CN208082697U - A kind of electrostatic precipitator for coal gas of high temperature - Google Patents

Abstract

The utility model relates to an electrostatic precipitator for high-temperature gas, which comprises: a casing with a gas inlet and outlet, an ash hopper arranged at the lower part of the casing, an electrode line and a dust-collecting plate arranged in the casing, which are used to insulate electrodes The insulator of the line and the shell, the hot gas purging mechanism for blowing the insulator, and the high-voltage power supply connected to the electrode line; the shape of the insulator is a hollow cylinder, and the hollow structure of the insulator faces the inside of the shell, and the bottom inside of the insulator There is a cylinder for passing through the electrode wire, and the side wall of the insulator is provided with a ventilation structure. The device can effectively reduce the adhesion of tar and dust particles on the insulator, and avoid creepage of the insulator.

Description

An electrostatic precipitator for high temperature gas

technical field

The utility model belongs to the technical field of high-temperature dust removal, and in particular relates to an electrostatic dust removal device for high-temperature gas.

Background technique

Coal-based polygeneration technology based on coal pyrolysis is an important technical means for efficient and clean utilization of coal. Pyrolysis and gasification of coal rich in volatile matter can obtain gas, tar and Semi-coke and coal gas can be separated and purified to obtain high-quality gas fuel, and tar can be further processed to obtain high-quality chemical products. Semi-coke can be directly used for combustion and power generation, so as to realize the clean utilization of coal graded conversion, which has broad application prospects.

The crude gas produced by coal pyrolysis and gasification contains a large amount of particulate matter such as fly ash and coal, and the tar obtained by direct condensation and separation contains a large amount of particulate matter, which will have a greater adverse effect on subsequent processing and utilization. High-temperature pyrolysis gas has the characteristics of high temperature (600°C and above), gas composition mainly in reducing atmosphere (such as CH ₄ , H ₂ ), and tar (easy to condense below 400°C), etc. more difficult. At present, an important problem hindering the industrial application of coal-based polygeneration technology is that the dust removal of high-temperature (above 400°C) pyrolysis gas has not been well resolved.

At present, high-temperature dust removal technologies mainly include cyclone dust removal technology, ceramic/metal filter dust removal technology, granular layer dust removal technology and electrostatic dust removal technology. Cyclone dust collectors have low dust removal efficiency for fine particles and can only be used as pretreatment equipment; ceramic/metal filter dust collectors have high dust removal efficiency, but ceramic filter dust collectors have poor thermal shock resistance and are fragile, and metal filter dust collectors are easy to corrode at high temperatures; Layer dust collectors face the problems of large pressure loss, high energy consumption and difficult regeneration of working fluid.

Electrostatic precipitator technology has the advantages of high dust removal efficiency, small pressure loss, and large amount of flue gas that can be treated. It has been widely used in conventional coal-fired power plants. However, in the environment of high-temperature pyrolysis gas, there are the following difficulties.

During the discharge process of the electrostatic precipitator, since the main components of pyrolysis gas are non-electronegative gases such as methane and hydrogen, the discharge current is mainly electron current, and the particle charging efficiency is greatly reduced, thereby affecting the dust removal efficiency; The gap between the corona inception voltage and the breakdown voltage is narrowed, resulting in the breakdown of the electrostatic precipitator during operation, which affects the stable operation of the precipitator.

The high-temperature pyrolysis gas is rich in tar. During the operation of the electrostatic precipitator, tar and dust particles are easy to adhere to the insulator, especially the inner wall of the insulator, causing creepage of the insulator and affecting the stable operation of the precipitator; dust particles mixed with tar The adhesion is enhanced, and it adheres to the dust collecting plate, making it difficult to clean the dust, thus affecting the stable operation of the dust collector.

Utility model content

The purpose of this utility model is to provide an electrostatic precipitator for high-temperature gas, which can effectively reduce the adhesion of tar and dust particles on the insulator and avoid creepage of the insulator.

The technical scheme provided by the utility model is:

An electrostatic precipitator for high-temperature gas, comprising: a casing with a gas inlet and outlet, an ash hopper arranged at the lower part of the casing, an electrode wire and a dust collection plate arranged in the casing, used to insulate the electrode wire from the casing body insulator, a hot gas blowing mechanism for blowing the insulator, and a high-voltage power supply connected to the electrode wire; the shape of the insulator is a hollow cylinder, and the hollow structure of the insulator faces the inside of the shell. The cylinder passing through the electrode line, and the side wall of the insulator is provided with a ventilation structure.

In the above technical solution, since the side wall of the insulator is provided with a ventilation structure, when the hot gas purging mechanism works on the insulator, it can control the temperature of the insulator at 350-450°C, preventing the tar in the pyrolysis gas from condensing on the surface and inside of the insulator. creepage, and at the same time, it can avoid the occurrence of leakage and other phenomena caused by the decrease of insulation performance due to excessive temperature.

The high-temperature gas in the utility model includes high-temperature cracking gas, high-temperature gasification gas, and the like.

The insulator in the utility model is fired with 99% corundum, which is a high-purity corundum insulator, which is used to ensure the insulation performance at high temperature and the insulation between the electrode wire and the shell; the insulation performance requirements of the high-purity corundum insulator meet: volume resistance The rate exceeds 10 ¹⁴ Ωcm at room temperature, and the Te value (the temperature at which the volume resistivity drops to 1MΩcm) is greater than 1000°C. The shape of the insulator is a hollow cylinder, the diameter of which is greater than 300mm, the height is greater than 500mm, and the thickness of the wall of the insulator is greater than 10mm.

Preferably, the ventilation structure is a ventilation hole, 4-16 holes are distributed on the side wall of the insulator, and the hole diameter is 10-50mm. It is further preferred to open a hole in the middle part of the side wall of the insulator.

Preferably, the length of the cylinder is greater than 600mm. The hollow cylinder is used to pass through the electrode wire, and its wall thickness can be greater than 5mm. The structure of the cylinder can extend the creepage distance.

The hot gas purging mechanism in the utility model includes a sleeve, a gas supply pipe connected to the sleeve and a gas electric heater; the sleeve is installed on the shell and sleeved outside the insulator. The hot gas purging mechanism is used for heat preservation and purging of insulators to prevent creepage caused by condensation of tar in the pyrolysis gas on the surface of insulators, and to avoid leakage caused by insulation performance degradation due to excessive temperature. By controlling the gas electric heater, the hot gas blowing wind speed at the ventilation structure of the insulator is controlled to be 0.5-5m/s, and the temperature of the insulator is controlled at 350-450°C.

Preferably, the hot gas in the hot gas purging mechanism adopts water vapor or hot coal gas (same composition as the oil-free gas in the electrostatic precipitator). The hot gas component in the hot gas purging mechanism cannot contain oxygen, so as to avoid mixing with the gas in the electrostatic precipitator under high temperature conditions and causing an explosion.

Preferably, a cavity is formed between the sleeve and the side wall of the insulator, so that the air supply pipe and the cavity communicate with the ventilation structure. This structural setting enables the purged hot gas to pass through the gas supply pipe, the cavity and the ventilation structure in sequence, and enter the inner side of the insulator, preventing tar in the pyrolysis gas from condensing on the inner side of the insulator to cause creepage.

Preferably, a sealing gasket is provided at the sealing position between the sleeve and the side wall of the insulator.

In the utility model, the middle of the housing is a hollow cylinder, and the two ends of the hollow cylinder are respectively conical gas inlets and gas outlets. The electrostatic precipitator adopts a cylindrical shell to prevent deformation caused by high-temperature thermal expansion. In addition, the cylindrical shell also has the advantages of compression resistance, explosion-proof, and a more uniform temperature field. The shape of the gas inlet and the gas outlet is tapered, which is beneficial to the control of the amount of gas entering and leaving. Preferably, the flow rate of the high-temperature dust-laden pyrolysis gas in the device is 0.8-1.5m/s to ensure that the dust particles have a relatively high migration rate in the device, and the residence time of the dust-laden gas in the device is 8-15s. Ensure that dust particles are adequately removed. Preferably, the gas inlet and the gas outlet are respectively provided with deflectors to ensure that the gas flows evenly in the device.

Preferably, a heating mechanism and a thermal insulation layer are provided outside the housing. The heating mechanism can be heated by electric heating or hot air. By adjusting the power of the electric auxiliary heating device or the flow of hot air, the temperature inside the shell is controlled at 400-600°C, which is used to prevent tar from condensing in the shell due to too low temperature and causing stickiness. Dust accumulation, and at the same time prevent the shell from being unstable during discharge and operation due to excessive temperature. The material of the insulation layer is rock wool board with a thickness of 150-200mm, and the temperature outside the insulation layer is controlled not to be higher than 50°C.

If the heating mechanism on the outside of the shell of the electrostatic precipitator is heated by hot gas, as a preference, the hot gas is inert gas such as hot nitrogen or hot flue gas, which can not only provide heating and heat preservation for the electrostatic precipitator, but also serve as a sealing layer to avoid the electrostatic precipitator. The internal gas is in contact with the outside air, and an explosion occurs.

Preferably, the high-voltage power supply is a high-voltage DC power supply with switchable polarity. The supply voltage of the switchable polarity high voltage direct current power supply may be 50-200kV. In a non-electronegative atmosphere (CH ₄ , H ₂ , N ₂ ), using a positive polarity high-voltage power supply has the advantages of high dust removal efficiency and low energy consumption _; In an atmosphere dominated by dust, it is more efficient to use a negative polarity high-voltage power supply. The switchable polarity high-voltage DC power supply used in this device can effectively deal with the problems of unstable operation and low dust removal efficiency caused by changes in the composition of pyrolysis gas.

In the utility model, the casing is provided with a plurality of dust-collecting pole plates, and the dust-collecting pole plates are arranged parallel to the direction of air flow in the casing; the electrode wires are arranged between adjacent dust-collecting pole plates. The dust-collecting pole plate is a C-shaped dust-collecting pole plate. The dust-collecting pole plate is rolled from 1.5-10 mm steel plate with a width of 350-850 mm. The dust-collecting electrode is spliced by multiple C-shaped dust-collecting pole plates. The C-shaped dust collection plate has a larger dust sinking area, which is beneficial to reduce the secondary dust of dust. The distance between adjacent dust collector plates is 400-800mm, and the wider distance between dust collectors is beneficial to increase the breakdown voltage, so that a higher power supply voltage can be used to improve the dust removal efficiency. Preferably, the electrode wires are smooth round wires with a diameter of 2-5 mm, and the distance between adjacent electrode wires is 400-900 mm. The use of light round wire is beneficial to increase the breakdown voltage, thereby improving the dust removal efficiency and operation stability.

Preferably, the dust-collecting pole plate is hung in the casing, and a high-frequency rapping mechanism is provided at the bottom thereof, which can prevent dust from clogging due to agglomeration.

Preferably, a high-frequency rapping mechanism is provided on the top of the electrode wire to prevent dust from adhering to the high-voltage electrode wire, causing corona wire hypertrophy and affecting dust removal efficiency and stable operation.

Preferably, a spoiler is provided between the housing and the outermost dust collecting plate. The baffle is used to reduce the proportion of dust-laden gas bypassing the air flow, thereby improving the overall dust removal efficiency.

In the utility model, the ash hopper is arranged at the lower part of the housing to collect dust. The number of ash hoppers can be selected according to actual working conditions, preferably 1 to 10. The ash hopper is provided with a high-frequency rapping mechanism. It can prevent dust from clogging due to agglomeration.

Preferably, a baffle is provided inside the ash hopper. The baffle is used to reduce the proportion of dust-laden gas bypassing the air flow, thereby improving the overall dust removal efficiency.

As a preference, the outer periphery of the ash hopper is provided with a thermal insulation mechanism and an ash hopper thermal insulation layer to prevent condensation of tar in the ash hopper.

As a preference, heat-resistant alloy steel or 310S stainless steel can be used for the housing, ash hopper, electrode wire and dust collecting plate of the device to achieve stable operation at a high temperature of 800°C.

Compared with the prior art, the beneficial effects of the utility model are reflected in:

(1) The electrostatic precipitator for high-temperature gas in this utility model improves the structure of the insulator, which can effectively reduce the adhesion of tar and dust particles on the insulator, and avoid creepage of the insulator.

(2) The electrostatic precipitator used for high-temperature gas in the utility model can be applied to the purification of high-temperature coal pyrolysis gas, and is used for particle collection of oily and dusty gas generated by coal pyrolysis. It can not only form a stable discharge in a high-temperature reducing atmosphere, but also realize stable operation at a high temperature of 400-600°C and effectively capture particulate matter in pyrolysis gas.

(3) The electrostatic precipitator used for high-temperature coal gas in this utility model achieves the purpose of purifying the gas, improving the quality of subsequent condensed tar and other gasification products by capturing the particulate matter in the pyrolysis gas of high-temperature coal, and can improve the efficiency of the system. Energy utilization efficiency; in addition, the operating resistance of the device is less than 600Pa.

Description of drawings

Fig. 1 is the structural representation of the electrostatic precipitator for high temperature pyrolysis gas;

Fig. 2 is the left view of the electrostatic precipitator for high temperature pyrolysis gas;

Fig. 3 is an enlarged view of area A in Fig. 1;

Figure 4 is a schematic structural view of an insulator;

Fig. 5 is a schematic structural view of the B-B plane in Fig. 4 .

Among them, 1. Shell; 101. Electrode wire; 102. Dust collecting plate; 103. Fixing frame; 104. Gas inlet; 105. Gas outlet; 106. Inlet deflector; High-frequency rapping mechanism; 109, heating mechanism; 110, insulation layer; 111, first baffle; 2, insulator; 201, cylinder; 202, perforation; 203, hollow structure; 204, sealing gasket; 205, ventilation hole; 206, cavity; 3, ash hopper; 301, ash discharge valve; 302, ash hopper insulation layer; 303, second baffle; 4, high voltage power supply; 401, electric wire; 5, gas electric heater; 501, cover Barrel; 502, air supply pipe; 503, air intake hole.

Detailed ways

The utility model will be further described below in conjunction with the accompanying drawings and specific examples, but the protection scope of the utility model is not limited thereto.

As shown in Figures 1 and 2, the electrostatic precipitator for high-temperature pyrolysis gas includes: a housing 1 with a gas inlet and outlet, an ash hopper 3 arranged at the bottom of the housing 1, and an electrode wire arranged in the housing 1 101 and dust collector plate 102, insulator 2 for insulating electrode wire 101 and shell 1, hot gas purging mechanism for blowing insulator 2, and high voltage power supply 4 connected to electrode wire 101.

The middle of the housing 1 is a hollow cylinder, and the two ends of the hollow cylinder are respectively tapered gas inlet 104 and gas outlet 105 . The electrostatic precipitator adopts a cylindrical shell to prevent deformation caused by high-temperature thermal expansion. In addition, the cylindrical shell also has the advantages of compression resistance, explosion-proof, and a more uniform temperature field. The gas inlet 104 and the gas outlet 105 are conical in shape, which is beneficial to the control of the amount of gas entering and exiting. The gas inlet 104 and the gas outlet 105 are respectively provided with an inlet deflector 106 and an outlet deflector 107 to ensure that the gas flows evenly in the device. The flow rate of high-temperature dusty pyrolysis gas in the device is 0.8-1.5m/s to ensure a high migration rate of dust particles in the device, and the residence time of dusty pyrolysis gas in the device is 8-15s to ensure that dust particles can be fully removed.

A heating mechanism 109 and a thermal insulation layer 110 are provided on the outer side of the housing 1 . The heating mechanism 109 can be heated by electric heating or hot gas. By adjusting the power of the electric auxiliary heating device or the flow rate of hot gas, the temperature inside the shell 1 is controlled at 400-600°C to prevent the tar from condensing in the shell 1 when the temperature is too low. , causing cohesive dust accumulation, while preventing the housing 1 from being unstable during discharge and operation due to excessive temperature. The insulation layer 110 is made of rock wool board with a thickness of 150-200mm, and the temperature outside the insulation layer 110 is controlled to be no higher than 50°C.

Among them, there are several dust collecting plates 102 inside the shell 1, and the dust collecting plates 102 are hung in the shell 1 through the fixing frame 103, and a high-frequency rapping mechanism 108 is provided at the bottom, which can prevent the dust from clogging due to agglomeration . The dust collection plate 102 is arranged parallel to the direction of air flow in the shell 1. The dust collection plate 102 is a C-shaped dust collection electrode plate, which is rolled from 1.5-10mm steel plate and has a width of 350-850mm. The dust collection electrode 102 is made of multiple pieces The C-shaped dust collection plates are spliced together. The C-shaped dust collection plate has a larger dust sinking area, which is beneficial to reduce the secondary dust of dust. The distance between adjacent dust-collecting plates 102 is 400-800mm, and a wider distance between dust-collecting poles is beneficial to increase the breakdown voltage, thereby adopting a higher power supply voltage and improving the dust-removing efficiency.

As shown in FIG. 2 , a first spoiler 111 is provided between the casing 1 and the outermost dust collecting plate 102 . The first baffle 111 is used to reduce the proportion of the dust-laden gas passing through the airflow bypass, thereby improving the overall dust removal efficiency.

The electrode wires 101 are arranged between adjacent dust-collecting pole plates 102. The electrode wires 101 are smooth round wires with a diameter of 2-5 mm, and the distance between adjacent electrode wires 101 is 400-900 mm. The use of light round wire is beneficial to increase the breakdown voltage, thereby improving the dust removal efficiency and operation stability. Similarly, a high-frequency rapping mechanism (not shown) is provided on the top of the electrode wire 101 to prevent dust from adhering to the high-voltage electrode wire 101, causing corona wire hypertrophy and affecting dust removal efficiency and stable operation.

The electrode wire 101 communicates with the high voltage power supply 4 through the wire 401 . The high-voltage power supply 4 is a high-voltage DC power supply with switchable polarity. The supply voltage of the switchable polarity high voltage direct current power supply may be 50-200kV. In a non-electronegative atmosphere (CH ₄ , H ₂ , N ₂ ), using a positive polarity high-voltage power supply has the advantages of high dust removal efficiency and low energy consumption _; In an atmosphere dominated by dust, it is more efficient to use a negative polarity high-voltage power supply. The switchable polarity high-voltage DC power supply used in this device can effectively deal with the problems of unstable operation and low dust removal efficiency caused by changes in the composition of pyrolysis gas.

As shown in Figures 3 to 5, the insulator 2 is fired with 99% corundum and is a high-purity corundum insulator, which is used to ensure the insulation performance at high temperature and the insulation between the electrode wire 101 and the shell 1; the high-purity corundum insulator is insulated The performance requirements are met: the volume resistivity exceeds 10 ¹⁴ Ωcm at normal temperature, and the Te value (the temperature when the volume resistivity drops to 1MΩcm) is greater than 1000°C.

The shape of the insulator 2 is a hollow cylinder, its diameter is greater than 300mm, its height is greater than 500mm, and the thickness of the wall of the insulator is greater than 10mm. The hollow structure 203 of the insulator 2 faces inside the housing 1 . A cylinder 201 is arranged on the inner side of the bottom of the insulator 2. The length of the cylinder is greater than 600mm, and its wall thickness can be greater than 5mm. The structure of the cylinder can extend the creepage distance. The cylinder 201 is provided with a perforation 202 for passing through the electrode wire 101, and the middle part of the side wall of the insulator 2 is provided with 4 ventilation holes 205, the diameter of which may be 10-50mm. Since the side wall of the insulator 2 is provided with ventilation holes 205, when the hot gas purging mechanism is working on the insulator 2, it can control the temperature of the insulator 2 at 350-450°C, so as to prevent the tar in the pyrolysis gas from condensing on the surface and inside of the insulator 2 and cause climbing. At the same time, it can avoid the occurrence of leakage and other phenomena caused by the decrease of insulation performance due to excessive temperature.

The hot gas purging mechanism includes a sleeve 501 , a gas supply pipe 502 connected to the sleeve 501 and an electric gas heater 5 . The sleeve 501 is installed on the shell 1 and sleeved on the outside of the insulator 2 . The hot gas purging mechanism is used for heat preservation and purging of the insulator 2 to prevent tar in the pyrolysis gas from condensing on the surface of the insulator 2 to cause creepage, and at the same time to avoid leakage caused by the decrease of insulation performance due to excessive temperature. By controlling the gas electric heater 5, the hot gas blowing wind speed at the ventilation hole 205 of the insulator is controlled to be 0.5-5m/s, and the temperature of the insulator 2 is controlled at 350-450°C.

As shown in Figure 3, a cavity 206 is formed between the sleeve 501 and the side wall of the insulator 2, and the air supply pipe 502 is connected to the air inlet 503 on the sleeve 501, so that the air supply pipe 502, the cavity 206 and the ventilation hole 205 communicate , the structure is set so that the purged hot gas can pass through the air supply 502, the cavity 206 and the ventilation hole 205 in sequence, and enter the inner side of the insulator 2, so as to prevent the tar in the pyrolysis gas from condensing on the inner side of the insulator 2 and cause creepage. A sealing gasket 204 is provided at the sealing place between the sleeve 501 and the side wall of the insulator 2 .

The ash hopper 3 is arranged at the lower part of the housing 1 for collecting dust, and the dust is discharged by opening the ash unloading valve 301 . The number of ash hoppers 3 can be selected according to actual working conditions, and there are three in the present embodiment. The ash hopper 3 can also be provided with a high-frequency rapping mechanism (not shown in the figure), which can prevent the dust from clogging due to agglomeration. In addition, a second baffle 303 is provided inside the ash hopper 3, and the second baffle 303 is used to reduce the proportion of the dust-containing gas passing through the air flow bypass, thereby improving the overall dust removal efficiency. The periphery of the ash hopper 3 is also provided with a thermal insulation mechanism (not shown in the figure) and an ash hopper insulation layer 302 to prevent tar from condensing in the ash hopper 3 .

The gas inlet 104, inlet deflector 106, electrode wire 101, dust collector plate 102, casing 1, ash hopper 3, gas outlet 105, and outlet deflector 107 in the components of the electrostatic precipitator are all made of heat-resistant alloy Steel or 310S stainless steel, able to withstand 800°C for long-term work stability.

The working process is as follows:

The high-temperature oily and dusty pyrolysis gas enters the housing 1 of the device after passing through the gas inlet 104 and the inlet deflector 106. The electrode wire 102 and the housing 1 are insulated by the high-purity corundum insulator 2. The insulator 2. There is a hot air purging mechanism on the outside. Through the operation of the hot air purging mechanism, the wind speed of the hot air purging at the ventilation hole 205 of the insulator 2 is controlled to 0.5-5m/s, and the surface temperature of the insulator is controlled at 350-450°C. Prevent tar in the pyrolysis gas from condensing on the surface of the insulator 2 to cause creepage, and at the same time avoid the phenomenon of leakage caused by the decrease of insulation performance due to excessive temperature.

The electrode wire 101 is connected with a switchable polarity high-voltage DC power supply, which is used to form a high-voltage electric field and corona discharge between the electrode wire 101 and the dust collecting plate 102. Under the action of electrostatic force, the dust particles in the high-temperature gas are carried charge, and move to the dust collector plate 102 under the action of electric field force. After a period of accumulation, the high-frequency rapping mechanism 108 vibrates to make the dust fall off from the dust collection plate 102 and fall into the ash hopper 3. After the dust has accumulated to a certain amount, the dust discharge valve 301 is opened to discharge the dust. Wait for the next step of processing and utilization; the purified gas enters the downstream process through the gas outlet 105 and the outlet deflector 107 .

The utility model can fully capture the fine particles in the oily and dusty pyrolysis gas at high temperature, so as to ensure the purity of the tar and the quality of the gas in the subsequent condensation preparation process of the tar. The dust removal efficiency can reach 95% at 600°C and 98% at 400°C, and the running resistance of the device is less than 600Pa.

Claims (10)

1. An electrostatic precipitator for high-temperature gas, characterized in that it comprises: a housing with a gas inlet and outlet, an ash hopper arranged at the bottom of the housing, an electrode wire and a dust collecting pole plate arranged in the housing, with The insulator used to insulate the electrode wire and the shell, the hot gas purging mechanism for blowing the insulator, and the high-voltage power supply connected to the electrode wire; the shape of the insulator is a hollow cylinder, and the hollow structure of the insulator faces the inside of the shell, and the insulator The inner side of the bottom of the insulator is provided with a cylinder for passing through the electrode wire, and the side wall of the insulator is provided with a ventilation structure. 2. The electrostatic precipitator for high-temperature gas according to claim 1, wherein the ventilation structure is a ventilation hole, and 4-16 holes are distributed on the side wall of the insulator, and the aperture is 10-50mm; The length of the cylinder is greater than 600mm. 3. The electrostatic precipitator for high-temperature gas according to claim 1, characterized in that, the hot gas purging mechanism comprises a sleeve, a gas supply pipe communicating with the sleeve and an electric gas heater; the sleeve is installed on The shell is sleeved outside the insulator. 4. The electrostatic precipitator for high-temperature gas according to claim 3, characterized in that a cavity is formed between the sleeve and the side wall of the insulator, so that the gas supply pipe and the cavity communicate with the ventilation structure. 5 . The electrostatic precipitator for high-temperature gas according to claim 1 , characterized in that, the middle of the housing is a hollow cylinder, and the two ends of the hollow cylinder are respectively tapered gas inlet and gas outlet. 6 . The electrostatic precipitator for high-temperature gas according to claim 1 , wherein a heating mechanism and an insulating layer are provided on the outer side of the housing. 7 . 7. The electrostatic precipitator for high-temperature gas according to claim 1, wherein the high-voltage power supply is a high-voltage DC power supply with switchable polarity. 8. The electrostatic precipitator for high-temperature gas according to claim 1, characterized in that, a plurality of dust-collecting pole plates are arranged in the housing, and the dust-collecting pole plates are arranged in parallel to the airflow direction in the housing; The electrode wires are arranged between adjacent dust collecting pole plates. 9 . The electrostatic precipitator for high-temperature gas according to claim 8 , wherein a baffle is provided between the casing and the outermost dust-collecting plate. 10 . 10. The electrostatic precipitator for high-temperature gas according to claim 1, characterized in that a baffle is provided inside the ash hopper.