Anti-blocking device and method for stepped filtering alkaline electrolytic water hydrogen production system

Abstract

The invention discloses an anti-blocking device and an anti-blocking method for an alkaline electrolytic water hydrogen production system with stepped filtration. The anti-blocking device comprises a washing tank, a circulating liquid outlet pipeline connected with the washing tank, and a multi-stage gradient filtration unit arranged on the circulating liquid outlet pipeline of an alkaline liquid circulating pipeline in series, the backwashing self-cleaning system is connected to the multi-stage gradient filtering unit; the liquid level interlocking protection unit comprises a liquid level sensor arranged in the washing tank and a controller connected with the liquid level sensor, and the controller is connected with an execution mechanism of the backwashing self-cleaning system; and the heat management unit is used for maintaining the temperature of the circulating liquid above a crystallization point aiming at a special working condition that alkali liquid is easy to crystallize and block in a low-temperature environment. Through organic combination of multi-stage filtration, online self-cleaning, intelligent interlocking and anti-crystallization design, the pipeline blockage problem of the washing tank of the alkaline electrolytic water hydrogen production system is thoroughly solved, and the operation continuity, safety and maintenance convenience of the system are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of alkaline water electrolysis hydrogen production technology, specifically to an anti-clogging device and method for a cascade filtration alkaline water electrolysis hydrogen production system. Background Technology

[0002] In an alkaline water electrolysis hydrogen production system, the hydrogen gas produced by the electrolyzer, mixed with a large amount of alkaline solution (KOH or NaOH solution), enters a scrubbing tank through an alkaline solution circulation pipeline for gas-liquid separation and cleaning. The scrubbing tank uses spray water to dilute the alkaline solution and clean the hydrogen gas. Subsequently, the circulating liquid is pumped back to the electrolyzer or enters a subsequent processing unit through pipelines.

[0003] In existing technologies, the circulating liquid or water replenishment pipeline in the washing tank is usually only equipped with a simple mesh filter or no fine filtration device. Because the electrolyte may generate tiny solid particles (such as electrode slough, system corrosion products, crystal precipitates, etc.) during operation, and impurities may be introduced during the washing process, these impurities easily accumulate at the filter, causing blockage. Once the filter is blocked, it will lead to: abnormal water replenishment, increased pressure in the water replenishment pipeline, decreased flow, or even interruption, affecting the washing effect; uncontrolled liquid level, due to poor water flow, the liquid level in the washing tank rises abnormally, posing an overflow risk and affecting system safety; system shutdown, frequent shutdowns for maintenance to clean the filter are necessary, reducing system operating efficiency and hydrogen production continuity.

[0004] Therefore, there is an urgent need for a filter design that can operate automatically and continuously and is not easily clogged, in order to ensure the stable operation of the scrubbing tank and the entire hydrogen production system. Summary of the Invention

[0005] The technical problem this invention aims to solve is to overcome the issues of abnormal water replenishment and rising liquid levels caused by easy clogging in existing washing tank filters, and to provide a self-cleaning, anti-clogging, and online-maintainable filtration device and method that enables real-time monitoring and intelligent response of the filter's status. The specific technical solution is as follows: A cascade filtration system for alkaline water electrolysis to produce hydrogen, comprising a washing tank for achieving gas-liquid separation of the electrolyte, a water supply pipe connected to the washing tank, and a circulating liquid outlet pipe, wherein the anti-clogging filtration device includes: A multi-stage gradient filtration unit is connected in series on the circulating liquid outlet pipe of the alkali circulation pipeline to perform graded filtration of the alkali solution output from the washing tank. A backwashing self-cleaning system is connected to the multi-stage gradient filtration unit and is used to perform online backwashing on at least one stage filter in the multi-stage gradient filtration unit. The liquid level interlock protection unit includes a liquid level sensor installed in the washing tank and a controller connected to the liquid level sensor. The controller is also connected to the actuator of the backwash self-cleaning system.

[0006] Preferably, a water supply valve is provided on the water supply pipeline, and the water supply valve is connected to the controller.

[0007] Preferably, the actuator of the backwash self-cleaning system includes a flushing valve.

[0008] The present invention provides an anti-clogging device for a cascade filtration alkaline electrolysis water hydrogen production system, which also includes an optional heat management unit to maintain the circulating liquid temperature above the crystallization point in special working conditions where alkaline solutions are prone to crystallization and clogging at low temperatures.

[0009] Preferably, the multi-stage gradient filtration unit includes a primary coarse filter and a secondary fine filter arranged in series on the circulating liquid outlet pipe according to the flow direction of the circulating liquid; a circulating pump is provided on the circulating liquid outlet pipe; the primary coarse filter is a detachable basket or hanging basket filter, which is located before the inlet of the circulating pump or at the suction port inside the washing tank; the secondary fine filter is a cartridge filter, which is located after the outlet of the circulating pump.

[0010] Preferably, the secondary fine filter is a switchable or parallel-connected cartridge filter.

[0011] The circulating pump is connected to the controller.

[0012] The aforementioned multi-stage gradient filtration unit, through a primary coarse filter and a secondary fine filter arranged in series, can achieve graded interception from coarse to fine, effectively protecting the fine filter and extending its lifespan.

[0013] Preferably, the primary coarse filter has a filtration accuracy of 80 to 200 mesh; the secondary fine filter has a filtration accuracy of 10 to 50 micrometers.

[0014] Preferably, the backwash self-cleaning system is connected to the secondary fine filter and specifically includes: a flushing pipeline with its inlet connected to a high-pressure clean fluid source and its outlet connected to the post-filter side of the secondary fine filter; a flushing valve disposed on the flushing pipeline as the actuator of the backwash self-cleaning system; a drain pipeline and a drain valve disposed on the drain pipeline, the drain pipeline being connected to the pre-filter side of the secondary fine filter.

[0015] Furthermore, shut-off valves are provided at both ends of the primary coarse filter and the secondary fine filter to facilitate backwashing.

[0016] Preferably, a booster pump can also be installed on the flushing pipeline.

[0017] Furthermore, the backwash self-cleaning system also includes a differential pressure sensor for determining the clogging status of the multi-stage gradient filtration unit. Its two ends are respectively connected to the pre-filter side and the post-filter side of the secondary fine filter, and it is used to monitor the differential pressure ΔP across the secondary fine filter. The differential pressure sensor is connected to the controller.

[0018] By setting a differential pressure sensor, the controller can use high-pressure clean fluid to flush the filter element from the inside out when the differential pressure across the filter reaches a set value or the liquid level in the washing tank rises abnormally. This flushes the impurities attached to the surface of the filter element into the drain pipe and discharges them from the system, achieving self-cleaning without disassembling the filter element.

[0019] In this invention, the controller in the liquid level interlock protection unit is configured to: control the activation of the reverse flushing self-cleaning system when the pressure difference ΔP exceeds the first preset threshold P1, or when the liquid level L detected by the liquid level sensor in the washing tank exceeds the first warning water level L1.

[0020] The controller is further configured to control the backwashing self-cleaning system to perform backwashing according to the following steps: shutting off the circulation pump and pausing the flow of circulating fluid; opening the flushing valve and the drain valve to allow high-pressure clean fluid to flow back into the secondary fine filter from the post-filter side; after flushing for a predetermined time, closing the flushing valve and the drain valve; and restarting the circulation pump.

[0021] Furthermore, the liquid level interlock protection unit also includes an emergency bypass pipeline installed on the multi-stage gradient filtration unit and an emergency bypass valve installed on the emergency bypass pipeline; the controller is further configured to: when the liquid level L in the washing tank continues to rise after triggering backwashing and exceeds the higher second warning level L2, control the opening of the emergency bypass valve and generate an alarm signal.

[0022] Furthermore, the optional heat management unit is an electric heating tape or a jacketed heat exchanger laid outside the multi-stage gradient filtration unit and the alkali circulation pipeline, and is equipped with a temperature sensor connected to the controller to maintain the temperature of the fluid flowing through the filtration device above its crystallization point, so as to prevent the alkali from crystallizing at low temperature and causing the filtration device to become clogged.

[0023] As a further improvement of the present invention, the multi-stage gradient filtration unit further includes a cyclone electromagnetic particle catcher disposed on the circulating liquid outlet pipe and located between the primary coarse filter and the washing tank for capturing microparticles in the alkaline solution. The cyclone electromagnetic particle catcher includes a vertically arranged circular pipe with a closed cover at the top, a tangential inlet disposed on one side of the upper part of the circular pipe and tangentially entering the circular pipe, a central outlet pipe inserted into the circular pipe from the center of the upper end of the closed cover, a settling funnel connected to the lower end of the circular pipe, an annular magnet disposed on the outer wall of the circular pipe for capturing ferromagnetic particles in the alkaline solution, and an object disposed inside the circular pipe for capturing OH- ions carried in the alkaline solution. - A pair of annular thin-walled electrodes for ionic colloidal particles, wherein the polarities of the power supplies applied to the pair of annular thin-walled electrodes are opposite, and one of the pair of annular thin-walled electrodes is located on the inner wall of the circular pipe, while the other of the pair of annular thin-walled electrodes is located on the outer wall of the central outlet pipe; the cyclone electromagnetic particle catcher is also provided with an ultrasonic transducer for shaking the collected microparticles into a settling funnel.

[0024] In this invention, a bottom discharge valve is provided at the lower end of the settling funnel for periodic sewage discharge.

[0025] In this invention, the annular magnet in the cyclone electromagnetic particle collector is used to collect ferromagnetic particles in the alkaline solution, and a pair of annular thin-walled electrodes are used to collect colloidal particles in the alkaline solution. The annular magnet can be a permanent annular magnet or an electromagnetic induction annular magnet; to facilitate the detachment of ferromagnetic particles after collection, an electromagnetic induction annular magnet is preferred.

[0026] When a DC power supply is applied between a pair of annular thin-walled electrodes, a uniform radial DC electric field is formed, thereby attracting OH- charged electrodes. - Ionic colloidal particles are captured onto the positive electrode of a pair of annular thin-walled electrodes through directional migration.

[0027] Preferably, the polarity of the power supply applied to the pair of annular thin-walled electrodes can be switched between positive and negative.

[0028] The aforementioned cyclone electromagnetic particle catcher can operate in two modes: a conventional operating mode and a sorting operating mode.

[0029] In normal operating mode, since a ring magnet is installed on the outer wall of the circular pipe, when the ring magnet is working, the ferromagnetic particles in the alkaline solution will adhere to and be fixed on the surface of the ring thin-walled electrode on the inner wall of the circular pipe under the combined action of the centrifugal force of the swirling flow and the magnetic adsorption force of the ring magnet, thus achieving the capture of ferromagnetic particles.

[0030] In normal operating mode, the annular thin-walled electrode located on the inner wall of the circular pipe is powered by a positive electrode, and the annular thin-walled electrode located on the outer wall of the central outlet pipe is powered by a negative electrode, carrying OH... - Under the combined action of centrifugal force and electric field, ionic colloidal particles adhere to and are fixed on the surface of the annular thin-walled electrode on the inner wall of the circular pipe, achieving the effect of carrying OH groups. - Capture of ionic colloidal particles.

[0031] Therefore, under normal operating conditions, the annular thin-walled electrode surface on the inner wall of the circular pipe can simultaneously capture ferromagnetic particles and OH- charged particles in the alkaline solution. - Ionic colloidal particles.

[0032] Note that when entering the sewage discharge procedure from the above-mentioned normal working mode, the circulation pump needs to be turned off, the three-way switching discharge valve needs to be opened, and the power supply to the split combination electromagnetic ring and a pair of annular thin-walled electrodes needs to be cut off.

[0033] In this invention, the central outlet pipe has a larger diameter to form a high-speed annular thin-layer swirling fluid between the circular pipe and the central outlet pipe, thereby shortening the magnetic action distance and enhancing the magnetic adsorption effect of ferromagnetic microparticles in the alkaline solution.

[0034] Preferably, the annular magnet is a segmented composite electromagnetic ring, which is formed by a number of sector-shaped windings (which may have iron cores), fixed to a pair of half-joint clamps, and fixed to the outer wall of the circular pipe by the clamps; each sector-shaped winding has a pair of N-S pole pairs, and the sector-shaped windings are arranged in an alternating N-S arrangement in the circumferential direction. Preferably, the clamp is formed by a pair of semi-annular clamps joined together.

[0035] In the sorting operation mode, the annular thin-walled electrode located on the inner wall of the circular pipe is powered by a negative electrode, while the annular thin-walled electrode located on the outer wall of the central outlet pipe is powered by a positive electrode. This ensures that the alkaline solution contains OH-. - Under the influence of an electric field, ionic colloidal particles overcome the centrifugal force of the swirling current and are captured on the surface of the annular thin-walled electrode located on the outer wall of the central outlet tube. Ferromagnetic particles in the alkaline solution, under the combined action of centrifugal force and the magnetic attraction of the annular magnet, adhere to and are fixed to the surface of the annular thin-walled electrode on the inner wall of the circular tube, thus achieving the attraction of ferromagnetic particles and OH- charged particles. - Separate collection of ionic colloidal particles. Note that in the sorting mode, the electric field strength needs to be appropriately increased to overcome the centrifugal force of the colloidal particles and achieve effective collection.

[0036] Furthermore, in order to achieve the separation and discharge of the two different types of particles, the bottom discharge valve needs to be set as a three-way switching discharge valve to separate the ferromagnetic particle-containing contaminated liquid from the OH-containing liquid. -The separate and alternating discharge of ion-colloidal particulate contaminated liquids facilitates the further recovery and treatment of precious metals in the contaminated liquids.

[0037] Note that when entering the sorting and wastewater discharge process in the above sorting working mode, the circulating pump needs to be turned off, and the three-way switching discharge valve needs to be opened at the same time. Moreover, the three-way switching discharge valve, the segmented combined electromagnetic ring, and the pair of annular thin-walled electrodes need to work together in the following manner: (1) When the power supply of the split combination electromagnetic ring is turned off, its pair of annular thin-walled electrodes remain powered on. The three-way switching discharge valve switches to the discharge branch pipe of the ferromagnetic particle contaminant liquid. With the assistance of the ultrasonic transducer, the ultrasonic energy propagates in the liquid, accelerating the ferromagnetic particles to fall off from the surface of the annular thin-walled electrode on the inner wall of the circular pipe and discharge with the contaminant liquid to the discharge branch pipe of the ferromagnetic particle contaminant liquid.

[0038] (2) When the power supply to a pair of annular thin-walled electrodes is turned off, the split-type electromagnetic ring keeps the power supply on, and the three-way switching discharge valve switches to the position with OH. - In the branch pipe for discharging ion-colloidal particulate contaminated liquid, with the assistance of an ultrasonic transducer, ultrasonic energy propagates in the liquid, accelerating the OH- ions... - Ionic colloidal particles detach from the surface of the annular thin-walled electrode on the outer wall of the central outlet tube and are discharged along with the contaminated liquid to a location containing OH groups. - Branch pipe for discharging ionized colloidal particulate contaminant liquid.

[0039] In this invention, the cyclone electromagnetic particle catcher is also equipped with an electrophoretic backwashing mode, which includes periodically performing short-term reverse electrophoretic rinsing of the electrodes to prevent electrode scaling.

[0040] In this invention, the cyclone electromagnetic particle catcher is also provided with a demagnetization working mode. The demagnetization working mode includes applying an alternating magnetic field with decreasing amplitude before turning off the magnetic field, so as to reduce the residual magnetic attraction force of the ferromagnetic particles, so that the ferromagnetic particles can quickly fall off under the action of ultrasound and sink into the settling funnel below.

[0041] The above-mentioned demagnetization working mode can be interspersed in the sewage discharge process of the regular working mode and the sorting working mode, and should be activated just before the power supply of the segmented combined electromagnetic ring is turned off.

[0042] In this invention, the ultrasonic transducer inside the cyclone electromagnetic particle eliminator not only has the function of dropping materials, but also works in synergy with the high-speed cyclone to achieve the functions of preventing crystallization and removing scale inside the cyclone electromagnetic particle eliminator.

[0043] Preferably, there are several ultrasonic transducers, which are built into the upper part of the inner wall of the settling funnel and arranged at intervals along the circumference.

[0044] Preferably, a cross-shaped support frame is provided at the upper position inside the settling funnel, and the number of ultrasonic transducers is four. The four ultrasonic transducers are installed on the cross-shaped support frame and located directly below the annular space formed by the circular pipe and the central outlet pipe.

[0045] In this invention, the ultrasonic transducer is connected to an ultrasonic generator, and the ultrasonic generator is connected to a controller.

[0046] Preferably, an umbrella-shaped flow-blocking guide is provided inside the settling funnel and directly below the central outlet pipe. It is used to prevent the swirling flow from moving downward to the lower part of the settling funnel and to guide the swirling flow to converge from above the umbrella-shaped flow-blocking guide and enter the central outlet pipe. The umbrella-shaped flow-blocking guide is fixed on the cross support frame.

[0047] Preferably, the upper umbrella surface of the umbrella-shaped flow guide is configured as a concave arc streamline shape with the umbrella top axis as the center of symmetry, which can effectively reduce the resistance of the swirling flow entering the central liquid outlet pipe, thereby further reducing the disturbance of the swirling flow to the settling zone.

[0048] By installing an umbrella-shaped flow-blocking guide inside the settling funnel and directly below the central outlet pipe, the upper swirling collection zone and the lower settling and discharge zone can be effectively decoupled, preventing particles that fall to the bottom of the settling funnel from floating upwards.

[0049] Preferably, the circular pipe and the central outlet pipe are made of an insulating material that is pressure-resistant, alkali-resistant, and facilitates magnetic field penetration, such as an FRP composite pipe.

[0050] A method for preventing clogging in a cascade filtration alkaline water electrolysis hydrogen production system includes the following steps: S0: Circulation pump driving steps: Turn on the circulation pump. The alkaline solution in the washing tank flows through the primary coarse filter and the secondary fine filter in sequence under the drive of the circulation pump. After filtration, it returns to the system. S1: Real-time monitoring steps: Monitor the liquid level L of the washing tank and monitor the clogging status parameters of the multi-stage gradient filtration unit; Preferably, the clogging status parameter includes the pressure difference ΔP across the filter measured by a differential pressure sensor; S2: Automatic flushing step: When the liquid level L exceeds the first warning level L1, and / or the blockage status parameter exceeds a preset threshold, the backwashing self-cleaning system is automatically activated to perform online backwashing of the filter. S3: Safety protection steps: If the liquid level L continues to rise and exceeds the second warning level L2 after the automatic flushing step is performed, the emergency bypass pipeline will be automatically opened and a system maintenance alarm will be issued. At the same time, the electrolytic cell load will be reduced or a shutdown operation will be performed to ensure system safety.

[0051] Preferably, the specific operation process of the online backwashing in step S2 is as follows: the controller shuts off the circulation pump and pauses the main process of alkaline solution circulation; the flushing valve and the drain valve are opened, and the fine filter element is backwashed for a predetermined time T1 using high-pressure clean fluid (such as clean water or special flushing liquid); the flushing valve and the drain valve are closed, and the circulation pump is restarted.

[0052] As a further improvement to the anti-clogging method of the alkaline electrolysis water production system with cascade filtration in this invention, the method further includes the following steps: S4: Swirl Electromagnetic Particle Collector Step: During the process of the circulating alkaline solution flowing through the swirl electromagnetic particle collector, the particles in the alkaline solution are collected through the synergistic interaction of the swirling flow, magnetic field, and electric field.

[0053] Specifically, follow these sub-steps to operate collaboratively: S4.1 Conventional Collection Mode Operation: The controller energizes the segmented combined electromagnetic ring to generate a circumferential alternating magnetic field, while simultaneously applying a DC voltage to the pair of annular thin-walled electrodes, making the inner wall electrode of the circular pipe positive and the outer wall electrode of the central outlet pipe negative. Under the tangential inflow, the alkaline solution forms a high-speed swirling flow, and ferromagnetic particles are adsorbed onto the inner wall of the circular pipe under the combined action of centrifugal force and magnetic force, carrying OH groups. - Colloidal particles (such as Ni(OH)2 or Ru(OH)4) also migrate to the inner wall electrode surface of the circular pipe under the combined action of electrophoretic force and centrifugal force, achieving co-situ capture of the two types of particles; S4.2 Periodic electrophoretic backwashing: Every few hours of operation, the electrode polarity is automatically switched so that the electrode on the inner wall of the circular pipe is negative and the electrode on the outer wall of the central outlet pipe is positive. This is maintained for a few seconds to use the reverse electrophoretic force to peel off the colloidal layer accumulated on the electrode surface and prevent scale hardening. S4.3 Sorting, Collection, and Discharge Mode (Optional): The controller switches to sorting mode, setting the inner wall electrode of the circular pipe as the negative electrode and the outer wall electrode of the central outlet pipe as the positive electrode; increasing the electric field strength to allow OH- charged particles to pass through. - Colloidal particles (such as Ni(OH)2 or Ru(OH)4) are sufficient to overcome centrifugal force and migrate towards the center; ferromagnetic particles are still adsorbed on the inner wall; the circulation pump is turned off, and the three-way switching discharge valve and ultrasonic transducer are started to discharge the two types of pollutant liquids in sequence: first, the electromagnetic ring is turned off and the electric field is maintained to discharge the ferromagnetic particle liquid; then the electric field is turned off and the magnetic field is maintained to discharge the colloidal particle liquid.

[0054] In this invention, the ultrasonic transducer operates intermittently at a frequency of 20–40 kHz (duty cycle 10–30%), which can promote particle shedding and also inhibit the crystallization of alkaline solution in the low-temperature region through cavitation micro-perturbation.

[0055] Preferably, the sewage discharge pipe is equipped with an alkali-compatible flow metering device, and the controller is configured to: when starting sewage discharge, monitor the discharge flow rate in real time through the alkali-compatible flow metering device, and automatically close the three-way switching discharge valve when the cumulative discharge volume reaches a preset value, while simultaneously turning on the circulation pump.

[0056] This invention constructs an intelligent, efficient, and reliable anti-clogging system through the synergistic effects of multi-stage gradient filtration, online self-cleaning, liquid level safety interlock, and active heat management. In particular, by introducing a cyclone electromagnetic particle catcher, an active collection and sorting stage based on particulate matter properties is added to the front end of the physical filtration process. This fundamentally reduces the impurity load entering the fine filter, significantly extends the filter's service life and maintenance cycle, and improves the operational stability, safety, and economy of the entire alkaline water electrolysis hydrogen production system.

[0057] The beneficial effects of the present invention are further explained as follows: First, the anti-clogging device and method for an alkaline electrolysis water hydrogen production system of the present invention, through the organic combination of multi-stage gradient filtration, online self-cleaning, intelligent interlocking and anti-crystallization design, realizes the distribution of filtration load, avoids the direct impact and clogging of fine filters by large particles, effectively improves the anti-clogging ability, and extends the life of fine filters. Thus, it completely solves the problem of pipe blockage in the washing tank of the alkaline electrolysis water hydrogen production system, significantly improves the continuity, safety and maintenance convenience of the system operation, and has high engineering application value.

[0058] Secondly, the anti-clogging device and method for a cascade filtration alkaline electrolysis water hydrogen production system of the present invention can automatically clean the filter element online without interrupting the main process or with a very short interruption through a backwashing system, maintain the continuous operation of the system, and greatly reduce downtime maintenance time.

[0059] Third, the anti-clogging device and method for a cascade filtration alkaline water electrolysis hydrogen production system of the present invention, through liquid level interlock protection, links the filter status with the system's core safety parameter (liquid level), realizing intelligent predictive maintenance and proactive safety protection, and effectively preventing overflow accidents.

[0060] Fourth, the anti-clogging device and method for a cascade filtration alkaline electrolysis water hydrogen production system of the present invention effectively solves the special clogging cause of alkaline crystallization under low temperature conditions by setting up a heat management unit, thereby improving the reliability of the system under all-weather conditions.

[0061] Fifth, the present invention provides an anti-clogging device and method for a cascade filtration alkaline electrolysis water hydrogen production system. The primary coarse filter has a quick-disassembly structure, which facilitates daily inspection and cleaning of large particles. The fine filter reduces the frequency of disassembly through self-cleaning, thereby reducing maintenance workload and costs.

[0062] Sixth, the present invention provides an anti-clogging device and method for a cascade filtration alkaline water electrolysis hydrogen production system. It introduces an innovatively designed cyclone electromagnetic particle catcher, achieving stratified and classified collection of impurities of different properties and sizes through a combination of "cyclone electromagnetic particle catcher (pretreatment) + multi-stage gradient filtration (post-treatment)". The cyclone electromagnetic particle catcher actively removes most ferromagnetic and colloidal particles, greatly reducing the load on the downstream mechanical filter, significantly decreasing the clogging rate of the fine filter, reducing backwashing frequency, and effectively extending the filter element's service life and maintenance cycle.

[0063] Seventh, the present invention provides an anti-clogging device and method for a cascade filtration alkaline electrolysis water hydrogen production system. The cyclone electromagnetic particle collector's sorting mode can achieve preliminary separation of iron filings (possibly from equipment corrosion) and precious metal catalyst particles (from high-performance electrode coating peelings), which facilitates subsequent resource recycling and improves environmental protection and economy. Attached Figure Description

[0064] Figure 1 This is a schematic diagram of the overall structure of an anti-clogging device for a cascade filtration alkaline electrolysis water hydrogen production system according to the present invention; Figure 2 yes Figure 1 A schematic diagram of an improved scheme in which the secondary fine filters are arranged in parallel.

[0065] Figure 3 yes Figure 1 A schematic diagram of the cyclone electromagnetic particle eliminator in the image; Figure 4 yes Figure 3 A schematic diagram (top view) of the structure of the ring magnet (segmented combined electromagnetic ring).

[0066] In the diagram: 1. Washing tank; 2. Water supply pipe; 3. Circulating liquid outlet pipe; 4. Multi-stage gradient filtration unit; 5. Alkali circulation pipe; 6. Electrolytic cell; 7. Backwash self-cleaning system; 8. Liquid level interlock protection unit; 9. Liquid level sensor; 10. Controller; 11. Actuator (flushing valve); 12. Heat management unit (electric heating tape or jacketed heat exchanger); 13. Primary coarse filter; 14. Secondary fine filter; 15. Circulating pump; 16. Flushing pipe; 17. High-pressure clean fluid source; 18. Sewage pipe; 19. Sewage valve. 20. Differential pressure sensor; 21. Emergency bypass pipeline; 22. Emergency bypass valve; 23. Cyclone electromagnetic particle catcher; 24. Sealing cover; 25. Circular pipe; 26. Tangential inlet; 27. Central outlet pipe; 28. Settling funnel; 29. ​​Ring magnet (segmented combined electromagnetic ring); 30. Ring thin-walled electrode; 31. Ultrasonic transducer; 32. Sewage discharge pipe; 33. Bottom discharge valve (three-way switching discharge valve); 34. Sector winding; 35. Clamp; 36. Branch pipe for discharging ferromagnetic particle contaminated liquid; 37. OH- - 38. Branch pipe for discharge of ion-colloidal particulate pollutant liquid; 39. Alkali-compatible flow metering device; 40. Cross support frame; 51. Umbrella-shaped flow deflector. Detailed Implementation

[0067] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and examples. The following examples are only used to more clearly illustrate the technical solutions of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0068] Example 1: like Figures 1 to 4 The illustration shows an embodiment of an anti-clogging device for an alkaline water electrolysis hydrogen production system with cascade filtration according to the present invention. The device includes a washing tank 1 for achieving gas-liquid separation of the electrolyte, a water supply pipe 2 connecting the washing tank 1, and a circulating liquid outlet pipe 3. The anti-clogging filtration device includes: A multi-stage gradient filtration unit 4 is connected in series on the circulating liquid outlet pipe 3 of the alkaline liquid circulation pipe 5, and is used to perform graded filtration of the alkaline liquid output from the washing tank 1. The backwashing self-cleaning system 7 is connected to the multi-stage gradient filter unit 4 and is used to perform online backwashing on at least one stage filter in the multi-stage gradient filter unit 4. The liquid level interlock protection unit 8 includes a liquid level sensor 9 installed in the washing tank 1 and a controller 10 connected to the liquid level sensor 9. The controller 10 is also connected to the actuator 11 of the backwash self-cleaning system 7.

[0069] Preferably, a water supply valve is provided on the water supply pipeline 2, and the water supply valve is connected to the controller 10.

[0070] Preferably, the actuator 11 of the backwash self-cleaning system 7 includes a flushing valve.

[0071] The anti-clogging device for the alkaline electrolysis water production system of this embodiment also includes an optional heat management unit 12, which maintains the temperature of the circulating liquid above the crystallization point for special working conditions where alkaline solution is prone to crystallization and clogging in low-temperature environments.

[0072] Preferably, the multi-stage gradient filtration unit 4 includes a primary coarse filter 13 and a secondary fine filter 14 arranged in series on the circulating liquid outlet pipe 3 according to the flow direction of the circulating liquid; a circulating pump 15 is provided on the circulating liquid outlet pipe 3; the primary coarse filter 13 is a detachable basket-type or hanging basket-type filter, which is located before the inlet of the circulating pump 15 or at the suction port inside the washing tank 1; the secondary fine filter 14 is a cartridge filter, which is located after the outlet of the circulating pump 15.

[0073] Preferably, the secondary fine filter 14 is a cartridge filter that can be switched or connected in parallel.

[0074] The circulating pump 15 is connected to the controller 10.

[0075] The multi-stage gradient filtration unit 4, through the primary coarse filter 13 and the secondary fine filter 14 arranged in series, can achieve graded interception from coarse to fine, effectively protecting the secondary fine filter 14 and extending its lifespan.

[0076] Preferably, the primary coarse filter 13 has a filtration accuracy of 80 mesh to 200 mesh; the secondary fine filter 14 has a filtration accuracy of 10 micrometers to 50 micrometers.

[0077] Preferably, the backwash self-cleaning system 7 is connected to the secondary fine filter 14, specifically including: a flushing pipeline 16, the inlet of which is connected to a high-pressure clean fluid source 17, and the outlet of which is connected to the post-filter side of the secondary fine filter 14; a flushing valve 11, which is disposed on the flushing pipeline 16 and serves as the actuator 11 of the backwash self-cleaning system 7; a drain pipeline 18 and a drain valve 19 disposed on the drain pipeline 18, the drain pipeline 18 being connected to the pre-filter side of the secondary fine filter 14.

[0078] Furthermore, shut-off valves are provided at both ends of the primary coarse filter 13 and the secondary fine filter 14 to facilitate backwashing.

[0079] Preferably, a booster pump can also be installed on the flushing pipeline 16.

[0080] Furthermore, the backwash self-cleaning system 7 also includes a differential pressure sensor 20 for determining the clogging status of the multi-stage gradient filtration unit 4. Its two ends are respectively connected to the pre-filter side and the post-filter side of the secondary fine filter 14, and it is used to monitor the differential pressure ΔP across the secondary fine filter 14. The differential pressure sensor 20 is connected to the controller 10.

[0081] By setting a differential pressure sensor 20, the controller 10 can use a high-pressure clean fluid source 17 to flush the filter element from the inside out when the differential pressure across the filter reaches a set value or the liquid level in the washing tank 1 rises abnormally. This flushes the impurities attached to the surface of the filter element into the drain pipe 18 and discharges them from the system, thus achieving self-cleaning without disassembling the filter element.

[0082] In this embodiment, the controller 10 in the liquid level interlock protection unit 8 is configured to: control the start of the reverse flushing self-cleaning system 7 when the pressure difference ΔP exceeds the first preset threshold P1, or when the liquid level L in the washing tank 1 detected by the liquid level sensor 9 exceeds the first warning water level L1.

[0083] The controller 10 is further configured to control the backwashing self-cleaning system 7 to perform backwashing according to the following steps: shutting off the circulation pump 15 and pausing the flow of circulating fluid; opening the flushing valve 11 and the drain valve 19 to allow the high-pressure clean fluid source 17 to flow in reverse from the post-filter side of the secondary fine filter 14; after flushing for a predetermined time, closing the flushing valve 11 and the drain valve 19; and restarting the circulation pump 15.

[0084] Furthermore, the liquid level interlock protection unit 8 also includes an emergency bypass pipeline 21 disposed on the multi-stage gradient filtration unit 4 and an emergency bypass valve 22 disposed on the emergency bypass pipeline 21; the controller 10 is further configured to: when the liquid level L in the washing tank 1 continues to rise after triggering backwashing and exceeds the higher second warning water level L2, control the opening of the emergency bypass valve 22 and generate an alarm signal.

[0085] Furthermore, the optional heat management unit 12 is an electric heating tape or a jacketed heat exchanger laid outside the multi-stage gradient filtration unit 4 and the alkali circulation pipeline 5, and is equipped with a temperature sensor connected to the controller 10 to maintain the temperature of the fluid flowing through the filtration device above its crystallization point, so as to prevent the alkali from crystallizing at low temperature and causing the filtration device to become clogged.

[0086] As a further improvement to this embodiment, the multi-stage gradient filtration unit 4 further includes a cyclone electromagnetic particle catcher 23 disposed on the circulating liquid outlet pipe 3 and located between the primary coarse filter 13 and the washing tank 1 for capturing microparticles in the alkaline solution. The cyclone electromagnetic particle catcher 23 includes a vertically arranged circular pipe 25 with a closed cover plate 24 at the top, a tangential inlet 26 disposed on one side of the upper part of the circular pipe 25 and tangentially entering the circular pipe 25, a central outlet pipe 27 inserted into the circular pipe 25 from the center of the upper end of the closed cover plate 24, a settling funnel 28 connected to the lower end of the circular pipe 25, a ring magnet 29 disposed on the outer wall of the circular pipe 25 for capturing ferromagnetic particles in the alkaline solution, and an OH- ion magnet disposed inside the circular pipe 25 for capturing OH- ions in the alkaline solution. - A pair of annular thin-walled electrodes 30 for ionic colloidal particles, wherein the polarities of the power supply applied to the pair of annular thin-walled electrodes 30 are opposite, and one of the pair of annular thin-walled electrodes 30 is located on the inner wall of the circular pipe 25, while the other of the pair of annular thin-walled electrodes 30 is located on the outer wall of the central outlet pipe 27; the cyclone electromagnetic particle catcher 23 is also provided with an ultrasonic transducer 31 for shaking the captured microparticles into the settling funnel 28.

[0087] In this embodiment, a bottom discharge valve 33 is provided at the lower end of the settling funnel 28 for periodic sewage discharge.

[0088] In this embodiment, the annular magnet 29 in the cyclone electromagnetic particle collector 23 is used to collect ferromagnetic particles in the alkaline solution, and a pair of annular thin-walled electrodes 30 are used to collect colloidal particles in the alkaline solution. The annular magnet 29 can be a permanent annular magnet or an electromagnetic induction annular magnet; to facilitate the detachment of ferromagnetic particles after collection, an electromagnetic induction annular magnet is preferred.

[0089] When a DC power supply is applied between a pair of annular thin-walled electrodes 30, a uniform radial DC electric field is formed, thereby attracting OH- charged electrodes. - Ionic colloidal particles are captured onto the positive electrode of a pair of annular thin-walled electrodes 30 through directional migration.

[0090] Preferably, the polarity of the power supply applied to the pair of annular thin-walled electrodes 30 can be switched between positive and negative.

[0091] The aforementioned cyclone electromagnetic particle catcher 23 can operate in two modes: a conventional operating mode and a sorting operating mode.

[0092] In normal working mode, since an annular magnet 29 is provided on the outer wall of the circular pipe 25, when the annular magnet 29 is working, the ferromagnetic particles in the alkaline solution will adhere to and be fixed on the surface of the annular thin-walled electrode 30 on the inner wall of the circular pipe 25 under the combined action of the centrifugal force of the swirling flow and the magnetic adsorption force of the annular magnet 29, thus achieving the capture of ferromagnetic particles.

[0093] In normal operating mode, the annular thin-walled electrode 30 located on the inner wall of the circular pipe 25 is powered by a positive electrode, and the annular thin-walled electrode 30 located on the outer wall of the central outlet pipe 27 is powered by a negative electrode, carrying OH... - Under the combined action of centrifugal force and electric field, ionic colloidal particles adhere to and are fixed on the surface of the annular thin-walled electrode 30 on the inner wall of the circular pipe 25, achieving the effect of carrying OH- ions. - Capture of ionic colloidal particles.

[0094] Therefore, under normal operating conditions, the surface of the annular thin-walled electrode 30 on the inner wall of the circular pipe 25 can simultaneously capture ferromagnetic particles and OH- charged particles in the alkaline solution. - Ionic colloidal particles.

[0095] Note that when entering the sewage discharge procedure from the above-mentioned normal working mode, the circulation pump 15 needs to be turned off, the bottom discharge valve 33 needs to be opened, and the power supply to the annular magnet 29 and a pair of annular thin-walled electrodes 30 needs to be cut off.

[0096] In this embodiment, the central outlet pipe 27 has a larger diameter to form a high-speed annular thin-layer swirling fluid between the circular pipe 25 and the central outlet pipe 27, thereby shortening the magnetic action distance and enhancing the magnetic adsorption effect of ferromagnetic microparticles in the alkaline solution.

[0097] Preferably, the annular magnet 29 is a segmented composite electromagnetic ring, which is formed by a number of sector-shaped windings 34 (which may have iron cores), fixed to a pair of half-joint clamps 35, and fixed to the outer wall of the circular pipe 25 by the clamps 35; each sector-shaped winding 34 has a pair of N-S magnetic pole pairs, and the sector-shaped windings 34 are arranged in an alternating N-S arrangement in the circumferential direction. Preferably, the clamps 35 are formed by a pair of semi-annular clamps joined together.

[0098] In the sorting operation mode, the annular thin-walled electrode 30 located on the inner wall of the circular pipe 25 is powered by a negative electrode, and the annular thin-walled electrode 30 located on the outer wall of the central outlet pipe 27 is powered by a positive electrode. This ensures that the alkaline solution contains OH-. -Under the influence of an electric field, ionic colloidal particles overcome the centrifugal force of swirling flow and are captured on the surface of the annular thin-walled electrode 30 located on the outer wall of the central outlet pipe 27. Ferromagnetic particles in the alkaline solution, under the combined action of centrifugal force of swirling flow and the magnetic attraction of the annular magnet 29, adhere to and are fixed on the surface of the annular thin-walled electrode 30 located on the inner wall of the circular pipe 25, thus achieving the attraction of ferromagnetic particles and OH- charged particles. - Separate collection of ionic colloidal particles. Note that in the sorting mode, the electric field strength needs to be appropriately increased to overcome the centrifugal force of the colloidal particles and achieve effective collection.

[0099] Furthermore, in order to achieve the separation and discharge of the two different types of particles, the bottom discharge valve 33 needs to be set as a three-way switching discharge valve to separate the ferromagnetic particle-containing contaminated liquid from the OH-containing liquid. - The separate and alternating discharge of ion-colloidal particulate contaminated liquids facilitates the further recovery and treatment of precious metals in the contaminated liquids.

[0100] Note that when the above sorting working mode enters the sorting and sewage discharge process, the circulating pump 15 needs to be turned off, and the bottom discharge valve 33 needs to be opened at the same time. Moreover, the bottom discharge valve 33, the annular magnet 29 and the pair of annular thin-walled electrodes 30 need to work together in the following manner: (1) When the power supply of the ring magnet 29 is turned off, its pair of ring thin-walled electrodes 30 remain powered on. The bottom discharge valve 33 is switched to the branch pipe 36 for the discharge of ferromagnetic particle contaminant liquid. With the assistance of the ultrasonic transducer 31, the ultrasonic energy propagates in the liquid, accelerating the ferromagnetic particles to fall off from the surface of the ring thin-walled electrodes 30 on the inner wall of the circular pipe 25 and be discharged with the contaminant liquid to the branch pipe 36 for the discharge of ferromagnetic particle contaminant liquid.

[0101] (2) When the power supply to the pair of annular thin-walled electrodes 30 is turned off, the annular magnet 29 remains powered on, and the bottom discharge valve 33 switches to the position with OH. - In the branch pipe 37 for discharging ion-colloidal particulate contaminated liquid, with the assistance of ultrasonic transducer 31, ultrasonic energy propagates in the liquid, accelerating the flow of OH-. - The ion-colloidal particles detach from the surface of the annular thin-walled electrode 30 on the outer wall of the central outlet tube 27 and are discharged along with the contaminated liquid to a location containing OH groups. - Branch pipe 37 for discharging ionized colloidal particulate contaminant liquid.

[0102] In this embodiment, the cyclone electromagnetic particle catcher 23 is also provided with an electrophoretic backwashing working mode, which includes periodically performing short-term reverse electrophoretic rinsing on the annular thin-walled electrode 30 to prevent scaling on the annular thin-walled electrode 30.

[0103] In this embodiment, the cyclone electromagnetic particle catcher 23 is also provided with a demagnetization working mode. The demagnetization working mode includes applying an alternating magnetic field with decreasing amplitude before turning off the magnetic field, so as to reduce the remanent magnetic attraction force of the ferromagnetic particles, so that the ferromagnetic particles can quickly fall off under the action of the ultrasonic transducer 31 and sink into the settling funnel 28 below.

[0104] The above-mentioned demagnetization working mode can be interspersed in the sewage discharge procedures of the regular working mode and the sorting working mode, and should be activated just before the power supply to the ring magnet 29 is about to be turned off.

[0105] In this embodiment, the ultrasonic transducer 31 inside the cyclone electromagnetic particle eliminator 23 not only has the function of dropping materials, but also works in conjunction with the high-speed cyclone to achieve the functions of preventing crystallization and removing scale inside the cyclone electromagnetic particle eliminator 23.

[0106] Preferably, there are several ultrasonic transducers 31, which are built into the upper part of the inner wall of the settling funnel 28 and arranged at intervals along the circumference.

[0107] Preferably, a cross support frame 39 is provided at the upper position inside the settling funnel 28, and the number of ultrasonic transducers 31 is four. The four ultrasonic transducers 31 are installed on the cross support frame 39 and located directly below the annular space formed by the circular pipe 25 and the central liquid outlet pipe 27.

[0108] In this embodiment, the ultrasonic transducer 31 is connected to an ultrasonic generator, and the ultrasonic generator is connected to a controller 10.

[0109] Preferably, an umbrella-shaped flow-blocking guide 40 is provided inside the settling funnel 28 and directly below the central outlet pipe 27. It is used to prevent the swirling flow from moving downward to the lower region of the settling funnel 28 and to guide the swirling flow to converge from above the umbrella-shaped flow-blocking guide 40 and enter the central outlet pipe 27. The umbrella-shaped flow-blocking guide 40 is fixed on the cross support frame 39.

[0110] Preferably, the upper umbrella surface of the umbrella-shaped flow guide 40 is configured as a concave arc streamline shape with the umbrella top axis as the center of symmetry, which can effectively reduce the resistance of the swirling flow entering the central liquid outlet pipe 27, thereby further reducing the disturbance of the swirling flow to the settling zone.

[0111] By setting an umbrella-shaped flow-blocking guide 40 inside the settling funnel 28 and directly below the central outlet pipe 27, the upper swirling collection zone and the lower settling and sewage discharge zone can be effectively decoupled, preventing particles falling to the bottom of the settling funnel 28 from floating upwards.

[0112] Preferably, the circular pipe 25 and the central outlet pipe 27 are made of insulating materials that are pressure-resistant, alkali-resistant, and facilitate magnetic field penetration, such as FRP composite pipes.

[0113] Example 2: A method for preventing clogging in an alkaline water electrolysis hydrogen production system using the stepped filtration method of Example 1 includes the following steps: S0: Circulation pump 15 driving steps: Turn on circulation pump 15. Under the drive of circulation pump 15, the alkaline solution in washing tank 1 flows through primary coarse filter 13 and secondary fine filter 14 in sequence, and returns to the system after filtration. S1: Real-time monitoring steps: Monitor the liquid level L of the washing tank 1 and monitor the clogging status parameters of the multi-stage gradient filtration unit 4; Preferably, the blockage status parameter includes the pressure difference ΔP across the filter measured by the differential pressure sensor 20; S2: Automatic flushing step: When the liquid level L exceeds the first warning level L1, and / or the blockage status parameter exceeds a preset threshold, the backwashing self-cleaning system 7 is automatically activated to perform online backwashing of the filter. S3: Safety protection steps: If the liquid level L continues to rise and exceeds the second warning level L2 after the automatic flushing step is performed, the emergency bypass pipeline 21 will be automatically opened and a system maintenance alarm will be issued. At the same time, the load on the electrolytic cell 6 will be reduced or a shutdown operation will be performed to ensure system safety.

[0114] Preferably, the specific operation process of the online backwashing in step S2 is as follows: the controller 10 shuts down the circulation pump 15 and pauses the main process of alkaline solution circulation; the flushing valve 11 and the drain valve 19 are opened, and the secondary fine filter 14 filter element is backwashed for a predetermined time T1 using the high-pressure clean fluid source 17 (such as clean water or special flushing liquid); the flushing valve 11 and the drain valve 19 are closed, and the circulation pump 15 is restarted.

[0115] As a further improvement to the anti-clogging method of the alkaline electrolysis water production system with cascade filtration in this embodiment, the method further includes the following steps: S4: Swirl electromagnetic particle trapping step: During the process of the alkaline circulating liquid flowing through the swirl electromagnetic particle trap 23, the particles in the alkaline liquid are captured through the mutual coordination of swirling, magnetic field and electric field.

[0116] Specifically, follow these sub-steps to operate collaboratively: S4.1 Normal Collection Mode Operation: The controller 10 controls the annular magnet 29 to be energized to generate a circumferential alternating magnetic field, while simultaneously applying a DC voltage to the pair of annular thin-walled electrodes 30, making the annular thin-walled electrode 30 on the inner wall of the circular pipe 25 the positive electrode and the annular thin-walled electrode 30 on the outer wall of the central outlet pipe 27 the negative electrode; the alkaline solution forms a high-speed swirling flow under the action of the tangential inlet 26, and the ferromagnetic particles are adsorbed onto the inner wall of the circular pipe 25 under the combined action of centrifugal force and magnetic force, carrying OH groups. - Colloidal particles (such as Ni(OH)2 or Ru(OH)4) also migrate to the surface of the annular thin-walled electrode 30 on the inner wall of the circular pipe 25 under the combined action of electrophoretic force and centrifugal force, thus achieving co-situ capture of the two types of particles. S4.2 Periodic electrophoretic backwashing: Every few hours of operation, the polarity of the annular thin-walled electrode 30 is automatically switched so that the annular thin-walled electrode 30 on the inner wall of the circular pipe 25 is negative and the annular thin-walled electrode 30 on the outer wall of the central outlet pipe 27 is positive. This is maintained for a few seconds to use the reverse electrophoretic force to peel off the colloidal layer accumulated on the surface of the annular thin-walled electrode 30 and prevent scaling and hardening. S4.3 Sorting, Collection, and Discharge Mode (Optional): The controller 10 switches to the sorting mode, setting the annular thin-walled electrode 30 on the inner wall of the circular pipe 25 as the negative electrode and the annular thin-walled electrode 30 on the outer wall of the central outlet pipe 27 as the positive electrode; increasing the electric field strength to allow OH- charged particles to pass through. - Colloidal particles (such as Ni(OH)2 or Ru(OH)4) are sufficient to overcome centrifugal force and migrate towards the central outlet pipe 27; ferromagnetic particles are still adsorbed on the inner wall; the circulation pump 15 is turned off, the bottom discharge valve 33 and the ultrasonic transducer 31 are started, and the two types of pollutant liquids are discharged in sequence: first, the annular magnet 29 is turned off and the electric field is maintained to discharge the ferromagnetic particle liquid; then the electric field is turned off and the annular magnet 29 is maintained to discharge the colloidal particle liquid.

[0117] In this embodiment, the ultrasonic transducer 31 operates intermittently at a frequency of 20–40 kHz (duty cycle 10–30%), which can promote particle shedding and also inhibit the crystallization of alkaline solution in the low-temperature region through cavitation micro-perturbation.

[0118] Preferably, the sewage discharge pipe 32 is equipped with an alkali-compatible flow metering device 38, and the controller 10 is configured to: when starting sewage discharge, monitor the discharge flow rate in real time through the alkali-compatible flow metering device 38, and automatically close the bottom discharge valve 33 when the cumulative discharge volume reaches a preset value, while simultaneously turning on the circulation pump 15.

[0119] This embodiment utilizes the synergistic effect of the multi-stage gradient filtration unit 4, the backwash self-cleaning system 7, the liquid level interlock protection unit 8, and the heat management unit 12 to construct an intelligent, efficient, and reliable anti-clogging system. In particular, by introducing the cyclone electromagnetic particle catcher 23, an active collection and sorting stage based on the properties of particulate matter is added to the front end of the physical filtration process. This fundamentally reduces the impurity load entering the secondary fine filter 14, significantly extending the filter's service life and maintenance cycle, and improving the operational stability, safety, and economy of the entire alkaline water electrolysis hydrogen production system.

[0120] Example 3: This is a standard industrial hydrogen production system (producing approximately 500 tons of hydrogen per year). This embodiment is applicable to most industrial continuous hydrogen production scenarios.

[0121] System Configuration Washing tank 1 is a vertical cylindrical tank with a volume of 6 cubic meters and a design pressure of 1.8 MPa. The core of the filtration system includes: Primary coarse filter 13: Located at the bottom outlet of the washing tank 1, it is a 316L stainless steel basket filter with a pore size of 1.0 mm (approximately 18 mesh) to intercept all large particles that may damage the circulation pump 15 or jam the secondary fine filter 14.

[0122] Secondary fine filter 14: Located after the circulation pump 15, it adopts a parallel dual-filter tank design, with each filter tank containing multiple 25-micron precision polypropylene melt-blown pleated filter cartridges. One is in use, one is on standby, or both can operate simultaneously.

[0123] The reverse flushing self-cleaning system 7 consists of a high-pressure clean fluid source 17 pipeline, an actuator 11 (pneumatic diaphragm regulating valve), a small booster pump, and a corresponding drain valve 19.

[0124] Liquid level interlock protection unit 8: The core is the controller 10, which receives in real time the signals from the differential pressure sensor 20 installed before and after the secondary fine filter 14, the liquid level sensor 9 of the washing tank 1, and the pipeline temperature sensor.

[0125] Workflow and Control Logic Normal operation: After the alkaline solution is initially filtered by the primary coarse filter 13, it is sent by the circulation pump 15 to the secondary fine filter 14 for fine filtration, and the clean alkaline solution is returned to the system.

[0126] Automatic backwash trigger: Triggered when any of the following conditions are met: (A) The pressure difference across the secondary fine filter 14 lasts for more than 0.12 MPa for 60 seconds.

[0127] (B) The liquid level in washing tank 1 rises at an abnormal rate (e.g., more than 5 cm per minute), and other causes such as a faulty water supply valve have been ruled out.

[0128] Backwash sequence (taking single tank flushing as an example): The controller 10 issues a command to slowly close the outlet valve of the filter tank to be flushed, and at the same time switch to the standby filter tank.

[0129] After completely closing the outlet valve, immediately open the drain valve 19 of the filter tank to release pressure.

[0130] After a short delay, the flushing valve 11 is opened for backwashing. A high-pressure clean fluid source 17 of 0.8–1.0 MPa flows out from inside the filter element in the reverse direction, forcefully stripping the dirt off the outer surface of the filter element.

[0131] Waste flows with the water through drain valve 19 into the waste liquid tank; high-intensity flushing lasts for about 45–60 seconds.

[0132] Close the flushing valve 11 and the drain valve 19 in sequence, and finally slowly open the filter tank outlet valve to put it back into the system. The whole process takes about 2-3 minutes and has little impact on the main process.

[0133] Safety interlock protection: If the blockage is not cleared after rinsing and the liquid level continues to rise to a high alarm value (such as 85% of the tank height), the system will issue a warning.

[0134] If the liquid level rises to a higher alarm value (such as 90%), the controller 10 will automatically open the emergency bypass valve 22 to ensure that the washing tank 1 does not overflow, and at the same time issue an emergency maintenance alarm.

[0135] When the liquid level reaches an emergency high level (e.g., 95%), the system interlocks to stop the operation of electrolytic cell 6 to ensure absolute safety.

[0136] Anti-crystallization management: A heat management unit 12 (self-regulating electric heating tape) is installed on the outer shell of the multi-stage gradient filter unit 4 and the alkali circulation pipeline 5. It automatically activates when the temperature drops below 15 degrees Celsius to maintain the local temperature at 20–30 degrees Celsius and prevent alkali crystallization.

[0137] Example 4: This embodiment of a modular containerized hydrogen production unit is designed for applications requiring compact space and rapid deployment.

[0138] Design Features The entire filtration, flushing, and control unit is highly integrated into a steel module approximately 2.5 meters long, 1.5 meters wide, and 2.2 meters high. It employs a layered layout: the lower layer houses the circulation pump 15 and the primary coarse filter tank 13; the middle layer houses the secondary fine filter tank 14; and the upper layer contains the control cabinet for the controller 10. All piping connections use compression fittings for easy and quick installation and maintenance.

[0139] Intelligent diagnostic function The controller 10 has an embedded algorithm that can automatically identify various abnormal patterns: Progressive clogging: The differential pressure sensor 20 signal rises steadily and slowly, and the system performs standard backflushing as planned.

[0140] Sudden blockage: The differential pressure sensor 20 signal jumps sharply in a short period of time, and the system immediately performs a pulse flushing at a higher pressure (such as 1.2 MPa).

[0141] Filter element damage: The differential pressure sensor 20 signal drops abnormally and the turbidity of the outlet liquid increases. The system automatically locks the faulty secondary fine filter 14 and switches to the standby tank, prompting the user to replace the filter element.

[0142] Valve malfunction: The valve action command and feedback signal do not match. After the system attempts to repeat the operation, it locks the malfunction, switches to manual mode, and issues an alarm.

[0143] Example 5: To address high solids content or harsh operating conditions, this embodiment is suitable for initial operation of electrolytic cells after major overhaul, and for scenarios involving the use of recycled alkali or raw materials with high impurity levels.

[0144] Three-stage filtration enhancement An additional hydrocyclone separator is added before the standard two-stage filtration, or a higher-performance hydrocyclone electromagnetic particle catcher 23 is used to pre-remove more than 80% of coarse particles larger than 100 micrometers. An automatic slag discharge valve is installed at the bottom for timed slag discharge. The fine filtration stage uses two filter cartridges in series: the first stage uses a 50-micron filter cartridge to bear the main load, and the second stage uses a 10-micron filter cartridge for "polishing" filtration. A booster pump is installed between the two stages to compensate for the pressure drop.

[0145] Enhanced backwashing program The flushing pressure is increased to 1.5 MPa, and a "gas-liquid pulse" mode is adopted: water is flushed first, then compressed air is injected instantaneously to generate a "hammer" effect to loosen the filter cake, and then water is flushed again. This cycle is repeated several times, which has an excellent removal effect on viscous substances.

[0146] Example 6: Application in extremely cold regions: This embodiment is designed for regions where the ambient temperature is consistently below zero during winter.

[0147] All-round heat preservation and heat tracing The tank of the multi-stage gradient filtration unit 4, all valves, and the sewage pipe 18 are all insulated with thick polyurethane and wrapped with a heat management unit 12 (electric heating tape). The temperature sensor is linked with the controller 10 to automatically adjust the power of the heat management unit 12 according to the ambient temperature, ensuring that the temperature of any part is not lower than 5 degrees Celsius.

[0148] Anti-freeze shutdown and startup procedures When the system shuts down, it automatically executes a purging procedure: closing the inlet valve, opening the drain valve 19 and the exhaust valve in sequence, and finally purging the residual liquid in the alkaline solution circulation pipeline 5 with nitrogen. During standby, the thermal management unit 12 is maintained at a minimum operating level. Before restarting, the system is preheated to above 15 degrees Celsius before it can be put into operation and the backwash self-cleaning system 7 function can be activated.

[0149] Example 7: This embodiment of the intelligent predictive maintenance system is designed for modern smart factories and aims to achieve superior operational efficiency.

[0150] Data-driven decision making The system not only monitors real-time data, but also trains a predictive model using long-term historical data (differential pressure sensor 20 signal, flow rate, temperature, flushing effect, load rate, etc.). The model can predict the development trend of differential pressure in the secondary fine filter 14 24–48 hours in advance and identify the type of blockage (such as particulate or crystalline blockage).

[0151] Optimize operating strategies Based on the prediction results, the system no longer mechanically triggers flushing according to a fixed differential pressure threshold, but instead proactively performs preventative flushing at the optimal time point (such as before the next planned shutdown or during periods of low electricity prices). At the same time, the flushing parameters are automatically adjusted according to the identified blockage type (e.g., for crystalline blockages, the temperature of the high-pressure clean fluid source 17 is appropriately increased or the thermal management unit 12 is activated for preheating).

[0152] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A clogging prevention device for a stepped filtration alkaline water electrolysis hydrogen production system, characterized in that, The system includes a washing tank for achieving gas-liquid separation of the electrolyte, a water supply pipe connected to the washing tank, and a circulating liquid outlet pipe. The anti-clogging filter device comprises: A multi-stage gradient filtration unit is connected in series on the circulating liquid outlet pipe of the alkali circulation pipeline to perform graded filtration of the alkali solution output from the washing tank. A backwashing self-cleaning system is connected to the multi-stage gradient filtration unit and is used to perform online backwashing on at least one stage filter in the multi-stage gradient filtration unit. The liquid level interlock protection unit includes a liquid level sensor installed in the washing tank and a controller connected to the liquid level sensor. The controller is also connected to the actuator of the backwash self-cleaning system. The heat management unit is designed to maintain the circulating fluid temperature above the crystallization point, especially in low-temperature environments where alkali solutions are prone to crystallization and blockage. The multi-stage gradient filtration unit is equipped with a cyclone electromagnetic particle catcher for capturing microparticles in the alkaline solution. The cyclone electromagnetic particle catcher has a conventional operating mode and a sorting operating mode. In the sorting operating mode, the cyclone electromagnetic particle catcher separates ferromagnetic particles and particles carrying OH groups from the alkaline solution. - The ion-colloidal particles were collected separately.

2. The anti-clogging device for a stepped filtration alkaline electrolysis water hydrogen production system according to claim 1, characterized in that, The multi-stage gradient filtration unit includes a primary coarse filter and a secondary fine filter connected in series on the circulating liquid outlet pipe according to the flow direction of the circulating liquid; a circulating pump is installed on the circulating liquid outlet pipe; the primary coarse filter is a detachable basket or hanging basket filter, which is installed before the inlet of the circulating pump or at the suction port inside the washing tank; the secondary fine filter is a cartridge filter, which is installed after the outlet of the circulating pump.

3. The anti-clogging device for a stepped filtration alkaline electrolysis water hydrogen production system according to claim 1, characterized in that, The backwash self-cleaning system is connected to the secondary fine filter and specifically includes: a flushing pipeline with its inlet connected to a high-pressure clean fluid source and its outlet connected to the post-filter side of the secondary fine filter; a flushing valve disposed on the flushing pipeline as the actuator of the backwash self-cleaning system; a drain pipeline and a drain valve disposed on the drain pipeline, the drain pipeline being connected to the pre-filter side of the secondary fine filter.

4. The anti-clogging device for a stepped filtration alkaline electrolysis water hydrogen production system according to claim 1, characterized in that, The backwash self-cleaning system also includes a differential pressure sensor for determining the clogging status of the multi-stage gradient filtration unit. Its two ends are respectively connected to the pre-filter side and the post-filter side of the secondary fine filter, and it is used to monitor the differential pressure ΔP across the secondary fine filter. The differential pressure sensor is connected to the controller.

5. The anti-clogging device for a stepped filtration alkaline electrolysis water hydrogen production system according to claim 4, characterized in that, The controller in the liquid level interlock protection unit is configured to start the reverse flushing self-cleaning system when the pressure difference ΔP exceeds the first preset threshold P1, or when the liquid level L detected by the liquid level sensor in the washing tank exceeds the first warning water level L1.

6. The anti-clogging device for a stepped filtration alkaline electrolysis water hydrogen production system according to claim 1, characterized in that, The liquid level interlock protection unit also includes an emergency bypass pipeline installed on the multi-stage gradient filtration unit and an emergency bypass valve installed on the emergency bypass pipeline; the controller is further configured to: when the liquid level L in the washing tank continues to rise after triggering backwashing and exceeds the higher second warning level L2, control the opening of the emergency bypass valve and generate an alarm signal.

7. The anti-clogging device for a stepped filtration alkaline electrolysis water hydrogen production system according to claim 1, characterized in that, The heat management unit is an electric heating tape or a jacketed heat exchanger installed outside the multi-stage gradient filtration unit and the alkali circulation pipeline. It is used to maintain the temperature of the fluid flowing through the filtration device above its crystallization point and prevent the alkali from crystallizing at low temperatures.

8. The anti-clogging device for a stepped filtration alkaline electrolysis water hydrogen production system according to claim 1, characterized in that, The cyclone electromagnetic particle catcher is installed on the circulating liquid outlet pipe and located between the primary coarse filter and the washing tank. The cyclone electromagnetic particle catcher includes a vertically mounted circular pipe with a closed cover at the top; a tangential inlet located on one side of the upper part of the circular pipe, tangentially entering the circular pipe; a central outlet pipe inserted into the circular pipe from the center of the upper end of the closed cover; a settling funnel connected to the lower end of the circular pipe; a ring magnet on the outer wall of the circular pipe for collecting ferromagnetic particles in the alkaline solution; and a magnet inside the circular pipe for collecting OH- ions in the alkaline solution. - A pair of annular thin-walled electrodes for ionic colloidal particles, wherein the polarities of the power supplies applied to the pair of annular thin-walled electrodes are opposite, and one of the pair of annular thin-walled electrodes is located on the inner wall of the circular pipe, while the other of the pair of annular thin-walled electrodes is located on the outer wall of the central outlet pipe; the cyclone electromagnetic particle catcher is also provided with an ultrasonic transducer for shaking the collected microparticles into a settling funnel.

9. A method for preventing clogging in an alkaline water electrolysis hydrogen production system employing a stepped filtration system according to any one of claims 1-8, characterized in that, Includes the following steps: S1: Real-time monitoring steps: Monitor the liquid level L of the washing tank and monitor the clogging status parameters of the multi-stage gradient filtration unit; S2: Automatic flushing step: When the liquid level L exceeds the first warning water level L1, and / or the blockage status parameter exceeds the preset threshold, the backwashing self-cleaning system is automatically started to perform online backwashing of the filter; S3: Safety protection steps: If the liquid level L continues to rise and exceeds the second warning level L2 after the automatic flushing step is performed, the emergency bypass pipeline will be automatically opened and a system maintenance alarm will be issued.

10. The anti-clogging method of the anti-clogging device for a stepped filtration alkaline electrolysis water hydrogen production system according to claim 9, characterized in that, It also includes the following steps: S4: Swirl Electromagnetic Particle Collector Step: During the process of the circulating alkaline solution flowing through the swirl electromagnetic particle collector, the particles in the alkaline solution are collected through the synergistic interaction of the swirling flow, magnetic field, and electric field.

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