Filtering system

Abstract

The utility model relates to the field of filtering of non-ferrous metal processing technology oil, in particular to a filtering system. The filtering system comprises a plate filter, the sump oil tank is used for storing sump oil to be filtered; the filter aid supply module comprises a mixing box for storing a filter aid and is used for supplying the filter aid; the oil cleaning tank is used for storing the filtered process oil; the filter pump is used as a driving source for pumping a filter aid and dirty oil into the plate filter; the system is characterized in that an inlet of the sump oil tank is communicated with an oil outlet of the plate filter through a sump oil return pipeline, and at least a local pipeline of the sump oil return pipeline is higher than the uppermost layer of a filter plate frame of the plate filter, so that back pressure is formed in an oil return pipe in the plate filter. Due to the arrangement mode that at least a local pipeline of the dirty oil return pipeline is higher than the uppermost layer of the filter plate frame of the plate filter, the oil return pipe of each layer of filter plate frame of the plate filter forms small back pressure, and the filtering effect is improved.

Description

Technical Field

[0001] The utility model relates to the field of nonferrous metal processing oil filtration, in particular to a filtration system. Background Art

[0002] During the rolling process of non-ferrous metal plates and strips, process oil is required to lubricate and cool the strips and rolls, as well as to control the convexity of the roll shape. The process oil output from the clean oil tank is sprayed onto the rolls and strips through components such as the oil supply pump, control valve and nozzle. The used process oil is returned to the dirty oil tank after spraying. The filter pump transports the dirty oil to the plate filter for filtration. The clean oil after filtration flows to the clean oil tank for repeated use.

[0003] At present, the three main oil pipes of the plate filter are the dirty oil inlet pipe, the clean oil return pipe and the circulating return pipe. The dirty oil inlet pipe is connected to the filter pump, and the clean oil return and circulating return pipes are connected to the clean oil tank and the dirty oil tank respectively. Because the oil tank is generally placed in the basement, and the plate filter is placed on the ground, the clean oil return and circulating return oil pipes are directly connected to the dirty oil tank through natural bend piping. The piping elevation is lower than the filter itself, so there will be a certain negative pressure in the return oil pipeline. The greater the negative pressure, the more filter aids will accumulate on the filter paper near the return oil pipeline, causing the filter aids of each layer of filter box to be sprayed unevenly, thus affecting the filtering effect. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide a filtering system capable of forming back pressure in the oil return pipe of the filter in view of the above-mentioned existing technical status.

[0005] The technical solution adopted by the utility model to solve the above technical problems is as follows: the filtering system includes a plate filter, the plate filter has an oil inlet and an oil outlet, an oil inlet pipe connected to the oil inlet is arranged inside the plate filter, and an oil return pipe connected to the oil outlet is arranged inside the plate filter; a dirty oil tank, the outlet of which is connected to the oil inlet of the plate filter through the dirty oil inlet pipe, and the inlet of which is connected to the oil outlet of the plate filter, and is used to store the dirty oil to be filtered;

[0006] A filter aid supply module, the filter aid supply module comprising a mixing box for storing the filter aid, the outlet of the mixing box being connected to the oil inlet of the plate filter for supplying the filter aid;

[0007] A clean oil tank, the inlet of which is connected to the oil outlet of the plate filter, and is used to store filtered process oil;

[0008] A filter pump is provided between the plate filter and the dirty oil tank and serves as a driving source for pumping filter aids and dirty oil into the plate filter;

[0009] Features:

[0010] The inlet of the dirty oil tank is connected to the oil outlet of the plate filter through a dirty oil return pipeline, and at least a part of the dirty oil return pipeline is higher than the uppermost layer of the filter plate frame of the plate filter, so that back pressure is formed in the oil return pipe inside the plate filter.

[0011] In order to save the user's cost, preferably, the dirty oil return pipeline has a first inverted U-shaped bend pipe that is higher than the height of the uppermost filter plate frame of the plate filter. The first inverted U-shaped bend pipe has a low installation cost, and the first inverted U-shaped bend pipe can also always seal a section of liquid. In particular, when filtering the rolling kerosene medium, the rolling oil sealed by the first inverted U-shaped bend pipe avoids direct connection between the plate filter and the dirty oil tank. When the plate filter catches fire, it will not detonate the basement oil tank, which plays a certain role in fire fighting.

[0012] In order to further improve the safety of the filtration system, preferably, the inlet of the clean oil tank is connected to the oil outlet of the plate filter through a clean oil return pipeline, and the clean oil return pipeline has a second inverted U-shaped bend pipe that is higher than the height of the uppermost filter plate frame of the plate filter. The second inverted U-shaped bend pipe can seal a section of liquid, especially when filtering rolling kerosene medium, the rolling oil sealed by the second inverted U-shaped bend pipe avoids direct connection between the plate filter and the clean oil tank, and when the plate filter catches fire, it will not detonate the basement oil tank, which plays a certain role in fire fighting.

[0013] In order to achieve the separate flow of filtered oil in the pre-coating stage and the filtering stage of the plate filter, preferably, the clean oil return pipeline is provided with a clean oil outlet on-off valve, and the dirty oil return pipeline is provided with a clean oil bypass on-off valve, and the clean oil outlet on-off valve and the clean oil bypass on-off valve are connected to a control module, and the control module is used to adjust the opening and closing states of the clean oil outlet on-off valve and the clean oil bypass on-off valve. In the pre-coating stage, the user can open the clean oil bypass on-off valve to allow the unfiltered dirty oil to flow back to the dirty oil tank; in the filtering stage, the user can open the clean oil outlet on-off valve to allow the filtered oil to flow to the clean oil tank.

[0014] In order to realize automatic control of the filtering system, preferably, the control module is configured to open the clean oil outlet on-off valve and close the clean oil bypass on-off valve when the first preset time has passed after the clean oil bypass on-off valve is opened. The user can preset the first preset time before the filtering system works, and when the filtering system is in operation, there is no need to manually adjust the opening and closing of the clean oil outlet on-off valve and the clean oil bypass on-off valve to control the flow direction of the filtered oil.

[0015] In order to facilitate users to use the filtering system to add filter aids to the plate filter, preferably, the dirty oil inlet pipe is separated into an oil supply bypass between the oil supply port of the filter pump and the oil inlet of the plate filter, and the filter aid supply module is connected to the oil outlet of the filter pump through the oil supply bypass; the filter aid supply module also includes:

[0016] A mixer having a first inlet, a second inlet and an outlet, wherein the first inlet is connected to a mixing box, the second inlet is connected to an oil outlet of a filter pump through a filter aid oil inlet pipe, and the outlet of the mixer is connected to an oil suction port of the filter pump for sucking in and mixing filter aid and dirty oil;

[0017] A filter aid adding valve is provided between the first inlet of the mixer and the mixing box, the inlet of the filter aid adding valve is communicated with the mixing box, and the outlet of the filter aid adding valve is communicated with the mixer, and is used to control the on-off state of the mixer and the mixing box;

[0018] The mixing module oil inlet valve is arranged in the oil supply bypass, and the outlet of the mixing module oil inlet valve is connected to the second inlet of the mixer, and is used to control the on-off of the oil supply bypass. After the filter aid and the dirty oil are mixed by the mixer, the filter aid can flow into the plate filter more easily. The setting of the mixing module oil inlet valve allows the user to prevent the secondary mixing of the filter aid and the dirty oil by closing the mixing module oil inlet valve after the filter aid enters the dirty oil inlet pipe, thereby improving the efficiency of the pre-coating stage. At the same time, the filter aid supply module is connected to the oil outlet of the filter pump through the oil supply bypass, so that the filter aid supply module and the main oil circuit share a filter pump, thereby reducing the cost of the filter system layout.

[0019] In order to continuously suck the filter aid in the mixing box into the mixer, preferably, the outlet of the mixing module oil inlet valve is simultaneously connected to the inlet of the mixing box, and a mixing box refueling valve is provided between the outlet of the mixing module oil inlet valve and the inlet of the mixing box. By opening the mixing box refueling valve, the user can allow the dirty oil in the oil supply bypass to enter the mixing box, so that the fluidity of the filter aid is enhanced and it is easier to be sucked into the mixer. After the user closes the mixing box refueling valve, the mixing ratio of the dirty oil and the filter aid in the mixer increases, the concentration of the filter aid in the pipeline decreases, and the fluidity increases. The user can open or close the mixing box refueling valve according to the requirements of the pre-coating and filtering sections for the flow rate of the filter aid entering the filter.

[0020] In order to facilitate users to repair the mixer, preferably, a first on-off valve is provided between the outlet of the mixing module oil inlet valve and the second inlet of the mixer, and a second on-off valve is provided on the filter aid oil inlet pipe. Users can perform separate maintenance on the mixer by closing the first on-off valve, the second on-off valve and the filter aid adding valve to block the oil flow of the filter aid supply module.

[0021] In order to facilitate the user to control the amount of filter aid added to the plate filter in the pre-coating stage and the filtering stage, preferably, the filter aid supply module includes a mixer and a filter aid injection valve, the filter aid injection valve is arranged between the first inlet of the mixer and the mixing box, the control module is connected to the filter aid injection valve, and the control module is configured to: open the filter aid injection valve within the first preset time after the clean oil bypass on-off valve is opened; after the first preset time after the clean oil bypass on-off valve is opened, continuously close or intermittently open and close the filter aid injection valve according to the opening and closing rhythm. The control module controls the opening and closing state of the filter aid injection valve in the pre-coating stage and the filtering stage to adjust the amount of filter aid entering the dirty oil inlet pipe, and the degree of automation is high.

[0022] Compared with the prior art, the utility model has the following advantages: by arranging the dirty oil return pipeline in such a way that at least a part of the pipeline is higher than the uppermost layer of the filter plate frame of the plate filter, a small back pressure is formed in the return pipe of each layer of the filter plate frame of the plate filter, and the back pressure will offset a part of the negative pressure in the return oil pipeline, so that the filter aid is more evenly distributed on the filter paper in the plate frame, thereby improving the filtering effect; at the same time, adjusting the height of the dirty oil return pipeline to form back pressure also reduces the user's oil circuit layout cost, and there is no need to add new hydraulic components to form back pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a hydraulic oil circuit diagram of an embodiment of the utility model;

[0024] Figure 2 This is a hydraulic oil circuit diagram of the filter aid supply module of an embodiment of the utility model. DETAILED DESCRIPTION

[0025] The present invention will be described in further detail below in conjunction with the accompanying drawings.

[0026] like Figures 1-2 The figure shows the best embodiment of the utility model. The filtration system of this embodiment is mainly used to filter the process oil used for strip and roller spraying. The oil tank in the general filtration system is generally placed in the basement, while the plate filter is placed on the ground. There is a height difference between the filter and the oil tank, so there will be a certain negative pressure in the return oil pipeline of the plate filter. The greater the negative pressure, the more filter aids will accumulate on the filter paper near the return oil pipeline, making the filter cake more uneven. Therefore, it will be beneficial to provide a filtration system that can form back pressure in the return oil pipe of the filter to reduce the negative pressure and improve the filtration effect. The structure of this filtration system will be described below:

[0027] See also Figure 1The filtering system comprises a plate filter 1, a dirty oil tank 2, a filter aid supply module 3, a clean oil tank 4 and a filter pump 5, wherein the plate filter 1 has an oil inlet and an oil outlet, an oil inlet pipe 11 connected to the oil inlet is provided inside the plate filter 1, and an oil return pipe 12 connected to the oil outlet is provided inside the plate filter 1. The outlet of the dirty oil tank 2 is connected to the oil inlet of the plate filter 1 through the dirty oil inlet pipe, and the inlet is connected to the oil outlet of the plate filter 1 for storing the dirty oil to be filtered; the filter aid supply module 3 comprises a mixing box 31 for storing the filter aid, and a mixing box 32 for storing the filter aid. The outlet of the combined box 31 is connected to the oil inlet of the plate filter 1 for supplying filter aids; the inlet of the clean oil tank 4 is connected to the oil outlet of the plate filter 1 for storing filtered process oil; the filter pump 5 is arranged between the plate filter 1 and the dirty oil tank 2 as a driving source for pumping the filter aids and dirty oil into the plate filter 1; the inlet of the dirty oil tank 2 is connected to the oil outlet of the plate filter 1 through the dirty oil return pipeline 6, and at least part of the dirty oil return pipeline 6 is higher than the top layer of the filter plate frame of the plate filter 1, so that back pressure is formed in the return pipe inside the plate filter 1. The dirty oil inlet pipe is provided with an on-off valve for controlling the on-off state of the dirty oil inlet pipe.

[0028] The dirty oil return pipeline 6 has a first inverted U-shaped bend pipe 61 that is higher than the height of the uppermost filter plate frame of the plate filter 1. The first inverted U-shaped bend pipe 61 has a low installation cost, and the first inverted U-shaped bend pipe 61 can also always seal a section of liquid. In particular, when filtering the rolling kerosene medium, the rolling oil sealed by the first inverted U-shaped bend pipe 61 avoids direct connection between the plate filter 1 and the dirty oil tank 2. When the plate filter 1 catches fire, it will not detonate the basement oil tank, which plays a certain role in fire fighting and saves the user's cost.

[0029] The inlet of the clean oil tank 4 is connected to the oil outlet of the plate filter 1 through the clean oil return pipeline 7, and the clean oil return pipeline 7 has a second inverted U-shaped bend pipe 71 higher than the height of the uppermost filter plate frame of the plate filter 1. The second inverted U-shaped bend pipe 71 can seal a section of liquid, especially when filtering rolling kerosene medium, the rolling oil sealed by the second inverted U-shaped bend pipe 71 avoids direct connection between the plate filter 1 and the clean oil tank 4, and when the plate filter 1 catches fire, it will not detonate the basement oil tank, which plays a certain role in fire fighting and further improves the safety of the filtering system.

[0030] A clean oil outlet on-off valve 72 is provided on the clean oil return pipeline 7, and a clean oil bypass on-off valve 62 is provided on the dirty oil return pipeline 6. The clean oil outlet on-off valve 72 and the clean oil bypass on-off valve 62 are connected to a control module, and the control module is used to adjust the opening and closing states of the clean oil outlet on-off valve 72 and the clean oil bypass on-off valve 62. In the pre-coating stage, the user can open the clean oil bypass on-off valve 62 to allow the unfiltered dirty oil to flow back to the dirty oil tank 2; in the filtering stage, the user can open the clean oil outlet on-off valve 72 to allow the filtered oil to flow to the clean oil tank 4, thereby realizing the separate flow of the filtered oil in the plate filter 1 in the pre-coating stage and the filtering stage.

[0031] The control module is configured to open the clean oil outlet on-off valve 72 and close the clean oil bypass on-off valve 62 after the first preset time has passed since the clean oil bypass on-off valve 62 was opened. The user can preset the first preset time before the filter system works. When the filter system is operating, there is no need to manually adjust the clean oil outlet on-off valve 72 and the clean oil bypass on-off valve 62 to control the flow direction of the filtered oil, thereby realizing the automatic control of the filter system. The control module can also control the on-off valve on the dirty oil return pipe, the clean oil bypass on-off valve 62, the filter aid injection valve 33, the mixing module oil inlet valve 34, the mixing box filling valve 35, the first on-off valve 36, and the second on-off valve 37.

[0032] See also Figure 2The dirty oil inlet pipe divides an oil supply bypass between the oil supply port of the filter pump 5 and the oil inlet of the plate filter 1, and the filter aid supply module 3 is connected to the oil outlet of the filter pump 5 through the oil supply bypass; the filter aid supply module 3 also includes a mixer 32, a filter aid addition valve 33 and a mixing module oil inlet valve 34, wherein the mixer 32 has a first inlet, a second inlet and an outlet, the first inlet is connected to the mixing box 31, the second inlet is connected to the oil outlet of the filter pump 5 through the filter aid oil inlet pipe, and the outlet of the mixer 32 is connected to the filter aid. The oil suction port of the filter pump 5 is connected to suck in the filter aid and the dirty oil and mix them; the filter aid adding valve 33 is arranged between the first inlet of the mixer 32 and the mixing box 31, the inlet of the filter aid adding valve 33 is connected to the mixing box 31, and the outlet of the filter aid adding valve 33 is connected to the mixer 32, which is used to control the on-off state of the mixer 32 and the mixing box 31; the mixing module oil inlet valve 34 is arranged in the oil supply bypass, and the outlet of the mixing module oil inlet valve 34 is connected to the second inlet of the mixer 32, which is used to control the on-off state of the oil supply bypass. After the filter aid and dirty oil are mixed by the mixer 32, the filter aid can flow into the plate filter 1 more easily. The setting of the mixing module oil inlet valve 34 allows the user to prevent the secondary mixing of the filter aid and the dirty oil by closing the mixing module oil inlet valve 34 after the filter aid enters the dirty oil inlet pipe, thereby improving the efficiency of the pre-coating stage. At the same time, the filter aid supply module 3 is connected to the oil outlet of the filter pump 5 through the oil supply bypass, so that the filter aid supply module 3 and the main oil circuit share a filter pump 5, which reduces the cost of the filter system layout and facilitates the user to use the filter system to add the filter aid to the plate filter 1. The mixing box 31 is provided with a stirring device for mixing the filter aid and the dirty oil. The filter aid adding valve 33 is an angle seat valve, which is remotely controlled; the mixer 32 is a venturi tube.

[0033] The outlet of the mixing module oil inlet valve 34 is connected to the inlet of the mixing box 31 at the same time, and a mixing box refueling valve 35 is provided between the outlet of the mixing module oil inlet valve 34 and the inlet of the mixing box 31. By opening the mixing box refueling valve 35, the user can allow the dirty oil in the oil supply bypass to enter the mixing box 31, so that the fluidity of the filter aid is enhanced and it is easier to be sucked into the mixer 32. After the user closes the mixing box refueling valve 35, the mixing ratio of the dirty oil and the filter aid in the mixer 32 increases, the concentration of the filter aid in the pipeline decreases, and the fluidity increases. The user can open or close the mixing box refueling valve 35 according to the requirements of the pre-coating and filtering sections for the flow rate of the filter aid entering the filter, so that the filter aid in the mixing box 31 can be continuously sucked into the mixer 32.

[0034] A first on-off valve 36 is provided between the outlet of the mixing module oil inlet valve 34 and the second inlet of the mixer 32, and a second on-off valve 37 is provided on the filter aid oil inlet pipe. The user can perform a separate maintenance on the mixer 32 by closing the first on-off valve 36, the second on-off valve 37 and the filter aid adding valve 33 to block the oil flow of the filter aid supply module 3, which facilitates the user to repair the mixer 32.

[0035] The filter aid supply module 3 includes a mixer 32 and a filter aid sampling valve 33. The filter aid sampling valve 33 is arranged between the first inlet of the mixer 32 and the mixing box 31. The control module is connected to the filter aid sampling valve 33. The control module is configured to: open the filter aid sampling valve 33 within the first preset time after the clean oil bypass on-off valve 62 is opened; and continuously close the filter aid sampling valve 33 or intermittently open and close the filter aid sampling valve 33 according to the opening and closing rhythm after the first preset time after the clean oil bypass on-off valve 62 is opened. The control module controls the opening and closing state of the filter aid sampling valve 33 in the pre-coating stage and the filtering stage to adjust the amount of filter aid entering the dirty oil inlet pipe. The automation level is high, which facilitates the user to control the amount of filter aid added to the plate filter 1 in the pre-coating stage and the filtering stage. If the filter aid adding valve 33 is opened and closed intermittently according to the opening and closing rhythm during the filtering stage, the opening and closing rhythm is opened for 5 seconds and then closed for 40 seconds. This opening and closing rhythm can make up for the filter aid washed away by the high-speed dirty oil on the filter paper during the filtering stage, thereby ensuring the filtering effect.

[0036] The workflow of this filtration system is divided into the pre-coating stage and the filtration stage. The specific process is as follows:

[0037] 1) Pre-coating stage: after closing all valves in the initialization state, open the on-off valve on the dirty oil inlet pipe, the clean oil bypass on-off valve 62, the filter aid adding valve 33, the mixing module inlet valve 34, the mixing box filling valve 35, the first on-off valve 36, the second on-off valve 37, and the dirty oil inlet pipe, the dirty oil return pipeline 6 and the filter aid supply module are circulated; turn on the filter pump 5, start the stirring device in the mixing box 31, the dirty oil and the filter aid are mixed in the mixing box 31 and then mixed with the dirty oil of another line by the mixer 32, at this time, the filter pump 5 is transported to the oil inlet pipe in the plate filter 1 and pre-coated on the filter paper, and then flows into the dirty oil tank 2 from the dirty oil return pipeline 6. In this process, the first inverted U-shaped bend pipe 61 forms back pressure in the return pipe 12, which reduces the influence of negative pressure and makes the filter aid evenly distributed on the filter paper. The above actions continue until the first preset time, that is, the pre-coating stage ends;

[0038] 2) Filtration stage: after reaching the first preset time, the control module closes the clean oil bypass on-off valve 62, opens the clean oil outlet on-off valve 72 and controls the filter aid adding valve 33 according to the opening and closing rhythm of opening for 5s and closing for 40s. The dirty oil flows from the dirty oil tank 2 through the plate filter 1 and is filtered by the filter paper before flowing into the clean oil tank 4. During this process, the second inverted U-shaped bend 71 forms a back pressure in the return oil pipe 12, which reduces the influence of the negative pressure and makes the supplemented filter aid evenly distributed on the filter paper. At the same time, it also makes the flow rate of the filtered oil stable. The filtered oil can be used to lubricate and cool the strip and the rollers, and then collected back into the dirty oil tank 2 after use. This stage stops after the oil in the dirty oil tank 2 is exhausted.

Claims

1. A filtering system, comprising a plate filter (1), the plate filter (1) having an oil inlet and an oil outlet, an oil inlet pipe (11) connected to the oil inlet being provided inside the plate filter (1), and an oil return pipe (12) connected to the oil outlet being provided inside the plate filter (1); a dirty oil tank (2), the outlet of which is connected to the oil inlet of the plate filter (1) via the dirty oil inlet pipe, and the inlet of which is connected to the oil outlet of the plate filter (1), for storing the dirty oil to be filtered; A filter aid supply module (3), the filter aid supply module (3) comprising a mixing box (31) for storing the filter aid, the outlet of the mixing box (31) being in communication with the oil inlet of the plate filter (1) for supplying the filter aid; A clean oil tank (4), the inlet of which is connected to the oil outlet of the plate filter (1), and is used to store filtered process oil; A filter pump (5) is provided between the plate filter (1) and the dirty oil tank (2) and serves as a driving source for pumping the filter aid and the dirty oil into the plate filter (1); Features: The inlet of the dirty oil tank (2) is connected to the oil outlet of the plate filter (1) via a dirty oil return pipeline (6); at least a portion of the dirty oil return pipeline (6) is higher than the uppermost layer of the filter plate frame of the plate filter (1), thereby forming a back pressure in the oil return pipe inside the plate filter (1).

2. The filtration system according to claim 1, characterized in that: The dirty oil return pipeline (6) has a first inverted U-shaped bend (61) that is higher than the height of the uppermost filter plate frame of the plate filter (1).

3. The filtration system according to claim 1 or 2, characterized in that: The inlet of the clean oil tank (4) is connected to the oil outlet of the plate filter (1) via a clean oil return pipeline (7), and the clean oil return pipeline (7) has a second inverted U-shaped bend (71) that is higher than the height of the uppermost filter plate frame of the plate filter (1).

4. The filtration system according to claim 3, characterized in that: The clean oil return pipeline (7) is provided with a clean oil outlet on-off valve (72), and the dirty oil return pipeline (6) is provided with a clean oil bypass on-off valve (62). The clean oil outlet on-off valve (72) and the clean oil bypass on-off valve (62) are connected to a control module, and the control module is used to adjust the opening and closing states of the clean oil outlet on-off valve (72) and the clean oil bypass on-off valve (62).

5. The filtration system according to claim 4, characterized in that: The control module is configured to: open the clean oil outlet on-off valve (72) and close the clean oil bypass on-off valve (62) when a first preset time has passed since the clean oil bypass on-off valve (62) was opened.

6. The filtration system according to claim 1, characterized in that: The dirty oil inlet pipe branches out an oil supply bypass between the oil supply port of the filter pump (5) and the oil inlet port of the plate filter (1); the filter aid supply module (3) is connected to the oil outlet port of the filter pump (5) through the oil supply bypass; the filter aid supply module (3) also includes: The mixer (32) has a first inlet, a second inlet and an outlet, wherein the first inlet is connected to the mixing box (31), the second inlet is connected to the oil outlet of the filter pump (5) through the filter aid oil inlet pipe, and the outlet of the mixer (32) is connected to the oil suction port of the filter pump (5) for sucking the filter aid and the dirty oil and mixing them; a filter aid adding valve (33) disposed between the first inlet of the mixer (32) and the mixing box (31), wherein the inlet of the filter aid adding valve (33) is in communication with the mixing box (31), and the outlet of the filter aid adding valve (33) is in communication with the mixer (32), and is used to control the on / off state of the mixer (32) and the mixing box (31); The mixing module oil inlet valve (34) is arranged in the oil supply bypass, and the outlet of the mixing module oil inlet valve (34) is communicated with the second inlet of the mixer (32) for controlling the on-off of the oil supply bypass.

7. The filtration system according to claim 6, characterized in that: The outlet of the mixing module oil inlet valve (34) is simultaneously connected to the inlet of the mixing box (31), and a mixing box refueling valve (35) is provided between the outlet of the mixing module oil inlet valve (34) and the inlet of the mixing box (31).

8. The filtration system according to claim 6 or 7, characterized in that: A first on-off valve (36) is provided between the outlet of the mixing module oil inlet valve (34) and the second inlet of the mixer (32), and a second on-off valve (37) is provided on the filter aid oil inlet pipe.

9. The filtration system according to claim 5, characterized in that: The filter aid supply module (3) comprises a mixer (32) and a filter aid sampling valve (33), wherein the filter aid sampling valve (33) is arranged between a first inlet of the mixer (32) and a mixing box (31), and the control module is connected to the filter aid sampling valve (33). The control module is configured to: open the filter aid sampling valve (33) within a first preset time after the clean oil bypass on-off valve (62) is opened; and continuously close the filter aid sampling valve (33) or intermittently open and close the filter aid sampling valve (33) according to an opening and closing rhythm after the first preset time after the clean oil bypass on-off valve (62) is opened.

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