BDD composite electrode, electrode preparation method and medical wastewater treatment equipment

Abstract

The invention discloses a BDD composite electrode, an electrode preparation method and medical wastewater treatment equipment, and relates to the technical field of medical wastewater treatment.The BDD composite electrode comprises a treatment pond and a pair of BDD composite electrodes, a lifting frame is vertically and movably installed at the top of the treatment pond, the pair of BDD composite electrodes are installed in the lifting frame, an inverted-V-shaped filter screen is located below the pair of BDD composite electrodes, and the inverted-V-shaped filter screen is located below the BDD composite electrodes. A pair of elastic traction rods are installed between the lifting frame and the inverted-V-shaped filter screen, residue collecting boxes communicated with the treatment pond are installed on the two sides of the treatment pond, abutting rods matched with the inverted-V-shaped filter screen in an abutting mode are elastically inserted in the communicating positions of the residue collecting boxes, and the waste residue scraping assemblies are installed on the two sides of the top of the inverted-V-shaped filter screen respectively. And the waste residue scraping assembly is in friction transmission with the abutting rod. Meanwhile, the inverted V-shaped filter screen is lifted through the elastic traction rod, so that the inverted V-shaped filter screen can generate high-frequency micro-amplitude vibration in the vertical stroke, the formation of a surface filter cake layer is destroyed, the effective flux of the filter screen is kept, and then the waste residue scraping assembly and the elastic traction rod are used for friction transmission.

Description

Technical Field

[0001] The present invention relates to the technical field of medical wastewater treatment, and in particular to a BDD composite electrode, an electrode preparation method, and medical wastewater treatment equipment. Background Art

[0002] Boron-doped diamond electrodes can be used for electrochemical treatment of wastewater. They have high oxidation ability and can decompose organic matter and kill pathogens. Medical wastewater may contain complex components such as drug residues, bacteria, and viruses, which require high efficiency and stability to treat. Therefore, compared with traditional electrodes, boron-doped diamond electrodes (BDD) have many advantages such as wide window, small background current, good electrochemical stability, good mechanical properties, strong corrosion resistance, and good conductivity. They have good prospects in the field of electrochemical oxidation treatment of medical wastewater.

[0003] The patent publication number of the existing patent application is: CN220317491U, and the publication date is January 9, 2024. The name of the patent is "An electrochemical sewage treatment device". The patent includes an electrolytic water treatment cell, a movable plate is provided above the top of the electrolytic water treatment cell, a DC regulated power supply is fixedly installed on the top of the movable plate, and a cathode rod and an anode rod are fixedly connected on both sides of the bottom of the movable plate. The electrochemical sewage treatment device, the utility model uses the electrolytic water treatment cell, cathode rod, movable plate, DC regulated power supply, electric telescopic rod, anode rod, an annular cleaning plate, annular scraper and connecting block in combination. The annular cleaning plate drives the annular scraper to continuously scrape the outer wall of the anode rod vertically, so that the condensate generated on the anode rod is scraped off by the annular scraper before it can form scale, thereby solving the problem of passivation of the anode rod during the electrochemical reaction, which increases the resistance of the anode rod and reduces the electrochemical sewage treatment effect.

[0004] The above application has its shortcomings. It is difficult to balance the conductivity and mechanical strength of the substrate in the traditional electrode structure. The single titanium substrate is easily passivated, resulting in a decrease in current efficiency. The nickel substrate has insufficient corrosion resistance and is prone to heavy metal dissolution. The gradient transition layer has poor matching of thermal expansion coefficients. Interface cracks are easily generated during high-temperature deposition, leading to peeling of the diamond layer. At the same time, fiber impurities and sediments in the existing BDD electrode wastewater treatment system are easily attached to the electrode surface to form a pollution layer, which greatly reduces the efficiency of free radical generation. The degradation efficiency drops too much after treating multiple batches of wastewater. Frequent manual cleaning will cause the equipment downtime to account for too much, seriously affecting the continuity of treatment. In addition, in the traditional multi-layer filtration structure, suspended solids are easily intercepted and form a dense accumulation layer on the filter surface, causing the filtration pressure difference to double. When the suspended solids concentration in the wastewater is too high, conventional backwashing operations cannot effectively restore the flux, affecting the actual treatment efficiency. Summary of the Invention

[0005] The application aims to provide a BDD composite electrode, an electrode preparation method and a medical wastewater treatment device to solve the above problems in the prior art.

[0006] To achieve the above-mentioned purpose, the application provides the following technical solutions.

[0007] A BDD composite electrode comprises a composite substrate composed of a foamed nickel inner core and a titanium shell, and the titanium shell is formed into a porous structure through magnetron sputtering deposition.

[0008] A gradient transition layer sequentially comprises a TiN layer, an Nb layer and an NbC layer.

[0009] A multi-level structure BDD layer has microporous holes and nanocone arrays on the surface, the height of the nanocones is 300-500 nm, and the pitch is 50-100 nm.

[0010] A brazing reinforced layer comprises a high-entropy alloy filler and an in-situ generated CeO2 passivation film, and the interface bonding strength of the electrode is greater than or equal to 180 MPa, and the specific surface area is greater than or equal to 15.8 m² / g.

[0011] Preferably, the total thickness of the gradient transition layer is 2.0-3.0 μm, the thickness ratio of the TiN layer is 10-15%, the thickness ratio of the Nb layer is 15-20%, and the thickness ratio of the NbC layer is 65-75%.

[0012] A preparation method of a BDD composite electrode comprises the following steps.

[0013] Step one: composite substrate preparation, the foamed nickel is immersed in 5-8% HCl for ultrasonic cleaning for 15-30 minutes, a titanium layer is deposited under the conditions of a magnetron sputtering power of 400-600 W and an Ar gas pressure of 0.3-0.8 Pa, and then a porous titanium shell is formed by etching in a 3-7% HF solution;

[0014] Step two: gradient transition layer deposition, a TiN layer is deposited by PECVD under a radio frequency power of 200-400 W, then a 0.4-0.6 μm pure niobium layer and a 1.2-1.8 μm NbC gradient layer are sequentially deposited by multi-target sputtering, and the carbon flow is linearly increased from 10 sccm to 30 sccm;

[0015] Step three: BDD layer construction, in a hot-wire CVD reactor, the CH4 / H2 volume ratio is controlled to be 2-4%, the boron doping concentration is controlled to be 4000-6000 ppm, and a 8-12 μm thick BDD layer is grown;

[0016] Step four: multi-level structure etching, microporous holes are formed by femtosecond laser under a scanning speed of 5-15 mm / s, and then nanocone arrays are formed by Ar / N2 mixed plasma etching under a power density of 0.5-1.5 W / cm.

[0017] Step 5: Interface strengthening treatment: high entropy alloy brazing filler metal is coated on the interface by powder metallurgy, and the finished electrode is obtained after vacuum brazing.

[0018] Preferably, the deposition rate of the NbC gradient layer in step 2 is controlled at 0.08-0.12 μm / min, the bias voltage of the plasma etching in step 4 is -50 to -100 V, the particle size D90 of the solder powder in step 5 is ≤ 5 μm, and the Ce element content is 0.5-1.2 wt%.

[0019] A medical wastewater treatment equipment comprises a treatment tank and at least one pair of the above-mentioned BDD composite electrodes, wherein a lifting frame is vertically movably installed on the top of the treatment tank, the pair of BDD composite electrodes are installed in the lifting frame, an inverted V-shaped filter screen is located below the pair of BDD composite electrodes, and a pair of elastic pulling rods are installed between the lifting frame and the inverted V-shaped filter screen, and a slag collecting box connected to it is installed on both sides of the treatment tank, and an abutting rod that abuts and cooperates with the inverted V-shaped filter screen is elastically inserted at the connection point, a pair of waste slag scraping assemblies are respectively installed on both sides of the top of the inverted V-shaped filter screen, and the waste slag scraping assemblies and the abutting rod are frictionally transmitted, a locking assembly is horizontally installed on the top of the elastic pulling rod, and the two are connected to each other, a slot matching the locking assembly is opened on the BDD composite electrode, when the lifting frame drives the inverted V-shaped filter screen to move up and abut the abutting rod, the elastic pulling rod moves up alone to drive the waste slag scraping assembly to operate, and then the locking assembly is pulled out of the slot.

[0020] Preferably, both sides of the inner wall of the lifting frame are slidingly connected to the outer wall of the processing pool respectively, a first shaft and a second shaft distributed up and down are installed in the processing pool, a driving motor connected to the end of the first shaft is installed outside the processing pool, a transmission belt is installed between the first shaft and the second shaft, both ends of the first shaft are fixedly connected to a transmission gear, one side of the lifting frame is vertically fixedly connected to a driven rack meshing with the transmission gear, and the second shaft is fixedly connected to a pair of abutting cams below the inverted V-shaped filter.

[0021] Preferably, the bottom of the elastic pulling rod passes through the inverted V-shaped filter and is installed with an abutment spring, and the top of the abutment spring is in contact with the bottom surface of the inverted V-shaped filter.

[0022] Preferably, the waste scraping assembly includes a plurality of transmission shafts rotatably mounted on the top surface of the filter screen, each of the transmission shafts is connected by a plurality of chain transmissions, and a transmission ring is fixedly sleeved on one of the transmission shafts, and an anti-slip strip that is frictionally transmitted with the transmission ring is vertically embedded on one side of the elastic pulling rod, and a plurality of scraping strips are installed outside two adjacent chains.

[0023] Preferably, the locking assembly includes a cylinder connected to the interior of the elastic pulling rod, a locking tongue adapted to the slot is movably sleeved in the cylinder, a piston rod is elastically embedded in the elastic pulling rod, and a retaining ring is fixedly connected to the inner wall of the treatment pool for preventing the piston rod and the elastic pulling rod from moving upward together.

[0024] Preferably, an annular descaling knife is movably installed inside the treatment tank, the annular descaling knife is located between the lifting frame and the BDD composite electrode, and a pushing cam for intermittently lifting the annular descaling knife is installed on the first shaft.

[0025] In this technical solution, an innovative electrode structure and equipment linkage mechanism are employed. A three-dimensional conductive network is constructed using a nickel / titanium foam composite substrate to reduce bulk resistance. A gradient transition layer is designed to achieve a continuous transition in thermal expansion coefficient, enhancing interfacial bonding strength. A multi-level BDD layer is constructed. The synergistic effect of micron-sized through-holes and nanocones increases the hydroxyl radical yield several times that of conventional electrodes. Furthermore, an elastic pull rod lifts the inverted V-shaped filter, causing it to generate high-frequency micro-vibrations during its vertical travel, disrupting the formation of the surface filter cake and maintaining effective filter flux. A scraping assembly and the elastic pull rod then frictionally drive the inverted V-shaped filter. When the filter reaches the slag collection box, the scraping assembly, driven by the elastic pull rod, scrapes impurities adhering to the filter toward the slag collection box, achieving a directional collection mode. Furthermore, further upward movement of the lifting frame, coupled with the elastic pull rod, allows the BDD composite electrode to be quickly disengaged, allowing it to be easily removed from the lifting frame. This reduces electrode maintenance time while ensuring stable high-current transmission.

[0026] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

[0027] This application document provides an overview of various implementations or examples of the technology described in this disclosure, and is not a comprehensive disclosure of the full scope or all features of the disclosed technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments described in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0029] Figure 1 This is a schematic diagram of the overall structure of a BDD composite electrode of the present invention;

[0030] Figure 2 This is a schematic diagram of the overall structure of a medical wastewater treatment device according to the present invention;

[0031] Figure 3 A top view of a treatment tank in a medical wastewater treatment device according to the present invention;

[0032] Figure 4 This is a structural schematic diagram of a lifting frame in a medical wastewater treatment device of the present invention;

[0033] Figure 5 This is a schematic diagram of the internal structure of a treatment tank in a medical wastewater treatment device of the present invention;

[0034] Figure 6 This is a schematic diagram of the connection between an elastic pulling rod and an inverted V-shaped filter screen in a medical wastewater treatment device of the present invention;

[0035] Figure 7 This is a schematic structural diagram of an elastic pull rod in a medical wastewater treatment device according to the present invention;

[0036] Figure 8 This is a partial cross-sectional view of an elastic pull rod in a medical wastewater treatment device of the present invention.

[0037] Description of reference numerals:

[0038] 1. BDD composite electrode; 101. Composite substrate; 102. Gradient transition layer; 103. Multi-level BDD layer; 104. Brazing strengthening layer; 105. Slot; 2. Treatment tank; 201. Abutment rod; 202. First shaft; 203. Second shaft; 204. Transmission belt; 205. Transmission gear; 206. Abutment cam; 207. Retaining ring; 208. Push cam; 209. Drive motor; 21 0. Impeller; 3. Lifting frame; 301. Driven rack; 4. Inverted V-shaped filter; 5. Elastic pulling rod; 501. Abutment spring; 502. Anti-slip strip; 503. Piston rod; 504. Connecting sleeve; 6. Slag collecting box; 7. Waste slag scraping assembly; 701. Drive shaft; 702. Drive ring; 703. Chain; 704. Scraper; 8. Locking assembly; 801. Cylinder; 802. Lock tongue; 9. Annular descaling knife. DETAILED DESCRIPTION

[0039] To make the purpose, technical solutions, and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0040] See also Figure 1 , an embodiment of the present invention provides a BDD composite electrode, comprising:

[0041] The composite substrate 101 is composed of a nickel foam inner core and a titanium shell, and the titanium shell is formed into a porous structure by magnetron sputtering deposition;

[0042] The gradient transition layer 102 sequentially comprises a TiN layer, an Nb layer and an NbC layer;

[0043] The multi-level structure BDD layer 103 has a micropore and a nanocone array on the surface, the height of the nanocone is 300-500 nm, and the pitch is 50-100 nm;

[0044] The soldering reinforcement layer 104 comprises a high-entropy alloy solder and an in-situ generated CeO2 passivation film, and the interface bonding strength of the electrode is ≥180 MPa, and the specific surface area is ≥15.8 m² / g.

[0045] Specifically, by innovating the electrode structure, a three-dimensional conductive network is constructed by using the nickel foam / titanium composite substrate, so that the bulk resistance is reduced, the gradient transition layer is designed to realize the continuous transition of the thermal expansion coefficient, the interface bonding strength is improved, the multi-level structure BDD layer is constructed, the micropore and the nanocone synergistically act to make the hydroxyl radical yield be several times that of the traditional electrode, the nickel foam / titanium composite substrate improves the current density distribution uniformity through the interpenetrating structure, the effective working area of the electrode is several times the geometric area, the energy consumption per unit volume of wastewater treatment is reduced compared with the traditional Ti / BDD electrode, the TiN / Nb / NbC gradient layer reduces the interface thermal stress, and the structure integrity is still maintained when the electrolyte temperature changes suddenly, the corrosion current density can be inhibited in cooperation with the CeO2 passivation film, the multi-level structure BDD layer synergistically catalyzes to prolong the residence time of wastewater, and the mass transfer and diffusion of organic matter are strengthened.

[0046] In a further embodiment of the present application, a BDD composite electrode according to claim 1, characterized in that the total thickness of the gradient transition layer 102 is 2.0-3.0 μm, wherein the thickness ratio of the TiN layer is 10-15%, the thickness ratio of the Nb layer is 15-20%, and the thickness ratio of the NbC layer is 65-75%, the optimization scheme realizes thinning and component precise control of the gradient transition layer 102, ensures corrosion resistance and electrical conductivity, and at the same time, the electrode interface reliability is improved to the industrial level requirement (ISO 18278-1 standard), and is particularly suitable for continuous electrolysis treatment of high-salt and high-temperature medical wastewater.

[0047] A preparation method of the above-mentioned BDD composite electrode, comprising the following steps:

[0048] Step one: composite substrate 101 preparation, immerse the nickel foam in 5-8% HCl for ultrasonic cleaning for 15-30 minutes, deposit a titanium layer under the conditions of a magnetron sputtering power of 400-600 W and an Ar gas pressure of 0.3-0.8 Pa, and then etch a porous titanium shell in a 3-7% HF solution.

[0049] Step two: Gradient transition layer 102 deposition, depositing TiN layer under 200-400W radio frequency power by PECVD, then depositing 0.4-0.6μm pure niobium layer and 1.2-1.8μm NbC gradient layer in sequence by multi-target sputtering, carbon flow is linearly increased from 10sccm to 30sccm;

[0050] Step three: BDD layer construction, in a hot wire CVD reactor, controlling CH4 / H2 volume ratio 2-4%, boron doping concentration 4000-6000ppm, growing 8-12μm thick BDD layer;

[0051] Step four: Multi-level structure etching, forming micron through hole under the condition of scanning speed 5-15mm / s by femtosecond laser, then etching nano-cone array by Ar / N2 mixed plasma under power density 0.5-1.5W / cm;

[0052] Step five: Interface strengthening treatment, coating high-entropy alloy solder on the interface in a powder metallurgy way, obtaining finished product electrode after vacuum brazing.

[0053] In further embodiments of the application, the deposition rate of the NbC gradient layer in step two is controlled at 0.08-0.12μm / min, the bias voltage of plasma etching in step four is -50 to -100V, the particle size D90 of the solder powder in step five is ≤5μm, and the content of Ce element is 0.5-1.2wt%.

[0054] Specifically, the electrode realizes efficient wastewater treatment through multi-dimensional synergistic effect, the three-dimensional conductive network constructed by the foam nickel / titanium composite substrate reduces the bulk resistance, the gradient transition layer 102 (TiN / Nb / NbC) inhibits the interface stress through continuous transition of the thermal expansion coefficient, the corrosion rate is controlled below 0.01mm / a by combining with the CeO2 passivation film, the micron through hole prolongs the residence time of wastewater, the removal rate of COD in wastewater is improved, the service life of the electrode is also prolonged, and the industrial-grade stability requirement is met.

[0055] Please refer to Figure 1-8The embodiment of the present invention provides a medical wastewater treatment device, comprising a treatment tank 2 and at least one pair of BDD composite electrodes 1, one of which is an anode and the other is a cathode. A lifting frame 3 is vertically movably installed on the top of the treatment tank 2, the pair of BDD composite electrodes 1 is installed in the lifting frame 3, an inverted V-shaped filter 4 is located below the pair of BDD composite electrodes 1, and a pair of elastic pulling rods 5 are installed between the lifting frame 3 and the inverted V-shaped filter 4. Both sides of the treatment tank 2 are equipped with a slag collecting box 6 connected thereto, and the connection is elastically plugged with a slag collecting box 6 that contacts the inverted V-shaped filter 4. A pair of waste scraping assemblies 7 are respectively installed on both sides of the top of the inverted V-shaped filter screen 4, and the waste scraping assemblies 7 and the abutment rod 201 are frictionally transmitted. The locking assembly 8 is horizontally installed on the top of the elastic pulling rod 5, and the two are connected to each other. A slot 105 matching the locking assembly 8 is provided on the BDD composite electrode 1. When the lifting frame 3 drives the inverted V-shaped filter screen 4 to move up and abut the abutment rod 201, the elastic pulling rod 5 moves up alone to drive the waste scraping assembly 7 to operate, and then the locking assembly 8 is pulled out from the slot 105.

[0056] Specifically, when the equipment is in operation, the wastewater is treated by the BDD composite electrode 1. When multiple batches of treatment are completed, the BDD composite electrode 1 and the inverted V-shaped filter screen 4 can be driven to rise by the lifting frame 3. When the elastic pulling rod 5 pulls the inverted V-shaped filter screen 4, since it is not rigidly connected to the inverted V-shaped filter screen 4, the inverted V-shaped filter screen 4 can shake and vibrate under the action of the water flow, and the impact of the water flow and its own vibration are used to effectively peel off most of the filter cake layer. When the inverted V-shaped filter screen 4 rises to the entrance of the slag collecting box 6, the abutment rod 201 is inserted into the groove reserved on the inner wall of the treatment tank 2, and one end of the abutment rod 201 is fixedly connected to a connecting spring in the groove, and the other end has a symmetrical inclined abutment surface. Since the inverted V-shaped filter screen 4 is abutted by the abutment rod 20 1, so when the abutment rod 201 is not completely pushed into the groove by the inverted V-shaped filter screen, only the elastic pulling rod 5 rises alone, thereby driving the waste scraping assembly 7 on the inverted V-shaped filter screen 4 through the elastic pulling rod 5 moving upward in a straight line, and quickly pushing the filter residue into the slag collecting box 6 to avoid insufficient vibration collection. Then, after continuing to lift the lifting frame 3, the elastic pulling rod 5 that rises to a certain height can enable the locking assembly 8 to release the electrode. The top of the BDD composite electrode 1 is fixed to the lifting frame 3 by a threaded connection. When the locking assembly 8 is inserted into the slot 105, the BDD composite electrode 1 cannot be disassembled. As long as the lifting frame 3 is lifted to a suitable height, the locking assembly 8 can be removed from the slot 105, and the disassembly of the bilateral electrodes is quickly completed.

[0057] Compared with the prior art, the embodiment of the present invention innovates the electrode structure and equipment linkage mechanism, uses a foam nickel / titanium composite matrix to construct a three-dimensional conductive network, reduces the bulk resistance, designs a gradient transition layer to achieve a continuous transition of the thermal expansion coefficient, improves the interface bonding strength, constructs a multi-level structure BDD layer, and the synergistic effect of micron through holes and nanocones increases the hydroxyl radical yield to several times that of traditional electrodes. At the same time, the elastic pulling rod 5 pulls up the inverted V-shaped filter 4, so that the inverted V-shaped filter 4 can generate high-frequency micro-amplitude vibration during the vertical stroke, destroying the formation of the surface filter cake layer and maintaining the effective flux of the filter. Then, the waste scraping assembly 7 and the elastic pulling rod 5 are used for friction transmission. When the inverted V-shaped filter screen 4 reaches the slag collecting box 6, the waste scraping assembly 7 is driven by the elastic pulling rod 5 to scrape the impurities attached to the filter screen toward the slag collecting box 6 to realize a directional collection mode. Moreover, after the lifting frame 3 moves further upward with the elastic pulling rod 5, the BDD composite electrode 1 can be quickly detached, so that it can be easily removed from the lifting frame 3. Under the premise of ensuring the stability of large current transmission, the electrode maintenance time is shortened. Through the coordinated innovation of mechanical vibration, directional scraping and rapid disassembly and assembly, the medical wastewater treatment flux is improved and the electrode maintenance cost is reduced. It is particularly suitable for continuous treatment scenarios of medical wastewater containing high concentrations of biofilm and colloidal impurities.

[0058] In a further embodiment of the present invention, both sides of the inner wall of the lifting frame 3 are slidably connected to the outer wall of the processing pool 2, and both sides of the processing pool 2 are fixedly connected to the limit blocks. The inner wall of the lifting frame 3 is vertically provided with a slide groove matching the limit blocks. A first shaft rod 202 and a second shaft rod 203 distributed up and down are installed in the processing pool 2. A driving motor 209 connected to the end of the first shaft rod 202 is installed outside the processing pool 2, and a transmission belt 204 is installed between the first shaft rod 202 and the second shaft rod 203. The two ends of the first shaft rod 202 are fixedly connected to a transmission gear 205, and one side of the lifting frame 3 is vertically fixedly connected to a driven rack 301 meshing with the transmission gear 205. The second shaft rod 203 is fixedly connected to a pair of abutting cams 206 below the inverted V-shaped filter screen 4, and an impeller 210 is also installed in the middle of the second shaft rod 203. Specifically, the driving motor 209 can drive the first shaft rod 202 and the second shaft rod 20 When the first shaft 202 rotates, its transmission gear 205 and the driven rack 301 on the lifting frame 3 are meshed together, and the lifting and lowering of the lifting frame 3 can be adjusted by the forward and reverse rotation of the first shaft 202. If the inverted V-shaped filter screen 4 pulled by the lifting frame 3 through the elastic pulling rod 5 is placed on the abutting cam 206, the second shaft 203 and the first shaft 202 rotate synchronously, the abutting cam 206 can be used to intermittently lift the inverted V-shaped filter screen 4, so that the inverted V-shaped filter screen 4 vibrates continuously, and the impeller 210 is used to stir the water flow, so that the debris attached to the inverted V-shaped filter screen 4 is separated from the water flow under the impact of the water flow, so that the waste residue can be quickly recovered when the inverted V-shaped filter screen 4 is subsequently lifted to the slag collecting box 6. At the same time, the closer the inverted V-shaped filter screen 4 is to the second shaft 203 below, the greater its own amplitude is, and the farther it is from the second shaft 203, the smaller its own amplitude is, thereby realizing dynamic slag removal and cleaning.

[0059] In a further embodiment of the present invention, the bottom of the elastic pulling rod 5 passes through the inverted V-shaped filter screen 4 and is installed with an abutment spring 501. The top of the abutment spring 501 contacts the bottom surface of the inverted V-shaped filter screen 4. Specifically, the abutment spring 501 forms a resonance system with the elastic pulling rod 5 through the pressure brought by the inverted V-shaped filter screen 4. When the lifting frame 3 moves vertically, the abutment spring 501 is subjected to the composite alternating load of the gravity of the inverted V-shaped filter screen 4 and the impact of the water flow. Through periodic compression and rebound, the mechanical energy is converted into high-frequency micro-vibration, which destroys the cohesion of the filter cake layer. In the scraping stage, the elastic potential energy accumulated by the abutment spring 501 can make the attached impurities easier to be peeled off by the waste scraping assembly 7. At the same time, the stiffness of the abutment spring 501 and the insertion of the elastic pulling rod 5 cooperate to suppress lateral vibration, ensure the accuracy of the scraping trajectory, and the equipment flux maintenance rate can be more lasting.

[0060] In a further embodiment of the present invention, the waste scraping assembly 7 includes a plurality of transmission shafts 701 rotatably mounted on the top surface of the filter screen, and the transmission shafts 701 are connected by a plurality of chains 703, and a transmission ring 702 is fixedly sleeved on one of the transmission shafts 701. An anti-slip strip 502 that is frictionally transmitted with the transmission ring 702 is vertically embedded on one side of the elastic pulling rod 5, and a plurality of scraping strips 704 are installed on the outside of two adjacent chains 703. Specifically, when the elastic pulling rod 5 is raised or lowered, the friction transmission between the anti-slip strip 502 and the transmission ring 702 converts the vertical movement into the rotation of the transmission shaft 701, allowing the chain 703 to drive the scraping strip 704 to slide along the surface of the inverted V-shaped filter screen 4. The blade edge of the scraping strip 704 exerts shear force on the filter residue, and combined with the elastic force of the abutting spring 501, it can scrape off colloidal agglomerates of various particle sizes, improve the cleaning effect, ensure that the scraping residue is not missed, and allow impurities to be pushed into the slag collecting box 6 along the filter screen.

[0061] In a further embodiment of the present invention, the locking assembly 8 includes a cylinder 801 connected to the interior of the elastic pulling rod 5. The interior of the elastic pulling rod 5 is hollow, and the air path in the rod body is connected to the cylinder 801. The cylinder 801 is movably connected with a lock tongue 802 that is adapted to the slot 105. A piston rod 503 is elastically embedded in the elastic pulling rod 5, and an elastic part is installed at the bottom of the piston rod 503. The outside of the elastic pulling rod 5 is movably connected with a connecting sleeve 504 connected to the bottom of the piston rod 503. The inner wall of the treatment pool 2 is fixedly connected with a retaining ring 207 for preventing the piston rod 503 from moving up together with the elastic pulling rod 5. The retaining ring 207 is sleeved on the outside of the elastic pulling rod 5, and its inner wall contacts the outer wall of the elastic pulling rod 5. The retaining ring 207 abuts against the connecting sleeve 504. Specifically, during the lifting process of the lifting frame 3, since the retaining ring 207 is sleeved on the outside of the elastic pulling rod 5, it can ensure that the lifting frame 3 as a whole will not deviate excessively when rising. When the lifting frame 3 is lifted to the electrode separation height, the piston rod 503 is blocked by the retaining ring 207 and moves downward relatively in the elastic pulling rod 5, and the gas in the cylinder 801 is drawn into the elastic pulling rod 5, so that the locking tongue 802 retracts toward the inside of the cylinder 801, and the locking tongue 802 leaves the slot 105 on the BDD composite electrode 1. The overall unlocking is smooth and the upward movement of the lifting frame 3 is utilized, which is easy to operate. When installing the electrode, it is necessary to first keep the lifting frame 3 with the elastic pulling rod 5 at the unlocking height of the locking assembly 8, install the upper electrode first, and then align the slot 105 with the position of the locking tongue 802. When the elastic pulling rod 5 descends, the piston rod 503 is reset under the push of the elastic member and pushes part of the gas into the cylinder 801, thereby pushing the locking tongue 802 to automatically insert into the slot 105 to complete the locking of the electrode, ensuring that the electrode is not loose under large shaking and high current conditions, and avoiding accidental separation of the electrode.

[0062] In a further embodiment of the present invention, an annular scale-removing knife 9 is movably installed inside the treatment pool 2, and the annular scale-removing knife 9 is located between the lifting frame 3 and the BDD composite electrode 1, and a pushing cam 208 for intermittently lifting the annular scale-removing knife 9 is installed on the first shaft 202. The annular scale-removing knife 9 is located on the lifting path of the BDD composite electrode 1, and a counterweight plate is installed on the annular scale-removing knife 9. Specifically, when the first shaft 202 rotates, it will not only drive the BDD composite electrode 1 to rise together, but also enable the annular scraper with a fixed height to comprehensively scrape and clean the surface of the moving BDD electrode, and the pushing cam 208 can intermittently lift the annular scale-removing knife 9, and the annular scale-removing knife 9 will automatically fall under the action of gravity, so that the impurities remaining on the blade when the annular scale-removing knife 9 is scraped are vibrated onto the inverted V-shaped filter 4, so as to facilitate the subsequent entry of the waste residue on the inverted V-shaped filter 4 into the slag collecting box 6.

[0063] The above description is merely illustrative of certain exemplary embodiments of the present invention. It goes without saying that those skilled in the art will be able to modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims.

Claims

1. A BDD composite electrode, characterized in that: include: A composite substrate (101) is composed of a nickel foam core and a titanium shell, wherein the titanium shell has a porous structure; A gradient transition layer (102) sequentially comprising a TiN layer, a Nb layer, and a NbC layer; A multi-level structured BDD layer (103) having micron through holes and nanocone arrays on its surface; The brazing strengthening layer (104) comprises a high entropy alloy brazing material and an in-situ generated CeO2 passivation film.

2. A BDD composite electrode according to claim 1, characterized in that: The total thickness of the gradient transition layer (102) is 2.0-3.0 μm, wherein the thickness of the TiN layer accounts for 10-15%, the thickness of the Nb layer accounts for 15-20%, and the thickness of the NbC layer accounts for 65-75%.

3. A method for preparing a BDD composite electrode according to any one of claims 1 to 2, characterized in that: The steps include: Step 1: Preparation of the composite substrate (101): immersing the nickel foam in 5-8% HCl for ultrasonic cleaning for 15-30 minutes, depositing a titanium layer under the conditions of magnetron sputtering power of 400-600 W and Ar pressure of 0.3-0.8 Pa, and then etching in 3-7% HF solution to form a porous titanium shell; Step 2: Deposition of the gradient transition layer (102), using PECVD at 200-400W RF power to deposit a TiN layer, followed by sequential deposition of a 0.4-0.6μm pure niobium layer and a 1.2-1.8μm NbC gradient layer by multi-target sputtering, with the carbon flow rate linearly increasing from 10sccm to 30sccm; Step 3: BDD layer construction: In a hot-filament CVD reactor, control the CH4 / H2 volume ratio to 2-4%, the boron doping concentration to 4000-6000ppm, and grow an 8-12μm thick BDD layer; Step 4: Multi-level structure etching, using femtosecond laser to form micron through-holes at a scanning speed of 5-15 mm / s, followed by etching with Ar / N2 mixed plasma at a power density of 0.5-1.5 W / cm2 to form nanocone arrays; Step 5: Interface strengthening treatment: high entropy alloy brazing filler metal is coated on the interface by powder metallurgy, and the finished electrode is obtained after vacuum brazing.

4. The method for preparing a BDD composite electrode according to claim 3, characterized in that: The deposition rate of the NbC gradient layer in step 2 is controlled at 0.08-0.12 μm / min, and the bias voltage of the plasma etching in step 4 is -50 to -100V.

5. A medical wastewater treatment equipment, characterized in that: It comprises a treatment tank (2) and at least one pair of BDD composite electrodes (1) according to any one of claims 1 to 2, wherein a lifting frame (3) is vertically and movably installed on the top of the treatment tank (2), and the pair of BDD composite electrodes (1) are installed in the lifting frame (3); An inverted V-shaped filter screen (4) is located below a pair of BDD composite electrodes (1), and a pair of elastic pulling rods (5) are installed between the lifting frame (3) and the inverted V-shaped filter screen (4). Both sides of the treatment pool (2) are installed with slag collecting boxes (6) connected thereto, and an abutting rod (201) that abuts against the inverted V-shaped filter screen (4) is elastically inserted at the connection point; A pair of waste scraping components (7) are respectively installed on both sides of the top of the inverted V-shaped filter (4), and the waste scraping components (7) and the abutting rod (201) are frictionally driven; A locking assembly (8) is horizontally mounted on the top end of the elastic pulling rod (5), and the two are connected to each other, and a slot (105) matching the locking assembly (8) is provided on the BDD composite electrode (1); When the lifting frame (3) drives the inverted V-shaped filter (4) to move upward and abut against the abutting rod (201), the elastic pulling rod (5) moves upward alone to drive the waste scraping assembly (7) to operate, and then the locking assembly (8) is pulled out from the slot (105).

6. The medical wastewater treatment equipment according to claim 5, characterized in that: Both sides of the inner wall of the lifting frame (3) are slidably connected to the outer wall of the treatment pool (2), and a first shaft (202) and a second shaft (203) are installed in the treatment pool (2) and are distributed up and down. A driving motor (209) connected to the end of the first shaft (202) is installed outside the treatment pool (2), and a transmission belt (204) is installed between the first shaft (202) and the second shaft (203). The first shaft (202) is fixedly connected to a transmission gear (205) at both ends. A driven rack (301) meshing with the transmission gear (205) is vertically fixedly connected to one side of the lifting frame (3), and the second shaft (203) is fixedly connected to a pair of abutting cams (206) below the inverted V-shaped filter.

7. The medical wastewater treatment equipment according to claim 5, characterized in that: The bottom of the elastic pulling rod (5) passes through the inverted V-shaped filter (4) and is installed with an abutment spring (501), and the top of the abutment spring (501) contacts the bottom surface of the inverted V-shaped filter (4).

8. The medical wastewater treatment equipment according to claim 5, characterized in that: The waste scraping assembly (7) includes a plurality of transmission shafts (701) rotatably mounted on the top surface of the filter (4), the transmission shafts (701) are connected to each other via a plurality of chains (703), and a transmission ring (702) is fixedly sleeved on one of the transmission shafts (701), an anti-slip strip (502) for friction transmission with the transmission ring (702) is vertically embedded on one side of the elastic pulling rod (5), and a plurality of scraping strips (704) are installed outside two adjacent chains (703).

9. The medical wastewater treatment equipment according to claim 5, characterized in that: The locking assembly (8) includes a cylinder (801) connected to the inside of the elastic pulling rod (5), a locking tongue (802) adapted to the slot (105) is movably sleeved in the cylinder (801), a piston rod (503) is elastically embedded in the elastic pulling rod (5), and a retaining ring (207) is fixedly connected to the inner wall of the treatment tank (2) for preventing the piston rod (503) and the elastic pulling rod (5) from moving upward together.

10. The medical wastewater treatment equipment according to claim 6, characterized in that: An annular descaling knife (9) is movably installed inside the treatment tank (2), and the annular descaling knife (9) is located between the lifting frame (3) and the BDD composite electrode (1), and a pushing cam (208) for intermittently lifting the annular descaling knife (9) is installed on the first shaft (202).

Images