Ultra-clean converter gas dry dedusting method

Abstract

Disclosed in the present invention is an ultra-clean converter gas dry dedusting method, comprising the following steps: S1, constructing an ultra-clean converter gas dry dedusting system, wherein dust-containing raw gas of a converter passes through an evaporative cooling flue and then sequentially flows through a high-efficiency heat exchanger, a banana bend dust collector and a swirl heat recovery device for heat recovery, and an output end of the swirl heat recovery device is connected to an electrostatic dust collector and a high-temperature-resistant explosion-proof ultra-clean dust collector by means of a raw gas pipe; S2, purification: causing gas after undergoing two-stage dedusting to pass through a gas axial fan and a silencer and then sending same to a gas switching station; S3, recovery: scrubbing and cooling compliant gas by means of a gas cooler and dehydrator and then sending same to a gas holder; and S4, flaring: sending non-compliant gas to a flare stack for ignition and flaring. The present invention has the advantage of high-quality heat recovery and reuse, solves the problem of excessive emissions from a flare stack during maintenance of the electrostatic dust collector, and is suitable for converter gas dry dedusting retrofitting projects.

Description

A Dry Dust Removal Method for Ultra-Clean Converter Gas Technical Field

[0001] This invention discloses an ultra-clean dry dust removal method for converter gas, which relates to the field of environmental protection equipment, and more specifically to a dry dust removal system for converter gas. Background Technology

[0002] With the increasing demand for Class A emission standards and ultra-low emission requirements from steel enterprises, most newly built and renovated converters adopt dry dust removal systems. Currently, common dry dust removal systems mainly include the first-generation converter primary dry dust removal system (LT method and DDS method) and the improved second-generation converter primary dry dust removal system (with the following configuration after the electrostatic precipitator: pre-coal cooling, dual coal cooling, coal cooling + metal filter cartridge, wet electrostatic precipitator, etc.).

[0003] The existing dry dust removal system for converters has several problems: First, the temperature is reduced from 900℃ to around 250℃ by spraying water mist through an evaporative cooler, resulting in a waste of high-quality heat that is not recovered. Second, the electrostatic precipitator process causes smoke to be emitted from the exhaust chimney during maintenance. Additionally, variations in the discharge level of the high-voltage power supply cause significant fluctuations in voltage and current between the electrodes and plates, affecting the dust removal efficiency of the electrostatic precipitator and leading to substantial fluctuations in dust emission concentration at the exhaust chimney outlet.

[0004] Chinese document CN110184411A relates to a fully dry dust removal system for high-efficiency, energy-saving, and ultra-clean emissions of primary flue gas from a converter. The converter is connected to a heat pipe waste heat boiler via a vaporization cooling flue. The vaporization cooling flue and the heat pipe waste heat boiler are connected to a waste water steam system. The heat pipe waste heat boiler is connected in sequence to a multi-tube explosion-proof flame arrester, a pulse bag filter, a fan, a switching station, and a chimney via flue gas ducts. The switching station is also connected to a gas holder. The heat pipe waste heat boiler, the multi-tube explosion-proof flame arrester, and the pulse bag filter are all connected to a pneumatic ash conveying system. In this scheme, after the converter flue gas enters the heat pipe waste heat boiler for cooling, the outlet flue gas temperature of the multi-tube explosion-proof flame arrester needs to be stabilized within the tolerance range of the bag filter. If the temperature is too high, the filter bags are easily burned. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an ultra-clean dry dust removal method for converter gas, which has the advantages of energy saving and environmental protection.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0007] A method for dry dust removal of ultra-clean converter gas includes the following steps:

[0008] S1. Construct an ultra-clean converter gas dry dust removal system, including a high-efficiency heat exchanger, a banana-bend dust collector, a cyclone heat recovery device, an electrostatic precipitator, a high-temperature explosion-proof ultra-clean dust collector, a cooling displacement fan, a clean gas pipe, a gas axial flow fan, a silencer, and a gas scrubbing and dehydrating device. The dust-laden raw gas from the converter is connected to the high-efficiency heat exchanger, the banana-bend dust collector, and the cyclone heat recovery device in sequence through a vaporization cooling flue for heat recovery. The output end of the cyclone heat recovery device is connected to the electrostatic precipitator and the high-temperature explosion-proof ultra-clean dust collector through the raw gas pipe. A clean gas pipe is installed at the outlet of the high-temperature explosion-proof ultra-clean dust collector.

[0009] S2. Purification: After the dusty raw coal gas undergoes high-efficiency gas-water heat exchange in a high-efficiency heat exchanger, it enters the banana bend dust collector. After passing through multiple baffles in the banana bend dust collector, 35% to 45% of the coarse dust particles are captured and output. After passing through the cyclone heat recovery device, the raw coal gas enters the electrostatic precipitator / high temperature explosion-proof ultra-clean dust collector for fine dust removal. The purified coal gas is then sent to the coal gas switching station after passing through the coal gas axial flow fan and silencer.

[0010] S3. Recovery: The qualified coal gas is washed and cooled by the coal gas cooling dehydrator and then sent to the gas holder.

[0011] S4. Venting: Substandard gas is sent to the venting chimney and ignited for venting.

[0012] Furthermore, the electrostatic precipitator is equipped with a first control valve at the inlet main pipe and a second control valve at the outlet main pipe;

[0013] The inlet main pipe of the high-temperature resistant explosion-proof ultra-clean dust collector is equipped with a third control valve;

[0014] When the first and second control valves are open and the third control valve is closed, the electrostatic precipitator and the high-temperature explosion-proof ultra-clean dust collector perform dust removal operations in series.

[0015] When the first and second control valves are closed and the third control valve is open, the high-temperature explosion-proof ultra-clean dust collector performs dust removal operation independently.

[0016] Furthermore, the high-temperature resistant explosion-proof ultra-clean dust collector is used in combination with two or more units, and the outlet concentration of the high-temperature resistant explosion-proof ultra-clean dust collector can be maintained at a stable 5 mg / Nm³. 3 Below, each dust collector outlet is connected to a clean gas pipe to output purified gas. Each dust collector transports dust to the fine ash bin through an ash collection pipe. Each dust collector is equipped with an explosion relief valve, a vibrator, a heating coil, and insulation. Each high-temperature explosion-proof ultra-clean dust collector is connected to a cooling and replacement fan through a pipeline.

[0017] In step S1, the cylinder diameter of the high-temperature explosion-proof ultra-clean dust collector is 1.0–10 m, and the filter media of the high-temperature explosion-proof ultra-clean dust collector is stainless steel, fluoropolymer, or P84, or...

[0018] Filter media including aramid fiber ≥20%, aramid fiber ≥20%, and stainless steel conductive fiber content ≥6%; or

[0019] Antistatic fiberglass membrane filter media, with a stainless steel conductive fiber content of ≥6%.

[0020] In step S2, the outlet temperature of the vaporization cooling flue is 750℃~850℃. After the raw coal gas passes through the high-efficiency heat exchanger, the high-quality heat in the raw coal gas is efficiently recovered, and the temperature drops to 600℃ before entering the banana bend dust collector. The axial extension lines of the inlet and outlet of the banana bend dust collector have an angle, causing the airflow direction to turn 180° and enter the cyclone heat recovery device. The cyclone heat recovery device is equipped with a cyclone device and a heat recovery device. Under the action of gravity and centrifugal force, the raw coal gas effectively separates coarse dust particles and enhances heat exchange, which is beneficial to heat recovery.

[0021] Furthermore, the bottom of the banana bend dust collector is equipped with a water-cooled drum to capture coarse dust particles. The water-cooled drum's ash discharge pipe is equipped with a pneumatic three-way discharge valve, a normal pneumatic double-layer flap valve, and an emergency pneumatic double-layer flap valve.

[0022] The water-cooled drum discharges ash to the intermediate ash silo via a pneumatic three-way unloading valve, a normal pneumatic double-layer flap valve, and a bucket elevator. The intermediate ash silo then feeds the material into the converter.

[0023] The water-cooled roller discharges ash to the coarse ash silo via a pneumatic three-way unloading valve and an emergency pneumatic double-layer flap valve. The coarse ash is then transported out of the coarse ash silo by a vacuum suction truck or pneumatically transported to the intermediate ash silo by a silo pump.

[0024] Furthermore, the gas switching station is equipped with a recovery cup valve and a venting cup valve. Qualified gas passes through the recovery cup valve, is washed and cooled by the gas cooling dehydrator, and is then sent to the gas holder. Qualified converter gas enters the gas washing dehydrator, where it is cooled to below 70°C after being saturated with water spray. Unqualified gas is sent to the venting chimney for ignition and venting through the venting cup valve.

[0025] In step S4, a nitrogen ejector pipe and a purge pipe are provided on one side of the venting chimney. The nitrogen ejector pipe delivers medium-pressure nitrogen with a pressure ≥1.2MPa, and the purge pipe delivers low-pressure nitrogen or saturated steam with a pressure ≥0.6MPa.

[0026] The dry dust removal method for ultra-clean converter gas of the present invention has the following beneficial effects:

[0027] 1. This invention eliminates the traditional evaporative cold water spray, solving the stubborn problem of easy scaling in evaporative cold water spray; it fully recovers the waste heat of converter gas, increasing the steam recovery amount per ton of steel by more than 50kg, making the system more energy-efficient;

[0028] 2. After adopting the high-temperature resistant explosion-proof ultra-clean dust collector process, the outlet concentration of the high-temperature resistant explosion-proof ultra-clean dust collector can be maintained at a stable 5 mg / Nm³. 3 The following system is more environmentally friendly. Attached Figure Description

[0029] Figure 1 is a schematic diagram of an embodiment of the dry dust removal method for ultra-clean converter gas of the present invention.

[0030] Figure 2 is an enlarged view of A in Figure 1.

[0031] Figure 3 is an enlarged view of B in Figure 1.

[0032] Figure 4 is an enlarged view of C in Figure 1. Detailed Implementation

[0033] The present invention will be further described below with reference to the accompanying drawings:

[0034] Example: Please refer to Figures 1 to 4. A method for dry dust removal of ultra-clean converter gas is described. S1. Construct an ultra-clean converter gas dry dust removal system, including a high-efficiency heat exchanger 3, a banana-bend dust collector 4, a cyclone heat recovery device 5, an electrostatic precipitator 16, a high-temperature explosion-proof ultra-clean dust collector 23, a cooling displacement fan 26, a clean gas pipe 27, a gas axial flow fan 28, a silencer 29, and a gas scrubbing and dehydrating device 31. The dust-laden raw gas from converter 1 is connected to the high-efficiency heat exchanger 3, the banana-bend dust collector 4, and the cyclone heat recovery device 5 in sequence through the vaporization cooling flue 2 for heat recovery. The output end of the cyclone heat recovery device 5 is connected to the electrostatic precipitator 16 and the high-temperature explosion-proof ultra-clean dust collector 23 through the raw gas pipe. The outlet of the high-temperature explosion-proof ultra-clean dust collector 23 is provided with a clean gas pipe 27.

[0035] S2. Purification: After the dusty raw coal gas undergoes high-efficiency gas-water heat exchange in the high-efficiency heat exchanger 3, it enters the banana bend dust collector 4. After passing through the multi-layer baffles in the banana bend dust collector 4, 35% to 45% of the coarse dust particles are captured and output in the banana bend dust collector 4. After passing through the cyclone heat recovery device 5, the raw coal gas enters the electrostatic precipitator 16 / high temperature explosion-proof ultra-clean dust collector 23 for fine dust removal. The purified coal gas is sent to the coal gas switching station after passing through the coal gas axial flow fan 28 and the silencer 29.

[0036] S3. Recovery: The qualified coal gas is washed and cooled by the coal gas cooling dehydrator 31 and then sent to the coal gas holder 32.

[0037] S4, Venting: Substandard gas is sent to the venting chimney 34 for ignition and venting.

[0038] The dry dust removal method for ultra-clean converter gas of this invention applies to converters ranging from 50t to 400t. Converter 1 is defined as: a decarburization converter, a dephosphorization converter, a vanadium extraction converter, a lava homogenization furnace, or a stainless steel converter. The material of the banana-shaped dust collector 4 is stainless steel, boiler steel, or Q345R.

[0039] The ultra-clean converter gas dry dust removal system constructed in this invention specifically includes a high-efficiency heat exchanger 3, a banana-bend dust collector 4, a cyclone heat recovery device 5, a water-cooled drum 6, a pneumatic three-way unloading valve 7, a normal pneumatic double-layer flap valve 8, a normal ash discharge pipe 9, a bucket elevator 10, an intermediate ash silo 11, an emergency pneumatic double-layer flap valve 12, an emergency ash discharge pipe 13, a coarse ash silo 14, a raw coal gas pipe 15, an electrostatic precipitator 16, a first metal hard-seal butterfly valve 17, and a first anti-fouling device. 18. Explosion-proof spectacle valve, 19. Second metal hard-seal butterfly valve, 20. Second explosion-proof spectacle valve, 21. Third metal hard-seal butterfly valve, 22. Third explosion-proof spectacle valve, 23. High-temperature resistant explosion-proof ultra-clean dust collector, 24. Silo pump, 25. Fine ash silo, 26. Cooling and displacement fan, 27. Clean gas pipe, 28. Gas axial flow fan, 29. Silencer, 30. Recovery cup valve, 31. Gas scrubber and dehydrater, 33. Venting cup valve, 34. Venting chimney, 35. Nitrogen ejector pipe, and 36. Purge pipe.

[0040] Converter 1 and high-efficiency heat exchanger 3 are connected by vaporization cooling flue 2. Banana bend dust collector 4 is installed between high-efficiency heat exchanger 3 and cyclone heat recovery device 5. High-efficiency heat exchanger 3 is equipped with heat exchange dense tubes to remove high-quality heat from converter gas through heat exchange, thereby reducing the temperature of converter gas.

[0041] The banana-shaped dust collector 4 is equipped with multiple baffles, which can increase the residence time of dust-laden converter gas in the banana-shaped dust collector 4 and improve the dust removal efficiency; the bottom of the banana-shaped dust collector 4 is equipped with a water-cooled roller 6 to transport the collected coarse ash out.

[0042] The cyclone heat recovery device 5 is equipped with a cyclone device and a heat recovery device; after the raw coal gas passes through the cyclone, coarse dust particles can be effectively separated and heat exchange is enhanced, which is beneficial to heat recovery.

[0043] The water-cooled drum 6 is equipped with a pneumatic three-way unloading valve 7, a normal pneumatic double-layer flap valve 8, and an emergency pneumatic double-layer flap valve 12 on the ash discharge pipe.

[0044] The water-cooled roller 6 discharges ash normally to the intermediate ash silo 11 via the pneumatic three-way unloading valve 7, the normal pneumatic double-layer flap valve 8 and the bucket elevator 10. The intermediate ash silo 11 then feeds material into the converter 1.

[0045] The water-cooled roller 6 discharges ash into the coarse ash silo 14 via the pneumatic three-way unloading valve 7 and the emergency pneumatic double-layer flap valve 12. The coarse ash silo 14 is transported out by a vacuum suction and discharge vehicle or pneumatically transported into the intermediate ash silo 11 by a silo pump.

[0046] The cyclone heat recovery device 5 and the electrostatic precipitator 16 are connected via the raw coal gas pipe 15;

[0047] The electrostatic precipitator 16 has a first control valve installed at its inlet main pipe. The first control valve can be a first metal hard-seal butterfly valve 17 and a first explosion-proof spectacle valve 18. The outlet main pipe is equipped with a second control valve. The second control valve can be a second metal hard-seal butterfly valve 19 and a second explosion-proof spectacle valve 20.

[0048] The inlet main pipe of the high-temperature explosion-proof ultra-clean dust collector 23 is equipped with a third control valve, which can be a third metal hard-seal butterfly valve 21 and a third explosion-proof spectacle valve 22.

[0049] The high-temperature resistant explosion-proof ultra-clean dust collector 23 is equipped with an explosion relief valve, a vibrator, a heating coil, and insulation on its cylinder.

[0050] The high-temperature explosion-proof ultra-clean dust collector 23 is equipped with a cooling and replacement fan 26. Once the dust collector is under maintenance, after the coal gas is replaced with nitrogen, the cooling and replacement fan 26 is started to blow air into the dust collector cylinder to cool down and ventilate.

[0051] The high-temperature explosion-proof ultra-clean dust collector 23 uses a silo pump 24 to pneumatically transport the collected fine ash to the fine ash silo 25; the fine ash silo 25 is equipped with a vacuum suction and discharge tanker interface;

[0052] The outlet of the high-temperature explosion-proof ultra-clean dust collector 23 is equipped with a clean gas pipe 27. The clean gas is sent to the gas switching station after passing through the gas axial flow fan 28 and the silencer 29. The qualified gas passes through the recovery cup valve 30, is washed and cooled by the gas cooling dehydrator 31, and is then sent to the gas holder 32. The unqualified gas is sent to the venting chimney 34 for ignition and venting through the venting cup valve 33.

[0053] The electrostatic precipitator 16 and the high-temperature explosion-proof ultra-clean dust collector 23 can operate in series, or the high-temperature explosion-proof ultra-clean dust collector can operate independently after closing the first metal hard-seal butterfly valve 17, the first explosion-proof spectacle valve 18, the second metal hard-seal butterfly valve 19, the second explosion-proof spectacle valve 20, and opening the third metal hard-seal butterfly valve 21 and the third explosion-proof spectacle valve 22. When the electrostatic precipitator and the high-temperature explosion-proof ultra-clean dust collector are used in combination, it is equivalent to adding another dust removal step at the outlet of the electrostatic precipitator. The dust exiting the electrostatic precipitator is captured by the high-temperature explosion-proof ultra-clean dust collector, thereby overcoming the corresponding defects mentioned in the background art.

[0054] The vent chimney 34 is equipped with a nitrogen ejector pipe 35 and a purge pipe 36. In the event of a power outage or a malfunction of the gas axial flow fan 28, the pneumatic shut-off valve on the nitrogen ejector pipe 35 is opened, and nitrogen is ejected for 15 seconds to ensure system safety. When converter gas is recovered from the vent chimney, the pneumatic shut-off valve on the purge pipe 36 is opened, and nitrogen or steam is purged for 30 seconds to prevent backfire in the vent chimney 34.

[0055] The process flow of the ultra-clean converter gas dry dust removal system in this invention is as follows:

[0056] Converter 1 → Gasification cooling flue 2 → High-efficiency heat exchanger 3 → Banana bend dust collector 4 → Cyclone heat recovery device 5 → Raw coal gas pipe 15 → Electrostatic precipitator 16 / High temperature resistant explosion-proof ultra-clean dust collector 23 → Clean coal gas pipe 27 → Coal gas axial flow fan 28 → Silencer 29 → Recovery cup valve 30 / Venting cup valve 33 → Coal gas cooling dehydrator 31 / Venting chimney 34 → Gas holder 32.

[0057] The outlet temperature of the enhanced vaporization cooling flue 2 is 750℃~850℃ (generally 800℃). After the raw coal gas passes through the high-efficiency heat exchanger 3 for gas-water high-efficiency heat exchange, the high-quality heat in the raw coal gas is efficiently recovered, and the temperature drops to 600℃ before entering the banana bend dust collector 4.

[0058] When the dust-laden coal gas passes through the banana-bend dust collector 4, it first undergoes collision with multiple layers of baffles. Due to the 180° change in flow direction, under the action of gravity and centrifugal force, 35% to 45% (generally 40%) of the coarse dust particles are captured in the banana-bend dust collector 4 and fall into the water-cooled drum 6.

[0059] The water-cooled drum 6 is arranged horizontally and is interlocked with the converter 1 process, operating periodically during smelting.

[0060] Under normal circumstances, the coarse ash collected by the water-cooled drum 6 enters the bucket elevator 10 through the pneumatic three-way discharge valve 7 and the normal pneumatic double-layer flap valve 8 via the normal ash discharge pipe 9. The bucket elevator 10 discharges the ash to the intermediate ash silo 11. The intermediate ash silo 11 feeds each batch of material into the converter 1 and can store coarse ash from up to two batches.

[0061] When the bucket elevator 10 is under maintenance, the coarse ash collected by the water-cooled drum 6 is discharged into the coarse ash silo 14 via the emergency ash discharge pipe 13 through the pneumatic three-way discharge valve 7 and the emergency pneumatic double-layer flap valve 12. The coarse ash silo 14 is then transported out by a vacuum suction truck or pneumatically transported into the intermediate ash silo 11 by a silo pump.

[0062] The explosion relief valve on the high-temperature explosion-proof ultra-clean dust collector 23 is equipped with three-stage explosion relief. Once the pressure inside the high-temperature explosion-proof ultra-clean dust collector 23 exceeds 6500Pa, the explosion relief valve will open to release pressure and protect the equipment and system safety. Once the temperature inside the dust collector is below 100℃, the heating coil will work and stop working when it reaches 120℃.

[0063] The qualified converter gas enters the gas scrubber 31. After being cooled by saturated water spray, the temperature drops from 150°C to below 70°C, so that the gas holder 32 can store more converter gas.

[0064] In this invention, the baffles of the banana-shaped dust collector 4 can be used in combination of two or more layers. The cylinder diameter of the high-temperature explosion-proof ultra-clean dust collector 23 is 1.0-10m, and two or more can be used in combination. The filter media of the high-temperature explosion-proof ultra-clean dust collector 23 is stainless steel, fluoropolymer, or P84, or filter media including aramid ≥20% and aramid ≥20% and stainless steel conductive fiber content ≥6%, or antistatic glass fiber membrane filter media with stainless steel conductive fiber content ≥6%. The dust concentration at the outlet of the high-temperature explosion-proof ultra-clean dust collector 23 is ≤5mg / Nm³. 3 The nitrogen ejector tube 35 delivers medium-pressure nitrogen with a pressure ≥1.2MPa. The purge tube 36 delivers low-pressure nitrogen or saturated steam with a pressure ≥0.6MPa.

[0065] By constructing and implementing the system of this invention, not only is the problem of high-quality heat not being recovered solved, but also the problem of excessive emissions from the venting chimney caused by the maintenance of the electrostatic precipitator is solved, as well as the problem of large fluctuations in the emission concentration at the venting chimney outlet. It is especially suitable for the dry dust removal retrofit project of primary flue gas in converters and has broad application prospects.

[0066] The above description is merely an embodiment of the invention's technical content. Any modifications or variations made by those skilled in the art using this invention are within the scope of the invention's claims, and are not limited to those disclosed in the embodiments.

Claims

1. A method for dry dust removal of ultra-clean converter gas, characterized in that... Includes the following steps: S1. Construct an ultra-clean converter gas dry dust removal system, including a high-efficiency heat exchanger, a banana-bend dust collector, a cyclone heat recovery device, an electrostatic precipitator, a high-temperature explosion-proof ultra-clean dust collector, a cooling displacement fan, a clean gas pipe, a gas axial flow fan, a silencer, and a gas scrubbing and dehydrating device. The dust-laden raw gas from the converter is connected to the high-efficiency heat exchanger, the banana-bend dust collector, and the cyclone heat recovery device in sequence through a vaporization cooling flue for heat recovery. The output end of the cyclone heat recovery device is connected to the electrostatic precipitator and the high-temperature explosion-proof ultra-clean dust collector through the raw gas pipe. A clean gas pipe is installed at the outlet of the high-temperature explosion-proof ultra-clean dust collector. S2. Purification: After the dusty raw coal gas undergoes high-efficiency gas-water heat exchange in a high-efficiency heat exchanger, it enters the banana bend dust collector. After passing through multiple baffles in the banana bend dust collector, 35% to 45% of the coarse dust particles are captured and output. After passing through the cyclone heat recovery device, the raw coal gas enters the electrostatic precipitator / high temperature explosion-proof ultra-clean dust collector for fine dust removal. The purified coal gas is then sent to the coal gas switching station after passing through the coal gas axial flow fan and silencer. S3. Recovery: The qualified coal gas is washed and cooled by the coal gas cooling dehydrator and then sent to the gas holder. S4. Venting: Substandard gas is sent to the venting chimney and ignited for venting.

2. The method for dry dust removal of ultra-clean converter gas according to claim 1, characterized in that: The converter can be a decarburization converter, a dephosphorization converter, a vanadium extraction converter, a lava homogenization furnace, or a stainless steel converter.

3. The method for dry dust removal of ultra-clean converter gas according to claim 1, characterized in that: The electrostatic precipitator is equipped with a first control valve at the inlet pipe and a second control valve at the outlet pipe. The inlet main pipe of the high-temperature resistant explosion-proof ultra-clean dust collector is equipped with a third control valve; When the first and second control valves are open and the third control valve is closed, the electrostatic precipitator and the high-temperature explosion-proof ultra-clean dust collector perform dust removal operations in series. When the first and second control valves are closed and the third control valve is open, the high-temperature explosion-proof ultra-clean dust collector performs dust removal operation independently.

4. The method for dry dust removal of ultra-clean converter gas according to claim 1, characterized in that: High-temperature explosion-proof ultra-clean dust collectors are used in combination of two or more units, and the outlet concentration of the high-temperature explosion-proof ultra-clean dust collector can be maintained at a stable 5 mg / Nm³. 3 Below, the outlet of each dust collector is connected to the clean gas pipe to output purified coal gas. Each dust collector transports dust to the fine ash bin through the ash collection pipe. Each dust collector is equipped with an explosion relief valve, a vibrator, a heating coil and an insulation structure. Each high-temperature explosion-proof ultra-clean dust collector is connected to a cooling and replacement fan through a pipeline.

5. A method for dry dust removal of ultra-clean converter gas according to any one of claims 1 to 4, characterized in that: The cylinder diameter of the high-temperature explosion-proof ultra-clean dust collector is 1.0–10 m. The filter media of the high-temperature explosion-proof ultra-clean dust collector is stainless steel, fluoropolymer, or P84, or... Filter media including aramid fiber ≥20%, aramid fiber ≥20%, and stainless steel conductive fiber content ≥6%; or Antistatic fiberglass membrane filter media, with a stainless steel conductive fiber content of ≥6%.

6. The method for dry dust removal of ultra-clean converter gas according to claim 1, characterized in that: In step S2, the outlet temperature of the vaporization cooling flue is 750℃~850℃. After the raw coal gas passes through the high-efficiency heat exchanger, the high-quality heat in the raw coal gas is efficiently recovered, and the temperature drops to 600℃ before entering the banana bend dust collector. The axial extension lines of the inlet and outlet of the banana bend dust collector have an angle, causing the airflow direction to turn 180° and enter the cyclone heat recovery device. The cyclone heat recovery device is equipped with a cyclone device and a heat recovery device. Under the action of gravity and centrifugal force, the raw coal gas effectively separates coarse dust particles and enhances heat exchange, which is beneficial to heat recovery.

7. The method for dry dust removal of ultra-clean converter gas according to claim 1, characterized in that: The bottom of the banana-shaped dust collector is equipped with a water-cooled drum to capture coarse dust particles. The water-cooled drum's ash discharge pipe is equipped with a pneumatic three-way discharge valve, a normal pneumatic double-layer flap valve, and an emergency pneumatic double-layer flap valve. Under normal operating conditions, the water-cooled drum discharges ash to the intermediate ash silo through the pneumatic three-way discharge valve, the normal pneumatic double-layer flap valve and the bucket elevator, and the intermediate ash silo feeds the material into the converter. During maintenance, the water-cooled roller discharges ash to the coarse ash silo via a pneumatic three-way unloading valve and an emergency pneumatic double-layer flap valve. The coarse ash is then transported out of the coarse ash silo by a vacuum suction truck or pneumatically transported to the intermediate ash silo by a silo pump.

8. The method for dry dust removal of ultra-clean converter gas according to claim 1, characterized in that: The gas switching station is equipped with a recovery cup valve and a venting cup valve. Qualified gas passes through the recovery cup valve, is washed and cooled by the gas cooling dehydrator, and is then sent to the gas holder. Qualified converter gas enters the gas washing dehydrator, where it is cooled to below 70℃ after being saturated with water spray. Unqualified gas is sent to the venting chimney for ignition and venting through the venting cup valve.

9. The method for dry dust removal of ultra-clean converter gas according to claim 1, characterized in that: In step S4, a nitrogen ejector pipe is installed on one side of the venting chimney. The medium-pressure nitrogen delivered by the nitrogen ejector pipe has a pressure ≥1.2MPa. If the system loses power or the gas axial flow fan fails, the pneumatic shut-off valve on the nitrogen ejector pipe is opened to eject nitrogen to ensure system safety.

10. The method for dry dust removal of ultra-clean converter gas according to claim 1, characterized in that: In step S4, a purge pipe is provided on one side of the venting chimney. The purge pipe uses low-pressure nitrogen or saturated steam as the medium. The pressure of the low-pressure nitrogen or saturated steam is ≥0.6MPa. When the converter gas is recovered from the venting chimney, the pneumatic shut-off valve of the purge pipe is opened, and nitrogen or steam is used for purging to prevent backfire in the venting chimney.

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