Online filter cake thickness monitor and measuring method thereof

Abstract

The invention discloses an online filter cake thickness monitor and a measuring method thereof, and relates to the field of filters, the technical scheme is that the online filter cake thickness monitor comprises a main pipe mounted on a filter tank body and a movable rod located in the main pipe and capable of stretching out and drawing back along the interior of the main pipe, a measuring plate is mounted on the surface of the movable rod, and a magnet is arranged on the measuring plate; the main pipe is internally provided with a driving structure for driving the movable rod to stretch out and draw back, the main pipe is internally provided with a detection module, and the tail end of the main pipe is provided with an electrical control module for controlling the movable rod to stretch out and draw back. On-line real-time monitoring of the thickness of the filter cake is achieved, manual regular inspection or off-line sampling is not needed, and timeliness and accuracy of monitoring are improved.

Description

Technical Field

[0001] This invention relates to the field of filters, and more specifically, to an online filter cake thickness monitor and its measurement method. Background Technology

[0002] In filtration processes, the critical impact of filter cake thickness on filtration efficiency and filter cartridge lifespan is manifested in the following ways: The filter cake, as a solid particle layer gradually forming on the filter cartridge surface during filtration, directly relates to the resistance of fluid flow through the cartridge. When the filter cake is thin, the pores between particles are large, allowing fluid to pass through smoothly and maintaining a high filtration efficiency. However, as the filter cake thickness increases, the pores are gradually filled with fine particles, significantly reducing the filter cake layer permeability and drastically increasing the fluid dynamic resistance. This not only leads to a significant decrease in filtration velocity but also necessitates increased system pressure to maintain flow rate, indirectly increasing energy consumption. Furthermore, excessively thick filter cakes can cause the filter cartridge to withstand excessive pressure for extended periods, easily leading to filter material fatigue or structural damage.

[0003] Because the filter cake is in a closed container (filter tank), the equipment is pressurized during operation, and the material is usually an opaque, non-conductive, or high-temperature hazardous liquid. As a result, it is impossible for humans to effectively detect the filter cake thickness by visual inspection or other instruments while the equipment is running. As a result, the industry currently relies on manual periodic shutdowns for inspection or offline sampling and measurement to monitor the filter cake thickness. This method not only fails to capture the dynamic changes in filter cake thickness in real time, but also easily leads to excessive accumulation of filter cake due to monitoring lag, which reduces the filtration effect. In addition, it requires frequent shutdowns, which seriously affects the continuity of production and increases labor costs and energy consumption.

[0004] Therefore, in order to solve the above-mentioned technical problems, this application proposes an online filter cake thickness monitor and its measurement method. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide an online filter cake thickness monitor and its measurement method.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an online filter cake thickness monitor, comprising a main tube installed on a filter tank, a movable rod located inside the main tube and capable of extending and retracting along the inside of the main tube, a measuring plate mounted on the surface of the movable rod, a magnet provided on the measuring plate, a drive structure for driving the extension and retraction of the movable rod provided inside the main tube, a detection module installed inside the main tube, and an electrical control module for controlling the extension and retraction of the movable rod installed at its end; Under the control of the electrical control module, the drive structure drives the movable rod to extend from the main pipe, so that the measuring plate is in close contact with the surface of the filter element inside the filter tank. When a filter cake forms on the filter element, the filter cake pushes the measuring plate and the movable rod in the opposite direction. The detection module calculates the thickness of the filter cake based on the change in the position of the magnet on the measuring plate. When the thickness reaches the value that needs to be cleaned, the detection module sends a signal to the electrical control module, which then controls the movable rod to retract into the main pipe, driving the measuring plate to move away from the filter element to clean the filter cake on the filter element. After cleaning is completed, the electrical control module controls the measuring plate to reset.

[0007] Preferably, the drive structure includes an extension port, a retraction port, and a retraction port provided on the main pipe.

[0008] Preferably, the electrical control module includes: Power supply module: Provides power to the electrical appliances on the electrical control module; Microprocessor control module: Based on the filter cake thickness signal transmitted by the detection module, it sends a signal to the drive module to control the extension and retraction state of the movable lever; Drive module: Based on the signals transmitted from the microprocessor control module, the drive structure is controlled to adjust its operating state in order to realize the extension and retraction of the movable rod.

[0009] Preferably, the detection module includes closely arranged Hall sensors or reed switches for detecting positional changes of magnets on the measuring plate.

[0010] Preferably, the main pipe is connected to the filter tank via a flange.

[0011] Preferably, a guide sleeve is provided between the movable rod and the main pipe.

[0012] Preferably, the head of the main pipe is equipped with an extension block connected to the flushing pipe, and the extension block has a cleaning port that faces the measuring plate when it is retracted, thereby cleaning the plate.

[0013] The method for measuring the thickness of the above-mentioned online filter cake monitor includes the following steps: Step 1: The drive module of the electrical control module controls the drive structure, which takes in air through the extended air port and pushes the movable rod to extend smoothly along the guide sleeve inside the main pipe, so that the measuring plate (including magnet) installed on the surface of the movable rod is tightly attached to the filter cloth on the surface of the filter element inside the filter tank. This position is used as the initial reference for measuring the filter cake thickness. Step 2: During the filtration process, a filter cake gradually forms on the surface of the filter element. As the thickness of the filter cake increases, it pushes the measuring plate and the movable rod in the opposite direction, causing the magnet on the measuring plate to move synchronously. The movable rod maintains a stable displacement under the constraint of the guide sleeve. Step 3: The detection module inside the main unit (containing closely arranged Hall sensors or reed switches) senses the changes in the spatial position of the magnet in real time: the relative distance between the magnet and the magnetic sensitive element changes, causing the output voltage signal of the Hall sensor to change or the on / off state of the reed switch to change. These changing signals are transmitted to the microprocessor control module of the electrical control module in real time. Step 4: After receiving the signal from the detection module, the microprocessor control module converts the change in magnetic field into the actual displacement of the movable rod through a preset algorithm. This displacement is equal to the real-time thickness of the filter cake, thus completing the accurate calculation of the thickness data. Step 5: When the microprocessor control module determines that the filter cake thickness has reached the threshold for cleaning, it sends a signal to the drive module: The drive module controls the drive structure to retract the air inlet and extend the air outlet to exhaust the air through the retracting exhaust outlet, so that the movable rod drives the measuring plate to retract into the main tube until the measuring plate is far away from the filter element surface, so as to avoid blocking the subsequent cleaning operation. Step 6: When the movable rod retracts to the preset position, the surface of the measuring plate is opposite to the cleaning port on the expansion block. The cleaning medium is sprayed out from the cleaning port to remove residual filter cake particles, oil stains and other impurities attached to the surface of the measuring plate. At the same time, the electrical control module synchronously starts the air intake back-blowing component connected to the filter element, and back-blowing cleans the filter cake on the surface of the filter element through high-pressure airflow. Step 7: After cleaning is completed, the electrical control module first controls the air intake backflushing component to stop working, and then drives the movable rod to extend along the guide sleeve again, so that the measuring plate is tightly attached to the filter cloth on the surface of the filter element again, restoring the initial reference position, and continuing to monitor the filter cake thickness in real time.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention achieves online real-time monitoring of filter cake thickness by setting up a retractable movable rod, a measuring plate with a magnet, a detection module, and an electrical control module, eliminating the need for manual periodic shutdowns for inspection or offline sampling, thus improving the timeliness and accuracy of monitoring and solving the problems in the background technology; 2. In this invention, the main pipe and the filter tank are connected by a flange, making installation and disassembly convenient; a guide sleeve is set between the movable rod and the main pipe to ensure the smoothness and accuracy of the extension and retraction of the movable rod; the extension block can be used to clean the measuring plate when it is retracted, ensuring the cleanliness of the measuring plate and improving the accuracy of the measurement. 3. When the filter cake thickness reaches the value that needs to be cleaned, the detection module can send a signal to the electrical control module in a timely manner. The electrical control module controls the movable rod to retract, moving the measuring plate away from the filter element, which facilitates the cleaning of the filter cake and realizes the automated linkage of monitoring and cleaning. 4. The present invention installs the detection module inside the main pipe, forming a physical barrier. The main pipe and the filter tank can be completely isolated in terms of pressure and liquid, so that the detection module is not affected by the various properties of the liquid inside the tank. Attached Figure Description

[0015] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 For the present invention Figure 1 Another perspective on the specific structure; Figure 3 This is a schematic diagram of the specific structure of the monitoring instrument in this invention; Figure 4 For the present invention Figure 3 Another perspective on the specific structure; Figure 5 This is a schematic diagram of the internal structure of the main tube in this invention; Figure 6 This is a schematic diagram of the specific structure of the monitoring instrument after the electrical control module is removed in this invention; Figure 7 This is a schematic diagram of the filter tank in this invention when no monitoring instrument is installed.

[0016] In the diagram: 1. Main pipe; 101. Extended air port; 102. Retracted exhaust port; 103. Retracted air port; 2. Movable rod; 3. Measuring plate; 4. Filter element; 5. Detection module; 6. Electrical control module; 7. Flange; 8. Expansion block; 801. Cleaning port; 9. Filter tank. Detailed Implementation

[0017] like Figure 1-7 As shown, this invention provides an online filter cake thickness monitor, including a main pipe 1 installed on a filter tank. The main pipe 1 is connected to the filter tank via a flange 7, which facilitates installation and disassembly. The high strength of the flange 7 connection ensures that the main pipe 1 maintains a stable connection under conditions such as pressure fluctuations and fluid impacts within the filter tank, preventing a decrease in the fit between the measuring plate 3 and the filter element 4 due to loose connections, thus affecting monitoring accuracy. Simultaneously, the flange 7 connection provides good sealing, preventing fluid leakage from the filter tank and ensuring production environment safety and process stability. The main pipe 1 contains a movable rod 2 that can extend and retract within it. A guide sleeve is provided between the movable rod 2 and the main pipe 1 to ensure the smoothness and accuracy of the extension and retraction process of the movable rod 2.

[0018] A measuring plate 3 is mounted on the surface of the movable rod 2. The measuring plate 3 is equipped with a magnet. The main tube 1 has a drive structure inside that drives the movable rod 2 to extend and retract. The drive structure includes an extension air port 101, a retraction air port 102, and a retraction air port 103 opened on the main tube 1.

[0019] The main pipe 1 houses a detection module 5, which includes closely arranged Hall effect sensors or reed switches for detecting positional changes of the magnets on the measuring plate 3. At the end of the main pipe 1 is an electrical control module 6 that controls the extension and retraction of the movable rod 2. The electrical control module 6 includes a power supply module, a microprocessor control module, and a drive module. The power supply module supplies power to the electrical components in the electrical control module 6. Based on the filter cake thickness signal from the detection module 5, the microprocessor control module sends a signal to the drive module to adjust the extension and retraction of the movable rod 2. Based on the signal from the microprocessor control module, the drive module controls the drive structure to adjust its operating state to achieve the extension and retraction of the movable rod 2.

[0020] The head of the main pipe 1 is equipped with an extension block 8 connected to the flushing pipe. The extension block 8 has a cleaning port 801, which aligns with the cleaning port 801 when the measuring plate 3 retracts, thus cleaning it and ensuring the cleanliness of the measuring plate 3, improving measurement accuracy. Specifically, when the measuring plate 3 retracts into the main pipe 1 to a preset position under the control of the electrical control module 6, the surface of the measuring plate 3 is exactly opposite the cleaning port 801. At this time, the cleaning medium is sprayed out from the cleaning port 801, directly acting on the surface of the measuring plate 3. This cleaning process effectively removes residual filter cake particles, oil, or other impurities adhering to the measuring plate 3 when it is attached to the filter element 4 to monitor the filter cake thickness. If these contaminants are not cleaned in time, the surface roughness of the measuring plate 3 will be too high, affecting its tight adhesion to the surface of the filter element 4, causing an initial position reference offset, and thus causing errors in the filter cake thickness measurement.

[0021] In use, the drive module of the electrical control module 6 controls the drive structure to intake air through the air port 101, pushing the movable rod 2 out of the main pipe 1 so that the measuring plate 3 is in close contact with the surface of the filter element 4 (the filter cloth in close contact with the surface of the filter element 4) inside the filter tank. When a filter cake forms on the filter element 4, the filter cake pushes the measuring plate 3 and the movable rod 2 in the opposite direction. The Hall sensor or reed switch of the detection module 5 detects the position change of the magnet on the measuring plate 3 and transmits the signal to the microprocessor control module, which calculates the thickness of the filter cake. When the thickness reaches the value required for cleaning, the microprocessor control module sends a signal to the drive module. The drive module controls the drive structure to take in air through the retractable air port 103 and exhaust air through the extended air port 101 through the retracted exhaust port 102, causing the movable rod 2 to retract into the main pipe 1 and move the measuring plate 3 away from the filter element 4 to avoid obstructing the cleaning operation. On the other hand, the electrical control module 6 simultaneously controls the air intake back-blowing component connected to the filter element 4 to start, using high-pressure airflow to back-blow and clean the filter cake on the surface of the filter element 4. After cleaning is completed, the electrical control module 6 first controls the air intake back-blowing component to stop working, and then drives the movable rod 2 to extend so that the measuring plate 3 is reset and re-adhere to the filter cloth on the surface of the filter element 4 (the same as the initial steps), continuing to monitor the filter cake thickness in real time.

[0022] It should be noted that the Hall sensors or reed switches arranged closely in the detection module 5 act as magnetic sensitive elements, which can accurately sense the changes in the magnetic field generated by the magnet on the measuring plate 3. When the filter cake pushes the measuring plate 3 and the movable rod 2 to move, the spatial position of the magnet changes accordingly, and the relative distance and angle between the magnet and the Hall sensor or reed switch change, resulting in a corresponding change in the voltage signal output by the Hall sensor or the on / off state of the reed switch. These changing signals are transmitted to the microprocessor control module in real time, and the magnetic field change is converted into a specific displacement through a preset algorithm, thereby accurately calculating the distance that the filter cake pushes the measuring plate 3 to move, i.e., the actual thickness of the filter cake. This detection method based on magnetic coupling does not require mechanical contact, which can avoid the impact of friction and wear on the measurement accuracy. Moreover, the Hall sensor or reed switch has a fast response speed and high resolution, and can capture subtle changes in the thickness of the filter cake in real time. Furthermore, the present invention installs the detection module 5 entirely inside the main pipe 1, forming a physical barrier. The main pipe 1 and the filter tank can be completely isolated in terms of pressure and liquid, so that the detection module 5 is not affected by the various properties of the liquid inside the tank.

[0023] The present invention also provides a measurement method for the above-mentioned online filter cake thickness monitor: Step 1: The drive module of the electrical control module 6 controls the drive structure to take in air through the extended air port 101, and pushes the movable rod 2 to extend smoothly along the guide sleeve inside the main pipe 1, so that the measuring plate 3 (including magnet) installed on the surface of the movable rod 2 is tightly attached to the filter cloth on the surface of the filter element 4 inside the filter tank 9. This position is used as the initial reference for measuring the filter cake thickness. Step 2: During the filtration process, a filter cake gradually forms on the surface of the filter element 4. As the thickness of the filter cake increases, it will push the measuring plate 3 and the movable rod 2 in the opposite direction, causing the magnet on the measuring plate 3 to move synchronously. The movable rod 2 maintains a stable displacement under the constraint of the guide sleeve. Step 3: The detection module 5 inside the main unit 1 (containing closely arranged Hall sensors or reed switches) senses the changes in the spatial position of the magnet in real time: the relative distance between the magnet and the magnetic sensitive element changes, causing the output voltage signal of the Hall sensor to change or the on / off state of the reed switch to change. These changing signals are transmitted to the microprocessor control module of the electrical control module 6 in real time. Step 4: After receiving the signal from the detection module 5, the microprocessor control module converts the change in magnetic field into the actual displacement of the movable rod 2 through a preset algorithm. This displacement is equal to the real-time thickness of the filter cake, thus completing the accurate calculation of the thickness data. Step 5: When the microprocessor control module determines that the filter cake thickness has reached the cleaning threshold, it sends a signal to the drive module: The drive module controls the drive structure to take in air through the retractable air port 103 and exhaust air through the extended air port 101 and the retractable exhaust port 102, so that the movable rod 2 drives the measuring plate 3 to retract into the main tube 1 until the measuring plate 3 is away from the surface of the filter element 4, so as to avoid blocking the subsequent cleaning operation. Step 6: When the movable rod 2 retracts to the preset position, the surface of the measuring plate 3 is opposite to the cleaning port 801 on the expansion block 8. The cleaning medium is sprayed out from the cleaning port 801 to remove residual filter cake particles, oil stains and other impurities attached to the surface of the measuring plate 3. At the same time, the electrical control module 6 synchronously starts the air intake back-blowing component connected to the filter element 4, and back-blowing cleans the filter cake on the surface of the filter element 4 through high-pressure airflow. Step 7: After cleaning is completed, the electrical control module 6 first controls the air intake backflushing component to stop working, and then drives the movable rod 2 to extend along the guide sleeve again, so that the measuring plate 3 is tightly attached to the filter cloth on the surface of the filter element 4, restoring the initial reference position, and continuing to monitor the filter cake thickness in real time.

[0024] The online filter cake thickness monitor and its measurement method of the present invention have the following advantages: By setting up a retractable movable rod 2, a measuring plate 3 with a magnet, a detection module 5, and an electrical control module 6, online real-time monitoring of filter cake thickness is realized, eliminating the need for manual periodic shutdowns for inspection or offline sampling, thus improving the timeliness and accuracy of monitoring. The main pipe 1 is connected to the filter tank 9 via flange 7, making installation and disassembly convenient; a guide sleeve is provided between the movable rod 2 and the main pipe 1 to ensure the smoothness and accuracy of the extension and retraction of the movable rod 2; the extension block 8 is provided to clean the measuring plate 3 when it is retracted, ensuring the cleanliness of the measuring plate 3 and improving the accuracy of the measurement. When the filter cake thickness reaches the value that needs to be cleaned, the detection module 5 can send a signal to the electrical control module 6 in a timely manner. The electrical control module 6 controls the movable rod 2 to retract, moving the measuring plate 3 away from the filter element 4, which facilitates the cleaning of the filter cake and realizes the automatic linkage of monitoring and cleaning. The detection module 5 is installed inside the main pipe 1, forming a physical barrier. The main pipe 1 and the filter tank can be completely isolated in terms of pressure and liquid, so that the detection module 5 is not affected by the various properties of the liquid inside the tank.

[0025] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Those skilled in the art can readily implement the present invention based on the accompanying drawings and the above description. However, any modifications, alterations, or variations made by those skilled in the art without departing from the scope of the present invention, utilizing the disclosed technical content, are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, or variations made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the present invention.

Claims

1. An online filter cake thickness monitor, characterized in that: Includes a main pipe (1) installed on the filter tank (9), a movable rod (2) located inside the main pipe (1) and capable of extending and retracting along the inside of the main pipe (1), a measuring plate (3) installed on the surface of the movable rod (2), a magnet provided on the measuring plate (3), a drive structure for driving the movable rod (2) to extend and retract is provided inside the main pipe (1), a detection module (5) is installed inside the main pipe (1), and an electrical control module (6) for controlling the extension and retraction of the movable rod (2) is installed at its end; Under the control of the electrical control module (6), the drive structure drives the movable rod (2) to extend from the main pipe (1), so that the measuring plate (3) is in close contact with the surface of the filter element (4) inside the filter tank (9). When a filter cake is formed on the filter element (4), the filter cake pushes the measuring plate (3) and the movable rod (2) in the opposite direction. The detection module (5) calculates the thickness of the filter cake based on the position change of the magnet on the measuring plate (3). When the thickness reaches the value that needs to be cleaned, the detection module (5) sends a signal to the electrical control module (6), and the electrical control module (6) controls the movable rod (2) to retract into the main pipe (1), driving the measuring plate (3) to move away from the filter element (4) to clean the filter cake on the filter element (4). After cleaning, the electrical control module (6) controls the measuring plate (3) to reset.

2. The online filter cake thickness monitor according to claim 1, characterized in that: The drive structure includes an extension port (101), a retraction port (102), and a retraction port (103) provided on the main pipe (1).

3. The online filter cake thickness monitor according to claim 1, characterized in that: The electrical control module (6) includes: Power supply module: provides power to the electrical appliances on the electrical control module (6); Microprocessor control module: Based on the filter cake thickness signal transmitted by the detection module (5), it sends a signal to the drive module to control the extension and retraction state of the control lever (2); Drive module: Based on the signal transmitted from the microprocessor control module, control the drive structure to adjust the running state so as to realize the extension and retraction operation of the movable rod (2).

4. The online filter cake thickness monitor according to claim 1, characterized in that: The detection module (5) includes closely arranged Hall sensors or reed switches for detecting changes in the position of magnets on the measuring plate (3).

5. The online filter cake thickness monitor according to claim 1, characterized in that: The main pipe (1) is connected to the filter tank (9) via a flange (7).

6. The online filter cake thickness monitor according to claim 1, characterized in that: A guide sleeve is provided between the movable rod (2) and the main tube (1).

7. The online filter cake thickness monitor according to claim 1, characterized in that: The head of the main pipe (1) is equipped with an extension block (8) connected to the flushing pipe. The extension block (8) has a cleaning port (801) which is opposite to the cleaning port (801) when the measuring plate (3) is retracted, so as to clean it.

8. A measurement method based on the online filter cake thickness monitor according to any one of claims 1-7, characterized in that: Includes the following steps: Step 1: The drive module of the electrical control module (6) controls the drive structure to take in air through the extended air port (101) and push the movable rod (2) to extend smoothly along the guide sleeve inside the main pipe (1), so that the measuring plate (3) installed on the surface of the movable rod (2) fits tightly against the filter cloth on the surface of the filter element (4) inside the filter tank (9), and this position is used as the initial reference for measuring the filter cake thickness. Step 2: During the filtration process, a filter cake gradually forms on the surface of the filter element (4). When the thickness of the filter cake increases, it will push the measuring plate (3) and the movable rod (2) in the opposite direction, causing the magnet on the measuring plate (3) to move synchronously. The movable rod (2) maintains a stable displacement under the constraint of the guide sleeve. Step 3: The detection module (5) inside the main unit (1) senses the changes in the spatial position of the magnet in real time, and these change signals are transmitted to the microprocessor control module of the electrical control module (6) in real time. Step 4: After receiving the signal from the detection module (5), the microprocessor control module converts the change in magnetic field into the actual displacement of the movable rod (2) through a preset algorithm. This displacement is equal to the real-time thickness of the filter cake, thus completing the accurate calculation of the thickness data. Step 5: When the microprocessor control module determines that the filter cake thickness has reached the threshold for cleaning, it sends a signal to the drive module: The drive module controls the drive structure to take in air through the retractable air port (103), and exhaust air through the extended air port (101) and the retracted exhaust port (102), so that the movable rod (2) drives the measuring plate (3) to retract into the main tube (1) until the measuring plate (3) is far away from the surface of the filter element (4) to avoid blocking subsequent cleaning operations; Step 6: When the movable rod (2) retracts to the preset position, the surface of the measuring plate (3) is opposite to the cleaning port (801) on the expansion block (8). The cleaning medium is sprayed out from the cleaning port (801) to remove the impurities attached to the surface of the measuring plate (3). At the same time, the electrical control module (6) synchronously starts the air intake back-blowing component connected to the filter element (4) and back-blowing cleans the filter cake on the surface of the filter element (4) through high-pressure airflow. Step 7: After cleaning, the electrical control module (6) first controls the air intake backflushing component to stop working, and then drives the movable rod (2) to extend along the guide sleeve again, so that the measuring plate (3) is tightly attached to the filter cloth on the surface of the filter element (4) to restore the initial reference position and continue to monitor the filter cake thickness in real time.

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