Electrolytic bath and method for effectively inhibiting scale accumulation of polar plate

Abstract

The invention provides an electrolytic bath and method for effectively inhibiting scale accumulation of a polar plate, and relates to the technical field of sewage treatment.The electrolytic bath comprises an anti-scale electrode device, an anti-scale electrode device, a water storage tank, a water storage tank and a control system, and the anti-scale electrode device comprises an anti-scale electrode group used for reacting with low-hardness water to generate aluminum ions; a bypass pipeline of a water inlet pipeline of the wastewater inlet and outlet unit is provided with an anti-scale electrode device; the tank body unit is used for reacting with calcium and magnesium ions in the wastewater to be treated to generate hydroxyl so as to combine aluminum ions with the calcium and magnesium ions to generate hydrotalcite-like scale; and the cleaning unit is used for flushing the hydrotalcite-like scale. The structure of the pipeline type anti-scaling electrode device is easy to clean and disassemble, the concentration of generated aluminum ions can be automatically controlled through current, scale accumulation of a polar plate can be effectively inhibited, and the operation efficiency of the electrolytic cell is improved.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and more specifically, to an electrolytic cell and method for effectively inhibiting scale accumulation on electrode plates. Background Technology

[0002] Electrocatalytic oxidation is widely used in wastewater treatment due to its advantages such as simple operation, small footprint, increased intelligence, and less pollution. Generally, electrocatalytic oxidation electrodes use titanium-plated anodes and metal cathodes. When there are certain amounts of calcium, magnesium, or barium ions in the wastewater, the pH increases due to hydrogen evolution on the cathode surface, easily leading to significant cathode scaling. This scaling layer causes increased voltage and power consumption in the electrolytic cell. If not treated promptly, as the scaling accumulates, it can cause short circuits on the electrodes, and in severe cases, it can even break down the electrodes.

[0003] Currently, common methods to control scale accumulation on electrode plates generally involve acid washing or electrode reversal. Electrode reversal has the drawback of insufficient H+ ions to dissolve the scale layer, and it typically uses a large current, which can easily damage the metal electrodes. Acid washing can effectively remove scale from the electrode surface, but it requires a large amount of acid and intermittent operation of the electrolytic cell.

[0004] To address the problems of existing technologies, this invention provides an electrolytic cell and method for effectively suppressing scale accumulation on electrode plates. Summary of the Invention

[0005] In view of the problems of existing technologies, the present invention aims to solve the problem of scale buildup on electrode plates affecting the operating efficiency of electrolytic cells.

[0006] This invention provides an electrolytic cell that effectively inhibits scale accumulation on electrode plates, the electrolytic cell comprising:

[0007] Anti-scaling electrode device, comprising an anti-scaling electrode assembly for reacting with low-hardness water to generate aluminum ions;

[0008] The wastewater inlet and outlet unit has the scale prevention electrode device installed in the bypass pipe of its inlet pipe;

[0009] The tank unit is used to react with calcium and magnesium ions in the wastewater to be treated to generate hydroxide ions, which combine with aluminum ions and calcium and magnesium ions to form a hydrotalcite-like scale.

[0010] The cleaning unit is used to rinse away hydrotalcite-like scale.

[0011] According to one embodiment of the present invention, the anti-scaling electrode device comprises:

[0012] The anti-scaling electrode assembly includes at least one set of anti-scaling electrodes, each set of anti-scaling electrodes including an anti-scaling anode and an anti-scaling cathode, wherein the anti-scaling anode is used to react with low-hardness water to generate aluminum ions;

[0013] A fixing unit is used to fix the anti-scaling electrode assembly to the target pipe section;

[0014] A power supply unit is used to supply power to the anti-scaling electrode assembly.

[0015] According to one embodiment of the present invention, the anti-scaling anode is an aluminum electrode, and the anti-scaling cathode is a stainless steel or titanium electrode.

[0016] According to one embodiment of the present invention, the anti-scaling electrode is spiral, columnar, or flat, with a length less than the diameter of the target pipe section, and an adjustable current range of 0–40A.

[0017] According to one embodiment of the present invention, the fixing unit includes: a washer, a screw, and a fixing plate; the power supply unit includes: a cable and a cable fastener; wherein:

[0018] The anti-scaling electrode is fixed by the fixing plate and led out of the target pipe section by the screw;

[0019] The cable is connected to the screw and is fixed to the target pipe section using the cable fasteners.

[0020] The target pipe section and the power supply unit are sealed and waterproofed by the gasket set on the screw.

[0021] According to one embodiment of the present invention, the wastewater inlet / outlet unit comprises:

[0022] The water inlet pipe and the bypass pipe are installed at the water inlet end of the tank unit;

[0023] A magnetization device, which is installed at the inlet end of the anti-scaling electrode device, is used to magnetize low-hardness water;

[0024] A valve is provided at the inlet end of the magnetizing device;

[0025] The water outlet is located at the outlet end of the tank unit.

[0026] According to one embodiment of the present invention, the tank unit includes: an electrolytic tank, an electrode assembly, and a power supply, wherein the electrode assembly is disposed in the electrolytic tank and is used to react with calcium and magnesium ions in the wastewater to be treated to generate hydroxide ions; the power supply is used to supply power to the electrode assembly.

[0027] According to one embodiment of the present invention, the cleaning unit comprises: a high-pressure pump, a return pump, a spray assembly, and a sludge collection device, wherein:

[0028] The high-pressure pump is used to provide flushing pressure and water volume to the spray assembly;

[0029] At least one set of the spray assembly is provided above and below the electrode group, and the coverage area of ​​each set of spray assemblies overlaps with each other;

[0030] The sludge collection device is located at the bottom of the electrolytic cell and is used to collect the hydrotalcite-like scale.

[0031] The reflux pump is connected to the outlet end of the electrolytic cell and is used to pump the low-hardness water flowing out of the electrolytic cell to the bypass pipeline.

[0032] According to another aspect of the present invention, a method for effectively suppressing scale accumulation on electrode plates is also provided, performed by an electrolytic cell as described in any of the preceding claims, the method comprising:

[0033] The anti-scaling electrode device is installed through the bypass pipe of the wastewater inlet / outlet unit inlet pipe, wherein the anti-scaling electrode device includes an anti-scaling electrode assembly for reacting with low-hardness water to generate aluminum ions.

[0034] The tank unit reacts with calcium and magnesium ions in the wastewater to be treated to generate hydroxide ions, which combine with aluminum ions and calcium and magnesium ions to form a hydrotalcite-like scale.

[0035] The cleaning unit washes away hydrotalcite-like scale.

[0036] According to another aspect of the invention, a storage medium is also provided, which includes instructions for performing the methods described above.

[0037] This invention provides an electrolytic cell and method for effectively inhibiting scale accumulation on electrode plates, which has the following advantages compared with the prior art:

[0038] 1) After being magnetized by the magnetization device, the low-hardness water is electrolyzed by the pipeline-type anti-scaling electrode device 4, generating a large amount of aluminum ions. These aluminum ions combine with calcium and magnesium ions to form a hydrotalcite-like scale. Furthermore, the aluminum ions generated during electrolysis also form aluminum hydroxide with a specific shape, which has better adsorption properties. Under high-pressure water flow, the scale on the electrode plates is easily washed away, and the device effectively adsorbs organic matter from wastewater (especially produced water from oilfield gas), thus better reducing the COD (Chemical Oxygen Demand) of the wastewater.

[0039] 2) The structure of the pipeline-type anti-scaling electrode device 4 is easy to clean and disassemble; the concentration of aluminum ions generated can be automatically controlled by the current.

[0040] 3) The high-pressure nozzle 22 has a circular spray range and can rotate automatically under the action of water flow, resulting in a wider range of action and no dead corners in cleaning. In addition, the high-pressure nozzle 22 uses less water.

[0041] 4) By observing the voltage changes of the power supply 7, it is possible to effectively determine whether the electrode assembly 9 inside the electrolytic cell 5 needs backwashing. Using high-pressure water flow instead of acid washing or electrode reversal can extend the service life of the electrode assembly 9 to a certain extent.

[0042] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the description, claims, and drawings. Attached Figure Description

[0043] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with the embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0044] Figure 1 A schematic diagram of an electrolytic cell for effectively suppressing scale accumulation on electrode plates according to an embodiment of the present invention is shown;

[0045] Figure 2 A schematic diagram of a pipeline-type anti-scaling electrode device according to an embodiment of the present invention is shown;

[0046] Figure 3 A top view of an electrolytic cell according to an embodiment of the present invention is shown;

[0047] Figure 4 A flowchart illustrating the steps of a method for effectively suppressing scale accumulation on electrode plates according to an embodiment of the present invention is shown.

[0048] In the accompanying drawings, the same parts use the same reference numerals. Also, the drawings are not drawn to scale.

[0049] In the attached drawings, the meanings of the reference numerals are as follows: 1-1-High-pressure pump; 1-2-Recirculation pump; 2-Inlet pipe; 2'-Bypass pipe; 3-Valve; 4-Anti-scaling electrode device; 5-Electrolytic cell body; 6-Inlet baffle; 7-Power supply; 8-Spray assembly; 9-Electrode group; 10-Outlet; 11-Sludge collection tank; 12-Sludge discharge outlet; 13-1-Electromagnetic device; 13-2-Electromagnetic coil; 14-Washer; 15-Screw; 16-Cable; 17-Fixing plate; 18-Anti-scaling anode; 19-Anti-scaling cathode; 20-Cable fastener; 21-Sprayer head bracket; 22-High-pressure spray head. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0051] The existing technology (CN114349124A) is not applicable to the electrocatalytic oxidation wastewater treatment process. The existing technologies (CN211726853U, CN206521529U, CN112011799A) cannot reduce the difficulty of cleaning dirt at the source.

[0052] Existing technologies (CN104878407A, Research on Removal of Cathode Scale Using Electrode Reversal Method [J], Research on Mitigation Technology of Cathode Scale by Electrocoagulation + Electrooxidation Treatment of Coalbed Methane Produced Water [D]) use acid washing or electrode reversal to control the accumulation of scale on the electrode plates. Electrode reversal has the disadvantage that the generated H+ is insufficient to dissolve the scale layer, and it generally uses a large current, which can easily damage the metal electrode. Acid washing can effectively remove scale from the electrode surface, but it requires a large amount of acid and intermittent operation of the electrolytic cell.

[0053] Existing technologies (Research on controlling electrode scaling intensity by induced crystallization method [J], One-step preparation of iron / aluminum hydrotalcite nanosheets by electrochemical sacrificial double anode method [J], Preparation and application of Ca-Mg-Al-Fe layered metal hydroxide materials [J]) only studied the formation mode of hydrotalcite-like structures, and did not provide technical means to solve the problem of easy scaling on the electrode plates of existing electrolytic cells and the impact on current efficiency.

[0054] To address the aforementioned shortcomings of existing technologies, and based on the technical problems of easy scaling on the electrode plates of existing electrolytic cells, which affects current efficiency, this invention utilizes a pipeline-type anti-scaling electrode device 4 to provide aluminum ions, causing them to form hydrotalcite-like scale, which flows out of the electrolytic cell under the strong flushing action of high-pressure water jets. A matching electrolytic cell is also provided.

[0055] Figure 1 A schematic diagram of an electrolytic cell for effectively suppressing scale accumulation on electrode plates according to an embodiment of the present invention is shown.

[0056] like Figure 1 As shown, the electrolytic cell includes: an anti-scaling electrode device 4, a wastewater inlet / outlet unit, a tank unit, and a cleaning unit. The anti-scaling electrode device 4 includes an anti-scaling electrode assembly for reacting with low-hardness water to generate aluminum ions; the bypass pipe 2' of the wastewater inlet / outlet unit is equipped with the anti-scaling electrode device 4; the tank unit reacts with calcium and magnesium ions in the wastewater to generate hydroxide ions (OH-), which combine with aluminum and calcium / magnesium ions to form a hydrotalcite-like scale; the cleaning unit is used to rinse away the hydrotalcite-like scale.

[0057] In one embodiment, the wastewater inlet / outlet unit includes: an inlet pipe 2, a bypass pipe 2', a valve 3, a magnetization device (composed of an electromagnetic device 13-1 and an electromagnetic coil 13-2), and an outlet 10. The inlet pipe 2 and the bypass pipe 2' are located at the inlet end of the tank unit; the magnetization device is located at the inlet end of the anti-scaling electrode device 4 and is used to magnetize low-hardness water; the valve 3 is located at the inlet end of the magnetization device; and the outlet 10 is located at the outlet end of the tank unit.

[0058] like Figure 1 As shown, the inlet pipe 2 is located at the inlet end of the electrolytic cell 5, and the bypass pipe 2' is detachably connected to the inlet pipe 2. Specifically, a bypass pipe 2' is provided on the inlet pipe 2, and both ends of the bypass pipe 2' are connected to the inlet pipe 2 in parallel. That is, low-hardness water from the outside or part of the return liquid from the electrolytic cell 5 enters the electrolytic cell 5 through the bypass pipe 2', while the wastewater to be treated enters the electrolytic cell 5 through the inlet pipe 2.

[0059] In one embodiment, the magnetization device may employ a permanent magnet or an electronic magnetizer for generating a frequency-converting electronic signal. Specifically, the magnetic field strength of the permanent magnet is 400–1000 mT. When using an electronic magnetizer for generating a frequency-converting electronic signal, the frequency converter outputs a current of 10–100 A and an output frequency of 40–500 Hz. Furthermore, the magnetization treatment time for low-hardness water is 1–5 minutes.

[0060] In practical applications, the anti-scaling electrode device 4 is installed on the bypass pipe 2' of the inlet pipe 2. Water inflow is controlled by valve 3, and the bypass pipe 2' is replaceable. When the anti-scaling anode 18 of the anti-scaling electrode device 4 is consumed to a certain extent, valve 3 is closed, and the target pipe section where the anti-scaling electrode device 4 is located can be removed for periodic replacement or cleaning of the anti-scaling anode 18. It should be noted that the timing of replacing or cleaning the anti-scaling electrode device 4 can be set according to actual needs, and this invention does not impose any limitations on this.

[0061] It should be noted that the anti-scaling electrode device 4 can be installed separately in the bypass pipe 2', or the magnetization device and the anti-scaling electrode device 4 can be installed together in the bypass pipe 2'.

[0062] When a magnetizing device is installed at the inlet of the anti-scaling electrode device 4, the water is magnetized after passing through the magnetizing device and then electrolyzed by the anti-scaling electrode device 4 to produce water containing aluminum ions. Specifically, under the action of current, the anti-scaling anode 18 of the anti-scaling electrode device 4 produces a large amount of aluminum ions through an oxidation reaction. The current of the anti-scaling electrode group is adjusted according to the calcium and magnesium concentration in the wastewater to produce an appropriate amount of aluminum ions (Al). 3+The wastewater after electrolysis by the anti-scaling electrode device 4 contains aluminum ions, magnesium ions, and calcium ions. Inside the electrolytic cell 5, the electrolyzed wastewater undergoes a hydrogen evolution reaction with the cathode of the electrode assembly 9, generating a large amount of OH- ions on the surface. At this time, the aluminum and calcium / magnesium ions in the wastewater combine with the OH- ions to form a hydrotalcite-like scale. This type of scale does not firmly bond with the cathode of the electrode assembly 9. Under the scouring action of high-speed water flow, the hydrotalcite scale on the surface of the cathode electrode is easily washed away by the water flow and does not easily accumulate on the cathode electrode.

[0063] The present invention generates a large number of aluminum ions through the pipeline anti-scaling electrode device 4, which promotes the formation of hydrotalcite-like scale on the cathode surface of the electrode group 9 in the electrolytic cell 5. Under the action of the high-pressure water flow of the spray assembly 8, the scale on the electrode plate is easily washed away.

[0064] like Figure 1 As shown, the tank unit includes: an electrode assembly 9, a power supply 7, an electrolytic cell 5, and an inlet baffle 6. In one embodiment, the electrode assembly 9 is used to react with calcium and magnesium ions in the wastewater to generate hydroxide ions (OH-). The power supply 7 is used to supply power to the electrode assembly 9. The inlet baffle 6 is located at the inlet end of the electrolytic cell 5.

[0065] like Figure 1 As shown, the cleaning unit includes: a high-pressure pump 1-1, a return pump 1-2, a spray assembly 8, and a sludge collection device. In one embodiment, the high-pressure pump 1-11 provides rinsing pressure and water volume to the spray assembly 8. At least one set of spray assemblies 8 is disposed above and below the electrode group 9 within the tank unit, with the coverage areas of each set of spray assemblies 8 overlapping. The sludge collection device is located at the bottom of the tank unit for collecting hydrotalcite-like scale.

[0066] Inside the electrolytic cell 5, an electrode assembly 9 consisting of an anode electrode and a cathode electrode is provided. A spray assembly 8 is provided above and / or below the cathode electrode. The spray assembly 8 and the cathode electrode are on the same plane in the vertical direction, which facilitates the water flow from the spray assembly 8 to spray onto the cathode electrode and wash away the scale adhering to its surface.

[0067] The sludge collection device includes a sludge collection tank 11 and a sludge discharge outlet 12. The sludge collection tank 11 is located at the bottom of the electrolytic cell 5 and is used to collect the sludge (including hydrotalcite-like scale) that falls from the electrode group 9 after being washed by the cleaning unit, and discharges it through the sludge discharge outlet 12.

[0068] like Figure 1 As shown, a valve 3 is installed on the bypass pipeline 2'. The return liquid from the electrolytic cell 5 is transported to the bypass pipeline 2' by the return pump 1-2. After being magnetized by the electromagnetic device 13-1, it is electrolyzed by the anti-scaling electrode device 4. Meanwhile, the wastewater to be treated enters the electrolytic cell 5 directly through the inlet pipeline 2, which makes it easier to control the A1 within the electrolytic cell 5. 3+The concentration of Al was maintained within the electrolytic cell 5 throughout the entire treatment process. 3+ When the concentration is within a certain range, it forms a hydrotalcite-like scale that is easy to wash away and aluminum hydroxide flocs with good adsorption properties for organic matter. A sludge collection tank 11 and a water outlet 10 are provided at the bottom of the electrolytic cell 5. The purified water after electrolysis is discharged from the water outlet 10, and the remaining solid matter is discharged through the sludge discharge outlet 12 of the sludge collection tank 11.

[0069] In one embodiment, the cleaning unit further includes a nozzle bracket 21 for mounting the spray assembly 8. Specifically, an electrode group 9 consisting of multiple sets of cathode and anode electrodes is disposed within the electrolytic cell 5, and the electrode group 9 is electrically connected to a power supply 7 outside the electrolytic cell 5. In the vertical direction within the electrolytic cell 5, spray assemblies 8 are respectively disposed above and below the electrode group 9. The spray assembly 8 is connected to a high-pressure pump 1-1 via pipelines. Under the action of the high-pressure pump 1-1, high-pressure water is delivered to the spray assembly 8 and then sprayed onto the electrode group 9 to wash away the substances adhering to the electrodes.

[0070] like Figure 3 As shown, the spray assembly 8 includes a high-pressure nozzle 22, which can be a self-rotating nozzle or a fixed rotating nozzle. In one embodiment, the electrodes of the electrode group 9 are flat plates, with the plate surface of each electrode being substantially parallel to the vertical direction. Projected horizontally onto the electrolytic cell 5, the high-pressure nozzle 22 is essentially located at the center of the electrode cross-section; this design effectively washes away any adhering substances around the electrodes. The water pressure sprayed from the spray assembly 8 is 500 kPa to 2000 kPa, and the water flow rate is 20 to 100 L / min, which can more effectively wash away the hydrotalcite-like scale adhering to the cathode electrode.

[0071] Furthermore, the spray components 8 arranged above and below the electrode group 9 inside the electrolytic cell 5 are staggered, and the water flow is emitted in a cone shape to wash away the deposits on the outer periphery of the electrodes.

[0072] It should be noted that the wastewater to be treated includes produced water from oil and gas fields (produced water containing calcium, magnesium, and organic matter). Typically, produced water from oil and gas fields contains petroleum components and polymers, and has a certain viscosity. Produced water is a byproduct of oilfield extraction and contains petroleum components and polymers.

[0073] The scale-preventing electrode assembly can handle low-hardness water with a hardness range of: calcium ion concentration <250mg / L (calculated as calcium hardness) or magnesium ion concentration <60mg / L (calculated as magnesium hardness).

[0074] The inlet water for the electrolytic cell 5 includes: wastewater to be treated that directly enters the electrolytic cell 5 through the inlet pipe 2, and low-hardness water that enters the electrolytic cell 5 after electrolysis by the anti-scaling electrode device 4 installed through the bypass pipe 2'. The low-hardness water entering the bypass pipe 2' can come from the discharged return water after electrolysis treatment inside the electrolytic cell 5, or it can use an external water source, as long as its hardness is within the hardness range.

[0075] In addition, when a magnetization device is installed at the inlet of the anti-scaling electrode device 4, the low-hardness water is first magnetized by the magnetization unit before electrolysis through the bypass pipe 2' of the anti-scaling electrode device 4. After magnetization, the low-hardness water enters the anti-scaling electrode device 4 for electrolysis, where aluminum hydroxide (Al-LDHs) is formed first. The floc aggregation phenomenon generated during electrolysis is improved after magnetization, and the flocs gradually increase in size through flow and collision within the pipe. Upon entering the electrolysis tank 5, they can induce the formation of hydrotalcite-like flocs through continuous collision and combination. The aluminum hydroxide flocs that are not bound to calcium and magnesium aggregate and settle better. After entering the electrolysis tank 5, they are beneficial for adsorbing and removing organic matter, especially organic matter in produced water from oil and gas fields.

[0076] Therefore, the aluminum hydroxide flocs generated by the bypass pipeline 2' after electrolysis by the anti-scaling electrode device 4 can better adsorb organic matter in the produced water of oil and gas fields. The water hardness is reduced and the organic matter content is significantly reduced after electrolysis treatment by the electrode group 9 in the electrolysis tank 5.

[0077] A portion of the water entering the electrolytic cell 5 undergoes magnetization and treatment with the aluminum anode electrode 18, generating flocs within the electrolytic cell 5 that facilitate sedimentation and effectively adsorb and remove organic matter from the wastewater. In contrast, existing technologies that place the electrolytic cell in a magnetic field produce very small and fragmented flocs under electromagnetic influence, which are less effective at adsorbing and capturing organic matter in the wastewater.

[0078] This invention controls the ratio of aluminum ions and the total concentration of calcium and magnesium ions generated during electrolysis in the anti-scaling electrode device 4 after magnetization within a certain range, thereby forming a hydrotalcite-like scale and aluminum hydroxide flocculents with good adsorption capacity for organic matter (especially produced water from oil and gas fields). Inside the electrolytic cell 5, on the one hand, it can continue to adsorb organic matter in the wastewater; on the other hand, its bond with the cathode electrode of the electrode assembly 9 is not strong and it is easily washed away.

[0079] This invention provides an electrolytic cell that effectively inhibits scale accumulation on electrode plates, comprising: a high-pressure pump 1-1, a reflux pump 1-2, a valve 3, an anti-scaling electrode device 4, an electrolytic cell body 5, a water inlet baffle 6, a power supply 7, a spray assembly 8, an electrode assembly 9, a water outlet 10, a sludge collection tank 11, a sludge discharge outlet 12, an electromagnetic device 13-1, an electromagnetic coil 13-2, and a nozzle support 21. The anti-scaling electrode device 4 generates a large number of aluminum ions, promoting the formation of hydrotalcite-like scale on the cathode surface of the electrode assembly 9 within the electrolytic cell body 5. Under the action of high-pressure water flow, the scale on the electrode plates is easily washed away. The high-pressure spray assembly 8 has a circular cleaning range and can automatically rotate under the action of water flow, resulting in a wider cleaning range without creating cleaning dead zones. Furthermore, the high-pressure spray assembly 8 uses less water.

[0080] Figure 2 A schematic diagram of a pipe-type anti-scaling electrode device according to an embodiment of the present invention is shown.

[0081] The anti-scaling electrode device 4 includes: an anti-scaling electrode assembly, a fixing unit, and a power supply unit. The anti-scaling electrode assembly includes at least one set of anti-scaling electrodes, each set including an anti-scaling anode 18 and an anti-scaling cathode 19. The anti-scaling anode 18 reacts with low-hardness water to generate aluminum ions. The fixing unit is used to fix the anti-scaling electrode assembly to the target pipe section. The power supply unit is used to supply power to the anti-scaling electrode assembly.

[0082] In one embodiment, the anti-scaling anode 18 is made of aluminum, and the anti-scaling cathode 19 is made of stainless steel or titanium. The anti-scaling electrodes are spiral, cylindrical, or flat, and are perpendicular to the target pipe section (bypass pipe 2'), that is, perpendicular to the water flow direction. The electrode length of each anti-scaling anode 18 and anti-scaling cathode 19 is smaller than the diameter of the target pipe section, and the current range of the anti-scaling electrodes is adjustable from 0 to 40A.

[0083] In one embodiment, the fixing unit includes: a washer 14, a screw 15, and a fixing plate 17. The power supply unit includes: a cable 16 and a cable fastener 20.

[0084] like Figure 2 As shown, the anti-scaling electrode (a single set of anti-scaling electrodes consisting of an anti-scaling anode 18 and an anti-scaling cathode 19) is fixed by the same fixing plate 17 and led out to the outside of the target pipe section through a conductive screw 15. Outside the target pipe section, a cable 16 is connected to the screw 15 and fixed to the target pipe section using cable fasteners 20. A gasket 14 on the screw 15 provides a waterproof seal between the target pipe section and the power supply unit.

[0085] Specifically, the anti-scaling anode 18 and anti-scaling cathode 19 can be columnar or plate-shaped, and are perpendicular to the wall of the bypass pipe 2'. The anti-scaling anode 18 and anti-scaling cathode 19 can be fixed inside the bypass pipe 2' in various ways.

[0086] like Figure 2 As shown, one end of the anti-scaling anode 18 and anti-scaling cathode 19 is fixed to the fixing plate 17, and the fixing plate 17 is fixed to the wall of the bypass pipe 2' by a conductive screw 15. Outside the bypass pipe 2', the cable 16 is electrically connected to the screw 15. Specifically, the cable 16 is connected to the screw 15 by a cable fastener 20, which provides power to the anti-scaling anode 18 and anti-scaling cathode 19. An insulating gasket 14 is provided between the cable fastener 20 and the outer wall of the bypass pipe 2'. The gasket 14 prevents liquid from leaking out of the bypass pipe 2' through the connection and also prevents the bypass pipe 2' from being energized.

[0087] In one embodiment, the number of anti-scaling electrodes in the anti-scaling electrode assembly is related to the processing flow rate, with each unit flow rate (m³) being [number missing]. 3 Each h corresponds to a set of anti-scaling electrodes, and these are accumulated. Furthermore, depending on the composition of the actual liquid to be treated, multiple sets of anti-scaling anodes 18 and anti-scaling cathodes 19 can be set up in parallel.

[0088] During normal operation, low-hardness water flows through the pipe-type anti-scaling electrode device 4. Under the action of current, the anti-scaling anode 18 generates a large amount of aluminum ions through an oxidation reaction. The current of the anti-scaling electrode group is adjusted according to the calcium and magnesium concentration, so that the ratio of aluminum ion concentration to total calcium and magnesium ion concentration in the wastewater within the electrolytic cell 5 is controlled within the range of 1:1 to 3:1. Within this range, hydrotalcite-like scale and aluminum hydroxide flocculents with good adsorption capacity for organic matter (especially produced water from oil and gas fields) can be formed within the electrolytic cell 5. Furthermore, the structure of the pipe-type anti-scaling electrode device 4 provided by this invention is easy to clean and disassemble, the aluminum ion concentration can be automatically controlled by current, and this invention can effectively inhibit scale accumulation on the electrode plates, thereby improving the operating efficiency of the electrolytic cell.

[0089] It should be noted that the aluminum ion concentration mentioned in this invention includes the total amount of Al existing in various forms. The aluminum ions are obtained through electrolysis using the anti-scaling electrode device 4. The resulting aluminum ions can form aluminum hydroxide with better adsorption properties in the magnetized wastewater, especially exhibiting excellent adsorption of organic matter in produced water from oil and gas fields.

[0090] In one embodiment, during the operation of the electrolytic cell, when the voltage of the power supply 7 inside the electrolytic cell 5 rises to more than 120% of the initial voltage, after the wastewater inside the electrolytic cell 5 is discharged, high-pressure water is sprayed out through the spray assembly 8 to rinse the electrodes. Under the scouring action of the high-speed water flow, the hydrotalcite-like scale on the cathode surface of the electrode assembly 9 can be quickly washed away with the water flow.

[0091] Figure 4 A flowchart illustrating the steps of a method for effectively suppressing scale accumulation on electrode plates according to an embodiment of the present invention is shown.

[0092] According to another aspect of the invention, a method for effectively suppressing scale accumulation on electrode plates is also provided, which is performed by an electrolytic cell that effectively suppresses scale accumulation on electrode plates.

[0093] like Figure 4 As shown, in step S1, an anti-scaling electrode device 4 is installed through the bypass pipe 2' of the wastewater inlet / outlet unit inlet pipe 2. The anti-scaling electrode device 4 includes an anti-scaling electrode assembly for reacting with low-hardness water to generate aluminum ions.

[0094] like Figure 4 As shown, in step S2, the calcium and magnesium ions in the wastewater to be treated react with the tank unit to generate hydroxide ions, which combine with aluminum ions and calcium and magnesium ions to form a hydrotalcite-like scale.

[0095] like Figure 4 As shown, in step S3, the hydrotalcite-like scale is rinsed off by the cleaning unit.

[0096] In practical applications, during normal operation, the return water from electrolysis treatment in the electrolytic cell 5, or low-hardness water from outside, sequentially passes through the magnetization device and the anti-scaling electrode device 4 before entering the electrolytic cell 5. Wastewater to be treated enters the electrolytic cell 5 through the inlet pipe 2. The two water flows mix and undergo electrolysis within the electrolytic cell 5. Specifically, the low-hardness water passes through the magnetization device and enters the anti-scaling electrode device 4. Inside the anti-scaling electrode device 4, the low-hardness water reacts with the anti-scaling anode 18, generating a large amount of aluminum ions. The solution containing a large amount of aluminum ions, as well as calcium and magnesium ions, enters the electrolytic cell 5 and undergoes a hydrogen evolution reaction at the cathode of the electrode assembly 9, generating a large amount of OH-, forming a hydrotalcite-like scale. This scale is easily removed from the cathode by spraying and discharged outside the electrolytic cell 5. This effectively prevents scale formation at the cathode within the electrolytic cell 5, improving the electrolysis efficiency of the electrolytic cell.

[0097] This invention provides a method for effectively inhibiting scale accumulation on electrode plates. The current of the anti-scaling electrode device 4 is adjusted according to the calcium and magnesium concentration in the wastewater, ensuring that the ratio of aluminum ion concentration to the total calcium and magnesium ion concentration in the wastewater within the electrolytic cell 5 is controlled within the range of 1:1 to 3:1. Aluminum and calcium / magnesium ions in the wastewater combine with OH- ions to form a hydrotalcite-like scale on the cathode surface of the electrode assembly 9. This type of scale is not firmly bonded to the cathode. Under the scouring action of high-speed water flow, the scale on the cathode surface can be quickly washed away. Changes in the voltage of the power supply 7 can effectively determine whether the electrodes in the electrolytic cell should be backwashed. Using high-pressure water flow instead of acid washing or electrode reversal can extend the service life of the electrodes to a certain extent.

[0098] The electrolytic cell and method for effectively inhibiting scale accumulation on the electrode plates provided by this invention can also be used in conjunction with a computer-readable storage medium. The storage medium stores a computer program, which is executed to run the method for effectively inhibiting scale accumulation on the electrode plates. The computer program is capable of executing computer instructions, which include computer program code. The computer program code can be in the form of source code, object code, executable file, or some intermediate form.

[0099] Computer-readable storage media can include: any entity or device capable of carrying computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc.

[0100] It should be noted that the contents of computer-readable storage media may be appropriately added to or subtracted from the contents according to the requirements of legislation and patent practice in a jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable storage media may not include electrical carrier signals and telecommunication signals.

[0101] The wastewater treated in the following examples and comparative examples was produced water from a gas field, with an initial COD of approximately 1500 mg / L and an initial total organic carbon (TOC) of 450 mg / L. GC-MS analysis revealed that large nitrogen-containing molecules, such as nitrogen-containing heterocyclic compounds like methyl / ethylpyridine, accounted for 37.2 wt% of the total, and were significant components of ammonia nitrogen and COD in the wastewater. Chlorinated compounds, such as hypochlorous acid toluene (29.5 wt%), were also significant contributors to COD. Additionally, some oxygen-containing compounds, including phenols, alcohols, and acids (23.3 wt%), were present. The calcium ion concentration in the wastewater was 200 mg / L, and the magnesium ion concentration was 50 mg / L.

[0102] In Example 1, the produced water from the oil and gas field adopts... Figure 1 In the electrolytic cell shown, water discharged from outlet 10 of part of the electrolytic cell 5 is magnetized by a magnetization device. The magnetized water then enters the anti-scaling electrode device 4. The electrolyzed mixture enters the electrolytic cell 5. Produced water from the oil and gas field to be treated enters the electrolytic cell 5 through inlet pipe 2 and undergoes electrolysis within the electrolytic cell 5. Specific process parameters are as follows:

[0103] Water treatment capacity (i.e., flow rate through inlet pipe 2) 2m 3The influent water stays in the electrolytic cell 5 for 2 hours. The concentration of aluminum ions to calcium and magnesium ions in the water to be treated within the electrolytic cell 5 is maintained at approximately 1:1.5. The anti-scaling electrode device 4 is equipped with two sets of anti-scaling electrodes connected in parallel. The anti-scaling electrode current is set to 32A, and a variable frequency magnetization device is used, with an output current of 50A and an output frequency of 400Hz. The electrode assembly within the electrolytic cell 5 contains 16 electrodes with a plate spacing of 3cm. Nine nozzles are installed above and below each electrode, with each nozzle having a working range of a circle with a diameter of 9cm. The high-pressure pump 1-1 provides a flushing pressure of 500kPa and a total water flow rate of 360L / min.

[0104] After 30 days of continuous operation, the cell voltage of the electrolyzer rose to 121% of the initial voltage. The electrolyzer power supply 7 was then shut off. Backwash pump 1-1 was started and operated for 30 minutes. The electrolyzer power supply 7 was then turned on, and the voltage returned to its initial value. In the water sample discharged after treatment by electrolyzer 5, the COD decreased to 522 mg / L, and the total calcium and magnesium ion concentration decreased to below 50 mg / L.

[0105] In Example 2, the wastewater treatment process and parameters are basically the same as in Example 1. The difference is that no magnetization device is installed in this example; that is, the return water discharged from the electrolytic cell 5 flows directly into the anti-scaling electrode device 4 for electrolysis without undergoing magnetization treatment. After treatment in the electrolytic cell 5, the COD in the discharged water sample is reduced to 750 mg / L, and the total concentration of calcium and magnesium ions is reduced to below 50 mg / L.

[0106] In Comparative Example 1, the wastewater treatment process and parameters are basically the same as in Example 1. The difference is that the electrolytic cell in this comparative example does not have a bypass pipe 2' or a magnetization device and anti-scaling electrode device 4 installed on the bypass pipe 2'. The water in the electrolytic cell 5 comes only from the wastewater to be treated. After the electrolytic cell has been running continuously for 10 days, the cell voltage rises to 115% of the initial voltage. The electrolytic cell power supply 7 is then turned off, and the wastewater is soaked overnight in 15% dilute hydrochloric acid before being discharged. The wastewater is then treated again, and the voltage returns to the initial voltage.

[0107] In Comparative Example 2, the wastewater treatment process and parameters were basically the same as in Example 1. The difference was that no magnetization device was installed on the bypass pipe 2', but an anti-scaling electrode device 4 was installed on the bypass pipe 2'; the coil of the frequency conversion magnetization device was wound around the entire electrolytic cell 5. Because the flocs in the electrolytic cell 5 did not grow into large flocs under the action of the magnetic field, the flocculation effect was poor, and the COD of the water sample discharged after treatment by the electrolytic cell was reduced to 700 mg / L.

[0108] In summary, this invention provides an electrolytic cell and method for effectively suppressing scale accumulation on electrode plates, which has the following advantages compared with the prior art:

[0109] 1) After being magnetized by the magnetization device, the low-hardness water is electrolyzed by the pipeline-type anti-scaling electrode device 4, generating a large amount of aluminum ions. These aluminum ions combine with calcium and magnesium ions to form a hydrotalcite-like scale. Furthermore, the aluminum ions generated during electrolysis also form aluminum hydroxide with a specific shape, which has better adsorption properties. Under high-pressure water flow, the scale on the electrode plates is easily washed away, and the device effectively adsorbs organic matter from wastewater (especially produced water from oilfield gas), thus better reducing the COD (Chemical Oxygen Demand) of the wastewater.

[0110] 2) The structure of the pipeline-type anti-scaling electrode device 4 is easy to clean and disassemble; the concentration of aluminum ions generated can be automatically controlled by the current.

[0111] 3) The high-pressure nozzle 22 has a circular spray range and can rotate automatically under the action of water flow, resulting in a wider range of action and no dead corners in cleaning. In addition, the high-pressure nozzle 22 uses less water.

[0112] 4) By observing the voltage changes of the power supply 7, it is possible to effectively determine whether the electrode assembly 9 inside the electrolytic cell 5 needs backwashing. Using high-pressure water flow instead of acid washing or electrode reversal can extend the service life of the electrode assembly 9 to a certain extent.

[0113] It should be understood that the embodiments disclosed herein are not limited to the specific structures, processing steps, or materials disclosed herein, but should be extended to equivalent substitutions of these features as understood by those skilled in the art. It should also be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting.

[0114] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0115] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0116] Certain terms are used throughout this application to refer to specific system components. As those skilled in the art will recognize, the same components may often be referred to by different names, and therefore this application is not intended to distinguish those components that differ only in name and not in function. In this application, the terms “comprise,” “include,” and “have” are used in an open-ended manner and should therefore be interpreted as meaning “including, but not limited to…”. Furthermore, the terms “substantially,” “materially,” or “approximately” as used herein refer to industry-accepted tolerances for the corresponding terms. The term “coupling,” as may be used herein, includes direct coupling and indirect coupling via additional components, elements, circuits, or modules, wherein, for indirect coupling, the intermediate component, element, circuit, or module does not alter the information of the signal but may adjust its current level, voltage level, and / or power level. Inferred coupling (e.g., one element is inferredly coupled to another element) includes direct and indirect coupling between two elements in the same manner as “coupling.”

[0117] The phrase "an embodiment" or "an embodiment" used in this specification means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. Therefore, the phrase "an embodiment" or "an embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment.

[0118] The embodiments of the present invention are given for illustrative and descriptive purposes only, and are not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles and practical application of the invention, and to enable those skilled in the art to understand the invention and to design various embodiments with various modifications suitable for a particular purpose.

[0119] While the embodiments disclosed in this invention are as described above, the content is merely for the purpose of facilitating understanding of the invention and is not intended to limit the invention. Any person skilled in the art to which this invention pertains may make any modifications and variations in form and detail of the implementation without departing from the spirit and scope disclosed herein; however, the scope of patent protection for this invention shall still be determined by the scope defined in the appended claims.

Claims

1. An electrolytic cell that effectively inhibits scale accumulation on electrode plates, characterized in that, The electrolytic cell comprises: Anti-scaling electrode device, comprising an anti-scaling electrode assembly for reacting with low-hardness water to generate aluminum ions; The wastewater inlet and outlet unit has the scale prevention electrode device installed in the bypass pipe of its inlet pipe; The tank unit is used to react with calcium and magnesium ions in the wastewater to be treated to generate hydroxide ions, which combine with aluminum ions and calcium and magnesium ions to form a hydrotalcite-like scale. The cleaning unit is used to rinse away hydrotalcite-like scale.

2. The electrolytic cell for effectively inhibiting scale accumulation on electrode plates as described in claim 1, characterized in that, The anti-scaling electrode device includes: The anti-scaling electrode assembly includes at least one set of anti-scaling electrodes, each set of anti-scaling electrodes including an anti-scaling anode and an anti-scaling cathode, wherein the anti-scaling anode is used to react with low-hardness water to generate aluminum ions; A fixing unit is used to fix the anti-scaling electrode assembly to the target pipe section; A power supply unit is used to supply power to the anti-scaling electrode assembly.

3. An electrolytic cell for effectively inhibiting scale accumulation on electrode plates as described in claim 2, characterized in that, The anti-scaling anode is made of aluminum, and the anti-scaling cathode is made of stainless steel or titanium.

4. An electrolytic cell for effectively inhibiting scale accumulation on electrode plates as described in claim 2 or 3, characterized in that, The anti-scaling electrode is spiral, cylindrical, or flat, with a length smaller than the diameter of the target pipe section, and an adjustable current range of 0–40A.

5. An electrolytic cell for effectively inhibiting scale accumulation on electrode plates as described in any one of claims 2-4, characterized in that, The fixing unit includes: a washer, a screw, and a fixing plate; the power supply unit includes: a cable and cable fasteners; wherein: The anti-scaling electrode is fixed by the fixing plate and led out of the target pipe section by the screw; The cable is connected to the screw and is fixed to the target pipe section using the cable fasteners. The target pipe section and the power supply unit are sealed and waterproofed by the gasket set on the screw.

6. An electrolytic cell for effectively inhibiting scale accumulation on electrode plates as described in any one of claims 1-5, characterized in that, The wastewater inlet / outlet unit includes: The water inlet pipe and the bypass pipe are installed at the water inlet end of the tank unit; A magnetization device, which is installed at the inlet end of the anti-scaling electrode device, is used to magnetize low-hardness water; A valve is provided at the inlet end of the magnetizing device; The water outlet is located at the outlet end of the tank unit.

7. An electrolytic cell for effectively inhibiting scale accumulation on electrode plates as described in any one of claims 1-6, characterized in that, The tank unit includes: an electrolytic cell, an electrode assembly, and a power supply. The electrode assembly is disposed in the electrolytic cell and is used to react with calcium and magnesium ions in the wastewater to be treated to generate hydroxide ions. The power supply is used to supply power to the electrode assembly.

8. An electrolytic cell for effectively inhibiting scale accumulation on electrode plates as described in claim 7, characterized in that, The cleaning unit includes: a high-pressure pump, a return pump, a spray assembly, and a sludge collection device, wherein: The high-pressure pump is used to provide flushing pressure and water volume to the spray assembly; At least one set of the spray assembly is provided above and below the electrode group, and the coverage area of ​​each set of spray assemblies overlaps with that of the others; The sludge collection device is located at the bottom of the electrolytic cell and is used to collect the hydrotalcite-like scale. The reflux pump is connected to the outlet end of the electrolytic cell and is used to pump the low-hardness water flowing out of the electrolytic cell to the bypass pipeline.

9. A method for effectively inhibiting scale accumulation on electrode plates, characterized in that, Performed by an electrolytic cell as described in any one of claims 1-8, the method comprises: The anti-scaling electrode device is installed through the bypass pipe of the wastewater inlet / outlet unit inlet pipe, wherein the anti-scaling electrode device includes an anti-scaling electrode assembly for reacting with low-hardness water to generate aluminum ions. The tank unit reacts with calcium and magnesium ions in the wastewater to be treated to generate hydroxide ions, which combine with aluminum ions and calcium and magnesium ions to form a hydrotalcite-like scale. The cleaning unit washes away hydrotalcite-like scale.

10. A storage medium, characterized in that, It contains instructions for performing the method as described in claim 9.

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