Electrode insulation structure and insulation method for gas discharge reactor

Abstract

An electrode insulation structure and insulation method for a gas discharge reactor, belonging to the technical field of air pollution control and environmental protection, characterized in that the electrode insulation structure consists of a sleeve, an airflow inlet, a fixing plate, a waterproof pipe and a waterproof cover, the surface of the waterproof pipe is provided with a multi-layer insulating isolation ring, and a dry airflow is also passed between the sleeve and the electrode rod to effectively insulate the electrode rod from the reactor shell, thereby preventing the water vapor and droplets in the gas discharge reactor from affecting the electrode insulation, and achieving the electrical insulation effect between the electrode rod and the reactor shell.

Description

Technical Field

[0001] The invention relates to an electrode insulation structure and an insulation method of a gas discharge reactor, in particular to the insulation between an electrode of a gas discharge reactor and a reactor shell, and belongs to the technical field of air pollution control and environmental protection. Background Art

[0002] Gas discharge is a new type of waste gas treatment and gas molecule recombination technology. Its basic principle is to use gas discharge to generate a large number of high-energy electrons, atoms and free radicals. These high-energy electrons, atoms and free radicals react with target gas molecules in the gas and oxidize or transform them. A positive (or negative) electrode pair with a high voltage needs to be applied to achieve gas discharge. The applicant of the present invention has also disclosed related methods and devices (publication numbers CN107398144A and CN107417493A) for treating harmful gases in gas streams. In practical applications, since the gas stream often contains moisture and high humidity, the insulation between the discharge electrode and the reactor shell is particularly important for the normal operation of the discharge reactor, and the usual method of insulation using insulators is not suitable. The purpose of the present invention is to design and provide an electrode insulation structure and insulation method for a gas discharge reactor to solve the insulation problem between the electrode and the reactor shell under high humidity and spray water conditions in the reactor. Summary of the invention

[0003] The technical solution adopted by the present invention is: an electrode insulation structure of a gas discharge reactor, characterized in that the electrode insulation structure consists of an electrode rod, a sleeve, an air flow inlet, a fixed disk, a waterproof tube and a waterproof cover. The sleeve passes through the reactor shell, one end of which is outside the reactor shell and the other end is inside the reactor. The electrode rod is connected to the discharge electrode in the reactor through the sleeve, and the other end is connected to a high-voltage power supply and is sealed. The sleeve outside the reactor shell is also provided with an air flow inlet to introduce dry air flow. There is a gap between the electrode rod and the sleeve for air flow to flow through, and the outer end is sealed. One end of the sleeve inside the reactor shell is connected to the fixed disk, and a waterproof sleeve and a waterproof cover are provided on the fixed disk.

[0004] The insulation method of the electrode insulation structure of a gas discharge reactor described in the present invention is characterized in that the electrode insulation structure is provided with a waterproof sleeve and a waterproof cover to prevent water droplets in the airflow in the discharge reactor from entering the sleeve, and at the same time, the airflow is introduced into the gap between the electrode rod and the sleeve in the reactor through the airflow inlet on the sleeve, so that the space between the electrode rod and the waterproof tube is filled with dry airflow, thereby achieving the effect of electrical insulation between the electrode rod and the reactor shell.

[0005] The electrode rod of the present invention is composed of a conductive rod and an insulating layer. The conductive rod is generally made of metal materials such as stainless steel with good conductivity, and is generally round in shape, but can also be square or other shapes with equivalent effects. The insulating layer can generally be made of materials with good insulation properties such as epoxy, silicone, nylon, tetrafluoroethylene and ceramics, and can be selected according to specific conditions such as withstand voltage and strength. For details, please refer to the relevant design manual. The electrode rod and the insulating layer should generally fit tightly, the length of the insulating layer should be greater than the length of the casing, and the distance between the insulating layer port of the electrode rod and the casing port should generally be no less than the distance between two adjacent electrodes.

[0006] The materials of the sleeve, fixed plate, waterproof pipe and waterproof cover described in the present invention need to have a certain strength, and can generally be non-combustible or flame-retardant materials such as ceramics and PVC, or materials with good insulation properties such as epoxy resin, silica gel, nylon and tetrafluoroethylene, or metal materials. The gap distance between the sleeve and the electrode rod can be set as needed to facilitate the passage of airflow. The larger the gap distance, the larger the required dry airflow, preferably 2-10mm. The fixed plate is generally fixed on the sleeve to facilitate overall installation, and can also be fixed on the reactor shell or tower body to install the waterproof pipe and waterproof cover. The waterproof cover can be a semicircular, semi-elliptical structure to facilitate the smooth flow of water droplets or water flow above. The waterproof pipe is generally cylindrical, and can also be other shapes such as square, with equivalent effects. The length and width of the waterproof cover should be greater than the length and width of the waterproof pipe, preferably more than 2 times, and a certain distance should be maintained between the two, which can be determined according to the size of the waterproof cover and the waterproof pipe. There are no special requirements, preferably 30-100mm. The distance between the inner wall of the waterproof tube and the electrode rod should generally be no less than half of the distance between two adjacent electrodes, preferably 1.1-2 times. If a metal material is used as the waterproof tube, the distance between the inner wall of the waterproof tube and the electrode rod should be appropriately increased. The distance between the inner wall of the waterproof tube and the electrode rod also has a certain relationship with the voltage applied to the electrode. The higher the applied voltage, the greater the distance between the waterproof tube and the electrode rod. Generally, when the voltage increases by about 5kV, the distance between the inner wall of the waterproof tube and the electrode rod should generally increase by more than 10mm.

[0007] In order to prevent the current in the reactor from being connected to the reactor shell through the water flow or water droplets that may accumulate on the outer surface of the waterproof pipe, when an insulating material is used as a drain pipe, a multi-layer insulating isolation ring can be set on the surface of the waterproof pipe to form a shape similar to a heat sink tube or a corrugated tube. The insulating isolation ring is generally in the shape of a ring or a disc, and the material is an insulating material, including ceramic, epoxy resin, silica gel, nylon, glass and tetrafluoroethylene. There should be a certain distance between the two adjacent insulating isolation rings, but there is no special requirement. It is generally more than 5mm, which has a certain relationship with the voltage applied to the electrode. The higher the applied voltage, the larger the spacing between the insulating isolation rings, preferably 15-30mm. Similarly, an insulating isolation ring of the same structure can also be set on the sleeve outside the reactor to improve the insulation performance.

[0008] The airflow described in the present invention can be air, or nitrogen, oxygen, carbon dioxide and flue gas, or related mixed gases, etc., and the effects are roughly the same. The airflow can be dried, and the relative humidity in the airflow is preferably less than 50%. If the airflow humidity is high, the distance between the inner wall of the waterproof tube and the electrode rod needs to be appropriately increased. The flow rate of the airflow is determined as needed, so that the space between the electrode rod and the waterproof tube is filled with the airflow. The flow rate is better, so that the water droplets that may float in can be blown away, preferably 2-4m / s. The airflow temperature is generally room temperature, and a hot airflow of a certain temperature can also be used to prevent condensation and condensation of water vapor on the electrode rod and the waterproof tube wall in the reactor. The temperature of the airflow is determined by the temperature resistance and heating energy consumption of the reactor shell and the insulating material, and there is no special requirement. For example, the flue gas temperature can be higher, and the hot air temperature can be lower (usually 40-60℃).

[0009] If the amount of water vapor and airflow entrained droplets in the reactor is small, the waterproof cover of the present invention may not be used, and the same insulation purpose can be achieved by using only the drain pipe. If the sleeve is made of a material with good high voltage insulation, the electrode rod may not need an insulating layer, and the other structures are the same and the effect is equivalent. If the insulating layer of the electrode rod is made of a material with good high voltage insulation, the sleeve, waterproof pipe and waterproof cover may also be made of metal materials, and the other structures are the same and the effect is equivalent.

[0010] The electrode insulation structure described in the present invention can be used for high-voltage end electrode insulation when a gas discharge reactor adopts direct current or pulse discharge. For high-voltage alternating current discharge, both positive and negative electrode pairs can be used, and it can also be applied to the insulation process of other high-voltage electrodes and shells.

[0011] The advantages of the present invention are: an insulating structure composed of a sleeve, an air flow inlet, a fixing plate, a waterproof pipe and a waterproof cover (optional), a dry air flow is also passed between the sleeve and the electrode rod, so that the electrode rod and the reactor shell are effectively insulated, and the surface of the waterproof pipe can also be provided with a multi-layer insulating isolation ring, thereby preventing the water vapor and droplets in the gas discharge reactor from affecting the electrode insulation, thereby achieving the effect of electrical insulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a schematic diagram of the electrode insulation structure of a gas discharge reactor described in the present invention. Figure 2 for Figure 1 Right view of .

[0013] In the figure: 1 conductive rod; 2 high voltage power supply terminal; 3 insulating layer; 4 sealing ring; 5 bushing; 6 air flow inlet; 7 reactor shell; 8 fixing plate; 9 waterproof cover; 10 waterproof pipe; 11 discharge terminal terminal; 12 insulating isolation ring. DETAILED DESCRIPTION

[0014] The present invention is further described in detail below with reference to the accompanying drawings.

[0015] Example 1: Schematic diagram of the electrode insulation structure of a gas discharge reactor according to the present invention Figure 1 As shown (there is no insulating spacer on the surface of the waterproof tube). The reactor wall thickness (7) is about 100 (unit: mm, the same below), the sleeve (5) is Φ32 (outer diameter, the same below) × 3 (wall thickness, the same below), and the length is 320. The fixed disk (8) has a diameter of Φ250 and a thickness of 10. The waterproof cover (9) is semi-cylindrical, with a size of Φ250 × 4 and a length of 200. The waterproof tube (10) is about Φ80 × 2 and has a length of 50. The above components are all made of PVC tubes, and one end of the waterproof cover and the waterproof tube are fixed on the disk. The electrode rod is composed of a stainless steel conductive rod (1) and an epoxy insulating layer (3), wherein the epoxy insulating layer is Φ22×6, 410 in length, the outer end is 50 in length longer than the sleeve, and the inner end is 40 in length longer than the sleeve. The conductive rod is a Φ8 316L stainless steel rod, the outer end is 50 in length longer than the epoxy insulating layer. The two ends of the conductive rod are respectively provided with high-voltage power supply terminals (2) and discharge terminal terminals (11) which are respectively connected to the high-voltage power supply and the discharge electrode. The sleeve is provided with an airflow inlet (6) about 100 from the outer end to connect with the dry airflow, and the outer end is sealed with a sealing ring (4). The distance between two adjacent electrodes in the reactor is about 30.

[0016] The experimental conditions are as follows: the dry air flow is indoor air, the temperature is about 20℃, the humidity is about 50%, 35% and 20% respectively, and the air flow rate is about 1m 3 / h, the gas temperature in the reactor is about 60℃, the humidity is about 90%, the inner wall of the reactor shell is moist, and water drops fall from the gaps in the air flow above. The average droplet size is about 3mm, and the average spray density is about 200 / (m 2 ·s). When the applied voltage is about 15, 18 and 22 kV respectively, the insulation performance between the electrode rod and the reactor shell is good, and no conductive breakdown occurs.

[0017] Example 2: Based on Example 1, the size of the waterproof pipe is changed to about Φ40×2, and the distance between the inner wall and the outer surface of the electrode rod is about half, and the rest is the same as Example 1. The insulation performance of the electrode rod and the reactor shell is also roughly the same, and no conductive breakdown occurs. When there are water droplets on the outer surface of the drain pipe and the inner surface of the fixing plate, the insulation performance is reduced by about 20% compared with Example 1.

[0018] Example 3: Based on Example 1, the waterproof cover is removed and the waterproof tube (10) is enlarged to Φ100×3 and 60 in length. The sleeve, fixing plate and waterproof cover are all made of stainless steel. The rest is the same as Example 1.

[0019] The experimental conditions are: the dry air flow rate is about 3m 3 / h, relative humidity is about 30%, temperature is about 20°C, the distance between the two electrodes in the reactor is about 50, and other conditions are the same as in Example 1. The high voltage power supply is DC or pulse power supply, when the applied voltage is about 20 kV, the insulation performance between the electrode and the reactor shell is good, and no conductive breakdown occurs.

[0020] Example 4: The electrode insulation structure of the gas discharge reactor is the same as that of Example 1.

[0021] The experimental conditions are as follows: the airflow is boiler flue gas, the temperature is about 60°C, the oxygen content is about 10%, the carbon dioxide content is about 12%, the relative humidity of the flue gas after drying is about 45%, and the other conditions are the same as those in Example 1. High voltage AC power supply, the positive and negative electrodes use the same insulation device, and the other conditions are the same as those in Example 1. When the applied voltage is about 20 kV and the frequency is 50 Hz, the insulation performance between the electrode and the reactor shell is good, and no conductive breakdown occurs.

[0022] Example 5: Schematic diagram of the electrode insulation structure of a gas discharge reactor according to the present invention Figure 1 The sleeve (5) is made of nylon insulating material, has a size of Φ32×10, a length of 320, and no epoxy insulating layer (3). Other structures are the same as those in Example 1.

[0023] The experimental conditions are the same as those in Example 1, and the insulation performance is substantially equivalent to that in Example 1.

[0024] Example 6: Schematic diagram of the electrode insulation structure of a gas discharge reactor according to the present invention Figure 1 The waterproof tube is provided with two layers of rubber insulating isolation rings with a spacing of 25 mm on the surface, the outer diameter of the isolation ring is Φ120 mm, the thickness is about 5 mm, and the other structures are the same as those in Example 1.

[0025] The experimental conditions are the same as those in Example 1. When water drops are present on the outer surface of the drain pipe and the inner surface of the fixing plate, the insulation performance is improved by about 20% compared with Example 1. If the distance between the two layers of rubber insulating isolation rings is reduced to about 5 mm, the insulation performance is improved by about 5% compared with Example 1.

[0026] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and the protection scope of the present invention is not limited thereto. For those skilled in the art, any modification of the technical solutions recorded in the embodiments, or any equivalent replacement, modification, change and improvement of some of the technical features thereof within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An electrode insulation structure for a gas discharge reactor, characterized in that The electrode insulation structure is composed of an electrode rod, a sleeve, an air flow inlet, a fixed plate, a waterproof tube and a waterproof cover. The sleeve passes through the reactor shell, one end of which is outside the reactor shell and the other end is inside the reactor shell. The electrode rod is connected to the electrode in the reactor through the sleeve, and the other end is connected to the high-voltage power supply. The port and the sleeve are sealed. The sleeve outside the reactor shell is also provided with an air flow inlet. There is a gap between the electrode rod and the sleeve for air flow to flow through. One end of the sleeve inside the reactor shell is connected to the fixed plate, and the fixed plate is provided with a waterproof tube and a waterproof cover; the electrode rod is composed of a conductive rod and an insulating layer. The conductive rod is a conductive material, and the insulating layer includes epoxy resin, silicone, nylon, tetrafluoroethylene and ceramic insulating materials.

2. The electrode insulation structure according to claim 1, characterized in that The length of the insulating layer is greater than the length of the sleeve.

3. The electrode insulation structure according to claim 1, characterized in that The length and width of the waterproof cover are both greater than the length and width of the waterproof tube.

4. The electrode insulation structure according to claim 1, characterized in that The distance between the inner wall of the waterproof tube and the electrode rod is not less than half of the distance between two adjacent electrodes.

5. The electrode insulation structure according to claim 1, characterized in that The waterproof pipe and the sleeve are provided with multi-layer insulating isolation rings on their surfaces.

6. The electrode insulation structure according to claim 5, characterized in that The insulating isolation ring is in the shape of a ring or a disc, and the distance between two adjacent insulating isolation rings is more than 5 mm.

7. The insulation method of the electrode insulation structure according to claim 1, characterized in that Airflow is introduced into the gap between the electrode rod and the sleeve in the reactor through the airflow inlet on the sleeve, so that the space between the electrode rod and the waterproof tube is filled with dry airflow, thereby achieving electrical insulation effect between the electrode rod and the reactor shell.

8. The insulation method of the electrode insulation structure according to claim 7, characterized in that The dry gas stream includes air, nitrogen, oxygen, carbon dioxide or flue gas.

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