Efficient demister and demisting method

Abstract

The invention provides an efficient demister, and belongs to the technical field of gas purification equipment. The demister comprises a direct-current high-voltage power supply, a cylinder body, a high-voltage electrode, an insulating sleeve and a liquid collecting screen plate, the positive electrode of a direct-current high-voltage power supply is connected with the high-voltage electrode, the negative electrode of the direct-current high-voltage power supply is connected with the barrel and the liquid collecting screen plate and is grounded, the barrel and the liquid collecting screen plate form a low-voltage electrode, and the distance between the high-voltage electrode and the low-voltage electrode is set to be 2-8 cm; in an operation state, a high-voltage electric field is formed around the high-voltage electrode, so that fog-containing gas realizes efficient fog drop trapping in the high-voltage electric field. The demister has the advantages of simple structure, high demisting efficiency, low energy consumption, safety and reliability in operation and the like, and is particularly suitable for demisting industrial waste gas and an air conditioning system.

Description

Technical Field

[0001] This invention belongs to the field of gas purification technology, specifically a high-efficiency demister and demister method. Background Technology

[0002] In industrial production and environmental control processes, water mist carried in gases needs to be removed by demisters. Common demister methods in existing technologies include mechanical separation and electrostatic adsorption. Mechanical demisters (such as baffles and cyclone separators) suffer from drawbacks such as high pressure loss and poor removal of micron-sized droplets; while electrostatic demisters, although effective to some extent, generally suffer from complex electrode structures, insufficient insulation reliability, and susceptibility to corona discharge and ozone generation, affecting demister efficiency and equipment stability.

[0003] CN120286188A discloses a novel flame-retardant, conductive, and sulfuric acid-resistant electrostatic demister. While it focuses on improving corrosion resistance and stress resistance through overall structural design, its demisting function still relies on the electric field between the traditional anode tube bundle and cathode wire, which may lead to uneven electric field strength across channels, affecting overall demisting efficiency. The reliability of its insulation system in terms of long-term corrosion resistance and anti-condensation remains to be verified.

[0004] In summary, existing demisting technologies, whether mechanical or electrostatic, still have shortcomings in terms of demisting efficiency (especially for fine droplets), system energy consumption, long-term operational stability (anti-scaling, corrosion resistance), ease of maintenance, and operational safety. Therefore, there is an urgent need for a new type of high-efficiency demister with a reasonable structural design, high demisting efficiency, low energy consumption, reliable insulation, and easy maintenance. Summary of the Invention

[0005] The purpose of this invention is to provide a high-efficiency demister and demister method. By optimizing the spacing configuration between the high-voltage electrode and the low-voltage electrode and the insulation structure, the demister efficiency is significantly improved, and the long-term stable operation of the equipment is ensured.

[0006] The technical solution adopted in this invention is as follows: A high-efficiency demister and demister method include a high-voltage DC power supply for converting low-voltage AC power into high-voltage DC power; a gas inlet in the middle of a cylinder, a gas outlet at the top, and a liquid outlet at the bottom; several filamentary high-voltage electrodes disposed inside the upper part of the cylinder and connected to the positive terminal of the high-voltage DC power supply; the negative terminal of the DC high-voltage power supply connected to the cylinder and a liquid collecting screen and grounded; a cylindrical insulating sleeve disposed at both ends of the high-voltage electrodes and embedded in the cylinder wall for insulation between the high-voltage electrodes and the cylinder; the high-voltage electrodes include the liquid collecting screen, and the cylinder is connected to the ground via a grounding wire; wherein the distance between the high-voltage electrodes and the low-voltage electrodes is any between 2 cm and 8 cm.

[0007] As described above, in the high-efficiency demister, the gas inlet is located at the bottom of the cylinder, the gas outlet is located at the top of the cylinder, and the liquid outlet is located at the bottom of the cylinder.

[0008] As described above, in the high-efficiency demister, the insulating sleeve is made of either ceramic material or high-performance engineering plastic; it has good insulation properties and mechanical strength.

[0009] As described above, in the high-efficiency demister, the DC voltage output of the high-voltage DC power supply is in the range of 15kV to 50kV.

[0010] As described above, in the high-efficiency demister, the high-voltage electrode is a metal wire electrode with a diameter of 1 mm to 3 mm.

[0011] As described above, the high-efficiency demister's cylinder is made of conductive metallic materials such as carbon steel and aluminum alloy, and is an integral part of the low-voltage electrode.

[0012] As described above, in a high-efficiency demister, the preferred distance between the high-pressure electrode and the low-pressure electrode is 5 cm.

[0013] As described above, the high-efficiency demister has a gas inlet at the bottom of the cylinder, a gas outlet at the top, and a liquid discharge port at the bottom.

[0014] As described above, the liquid collection mesh plate is arched, with holes, low at the edges and high in the middle.

[0015] The demisting method and operation process of this demister include the following steps: 1) Gas introduction process: The mist-containing gas enters the processing chamber formed inside the cylinder through a gas inlet located on one side of the cylinder; 2) Charging process: The gas entering the processing chamber passes through the high-voltage DC electric field region established by the high-voltage electrodes; under the action of this electric field, the water mist particles contained in the gas carry charges due to the corona discharge effect, thus completing the charging process. 3) Capture and migration process: Charged water mist particles migrate towards the low-pressure electrode (or liquid collecting electrode) with opposite polarity under the influence of airflow and electric field. Subsequently, these charged particles collide with the low-pressure electrode and are captured by its surface, thus achieving gas-liquid separation. 4) Purification and emission process: The clean gas that has been de-watered by the above steps flows continuously to the gas outlet at the top or side of the cylinder and is eventually discharged from the system; at the same time, the captured water mist condenses into droplets on the surface of the low-pressure electrode and falls along the electrode surface under the action of gravity, and is finally discharged from the system through the liquid outlet at the bottom of the cylinder, thus completing the entire de-misting process.

[0016] The working principle of this invention is as follows: The mist-containing gas enters the cylinder through the gas inlet. When it flows through the high-voltage DC region, a corona discharge is generated. The water mist particles are charged in the high-voltage DC electric field, forming charged particles. The negative charge is neutralized by the high-voltage electrode, and the positively charged particles flow with the airflow to the low-voltage electrode liquid collecting mesh plate. After contacting it, the positively charged water mist is adsorbed, and the water mist particles condense into droplets. After gathering along the inner wall of the cylinder, they are discharged from the bottom liquid outlet. The purified gas is discharged from the gas outlet of the system. Beneficial effects

[0017] This invention precisely sets the distance between the high-voltage electrode and the low-voltage electrode to 2~8 cm, making the electric field distribution more uniform and significantly improving the charging and collection efficiency of water mist particles, especially showing excellent removal effect on fine mist droplets.

[0018] By adopting a reasonable insulation structure and material selection, high-voltage leakage can be effectively prevented, ensuring the safe operation of the equipment.

[0019] The overall structure is simple and compact, making it easy to install and maintain. Its energy consumption is reduced by more than 20% compared to traditional defogging equipment, resulting in good economic and environmental benefits.

[0020] This invention relates to a high-efficiency demister and demister method, applicable to gas treatment applications such as industrial waste gas treatment, air conditioning systems, and solid-liquid separation. Its core function lies in the efficient capture of mist droplets, water vapor, and tiny liquid colloids entrained in the airflow, significantly reducing emissions of soluble salts, acid mist, and particulate matter, ensuring smooth process operation, improving emission quality, and achieving effective energy and resource recovery. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the high-efficiency demister of the present invention; Figure 2 This is a schematic diagram of the cross-section of the high-voltage electrode AA; Figure 3 This is a top view of the liquid collection mesh plate; Figure 4 This is a graph showing the relationship between voltage, current, and water output during the operation of this invention; Reference numerals: 1-High voltage DC power supply; 2-Gas outlet; 3-Liquid collecting screen; 4-Insulating sleeve; 5-High voltage electrode; 6-Cylinder body; 7-Gas inlet; 8-Liquid outlet. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] Example 1: Refer to the appendix of the instruction manual. Figure 1-3As shown, the high-efficiency demister of this embodiment has a cylindrical body (6) made of carbon steel plate, with dimensions of 300 mm in length, 200 mm in width, and 500 mm in height. A gas outlet (2) is provided at the upper end of the cylindrical body (6), and a liquid outlet (8) is provided at the lower end. The nominal diameters of the gas outlet and the liquid outlet are 150 mm and 100 mm, respectively. A gas inlet (7) is provided on the lower outer wall of the middle part of the cylindrical body (6). A liquid collecting screen plate (3) is provided at the top inside the cylindrical body (6), and several high-voltage electrodes (5) are provided below the liquid collecting screen plate (3). The high-voltage electrodes (5) are made of tungsten wire with a diameter of 2 mm, horizontally arranged in the upper part of the cylindrical body, and fixed to the cylindrical wall of the cylindrical body (6) by an insulating sleeve (4). The high-voltage electrodes (5) are connected to a high-voltage DC power supply (1). The negative terminal of the DC high-voltage power supply (1) is connected to the cylindrical body (6) and the liquid collecting screen plate (3) and grounded. The input voltage of the high-voltage DC power supply (1) is 380 V AC, and the output voltage is 50 kV DC. The low-pressure electrode is composed of a cylinder (6) and a liquid collection mesh plate (3), and the cylinder is grounded as a whole. The distance between the high-pressure electrode (5) and the low-pressure electrode is 4 cm.

[0024] During operation, the mist-containing gas enters the cylinder from the gas inlet (7) at a flow rate of 1.5 m / s. After the mist droplets are captured in the high-voltage electric field, the purified gas is discharged from the gas outlet (2). The captured droplets are collected on the liquid collection screen (3) and then periodically discharged along the inner wall of the cylinder from the bottom liquid outlet (8).

[0025] Demister testing and experiments: 1. Demister insulation test: Without introducing mist-containing gas, turn on the power supply, open the output current knob to any position (but not to the minimum), open the voltage knob to the maximum, the voltage display should be 50kV, and the current display should be 0, indicating that the demister insulation is good and can be put into operation. If there is a current display, it indicates that there is a short circuit or discharge, and it should be checked and dealt with.

[0026] 2. Demister Experiment: Fog-containing gas enters the cylinder from the gas inlet at a flow rate of 1.5 m / s. Turn on the power, first turn the current knob to the maximum, then adjust the voltage, increasing the voltage by 5kV each time. Observe the demisting effect, record the current value, and measure the amount of water removed in 5 minutes.

[0027] like Figure 4 As shown, when the voltage is less than 15kV, the current is almost zero, and the water output is also almost zero. When the voltage reaches 40kV, the current reaches its maximum value, and the water removal capacity also reaches its maximum value. When the voltage is between 15kV and 40kV, the current and water removal capacity increase with the increase of voltage. This characteristic explains the principle of the present invention. Under a certain electric field strength, water mist is turned into charged particles, and water mist is captured by adsorption through the electric field. The working voltage is a key parameter for water removal. Experimental data shows that the working voltage of the demister in this embodiment is between 20kV and 40kV, with the preferred range being between 35kV and 40kV.

[0028] The above description is merely an explanation of the basic principles and examples of the present invention and does not constitute a limitation on the scope of protection of the present invention. Any designs that are the same as or similar to the present invention are within the scope of protection of the present invention.

Claims

1. A high efficiency mist eliminator characterized by, The device includes: a high-voltage DC power supply (1) for converting low-voltage AC power into high-voltage DC power; a gas inlet (7) and a gas outlet (2) and a liquid outlet (8) are provided on the cylinder (6); a plurality of filamentous high-voltage electrodes (5) are disposed inside the cylinder (6) and connected to the positive terminal of the high-voltage DC power supply (1); the negative terminal of the DC high-voltage power supply (1) is connected to the cylinder (6) and the liquid collecting mesh plate (3) and grounded, and the liquid collecting mesh plate (3) is placed above the high-voltage electrodes (5); a cylindrical insulating sleeve (4) is disposed at both ends of the high-voltage electrodes (3) and embedded in the cylinder wall of the cylinder (6) to achieve insulation between the high-voltage electrodes (5) and the cylinder (6); the low-voltage electrode includes the liquid collecting mesh plate (3) and the cylinder (6); wherein the distance between the high-voltage electrodes (5) and the low-voltage electrodes is any between 2 cm and 8 cm.

2. The high efficiency mist eliminator of claim 1, wherein: The gas inlet (7) is located at the lower part of the cylinder (6), the gas outlet (2) is located at the top of the cylinder (6), and the liquid outlet (8) is located at the bottom of the cylinder (6).

3. The high efficiency mist eliminator of claim 1, wherein: The insulating sleeve (4) is made of either ceramic material or high-performance engineering plastic.

4. The high efficiency mist eliminator of claim 1, wherein: The DC voltage output of the high-voltage DC power supply (1) is in the range of 15kV to 50kV.

5. The high efficiency mist eliminator of claim 1, wherein: The high-voltage electrode (5) is a metal wire electrode with a diameter of 1 mm to 3 mm.

6. The high efficiency mist eliminator of claim 1, wherein: The cylinder (6) is made of conductive metal materials such as carbon steel and aluminum alloy.

7. The high efficiency mist eliminator of claim 1 wherein: The preferred distance between the high-voltage electrode (5) and the low-voltage electrode is 5 cm.

8. The high efficiency mist eliminator of claim 1, wherein: The liquid collection mesh plate (3) is arched, with holes, low at the edges and high in the middle.

9. A method for defogging using the high efficiency defogger according to any one of claims 1 to 8, characterized by Includes the following steps: 1) Gas introduction process: The mist-containing gas enters the processing chamber formed inside the cylinder (6) through the gas inlet (7) located on one side of the cylinder (6); 2) Charging process: The gas entering the processing chamber passes through the high-voltage DC electric field region established by the high-voltage electrode (5); causing the water mist particles contained in the gas to carry charges, thus completing the charging process; 3) Capture and migration process: Charged water mist particles migrate towards the low-pressure electrode with opposite polarity under the influence of airflow and electric field force; subsequently, these charged particles collide with the low-pressure electrode and are captured by its surface, thus achieving gas-liquid separation. 4) Purification and discharge process: The clean gas that has been cleaned by removing water mist through the above steps flows continuously to the gas outlet (2) at the top of the cylinder (6) to discharge the system; at the same time, the captured water mist condenses into droplets on the surface of the low-pressure electrode and falls along the electrode surface under the action of gravity, and is finally discharged through the liquid outlet (8) at the bottom of the cylinder (6).

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