Filter cake cleaning device and cleaning method of diaphragm filter press

Abstract

The filter cake cleaning device comprises a filter press and a cleaning mechanism, the filter press is provided with a thrust plate arranged on one side, and a feeding port communicated with a filter chamber of the filter press, two lower liquid outlet holes located in the bottom and two upper liquid outlet holes located in the top are formed in the thrust plate; the cleaning mechanism comprises a cleaning tank for storing cleaning liquid and a cleaning pump for pressurizing and conveying the cleaning liquid into a filter chamber of the filter press; the first transmission pipeline is used for converging liquid flowing out of the two lower liquid outlet holes and can balance the pressure at the two ends of the lower liquid outlet holes; the second transmission pipeline is used for converging the liquid flowing out of the two upper liquid outlet holes and can balance the pressure when the liquid flows out of the lower liquid outlet holes and the upper liquid outlet holes; and the cleaning waste liquid collecting tank is used for collecting the cleaning waste liquid output by the first conveying pipeline and the second conveying pipeline. The filter cake cleaning device has the beneficial effects that the cleaning uniformity of the filter cake can be improved, and the cleaning cost is saved.

Description

Technical Field

[0001] This invention relates to a filter cake cleaning device and cleaning method for a diaphragm filter press, belonging to the technical field of solid-liquid separation equipment. Background Technology

[0002] As a highly efficient solid-liquid separation device, the diaphragm filter press is widely used in various industries such as chemical, mining, metallurgy, environmental protection, and food processing due to its advantages such as high filtration accuracy, low filter cake moisture content, and large processing capacity. In the workflow of a diaphragm filter press, filter cake cleaning is a crucial subsequent process. Its core purpose is to remove residual soluble impurities from the filter cake, improve the purity of the filter cake product, or recover valuable components contained in the filter cake, while reducing the difficulty of subsequent pollutant treatment and ensuring that the final product quality and environmental emission standards are met.

[0003] Currently, among the filter cake cleaning methods commonly used in the industry, the most widely applied solution is to utilize the inlet and outlet liquid structure of the thrust plate. The core logic of this structural design is as follows: an inlet channel and an outlet channel are integrated into the thrust plate of the filter press. The cleaning liquid enters the filter chamber channel inside the filter press through the inlet (feed port) on the thrust plate, flows through the filter cake layer between the filter plates, and washes and penetrates the filter cake. The waste liquid after cleaning is discharged through the outlet on the thrust plate, thereby achieving overall cleaning of the filter cake. Furthermore, compared to other solutions that require additional independent cleaning pipelines, this cleaning method has significant structural advantages: First, it eliminates the need for complex cleaning pipelines and interfaces in the filter press frame, filter plate assembly, etc., simplifying the overall structural design of the equipment and reducing manufacturing costs and assembly difficulty; Second, the cleaning channel can be partially shared with the original filtration channel, reducing the space occupied by the pipelines and adapting to the structure of most existing diaphragm filter presses, demonstrating strong compatibility; Third, the operation process is simple, requiring only valve switching to achieve the conversion between filtration and cleaning modes, without the need for additional complex operating steps, thus reducing the skill requirements and labor intensity of operators.

[0004] However, in long-term application, the aforementioned cleaning structure has gradually revealed unavoidable technical defects, namely, the problem of uneven filter cake cleaning, specifically insufficient cleaning of the upper filter cake and excessive cleaning of the lower filter cake. This problem is mainly caused by the following two factors: Firstly, due to gravity, the cleaning liquid naturally tends to flow downwards after entering the filter chamber, resulting in a larger flow rate and faster velocity in the lower filter chamber area, and a longer contact time with the filter cake; while the cleaning liquid in the upper filter chamber area is prone to poor flow or even local stagnation, resulting in a significantly insufficient effective contact amount with the filter cake per unit time. Secondly, after entering from the inlet, the cleaning liquid needs to diffuse layer by layer along the length of the filter chamber. During the diffusion process, the pressure and flow rate of the cleaning liquid gradually decrease, further exacerbating the problem of insufficient cleaning liquid supply in the upper filter chamber, forming an unbalanced state of "excessive flushing in the lower layer and insufficient cleaning in the upper layer". Ultimately, this leads to incomplete cleaning of the upper filter cake. If resource recovery is carried out later, the purity of the recovered components will be reduced. If it is discharged directly, it may fail to meet environmental protection requirements due to excessive impurities. Over-cleaning of the lower filter cake not only causes serious waste of cleaning liquid, increases the cost of production water and the load on subsequent wastewater treatment, but may also damage the filter cake structure due to over-cleaning, resulting in loose and falling filter cakes. Summary of the Invention

[0005] The purpose of this invention is to provide a filter cake cleaning device and cleaning method for a diaphragm filter press, which can improve the uniformity of filter cake cleaning and save cleaning costs.

[0006] The present invention is achieved through the following technical solution.

[0007] A filter cake cleaning device for a diaphragm filter press includes a filter press and a cleaning mechanism. The filter press has a thrust plate disposed on one side. The thrust plate has an inlet communicating with the filter chamber of the filter press, two lower liquid outlets at the bottom and two upper liquid outlets at the top. The cleaning mechanism includes a cleaning tank for storing cleaning liquid and a cleaning pump for pressurizing and conveying the cleaning liquid into the filter chamber of the filter press.

[0008] And a first transfer pipe for converging the liquid flowing out from the two lower outlet holes, the first transfer pipe being configured to control the liquid inside to flow from bottom to top and to maintain the flow at the same height as the upper outlet holes, so that the cleaning liquid can fill the filter chamber of the filter press and then flow downward to balance the pressure at both ends of the lower outlet holes.

[0009] And a second transmission conduit for converging the liquid flowing out of the two upper liquid outlets, the second transmission conduit being configured to control the liquid inside to flow from bottom to top and to maintain the flow at the same height as the upper liquid outlets, and then flow downwards to balance the pressure when the liquid flows out of the lower liquid outlet and the upper liquid outlet;

[0010] A cleaning waste liquid collection tank is used to collect the cleaning waste liquid output from the first transmission pipe and the second transmission pipe.

[0011] As a further improvement of the present invention, the first transmission pipe includes a first pipe section extending horizontally, a second pipe section connecting the first pipe section and extending vertically upward, and a third pipe section extending horizontally connecting the other end of the second pipe section. The first pipe section is used to collect the liquid flowing out of the two lower liquid outlets, and the third pipe section is set at the same height as the upper liquid outlet.

[0012] As a further improvement of the present invention, a first manifold assembly is provided between the first pipe section and the lower liquid outlet, including a first manifold and two first liquid outlet pipes respectively connected to the two lower liquid outlets. The two first liquid outlet pipes are symmetrically arranged along the axis of the first manifold, and the first manifold is connected to the first pipe section.

[0013] As a further improvement of the present invention, the filter press is connected to a filtrate collection tank for receiving filtrate. The filtrate collection tank is connected to the first manifold via a filtrate transmission pipe, which extends vertically downwards. A first control valve is provided on the filtrate transmission pipe, and a second control valve is provided on the first manifold at the rear end of the filtrate transmission pipe. The first control valve is used to control the connection and disconnection between the first manifold and the first pipe section, and the second control valve is used to control the connection and disconnection between the first manifold and the filtrate transmission pipe.

[0014] As a further improvement of the present invention, the second transmission pipe includes a fourth pipe segment extending vertically downward, a fifth pipe segment connected at one end to the fourth pipe segment and extending horizontally, a sixth pipe segment connected to the other end of the fifth pipe segment, and a seventh pipe segment. The sixth pipe segment extends vertically upward, and the seventh pipe segment extends horizontally and is set at the same height as the upper liquid outlet.

[0015] As a further improvement of the present invention, a second manifold assembly is provided between the first transmission pipe and the upper liquid outlet, including a second manifold and two second liquid outlet pipes respectively connected to the two upper liquid outlets. The two second liquid outlet pipes are symmetrically arranged along the axis of the second manifold, and the second manifold is connected to the fourth pipe segment.

[0016] As a further improvement of the present invention, a first turbidity meter is provided on the first output pipe for detecting the turbidity of the liquid output at the lower outlet; a second turbidity meter is provided on the second transmission pipe for detecting the turbidity of the liquid output at the upper outlet.

[0017] As a further improvement of the present invention, the output end of the first transmission pipeline is provided with a first regulating valve, the opening of the first regulating valve being adjustable to adjust the liquid outflow rate at the lower outlet hole according to the real-time detection result of the first turbidity meter.

[0018] The output end of the second transmission pipeline is equipped with a second regulating valve. The opening degree of the second regulating valve can be adjusted to adjust the liquid outflow rate at the upper liquid outlet according to the real-time detection result of the second turbidity meter.

[0019] As a further improvement of the present invention, a third manifold is connected to the cleaning waste liquid collection tank, the third manifold being used to collect the liquid flowing out of the first transmission pipe and the second transmission pipe and transport it to the cleaning waste liquid collection tank.

[0020] The present invention also provides a method for cleaning filter cake in a diaphragm filter press, applicable to the filter cake cleaning device in the above-mentioned technical solution, comprising the following steps:

[0021] Step 1: Start the cleaning pump to pressurize and deliver the cleaning solution to the filter chamber of the filter press, so that the cleaning solution is in full contact with the filter cake in the filter chamber, and adjust the opening of the first regulating valve and the second regulating valve to be the same.

[0022] Step 2: The turbidity of the liquid output from the lower outlet is detected in real time using the first turbidity meter; at the same time, the turbidity of the liquid output from the upper outlet is detected in real time using the second turbidity meter.

[0023] Step 3: Based on the real-time detection results of the first and second turbidimeters, adjust the opening of the first regulating valve and the opening of the second regulating valve; when the turbidity value detected by the first turbidimeter is higher than the turbidity value detected by the second turbidimeter, increase the opening of the first regulating valve while decreasing the opening of the second regulating valve; when the turbidity value detected by the first turbidimeter is lower than the turbidity value detected by the second turbidimeter, increase the opening of the second regulating valve while decreasing the opening of the first regulating valve.

[0024] Step 4: Continue step 3 for a period of time. When the detection results of the first turbidity meter and the second turbidity meter both reach the preset turbidity standard, stop the delivery of the cleaning solution and complete the filter cake cleaning.

[0025] The beneficial effects of this invention are:

[0026] 1. During cleaning, the cleaning liquid in the filter chamber first flows out from the lower outlet to the first transmission pipe under the action of gravity. The first transmission pipe causes the liquid to flow from bottom to top and maintains the liquid level in the pipe at the same height as the upper outlet. At this time, the lower outlet is resisted by the liquid in the first transmission pipe, which prevents the cleaning liquid in the filter chamber from draining out quickly. This allows the filter chamber to be filled, ensuring full contact between the filter cake and the cleaning liquid. This avoids incomplete cleaning due to dead corners and improves the cleaning effect. After the filter is filled with cleaning liquid, it can flow out from the upper outlet and converge through the second transmission pipe. Similarly, the liquid level in the pipe is maintained at the same height as the upper outlet. At this time, the outflow resistance of the upper and lower outlets tends to be the same, which creates a stable pressure field in the filter chamber. The cleaning liquid penetrates the filter cake at a relatively uniform flow rate, improving the uniformity of filter cake cleaning.

[0027] 2. This device can improve the cleaning effect and reduce the cleaning cost simply by optimizing the transmission pipeline structure of the filter press; at the same time, it can be directly adapted to existing diaphragm filter presses with upper and lower liquid outlets. Only the pipeline design needs to be changed, without modifying the main structure of the filter press, making it highly adaptable.

[0028] 3. It can switch between filter press mode and cleaning mode by opening and closing the first and second control valves without disassembling or replacing the pipeline, which helps to reduce the labor intensity of operators.

[0029] 4. By setting up a first turbidity meter and a second turbidity meter to monitor the turbidity of the liquid flowing out of the upper and lower liquid outlets in real time, and by dynamically adjusting the liquid discharge rate in combination with the first and second regulating valves, the pressure distribution can be adjusted in a timely manner according to the cleaning status of the upper and lower parts of the filter cake. On the one hand, this ensures that the overall cleaning effect of the filter cake is consistent and avoids incomplete or excessive cleaning in some areas. On the other hand, it can reduce the consumption of cleaning liquid and save cleaning costs. Attached Figure Description

[0030] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings to aid in understanding the objectives and advantages of the present invention, wherein:

[0031] Figure 1 This is a schematic diagram of the structure of a filter press and a filter cake washing device working together.

[0032] Figure 2 A schematic diagram of the push plate;

[0033] Figure 3 A schematic diagram of the structure of the push plate and the first manifold assembly; Detailed Implementation

[0034] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0035] The directional terms such as up, down, left, right, front, back, front, back, top, and bottom mentioned or possibly used in this specification are defined relative to the construction shown in the accompanying drawings. The terms "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively. These are relative concepts and may therefore vary depending on their location and usage. Therefore, these or other directional terms should not be interpreted as restrictive.

[0036] Example 1:

[0037] A filter cake cleaning device for a diaphragm filter press is used to clean the filter cake of filter press 1, as described in the following figure. Figure 1-2 The system includes a filter press 1 and a cleaning mechanism. The filter press 1 includes a thrust plate 11 on one side, with two lower liquid outlet holes 13 formed at the bottom and two upper liquid outlet holes 14 formed at the top. The diameters of the upper and lower liquid outlet holes 14 are equal. The thrust plate 11 has a feed inlet 12 communicating with the filter chamber of the filter press, two lower liquid outlet holes 13 formed at the bottom, and two upper liquid outlet holes 14 formed at the top. The diameters of the upper and lower liquid outlet holes 14 are equal. The feed inlet is directly connected to the main feed pipeline inside the filter press 1, allowing material or cleaning liquid to directly enter the filter chamber of the filter plate assembly from the thrust plate. It should be noted that the feed inlet 12 of the filter press 1 can be set to one or more according to actual usage requirements. When multiple feed inlets are set, each feed inlet is connected to the internal feed pipeline of the filter press 1.

[0038] Reference Figure 1-3 The cleaning mechanism includes a cleaning tank 2 for storing cleaning fluid, a cleaning pump 3, a first transmission pipe 4 for collecting liquid flowing from two lower outlet holes 13, a second transmission pipe 5 for collecting liquid flowing from two upper outlet holes 14, and a cleaning waste liquid collection tank 6. Specifically, the cleaning pump 3 pressurizes the cleaning fluid in the cleaning tank 2 and transports it through the pipes to the filter chamber of the filter press 1, providing power for the cleaning fluid to permeate the filter cake. The cleaning waste liquid collection tank 6 is located below the filter press and is used to receive the cleaning waste liquid flowing from the first transmission pipe 4 and the second transmission pipe 5. The first transmission pipe 4 is configured to control the upward flow of liquid inside and maintain it at the same height as the upper outlet holes 14, and then flow downward, so that the cleaning fluid can fill the filter chamber of the filter press 1, thereby balancing the pressure at both ends of the lower outlet holes 13. The second transmission pipe 5 is configured to control the internal liquid to flow from bottom to top and maintain it at the same height as the upper liquid outlet 14, and then flow downwards, thereby balancing the pressure of the cleaning fluid flowing out of the lower liquid outlet 13 and the upper liquid outlet 14 to be equal.

[0039] It should be noted that the cleaning solution used is clean water. The liquid flowing out from the upper outlet 14 and the lower outlet 13 is the cleaning waste liquid.

[0040] During cleaning, the cleaning fluid in the filter chamber first flows out from the lower outlet 13 to the first transmission pipe 4 under the action of gravity. The first transmission pipe 4 causes the liquid to flow from bottom to top and maintains the liquid level in the pipe at the same height as the upper outlet 14. At this time, the lower outlet 13 is resisted by the liquid in the first transmission pipe 4, which prevents the cleaning fluid in the filter chamber from being discharged quickly from the lower outlet 13, thus filling the entire filter chamber. The filter cake is in full contact with the cleaning fluid, avoiding incomplete cleaning due to dead corners and improving the cleaning effect. After the filter is filled with cleaning fluid, the cleaning fluid can flow out from the upper outlet 14 and converge through the second transmission pipe 5. Similarly, the liquid level in the pipe is maintained at the same height as the upper outlet 14. At this time, the outflow resistance of the upper outlet 14 and the lower outlet 13 tends to be the same, so that a stable pressure field is formed in the filter chamber. The cleaning fluid penetrates the filter cake at a relatively uniform flow rate, improving the uniformity of filter cake cleaning and reducing cleaning fluid consumption.

[0041] Meanwhile, the waste liquid after cleaning is collected in the cleaning waste liquid collection tank 6, which facilitates subsequent treatment or recycling, reducing environmental protection costs and minimizing resource waste.

[0042] In this embodiment, compared with the prior art, this device can improve the cleaning effect and reduce the cleaning cost simply by optimizing the transmission pipeline structure of the filter press 1; at the same time, it can be directly adapted to the existing diaphragm filter press 1 with upper and lower liquid outlet holes 13, requiring only changes to the pipeline design without modifying the main structure of the filter press 1, thus having strong adaptability.

[0043] More specifically, the first transmission pipe 4 includes a horizontally extending first pipe section 41, a second pipe section 42 connected at one end to the first pipe section 41 and extending vertically upward, and a horizontally extending third pipe section 43 connected to the other end of the second pipe section 42. The first pipe section 41 is used to collect the liquid flowing out of the two lower liquid outlets 13. The third pipe section 43 is at the same height as the plane where the upper liquid outlet 14 is located, that is, the liquid in the second transmission pipe 5 can flow stably at the same height as the upper liquid outlet 14. The transmission pipe section adopts a three-section structure of horizontal section + vertical section + horizontal section.

[0044] In addition, the bottom-up flow design of the second pipe section 42 can prevent air bubbles from lingering in the pipe, reduce pressure fluctuations caused by air bubbles, and improve cleaning stability.

[0045] Furthermore, a first manifold assembly is provided between the first pipe section 41 and the lower outlet hole 13, including two first outlet pipes 16 and a first manifold 15 respectively connected to the two lower outlet holes 13. One end of the first outlet pipe 16 is connected to the lower outlet hole 13, and the other end is connected to the first manifold 15. The two first outlet pipes 16 are symmetrically arranged along the axis of the first manifold 15. One end of the first manifold 15 is connected to the first pipe section 41, so that the path length and resistance of the liquid flowing into the first manifold 15 are the same, avoiding the pressure imbalance of the two lower outlet holes 13 caused by the liquid flowing out too quickly on one side. The flow speed of the cleaning liquid in the lower area of ​​the corresponding filter chamber is consistent, avoiding the situation of "one side has been drained while the other side is still stagnant".

[0046] In this embodiment, a filtrate collection tank 7 is connected to the filter press 1. The filtrate collection tank 7 is used to collect the filtrate flowing out of the lower outlet 13 during the filtration stage. The filtrate collection tank 7 is connected to the first manifold 15 through a filtrate transfer pipe. The filtrate transfer pipe 71 extends vertically downward to ensure that the filtrate flows smoothly into the filtrate collection tank 7 under the action of gravity. In addition, a first control valve 7a is provided on the filtrate transfer pipe 71, and a second control valve 7b is provided on the first manifold 15 at a position behind the filtrate transfer pipe 71. The first control valve 7a is used to control the opening and closing between the first manifold 15 and the first transfer pipe 4, and the second control valve is used to control the opening and closing between the first manifold 15 and the filtrate transfer pipe. The opening and closing of the first control valve 7a and the second control valve 7b can be controlled by a control system.

[0047] In filter press operation, the first control valve 7a is opened and the second control valve 7b is closed, allowing the filtrate to flow into the filtrate transfer pipe. In cleaning operation, the first control valve 7a is closed and the second control valve 7b is opened, allowing all the cleaning fluid to flow into the first transfer pipe. Therefore, switching between filter press and cleaning operations can be achieved by controlling the opening and closing of the first control valve 7a and the second control valve 7b without disassembling or replacing the pipeline, which helps reduce the labor intensity of operators.

[0048] More specifically, the second transmission pipe 5 includes a vertically downward extending fourth pipe section 51, a horizontally extending fifth pipe section 52 connected to the fourth pipe section 51 at one end, a sixth pipe section 53 connected to the other end of the fifth pipe section 52, and a seventh pipe section 54. The sixth pipe section 53 extends vertically upward, and the seventh pipe section 54 extends horizontally and is positioned at the same height as the upper liquid outlet 14. When liquid enters the second transmission pipe 5, it first flows through the fourth pipe section 51, then through the fifth pipe section 52 and the sixth pipe section 53, and finally flows out through the seventh pipe section 54. When the seventh pipe section 54 is filled with liquid, the upward flow of liquid in the sixth pipe section 53 is resisted by the liquid in the seventh pipe section 54, causing the liquid to flow out of the upper liquid outlet 14 to be resisted by the liquid in the seventh pipe section 54.

[0049] Furthermore, a second manifold assembly is provided between the second pipe section 42 and the upper liquid outlet 14. This includes two second liquid outlet pipes (not shown in the figure) connected to the two upper liquid outlets 14, and a second manifold 17. Specifically, one end of the second manifold 17 has two interfaces, connecting to the two second liquid outlet pipes respectively, and the other end connects to the fourth pipe section 51. The two second liquid outlet pipes are symmetrically arranged along the axis of the second manifold 17, ensuring that the path length and resistance of the liquid flowing into the second manifold 17 are the same. This prevents excessively rapid liquid outflow from one side, which could lead to pressure imbalance in the two lower liquid outlets 13, thus improving the uniformity and stability of the cleaning process. The structure of this second manifold assembly is the same as that of the first manifold assembly and will not be described in detail.

[0050] In this embodiment, a third manifold 61 is connected to the cleaning waste liquid collection tank 6. One end of the manifold has two branch interfaces, which are respectively connected to the outlet of the first transmission pipe 4 and the outlet of the second transmission pipe 5. The other end is connected to the top inlet 12 of the cleaning waste liquid collection tank 6. The manifold is used to collect the liquid flowing out of the first transmission pipe 4 and the second transmission pipe 5 and stably transport it to the cleaning waste liquid collection tank 6.

[0051] In this embodiment, a first turbidimeter 4c is installed on the first output pipe to detect the turbidity of the liquid output at the lower outlet 13, and a second turbidimeter 4d is installed on the second transmission pipe 5 to detect the turbidity of the liquid transported at the upper outlet 14. Based on the real-time detection results of the first turbidimeter 4c and the second turbidimeter 4d, the distribution of filter cake in the filter chamber can be determined. It should be noted that the first turbidimeter 4c and the second turbidimeter 4d are installed at the output ends of the first transmission pipe 4 and the second transmission pipe 5, respectively, and should be installed on straight pipe sections to ensure the accuracy of the detection results.

[0052] Furthermore, the output end of the first transmission pipe 4 is equipped with a first regulating valve 4a, the opening of which is adjustable to adjust the liquid outflow velocity at the lower outlet 13 based on the real-time detection results of the first turbidimeter 4c. Similarly, the output end of the second transmission pipe 5 is equipped with a second regulating valve 4b, the opening of which is adjustable to adjust the liquid outflow velocity at the upper outlet 14 based on the real-time detection results of the second turbidimeter 4d. The openings of the first regulating valve 4a and the second regulating valve 4b can be controlled by a control system. When the opening of the first regulating valve 4a changes, the outflow resistance at the lower outlet 13 changes, thereby changing the liquid outflow velocity from the lower outlet 13. Therefore, by setting up a first turbidity meter 4c and a second turbidity meter 4d to monitor the turbidity of the liquid flowing out of the upper liquid outlet 14 and the lower liquid outlet 13 in real time, and by dynamically adjusting the liquid outlet speed in conjunction with the first regulating valve 4a and the second regulating valve 4b, the pressure distribution can be adjusted in a timely manner according to the cleaning situation of the upper and lower parts of the filter cake. On the one hand, this ensures that the overall cleaning effect of the filter cake is consistent and avoids incomplete or excessive cleaning in some areas. On the other hand, it can reduce the consumption of cleaning liquid and save cleaning costs.

[0053] It should be noted that the minimum opening degree of the first regulating valve 4a and the second regulating valve 4b is ≥20% to avoid the flow rate being too low due to the opening being too small, which would affect the detection results of the turbidity meter.

[0054] Example 2:

[0055] A filter cake cleaning method for a diaphragm filter press 1, applied to the filter cake cleaning device in Example 1, includes the following steps:

[0056] Step 1: Start the cleaning pump 3 to pressurize and deliver the cleaning solution into the filter chamber of the filter press 1, ensuring full contact between the cleaning solution and the filter cake in the filter chamber. At this time, maintain the openings of the first regulating valve 4a and the second regulating valve 4b at the same level. It should be noted that initially, the openings of the first regulating valve 4a and the second regulating valve 4b can be controlled at 50% to facilitate subsequent adjustments. Furthermore, during cleaning, open the second control valve 7b and close the first control valve 7a.

[0057] Step 2: The turbidity of the liquid flowing out of the lower outlet hole 13 is detected in real time by the first turbidity meter 4c installed on the first transmission pipe 4; at the same time, the turbidity of the liquid flowing out of the upper outlet hole 14 is detected in real time by the second turbidity meter 4d installed on the second transmission pipe 5. Based on the detection results of the first turbidity meter 4c and the second turbidity meter 4d, the distribution of filter cake in the filter chamber can be determined.

[0058] Step 3: Based on the real-time detection results of the first turbidity meter 4c and the second turbidity meter 4d, adjust the opening of the first regulating valve 4a and the second regulating valve 4b. Specifically, when the turbidity value detected by the first turbidity meter 4c is higher than the turbidity value detected by the second turbidity meter 4d, it indicates that the filter cake in the lower part of the filter chamber is too thick. Adjust the opening of the first regulating valve 4a to be greater than the opening of the second regulating valve 4b. This is achieved by increasing the opening of the first regulating valve 4a and decreasing the opening of the second regulating valve 4b. Increasing the opening of the first regulating valve 4a can increase the outflow velocity of the liquid at the lower outlet hole 13, thereby improving the cleaning efficiency of the thicker filter cake in the lower part of the filter chamber. Decreasing the opening of the second regulating valve 4b can reduce the outflow velocity of the liquid at the lower outlet hole 13, keeping the flow rate of the cleaning liquid out of the filter chamber relatively consistent. Similarly, when the turbidity value detected by the first turbidity meter 4c is lower than the turbidity value detected by the second turbidity meter 4d, it indicates that the filter cake in the upper part of the filter chamber is too thick. Adjust the opening of the first regulating valve 4a to be smaller than the opening of the second regulating valve 4b. Specifically, this is achieved by increasing the opening of the second regulating valve 4b and decreasing the opening of the first regulating valve 4a. Increasing the opening of the second regulating valve 4b can increase the liquid outflow rate at the upper liquid outlet 14, thereby improving the cleaning efficiency of the thicker filter cake in the upper part of the filter chamber. Conversely, decreasing the opening of the first regulating valve 4a can reduce the liquid outflow rate at the lower liquid outlet 13.

[0059] Step 4: Continue step 3 for a period of time until the detection results of the first turbidity meter 4c and the second turbidity meter 4d both reach the preset turbidity standard. Stop the delivery of cleaning solution to complete the filter cake cleaning and avoid over-cleaning the filter cake, which would waste resources. At the same time, after cleaning, the second control valve 7b can be closed and the first control valve 7a can be opened to switch back to the filtrate collection circuit for subsequent filtration operations.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A filter cake cleaning device for a diaphragm filter press, comprising a filter press (1) and a cleaning mechanism, wherein the filter press (1) has a thrust plate (11) on one side, and the thrust plate (11) has an inlet (12) communicating with the filter chamber of the filter press (1), two lower liquid outlets (13) at the bottom and two upper liquid outlets (14) at the top, characterized in that, The cleaning mechanism includes a cleaning tank (2) for storing cleaning fluid and a cleaning pump (3) for pressurizing and delivering the cleaning fluid into the filter chamber of the filter press (1). And a first transmission pipe (4) for converging the liquid flowing out from the two lower outlet holes (13), the first transmission pipe (4) being configured to control the liquid inside to flow from bottom to top and to maintain the flow at the same height as the upper outlet hole (14), and then flow downward, so that the cleaning liquid can fill the filter chamber of the filter press (1) to balance the pressure at both ends of the lower outlet holes (13); And a second transmission pipe (5) for converging the liquid flowing out of the two upper liquid outlets (14), the second transmission pipe (5) being configured to control the liquid inside to flow from bottom to top and to maintain the flow at the same height as the upper liquid outlets (14), and then flow downward to balance the pressure when the liquid flows out of the lower liquid outlet (13) and the upper liquid outlets (14); The cleaning waste liquid collection tank (6) is used to collect the cleaning waste liquid output from the first transmission pipe (4) and the second transmission pipe.

2. The filter cake washing device for a diaphragm filter press according to claim 1, characterized in that, The first transmission pipe (4) includes a first pipe section (41) extending horizontally, a second pipe section (42) connecting the first pipe section (41) and extending vertically upward, and a third pipe section (43) extending horizontally connecting the other end of the second pipe section (42). The first pipe section (41) is used to collect the liquid flowing out of the two lower liquid outlets (13), and the third pipe section (43) is set at the same height as the upper liquid outlet (14).

3. The filter cake cleaning device for a diaphragm press according to claim 2, characterized in that, A first manifold assembly is provided between the first pipe section (41) and the lower outlet hole (13), including a first manifold (15) and two first outlet pipes (16) respectively connected to the two lower outlet holes (13). The two first outlet pipes (16) are symmetrically arranged along the axis of the first manifold (15), and the first manifold (15) is connected to the first pipe section (41).

4. The filter cake washing device for a diaphragm filter press according to claim 3, characterized in that, The filter press (1) is connected to a filtrate collection tank (7) for receiving filtrate. The filtrate collection tank (7) is connected to the first manifold (15) through a filtrate transfer pipe (71). The filtrate transfer pipe (71) extends vertically downward. A first control valve (7a) is provided on the filtrate transfer pipe (71), and a second control valve (7b) is provided on the first manifold (15) behind the filtrate transfer pipe (71).

5. The filter cake washing device for a diaphragm filter press according to claim 1, characterized in that, The second transmission pipe (5) includes a fourth pipe section (51) extending vertically downward, a fifth pipe section (52) connected at one end to the fourth pipe section (51) and extending horizontally, a sixth pipe section (53) connected to the other end of the fifth pipe section (52), and a seventh pipe section (54). The sixth pipe section (53) extends vertically upward, and the seventh pipe section (54) extends horizontally and is set at the same height as the upper liquid outlet (14).

6. The filter cake washing device for a diaphragm filter press according to claim 5, characterized in that, A second manifold assembly is provided between the first transmission pipe and the upper liquid outlet (14), including a second manifold (17) and two second liquid outlet pipes respectively connected to the two upper liquid outlets (14). The two second liquid outlet pipes are symmetrically arranged along the axis of the second manifold (17), and the second manifold (17) is connected to the fourth pipe section (51).

7. The filter cake washing device for a diaphragm filter press according to claim 1, characterized in that, The first output pipe is equipped with a first turbidity meter (4c) for detecting the turbidity of the liquid output at the lower outlet (13); the second transmission pipe (5) is equipped with a second turbidity meter (4d) for detecting the turbidity of the liquid output at the upper outlet (14).

8. The filter cake washing device for a diaphragm filter press according to claim 7, characterized in that, The first transmission pipe (4) is provided with a first regulating valve (4a) at its output end. The opening of the first regulating valve (4a) is adjustable to adjust the liquid outflow speed at the lower outlet hole (13) according to the real-time detection result of the first turbidity meter (4c). The output end of the second transmission pipe (5) is provided with a second regulating valve (4b). The opening of the second regulating valve (4b) is adjustable to adjust the liquid outflow rate at the upper liquid outlet (14) according to the real-time detection result of the second turbidity meter (4d).

9. The filter cake washing device for a diaphragm filter press according to claim 1, characterized in that, The cleaning waste liquid collection tank (6) is connected to a third manifold (61), which is used to collect the liquid flowing out of the first transmission pipe (4) and the second transmission pipe (5) and transport it to the cleaning waste liquid collection tank (6).

10. A method for cleaning filter cake from a diaphragm filter press, characterized in that, The filter cake cleaning device applied to the diaphragm filter press according to claim 8 includes the following steps: Step 1: Start the cleaning pump (3) to pressurize and deliver the cleaning liquid to the filter chamber of the filter press (1) so that the cleaning liquid is in full contact with the filter cake in the filter chamber, and adjust the opening degree of the first regulating valve (4a) and the second regulating valve (4b) to be the same. Step 2: The turbidity of the liquid output from the lower outlet (13) is detected in real time by the first turbidity meter (4c); at the same time, the turbidity of the liquid output from the upper outlet (14) is detected in real time by the second turbidity meter (4d). Step 3: Based on the real-time detection results of the first turbidimeter (4c) and the second turbidimeter (4d), adjust the opening of the first regulating valve (4a) and the opening of the second regulating valve (4b); when the turbidity value detected by the first turbidimeter (4c) is higher than the turbidity value detected by the second turbidimeter (4d), increase the opening of the first regulating valve (4a) while decreasing the opening of the second regulating valve (4b); when the turbidity value detected by the first turbidimeter (4c) is lower than the turbidity value detected by the second turbidimeter (4d), increase the opening of the second regulating valve (4b) while decreasing the opening of the first regulating valve (4a). Step 4: Continue step 3 for a period of time. When the detection results of the first turbidity meter (4c) and the second turbidity meter (4d) both reach the preset turbidity standard, stop the delivery of the cleaning solution and complete the filter cake cleaning.

Images