this point, external regeneration is required to restore pore patency. Common methods include incineration, ultrasonic treatment, and solution immersion. These methods all cause varying degrees of damage to the filter media, significantly increasing production costs and severely impacting output for some expensive media. This problem is particularly severe for special liquids (such as catalytic slurry).

[0005] Backwashing requires a much more expensive backwash liquid than the undiluted solution. The backwash liquid reacts with the filter cake to form a concentrated backwash slurry, which cannot be recycled. The reprocessing of this concentrated backwash slurry is extremely difficult. This significantly increases investment and production costs. Summary of the Invention

[0006] Based on this, the purpose of the present invention is to provide a solid-liquid separation system and method that utilizes compressed air for backwashing, has a stable filtration output, and features a simple and efficient operation process that can significantly reduce costs.

[0007] The technical solution of the present invention is: a solid-liquid separation system, comprising:

[0008] High-level crude liquid storage tank: The high-level crude liquid storage tank includes a high-end tank and a second-highest tank. The high-end tank is located above the second-highest tank. The high-end tank is connected to the crude liquid through a pipeline. The lower part of the high-level crude liquid storage tank has a conical structure.

[0009] Cross-flow filter: The cross-flow filter includes a raw liquid inlet at the top and a raw liquid outlet at the bottom, a backwash compressed air inlet and an exhaust control outlet located on both sides of the cross-flow filter; the cross-flow filter also includes a clean liquid outlet located below the exhaust control outlet.

[0010] The solid-liquid separation system also includes a compressed air storage tank, a sludge removal oil pump, a centrifugal filter, a clean oil pump, and a bottom oil pump;

[0011] The raw liquid inlet is connected to the second-highest part of the storage tank via a pipeline;

[0012] The raw liquid bottom outlet is connected to the bottom oil pump via a pipeline, and the bottom oil pump is then connected to the raw liquid high-level storage tank via a pipeline.

[0013] The backwash compressed air inlet is connected to a compressed air storage tank via a pipeline;

[0014] The exhaust control outlet is connected to the raw liquid high-level storage tank via a pipeline;

[0015] The purified liquid outlet is connected to the purified oil pump via a pipeline;

[0016] The centrifugal filter is connected to the raw liquid high-level storage tank via pipelines and a sludge removal oil pump;

[0017] The lowest point of the raw liquid high-level storage tank is higher than the highest point of the cross-flow filter.

[0018] In this invention, compressed air is used for backwashing, resulting in stable filtration output, a simple and efficient operation process, and significant cost reduction. Furthermore, filtration is achieved through low-pressure, cross-flow filtration and compressed air backwashing.

[0019] Furthermore, the storage tank is connected to a first valve at its high end, and the first valve is connected to the raw liquid via a pipeline;

[0020] The storage tank is connected to a second valve at its secondary high end, and the second valve is connected to the raw liquid inlet via a pipeline.

[0021] Specifically, the backwash compressed air inlet is connected to a third valve, which is connected to the compressed air storage tank via a pipeline;

[0022] The exhaust control outlet is connected to a fourth valve, which is connected to the top inlet of the raw liquid high-level storage tank via a pipeline.

[0023] Furthermore, the bottom liquid outlet of the raw liquid is connected to a fifth valve, which is connected to a bottom oil pump, and the bottom oil pump is then connected to the top inlet of the high-level raw liquid storage tank through a pipeline.

[0024] The bottom outlet of the crude liquid high-level storage tank is connected to a sixth valve, which is connected to the inlet of the centrifugal filter through a pipeline; the centrifugal filter has an outlet at the bottom, which is connected to the top inlet of the crude liquid high-level storage tank through a sludge removal oil pump.

[0025] Specifically, the solid-liquid separation system also includes an oil mist treatment device. The raw liquid high-level storage tank is connected to a seventh valve, which is connected to the oil mist treatment device through a pipeline. The first valve is a liquid level regulating valve.

[0026] Furthermore, the cross-flow filter includes a filter wall, an exhaust control outlet and a clean liquid outlet located on the same side of the filter wall, and a backwash compressed air inlet located on the other side of the filter wall.

[0027] The filter wall is provided with a sintered metal filter tube, and the wall of the sintered metal filter tube is provided with filter tube holes.

[0028] Specifically, the metal sintered filter tube is a stainless steel sintered filter tube with a filtration accuracy of 10μm.

[0029] The liquid flow direction at the raw liquid inlet is perpendicular to the liquid flow direction at the purified liquid outlet.

[0030] A solid-liquid separation method, using the aforementioned solid-liquid separation system, includes the following steps:

[0031] Preparation steps: Start all equipment, adjust the compressed air pressure in the compressed air storage tank to the preset parameters; close the compressed air storage tank, open all other valves, and adjust the opening of the fourth and fifth valves according to the selected parameters during commissioning;

[0032] Filtration process: The raw liquid enters the high-level raw liquid storage tank from the high end of the storage tank through the first valve to ensure that the liquid level in the high-level raw liquid storage tank is stable, thereby ensuring that the cross-flow filter has stable filtration pressure;

[0033] The raw liquid flows by gravity from the second highest point of the raw liquid high-level storage tank to the cross-flow filter via the second valve. The filtered liquid is then pumped out by the clean oil pump. The raw liquid bottom liquid is pumped back to the raw liquid high-level storage tank via the fifth valve and enters the filtration process again. The raw liquid bottom liquid enters the upper space above the liquid surface of the raw liquid high-level storage tank from the top to release gas in the liquid. The flow rate of the raw liquid in the cross-flow filter is controlled by the opening of the fifth valve, and the opening size is determined by adjustment.

[0034] Backwashing process: After the backwashing cycle time is reached, the backwashing operation begins. At this time, the filtration process continues to operate as usual without any adjustments. The opening and closing action of the third valve is completed instantly; the backwashing process is complete.

[0035] Sludge removal process: The liquid in the high-level raw liquid storage tank consists of raw liquid and raw liquid bottom liquid after passing through the cross-flow filter. The centrifugal filter is in the normally open state. The raw liquid is transported from the bottom of the high-level raw liquid storage tank to the centrifugal filter through the sixth valve. The raw liquid achieves solid-liquid separation in the centrifugal filter, separating out the clean liquid and discharging the dry solid.

[0036] In addition, it also includes an oil mist treatment process. All oil mist is collected in the space above the liquid surface of the raw liquid high-level storage tank, and then passes through the seventh valve to the oil mist treatment device. After treatment by the oil mist treatment device, the gas is discharged after meeting environmental protection standards.

[0037] Compared with existing technologies, the advantages of this invention are: it utilizes compressed air for backwashing, resulting in stable filtration output, simple and efficient operation, and significant cost reduction. Furthermore, it employs low-pressure, cross-flow filtration with compressed air backwashing to achieve filtration.

[0038] In addition, the filter media of the present invention is not easily clogged, does not require high-cost backwashing liquid, does not produce backwashing slurry, and does not require external regeneration treatment, which can significantly reduce investment and operating costs.

[0039] Moreover, this invention can basically automate the operation.

[0040] To better understand and implement this invention, the following detailed description is provided in conjunction with the accompanying drawings. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the cross-flow filter structure of the present invention.

[0042] Figure 2 This is a schematic diagram of the overall system of the present invention.

[0043] Figure 3 This is a schematic diagram of the method flow of the present invention. Detailed Implementation

[0044] To make the objectives, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Several embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein.

[0045] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature.

[0046] In this invention, unless otherwise expressly specified and limited, "above" or "below" a second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of a second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" of a second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature. The terms "vertical," "horizontal," "left," "right," "above," "below," and similar expressions are for illustrative purposes only and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed or operated in a specific orientation, and therefore should not be construed as limiting the invention.

[0047] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0048] In this invention, catalytic slurry is used as the raw material. Catalytic slurry is a byproduct of the catalytic process in oil refineries, with a density exceeding 1100 kg / m³ and a viscosity greater than 1000 cst (kinematic viscosity at 100°C). It contains approximately 1% solids, mainly aluminum and silicon oxides. The presence of solids significantly reduces the application value of the raw material. If the solids can be removed as required, the application value of the raw material can be increased by more than two times. The solid particles in the raw material are fine, and the high-hardness aluminum and silicon oxides are clogging particles, leading to blockage and poor backwashing effect. Solid-liquid separation of catalytic slurry is an industry challenge. The applicant's invention patent (patent number: 2015101599999, patent name: A filtration device and its filtration method) was designed to solve this problem. After several years of application, the solid-liquid separation effect is good, but it suffers from problems such as too many moving equipment (centrifuges), small capacity of single equipment, low automation, and high management difficulty, making it difficult to cope with high-capacity operating conditions. Therefore, this invention was developed.

[0049] The presence of clogging particles is the main reason for the difficulty in solid-liquid separation. This invention prevents these particles from becoming embedded in the filter pores during the filtration process, ensuring smooth operation of the entire filtration cycle (filtration-backwashing-filtration). This invention employs low-pressure, cross-flow filtration and compressed air backwashing to achieve filtration.

[0050] like Figure 1-2 As shown, the specific solution of the present invention is as follows: a solid-liquid separation system, comprising:

[0051] Raw material high-level storage tank S1: Raw material high-level storage tank S1 includes a high-end tank 101 and a second-high-end tank 102. The high-end tank 101 is located above the second-high-end tank 102. The high-end tank 101 of the raw material high-level storage tank S1 is connected to the raw material through a pipeline. The lower part of the raw material high-level storage tank S1 has a conical structure.

[0052] Cross-flow filter S2: The cross-flow filter S2 includes a raw liquid inlet 10 at the top and a raw liquid bottom liquid outlet 60 at the bottom, a backwash compressed air inlet 50 and an exhaust control outlet 30 located on both sides of the cross-flow filter S2; the cross-flow filter S2 also includes a clean liquid outlet 40 located below the exhaust control outlet 30.

[0053] The solid-liquid separation system also includes a compressed air storage tank S3, a sludge removal oil pump S4, a centrifugal filter S5, a clean oil pump S6, and a bottom oil pump S7.

[0054] The raw liquid inlet 10 is connected to the secondary high end 102 of the storage tank via a pipeline;

[0055] The bottom liquid outlet 60 of the raw liquid is connected to the bottom oil pump S7 through a pipeline, and the bottom oil pump S7 is then connected to the high-level raw liquid storage tank S1 through a pipeline.

[0056] The backwash compressed air inlet 50 is connected to the compressed air storage tank S3 via a pipeline;

[0057] The exhaust control outlet 30 is connected to the raw liquid high-level storage tank S1 via a pipeline;

[0058] The clean liquid outlet 40 is connected to the clean oil pump S6 via a pipeline;

[0059] Centrifugal filter S5 is connected to raw liquid high-level storage tank S1 via pipeline and sludge removal oil pump S4;

[0060] The lowest point of the raw liquid high-level storage tank S1 is higher than the highest point of the cross-flow filter S2.

[0061] In this embodiment, a high-level raw material storage tank S1 is set up, and the raw material flows by gravity to a low-level cross-flow filter S2, maintaining a certain height difference between the two. This height difference provides a stable low-pressure filtration to the cross-flow filter S2. The height difference is designed to ensure that the filter tube pores do not become clogged, with the goal of maximizing output. The specific height difference is determined through commissioning. In this embodiment, a height difference of 2.5 meters is selected, meaning that the height difference between the second-highest point 102 of the high-level raw material storage tank S1 and the highest point of the cross-flow filter S2 is 2.5 meters, achieving low-pressure filtration.

[0062] Specifically, the high end of the storage tank 101 is connected to a first valve F1, which is connected to the raw liquid via a pipeline; the second high end of the storage tank 102 is connected to a second valve F2, which is connected to the raw liquid inlet 10 via a pipeline.

[0063] The backwash compressed air inlet 50 is connected to a third valve F3, which is connected to the compressed air storage tank S3 via a pipeline; the exhaust control outlet 30 is connected to a fourth valve F4, which is connected to the top inlet of the raw liquid high-level storage tank S1 via a pipeline.

[0064] The bottom liquid outlet 60 of the raw liquid is connected to the fifth valve F5, the fifth valve F5 is connected to the bottom oil pump S7, and the bottom oil pump S7 is then connected to the top inlet of the raw liquid high-level storage tank S1 through a pipeline.

[0065] The bottom outlet of the raw liquid high-level storage tank S1 is connected to a sixth valve F6, which is connected to the inlet of the centrifugal filter S5 through a pipeline; the centrifugal filter S5 has an outlet at the bottom, which is connected to the top inlet of the raw liquid high-level storage tank S1 through a sludge cleaning oil pump S4.

[0066] The solid-liquid separation system also includes an oil mist treatment device S8. The raw liquid high-level storage tank S1 is connected to a seventh valve F7, which is connected to the oil mist treatment device S8 through a pipeline. The first valve F1 is a liquid level regulating valve.

[0067] In this embodiment, the first valve F1 is a liquid level regulating valve. The raw liquid enters from the high end 101 of the storage tank through the first valve F1, and then from the second high end 102 of the storage tank through the second valve F2 to the cross-flow filter S2. The lower part of the raw liquid high-level storage tank S1 has a conical structure, which is conducive to the solid deposition and collection of the raw liquid to form a raw liquid with a large solid concentration. From the bottom of the cone, it goes to the centrifugal filter S5 through the sixth valve F6.

[0068] Specifically, the cross-flow filter S2 includes a filter wall 11, an exhaust control outlet 30 and a clean liquid outlet 40 located on the same side of the filter wall 11, and a backwash compressed air inlet 50 located on the other side of the filter wall 11.

[0069] A sintered metal filter tube 20 is installed inside the filter wall 11, and the wall of the sintered metal filter tube 20 is provided with filter tube pores 21. The sintered metal filter tube 20 is a stainless steel sintered filter tube with a filtration accuracy of 10μm. The liquid flow direction of the raw liquid inlet 10 is perpendicular to the liquid flow direction of the purified liquid outlet 40.

[0070] In this embodiment, the number of cross-flow filters S2 can be configured in parallel according to production requirements. The metal sintered filter tube 20 is selected as a stainless steel sintered filter tube with a filtration accuracy of 10μm. The filter pore size is selected based on the particle size with the largest proportion of solid particles to ensure that the filter pores can intercept the largest proportion of solid particles, while solid particles smaller than the filter pores are intercepted by the filter cake.

[0071] like Figure 1 As shown, a represents the original solution, b represents the purified solution, d represents the original solution base solution, e represents the backwash compressed air, and f represents the exhaust air.

[0072] like Figure 1-2 In traditional filtration, forward flow filtration is used, where the flow direction of the raw liquid is the same as that of the purified liquid. The present invention employs cross-flow filtration, where the flow direction of the raw liquid a is at a 90° angle to that of the purified liquid b. Raw liquid a flows into the upper part of the sintered metal filter tube 20 from the upper level of the high-level raw liquid storage tank S1 and flows out from the lower part of the sintered metal filter tube 20, returning to the high-level raw liquid storage tank S1 via the bottom oil pump S7. Purified liquid b is filtered out through the filter tube's filter holes 21.

[0073] During the flow of the raw liquid through the sintered metal filter tube 20, the density of the clogging particles is 2.5-4.5 times that of the raw liquid, exhibiting a strong tendency to settle. Most of these particles will flow with the raw liquid to the clean oil pump S6. The clogging particles that come into contact with the filter pores will only adhere and clog the pores due to the low filtration pressure, without causing clogging. The entire filter cake is loosely attached in the filter tube pore section 21, and some of the filter cake will be washed away with the flow of the raw liquid. This filter cake structure provides an excellent foundation for achieving good backwashing results in the backwashing process.

[0074] like Figure 1-2As shown in the figure, the compressed air storage tank S3 is used in this invention. Compressed air is used as the backwashing medium, so there is no backwashing liquid cost; no backwashing concentrate is generated; the backwashing process can be carried out simultaneously without interrupting the filtration process; the backwashing process is extremely simple to operate and takes very little time.

[0075] The backwashing effect requires that, while ensuring that all filter holes are restored to unobstructed flow, the compressed air pressure should be as low as possible; the amount of air entering the cross-flow filter S2 through the filter holes should be as small as possible; and the filter cake, while immersed in the original liquid, should be instantly detached by the compressed air and carried away with the flow of the original liquid.

[0076] The compressed air pressure is determined by testing; in this embodiment, 0.06 MPa is selected.

[0077] During the backwashing cycle, as the filter pores become increasingly clogged during filtration, the output of the purified liquid gradually decreases. When the output drops to a certain level, a backwashing operation is required. In this embodiment, the backwashing operation is performed when the output drops to 50% of the initial output, and the backwashing cycle time is set to 25 minutes.

[0078] The backwashing operation only requires the third valve F3 (compressed air control valve) to complete one opening and closing action. The shorter the completion time of this action, the better. Since the shortest time for the third valve F3 to complete one opening and closing action is about 2 seconds, this embodiment is calculated based on 4 seconds.

[0079] The centrifugal filter S5 in this embodiment is a device developed based on the applicant's invention patent (patent number: 2015101599999, patent name: a filtration device and its filtration method). High-concentration raw liquid achieves solid-liquid separation here and is discharged. Figure 2 The dried solid filter residue (c) shown below centrifugal filter S5 is returned to the high-level raw liquid storage tank S1 via the sludge removal oil pump S4. The number of centrifugal filters S5 can be configured in parallel according to production requirements.

[0080] like Figure 1-3 As shown, the process flow of the present invention is as follows:

[0081] A solid-liquid separation method, using a solid-liquid separation system, includes the following steps:

[0082] Preparation procedure: Start all equipment, adjust the compressed air pressure of compressed air tank S3 to the preset parameter; close compressed air tank S3, open all other valves, and set the opening degree of valves F4 and F5 according to the commissioning selection.

[0083] Filtration process: The raw liquid enters the raw liquid high-level storage tank S1 from the high end of the storage tank 101 through the first valve F1 to ensure that the raw liquid level in the raw liquid high-level storage tank S1 is stable, thereby ensuring that the cross-flow filter S2 has a stable filtration pressure.

[0084] The raw liquid flows by gravity from the second highest point 102 of the raw liquid high-level storage tank S1 to the cross-flow filter S2 via the second valve F2. The filtered clean liquid is then sent out by the clean oil pump S6. The raw liquid bottom liquid is sent back to the raw liquid high-level storage tank S1 via the bottom oil pump S7 through the fifth valve F5 and enters the filtration process again. The raw liquid bottom liquid enters the upper space of the liquid surface of the raw liquid high-level storage tank S1 from the top to release the gas in the liquid. The flow rate of the raw liquid in the cross-flow filter S2 is controlled by the opening of the fifth valve F5, and the opening size is determined by adjustment.

[0085] Backwashing process: After the backwashing cycle time is reached, the backwashing operation begins. At this time, the filtration process continues to operate as usual without any adjustment. The opening and closing action of the third valve F3 is completed instantly; the backwashing process is completed. The opening degree of the fourth valve F4 is very important. Its function is to discharge the backwash gas to the raw liquid high-level storage tank S1 as soon as possible, and to ensure that the backwashing pressure in the cross-flow filter S2 reaches the required level at the moment the third valve F3 is opened. The opening degree of the fourth valve F4 is selected and fixed through debugging.

[0086] Sludge removal process: The liquid in the raw liquid high-level storage tank S1 consists of raw liquid and raw liquid bottom liquid after passing through cross-flow filter S2. Centrifugal filter S5 is in the normally open state. The raw liquid is transported from the bottom of raw liquid high-level storage tank S1 to centrifugal filter S5 through the sixth valve F6. The raw liquid achieves solid-liquid separation in centrifugal filter S5, separating out the clean liquid and discharging the dry solid.

[0087] It also includes an oil mist treatment process. The catalytic oil slurry stock solution needs to be heated during the treatment process to reduce its viscosity. After heating, the stock solution will generate oil mist. In the backwashing process, compressed air and the stock solution will also generate oil mist when they come into contact.

[0088] All oil mists collect in the space above the liquid level of the raw liquid high-level storage tank S1, and then pass through the seventh valve F7 to the oil mist treatment device S8. After being treated by the oil mist treatment device S8, the gas is discharged after meeting environmental protection standards.

[0089] Compared with the traditional high-pressure positive flow filtration process, this invention uses filter media with exactly the same specifications and parameters and performs an operational comparison with the traditional high-pressure positive flow filtration process. The operational data is recorded in the table below, and the data shows that this invention has significant advantages in practical applications.

[0090]

[0091] This invention achieves its research and development goals, reduces operating costs and investment, and simplifies operation, enabling near-automatic operation. Based on the applicant's existing invention patent (patent number: 2015101599999, patent title: A filtration device and its filtration method), which has been in operation for many years with a purified liquid output of 75,000 tons / year and requires 38 centrifuges, the process of this invention requires only 6 centrifuges under the same conditions. This significantly reduces rotating equipment by over 80%, and the purified liquid quality is more stable. The process is simpler, has lower operating costs, requires less investment, and can achieve near-automatic operation compared to the applicant's pending invention patent (patent number: 2023102555530, patent title: A filtration system and filtration method).

[0092] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A solid-liquid separation system, characterized in that, include: Raw material high-level storage tank (S1): The raw material high-level storage tank (S1) includes a high-end tank (101) and a second-high-end tank (102). The high-end tank (101) is located above the second-high-end tank (102). The high-end tank (101) of the raw material high-level storage tank (S1) is connected to the raw material through a pipeline. The lower part of the raw material high-level storage tank (S1) has a conical structure. Cross-flow filter (S2): The cross-flow filter (S2) includes a raw liquid inlet (10) at the top and a raw liquid bottom liquid outlet (60) at the bottom, a backwash compressed air inlet (50) and an exhaust control outlet (30) located on both sides of the cross-flow filter (S2); the cross-flow filter (S2) also includes a clean liquid outlet (40) located below the exhaust control outlet (30); The solid-liquid separation system also includes a compressed air storage tank (S3), a sludge removal oil pump (S4), a centrifugal filter (S5), a clean oil pump (S6), and a bottom oil pump (S7). The raw liquid inlet (10) is connected to the second-highest part (102) of the storage tank via a pipeline; The raw liquid bottom liquid outlet (60) is connected to the bottom oil pump (S7) through a pipeline, and the bottom oil pump (S7) is then connected to the raw liquid high-level storage tank (S1) through a pipeline; The backwash compressed air inlet (50) is connected to the compressed air storage tank (S3) via a pipeline; The exhaust control outlet (30) is connected to the raw liquid high-level storage tank (S1) via a pipeline; The purified liquid outlet (40) is connected to the purified oil pump (S6) via a pipeline; The centrifugal filter (S5) is connected to the raw liquid high-level storage tank (S1) via a pipeline and a sludge removal oil pump (S4); The lowest point of the raw liquid high-level storage tank (S1) is higher than the highest point of the cross-flow filter (S2).

2. The solid-liquid separation system according to claim 1, characterized in that: The storage tank high end (101) is connected to a first valve (F1), which is connected to the raw liquid through a pipeline; The storage tank at the second-highest point (102) is connected to a second valve (F2), which is connected to the raw liquid inlet (10) via a pipeline.

3. The solid-liquid separation system according to claim 2, characterized in that: The backwash compressed air inlet (50) is connected to a third valve (F3), which is connected to the compressed air storage tank (S3) via a pipeline; The exhaust control outlet (30) is connected to a fourth valve (F4), which is connected to the top inlet of the raw liquid high-level storage tank (S1) via a pipeline.

4. A solid-liquid separation system according to claim 3, characterized in that: The raw liquid bottom outlet (60) is connected to a fifth valve (F5), the fifth valve (F5) is connected to a bottom oil pump (S7), and the bottom oil pump (S7) is then connected to the top inlet of the raw liquid high-level storage tank (S1) through a pipeline; The bottom outlet of the raw liquid high-level storage tank (S1) is connected to a sixth valve (F6), which is connected to the inlet of the centrifugal filter (S5) through a pipeline; the centrifugal filter (S5) has an outlet at the bottom, which is connected to the top inlet of the raw liquid high-level storage tank (S1) through a sludge cleaning oil pump (S4).

5. A solid-liquid separation system according to claim 4, characterized in that: The solid-liquid separation system also includes an oil mist treatment device (S8), and the raw liquid high-level storage tank (S1) is connected to a seventh valve (F7), which is connected to the oil mist treatment device (S8) through a pipeline; The first valve (F1) is a liquid level regulating valve.

6. A solid-liquid separation system according to claim 1, characterized in that: The cross-flow filter (S2) includes a filter wall (11), an exhaust control outlet (30) and a clean liquid outlet (40) located on the same side of the filter wall (11), and a backwash compressed air inlet (50) located on the other side of the filter wall (11). The filter wall (11) is provided with a metal sintered filter tube (20), and the wall of the metal sintered filter tube (20) is provided with a filter tube filter hole section (21).

7. A solid-liquid separation system according to claim 6, characterized in that: The metal sintered filter tube (20) is a stainless steel sintered filter tube with a filtration accuracy of 10μm.

8. A solid-liquid separation system according to claim 1, characterized in that: The liquid flow direction of the raw liquid inlet (10) is perpendicular to the liquid flow direction of the clean liquid outlet (40).

9. A solid-liquid separation method, using the solid-liquid separation system of claim 5, characterized in that, Includes the following steps: Preparation procedure: Start all equipment, adjust the compressed air pressure of compressed air tank (S3) to the preset parameter; close compressed air tank (S3), open all other valves, and set the opening degree of valves 4 (F4) and 5 (F5) according to the commissioning selection; Filtration process: The raw liquid enters the raw liquid high-level storage tank (S1) from the high end of the storage tank (101) through the first valve (F1) to ensure that the raw liquid level in the raw liquid high-level storage tank (S1) is stable, thereby ensuring that the cross-flow filter (S2) has a stable filtration pressure; The raw liquid flows by gravity from the second high point (102) of the raw liquid high-level storage tank (S1) to the cross-flow filter (S2) through the second valve (F2). The filtered liquid is then sent out by the clean oil pump (S6). The raw liquid bottom liquid is sent back to the raw liquid high-level storage tank (S1) through the fifth valve (F5) by the bottom oil pump (S7) and enters the filtration process again. The raw liquid bottom liquid enters the upper space of the liquid surface of the raw liquid high-level storage tank (S1) from the top to release the gas in the liquid. The flow rate of the raw liquid in the cross-flow filter (S2) is controlled by the opening of the fifth valve (F5). The opening size is determined by adjustment. Backwashing process: After the backwashing cycle time is reached, the backwashing operation begins. At this time, the filtration process continues to operate normally without any adjustments. The opening and closing action of the third valve (F3) is completed instantly; the backwashing process is complete. Sludge removal process: The liquid in the raw liquid high-level storage tank (S1) consists of raw liquid and raw liquid bottom liquid after passing through cross-flow filter (S2). The centrifugal filter (S5) is in the normally open state. The raw liquid is transported from the bottom of the raw liquid high-level storage tank (S1) to the centrifugal filter (S5) through the sixth valve (F6). The raw liquid achieves solid-liquid separation in the centrifugal filter (S5), separating out the clean liquid and discharging the dry solid.

10. The solid-liquid separation method according to claim 9, characterized in that: It also includes an oil mist treatment process. All oil mist is collected in the upper space above the liquid surface of the raw liquid high-level storage tank (S1), and then passes through the seventh valve (F7) to the oil mist treatment device (S8). After treatment by the oil mist treatment device (S8), the gas is discharged after meeting environmental protection standards.

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