Third-generation converter one-time dry dedusting system

Abstract

The invention discloses a third-generation converter one-time dry dust removal system which comprises a high-effect heat exchanger, a banana bend dust remover, a rotational flow heat recovery device and a high-temperature-resistant anti-explosion ultra-clean dust remover, raw gas of a converter enters the high-effect heat exchanger for heat exchange and recovery, the banana bend dust remover is arranged between the high-effect heat exchanger and the rotational flow heat recovery device, and the high-temperature-resistant anti-explosion ultra-clean dust remover is arranged between the banana bend dust remover and the rotational flow heat recovery device. The cyclone heat recovery device is connected with at least one high-temperature-resistant explosion-proof ultra-clean dust remover, clean coal gas is formed at a gas outlet of the high-temperature-resistant explosion-proof ultra-clean dust remover, the clean coal gas is sent to a coal gas switching station after passing through a coal gas axial flow fan and a coal gas washing dehydrator, and the coal gas which is detected to be qualified is sent to a coal gas cabinet. The traditional evaporation cold spray water and electrostatic dust collector process is omitted, the high-efficiency heat exchanger and anti-explosion ultra-clean dust collector process is adopted, the converter gas waste heat recovery efficiency is high, and the dust removal system is safe and environmentally friendly.

Description

Technical Field

[0001] The invention discloses a third-generation converter primary dry dust removal system, belonging to the technical field of environmental protection dust removal equipment. Background Art

[0002] Most converters in China's steel industry use dry dust removal systems. Currently, the most common dry dust removal systems 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 (set up behind the electrostatic precipitator: coal cooling front, double coal cooling, coal cooling + metal filter cartridge, wet electrostatic precipitator, etc.).

[0003] The main problems of the existing converter gas dry dust removal system are: first, the temperature is cooled by spraying water mist through the evaporative cooler, directly reducing the temperature from 900℃ to about 250℃, and this part of high-quality heat is wasted and not recovered; second, the electrostatic precipitator is used. Since the high-voltage power supply discharges continuously, once the mixed gas components in the electrostatic precipitator reach the explosion limit, it is easy to cause explosion leakage, causing damage to the equipment in the system and affecting the dust removal effect; in addition, the different degree of discharge of the high-voltage power supply will also cause large fluctuations in the voltage and current between the poles and the plates, resulting in the dust removal efficiency of the electrostatic precipitator being affected and the dust emission concentration at the chimney outlet fluctuating greatly.

[0004] Chinese document CN111575435A discloses a converter primary dry dust removal system for ultra-clean coal gas recovery, the system comprising a converter, an evaporative cooler and a dust collector; the dust removal system also comprises a high-temperature phase-change heat accumulator for stabilizing the flue gas temperature; the gas outlet of the converter is connected to the gas inlet of the high-temperature phase-change heat accumulator through a vaporization cooling flue; the gas outlet of the high-temperature phase-change heat accumulator is connected to the gas inlet of the evaporative cooler; the gas outlet of the evaporative cooler is connected to the gas inlet of the dust collector; the dust collector adopts a pulse-jet high-temperature resistant ceramic fiber filter tube dust collector to replace the original electrostatic precipitator in the dust removal system, but the use of the evaporative cooler in the scheme causes heat loss. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a third-generation converter primary dry dust removal system.

[0006] To achieve the above object, the present invention is achieved through the following technical solutions:

[0007] A third generation converter primary dry dust removal system, including a high-efficiency heat exchanger, a banana bend dust collector, a cyclone heat recovery device, a water-cooled chain conveyor, a raw gas pipe, a high-temperature resistant explosion-proof ultra-clean dust collector, a fine ash bin, a clean gas pipe, a gas axial flow fan, and a gas washing dehydrator;

[0008] The inlet of the high-efficiency heat exchanger is connected to the converter through the vaporization cooling flue. The raw gas of the converter enters the high-efficiency heat exchanger for heat exchange recovery. A banana-bend dust collector is provided between the high-efficiency heat exchanger and the cyclone heat recovery device. A water-cooled chain conveyor is provided at the bottom of the banana-bend dust collector. The water-cooled chain conveyor is used to collect coarse ash and output it.

[0009] The cyclone heat recovery device is connected to at least one high temperature resistant explosion-proof ultra-clean dust collector through a raw coal gas pipe, and the gas outlet of the high temperature resistant explosion-proof ultra-clean dust collector forms clean coal gas;

[0010] The air outlet of the high-temperature resistant and explosion-proof ultra-clean dust collector is connected to the clean gas pipe. The clean gas is sent to the gas switching station after passing through the gas axial flow fan and the gas washing and dehydrating device. The qualified gas after testing is sent to the gas tank.

[0011] Furthermore, the outlet temperature of the vaporization cooling flue is 750℃~850℃. After the raw gas passes through the high-efficiency heat exchanger, the high-quality heat in the raw gas is efficiently recovered, and the temperature drops to 600℃ before entering the banana bend dust collector, which is equipped with multiple baffles. The axial extension lines of the banana bend dust collector inlet and outlet have an angle to make the airflow direction turn 180° to facilitate the collection of coarse dust particles.

[0012] Further, the water-cooled chain conveyor is connected to an ash discharge pipe, on which a pneumatic three-way discharge valve, a normal pneumatic double-layer flap valve and an emergency pneumatic double-layer flap valve are provided;

[0013] The water-cooled chain conveyor normally discharges ash to the intermediate ash bin through a pneumatic three-way discharge valve, a normal pneumatic double-layer flap valve and a bucket elevator, and the intermediate ash bin is fed into the converter;

[0014] The water-cooled chain conveyor discharges ash to the coarse ash bin through a pneumatic three-way discharge valve and an emergency pneumatic double-layer flap valve. The coarse ash bin is used to transport the coarse ash out through a vacuum suction vehicle or to pneumatically transport the coarse ash to the intermediate ash bin through a bin pump.

[0015] Furthermore, a cyclone device and a heat recovery device are provided in the cyclone heat recovery device. After the raw coal gas passes through the cyclone, coarse dust particles can be effectively separated and heat exchange can be enhanced. The outlet of the cyclone heat recovery device is connected to the raw coal gas pipe. The side wall of the raw coal gas pipe is connected to the nitrogen dilution pipe, and a pneumatic shut-off valve is provided on the nitrogen dilution pipe. Nitrogen is blown into certain nodes of the converter operation to improve safety performance.

[0016] Furthermore, two or more high-temperature resistant explosion-proof ultra-clean dust collectors can be used in combination. The inlet of each dust collector is connected to the raw gas pipe, the outlet of each dust collector is connected to the clean gas pipe, the ash outlet of each dust collector is transported to the fine ash bin through the ash collecting pipe and the bin pump, each dust collector is equipped with an explosion relief valve, a vibrator, a heating coil and an insulation structure, and each high-temperature resistant explosion-proof ultra-clean dust collector is connected to the cooling replacement fan through a pipeline.

[0017] Furthermore, a muffler is provided on the pipeline between the gas axial flow fan and the gas washing and dehydrating device. The gas after washing and cooling by the gas washing and dehydrating device enters the gas switching station. A recovery cup valve is provided on the pipeline of qualified gas output from the gas switching station. A discharge cup valve is provided on the pipeline of unqualified gas output from the gas switching station. The unqualified gas is sent to the discharge chimney for ignition and discharge.

[0018] Furthermore, a nitrogen ejector pipe and a purge pipe are provided on one side of the venting chimney. The medium-pressure nitrogen transported by the nitrogen ejector pipe has a pressure ≥1.2MPa, and the transport medium of the purge pipe is low-pressure nitrogen or saturated steam, and the pressure of the low-pressure nitrogen or saturated steam is ≥0.6MPa.

[0019] The third generation converter primary dry dust removal system of the present invention has the following beneficial effects:

[0020] 1. The present invention eliminates the traditional evaporative cooling water spraying, and solves the stubborn problem of easy scaling of evaporative cooling; the waste heat of converter gas is fully recovered, the steam recovery amount per ton of steel is increased by more than 50kg, and the system is more energy-efficient;

[0021] 2. The present invention eliminates the traditional electrostatic precipitator process and adopts the high temperature resistant explosion-proof ultra-clean precipitator process, which solves the problem of system explosion discharge caused by frequent discharge of equipment, making the system safer; the outlet concentration of the high temperature resistant explosion-proof ultra-clean precipitator can maintain a stable 5mg / Nm 3 Below, the system is more environmentally friendly.

[0022] 3. The present invention not only solves the problem of high-quality heat not being recovered, but also solves the problem of easy explosion of dry dust removal systems, and solves the problem of large fluctuations in emission concentration at the chimney outlet. It is particularly suitable for dry dust removal projects of primary flue gas from converters and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0024] Figure 1 It is a structural schematic diagram of the third generation converter primary dry dust removal system of the present invention.

[0025] Figure 2 yes Figure 1 Enlarged view of part A in the middle.

[0026] Figure 3 yes Figure 1 Enlarged view of station B and schematic diagram of the connection between the corresponding pipelines, fine ash bin and cooling replacement fan.

[0027] Figure 4 yes Figure 1 Enlarged view of part C in the middle. DETAILED DESCRIPTION

[0028] The present invention will be further described below in conjunction with the accompanying drawings:

[0029] Example: See Figures 1 to 4 The third generation converter primary dry dust removal system of the present invention comprises a high-efficiency heat exchanger 3, a banana bend dust collector 4, a cyclone heat recovery device 5, a water-cooled chain conveyor 6, a pneumatic three-way discharge valve 7, a normal pneumatic double-layer flap valve 8, a normal ash discharge pipe 9, a bucket elevator 10, an intermediate ash bin 11, an emergency pneumatic double-layer flap valve 12, an emergency ash discharge pipe 13, a coarse ash bin 14, a nitrogen dilution pipe 15, a pneumatic switching valve 16, a waste gas pipe 17, a high temperature resistant explosion-proof Super-clean dust collector 18, rapper 19, heating coil 20, explosion relief valve 21, insulation structure 22, bin pump 23, pneumatic conveying pipeline, i.e. ash collecting pipe 24, fine ash bin 25, cooling replacement fan 26, clean coal gas pipe 27, coal gas axial flow fan 28, muffler 29, coal gas washing and dehydrating device 30, recovery cup valve 31, venting cup valve 33, venting chimney 34, nitrogen ejector 35 and purge pipe 36; the outlet of converter 1 is connected to vaporization cooling flue 2;

[0030] The converter 1 and the high-efficiency heat exchanger 3 are connected through the vaporization cooling flue 2, and a banana-bend dust collector 4 is provided between the high-efficiency heat exchanger 3 and the cyclone heat recovery device 5; a heat exchange close-packed pipe is provided inside the high-efficiency heat exchanger 3 to take away the high-quality heat in the converter gas through heat exchange, thereby reducing the temperature of the converter gas;

[0031] The banana bend dust collector 4 is provided with multiple layers of baffles, which can increase the residence time of dusty converter gas in the banana bend dust collector 4 and improve the dust removal efficiency; a water-cooled chain conveyor 6 is provided at the bottom of the banana bend dust collector 4 to convey the captured coarse ash out; the axial extension lines of the inlet and outlet of the banana bend dust collector have an angle to make the airflow direction turn 180 degrees, and the above angle is less than 60 degrees; the material of the banana bend dust collector 4 is stainless steel or boiler steel or Q345R; the baffles of the banana bend dust collector 4 can be used in combination of two or more layers;

[0032] The cyclone heat recovery device 5 is provided with a cyclone device and a heat recovery device; after the raw gas passes through the cyclone, the coarse dust particles can be effectively separated and the heat exchange can be enhanced, which is beneficial to heat recovery;

[0033] The ash discharge pipe of the water-cooled chain conveyor 6 is provided with a pneumatic three-way discharge valve 7, a normal pneumatic double-layer flap valve 8 and an emergency pneumatic double-layer flap valve 12;

[0034] The water-cooled chain conveyor 6 normally discharges ash to the intermediate ash bin 11 through the pipeline and the pneumatic three-way discharge valve 7, the normal pneumatic double-layer flap valve 8 and the bucket elevator 10, and the intermediate ash bin 11 feeds the material to the converter 1;

[0035] The water-cooled chain conveyor 6 discharges ash to the coarse ash bin 14 through the pneumatic three-way discharge valve 7 and the emergency pneumatic double-layer flap valve 12. The coarse ash bin 14 transports the coarse ash out of the coarse ash through a vacuum suction vehicle or pneumatically conveys the coarse ash to the intermediate ash bin 11 through a bin pump;

[0036] The cyclone heat recovery device 5 is connected to the high temperature explosion-proof ultra-clean dust collector 18 through the raw gas pipe 17; the cyclone heat recovery device 5 is connected to 2, 3, 4 or more high temperature explosion-proof ultra-clean dust collectors 18, the actual number of which is set according to the installation requirements, and the gas outlets of the ultra-clean dust collectors gather and output clean gas;

[0037] The high temperature resistant explosion proof ultra clean dust collector 18 is provided with an explosion relief valve 21, a vibrator 19, a heating coil 20 and a heat preservation structure 22, and the heat preservation structure can be a heat preservation layer made of heat preservation material;

[0038] The high temperature resistant explosion proof ultra clean dust collector 18 is provided with a cooling replacement fan 26; once the dust collector is overhauled, after the nitrogen replaces the coal gas, the cooling replacement fan 26 is started to blow air into the dust collector cylinder to play the role of cooling and ventilation;

[0039] The high temperature resistant explosion proof ultra clean dust collector 18 pneumatically transports the collected fine ash to the fine ash bin 25 through the bin pump 23; the fine ash bin 25 is provided with a vacuum suction tank truck interface;

[0040] A clean gas pipe 27 is provided at the outlet of the high temperature resistant explosion-proof ultra-clean dust collector 18. The clean gas is sent to the gas switching station after passing through the gas axial flow fan 28 and the muffler 29. The qualified gas passes through the recovery cup valve 30, is washed and cooled by the gas cooling dehydrator 31, and is sent to the gas cabinet 32; the unqualified gas passes through the release cup valve 33 and is sent to the release chimney 34 for ignition and release;

[0041] The nitrogen dilution pipe 15 is provided with a pneumatic shut-off valve 16;

[0042] The emission chimney 34 is provided with a nitrogen ejector pipe 35 and a purge pipe 36. The medium-pressure nitrogen delivered by the nitrogen ejector pipe 35 has a pressure of ≥1.2MPa. The delivery medium of the purge pipe 36 is low-pressure nitrogen or saturated steam, and the pressure of the low-pressure nitrogen or saturated steam is ≥0.6MPa.

[0043] The process flow of the third generation converter primary dry dust removal system of the present invention is as follows:

[0044] Converter 1→vaporization cooling flue 2→high-efficiency heat exchanger 3→banana bend separator 4→cyclone heat recovery device 5→raw gas pipe 17→high-temperature resistant and explosion-proof ultra-clean dust collector 18→clean gas pipe 27→gas axial flow fan 28→muffler 29→gas washing and dehydrating device 30→recovery cup valve 31 / discharge cup valve 33→gas cabinet 32 / discharge chimney 34.

[0045] In one embodiment of the present invention, the outlet temperature of the enhanced vaporization cooling flue 2 is 750°C to 850°C (generally 800°C). After the raw gas passes through the high-efficiency heat exchanger 3 for high-efficiency gas-water heat exchange, the high-quality heat in the raw gas is efficiently recovered, and the temperature drops to 600°C before entering the banana bend dust collector 4.

[0046] When the dusty waste gas passes through the banana bend dust collector 4, it first collides with multiple baffles. Since the flow direction also changes by 180°, under the action of gravity and centrifugal force, 35% to 45% (generally 40%) of the coarse particle dust is captured in the banana bend dust collector 4 and falls into the water-cooled chain conveyor 6.

[0047] The water-cooled chain conveyor 6 is arranged horizontally, is process-linked with the converter 1, and operates periodically during the smelting period.

[0048] Under normal circumstances, the coarse ash collected by the water-cooled chain conveyor 6 of the present invention passes through the pneumatic three-way discharge valve 7 and the normal pneumatic double-layer flap valve 8 through the normal ash discharge pipe 9 and enters the bucket elevator 10, and is discharged to the intermediate ash bin 11 by the bucket elevator 10; the intermediate ash bin 11 feeds each furnace into the converter 1, and can store coarse ash from up to two furnaces.

[0049] When the bucket elevator 10 is under maintenance, the coarse ash collected by the water-cooled chain conveyor 6 is urgently discharged to the coarse ash bin 14 through the pneumatic three-way discharge valve 7 and the emergency pneumatic double-layer flap valve 12 via the emergency ash discharge pipe 13. The coarse ash bin 14 transports the coarse ash out through the vacuum suction vehicle or pneumatically conveys the coarse ash to the intermediate ash bin 11 through a bin pump.

[0050] The explosion relief valve 21 on the high-temperature resistant explosion-proof ultra-clean dust collector 18 is equipped with a three-stage explosion relief. Once the pressure inside the high-temperature resistant explosion-proof ultra-clean dust collector 18 exceeds 6500Pa, the explosion relief valve 21 will start to release pressure to protect the safety of the equipment and system; once the temperature inside the dust collector is lower than 100°C, the heating coil 20 will work and stop working when it is heated to 120°C.

[0051] Qualified converter gas enters the gas scrubber and dehydrator 30, and after being cooled by saturated water spray, the temperature drops from 150°C to below 70°C, so that the gas tank 32 can store more converter gas.

[0052] In one embodiment of the present invention, at the initial stage of converter blowing and after the second gun lowering, the pneumatic shut-off valve 16 is opened and nitrogen is sprayed from the nitrogen dilution pipe 15 for 30 seconds to dilute the converter gas in the raw gas pipe 17 to prevent the content of converter gas and oxygen from reaching the explosion limit.

[0053] In the embodiment of the present invention, once the system is powered off or the gas axial flow fan 28 fails, the pneumatic shut-off valve on the nitrogen ejection pipe 35 is opened and nitrogen is ejected for 15 seconds to ensure system safety.

[0054] When the present invention is used, when the converter gas is recovered by venting, the pneumatic shut-off valve on the purge pipe 36 is opened, and nitrogen or steam is purged for 30 seconds to prevent the vent chimney 34 from backfired.

[0055] In one embodiment of the present invention, the cylinder diameter of the high temperature resistant explosion-proof ultra-clean dust collector 18 is 1.0-10m, and it can be used in parallel in combination of two or more. The inlet of each dust collector is connected to the raw gas pipe, and the air outlet of each dust collector is connected to the clean gas pipe. The ash outlet of each dust collector is transported to the fine ash bin through the ash collecting pipe; the filter material of the high temperature resistant explosion-proof ultra-clean dust collector 18 is stainless steel, FROMEX or P84; the filter material of the ultra-clean dust collector can also be aramid ≥20% and aramid ≥20% or anti-static glass fiber coated filter material, and the content of stainless steel conductive fiber filaments is ≥6%; the dust concentration at the outlet of the high temperature resistant explosion-proof ultra-clean dust collector 18 is ≤5mg / Nm 3 The third generation converter primary dry dust removal system of the present invention is suitable for 50t-400t converters, and the converter is defined as: a decarburization converter, a dephosphorization converter, a vanadium extraction converter, a lava homogenization furnace, or a stainless steel converter.

[0056] The above records are only embodiments of the present invention. Any modification or change made by a person familiar with the present technology using the present invention shall fall within the patent scope claimed by the present invention and shall not be limited to those disclosed in the embodiments.

Claims

1. A third generation converter primary dry dust removal system, characterized by: Including high-efficiency heat exchanger, banana bend dust collector, cyclone heat recovery device, water-cooled chain conveyor, raw gas pipe, high temperature resistant explosion-proof ultra-clean dust collector, fine ash bin, clean gas pipe, gas axial flow fan, gas washing dehydrator; The inlet of the high-efficiency heat exchanger is connected to the converter through the vaporization cooling flue. The raw gas of the converter enters the high-efficiency heat exchanger for heat exchange recovery. A banana-bend dust collector is provided between the high-efficiency heat exchanger and the cyclone heat recovery device. A water-cooled chain conveyor is provided at the bottom of the banana-bend dust collector. The water-cooled chain conveyor is used to collect coarse ash and output it. The cyclone heat recovery device is connected to at least one high temperature resistant explosion-proof ultra-clean dust collector through a raw coal gas pipe, and the gas outlet of the high temperature resistant explosion-proof ultra-clean dust collector outputs clean coal gas; The air outlet of the high-temperature resistant and explosion-proof ultra-clean dust collector is connected to the clean gas pipe. The clean gas is sent to the gas switching station after passing through the gas axial flow fan and the gas washing and dehydrating device. The qualified gas after testing is sent to the gas tank.

2. The third generation converter primary dry dust removal system according to claim 1 is characterized in that: The outlet temperature of the vaporization cooling flue is 750℃~850℃. After the raw gas passes through the high-efficiency gas-water heat exchanger, the high-quality heat in the raw gas is efficiently recovered, and the temperature drops to 600℃ before entering the banana bend dust collector, which is equipped with multiple baffles.

3. The third generation converter primary dry dust removal system according to claim 1 is characterized in that: The axial extension lines of the inlet and outlet of the banana bend dust collector have an angle that causes the airflow direction to turn 180°.

4. The third generation converter primary dry dust removal system according to any one of claims 1 to 3, characterized in that: The water-cooled chain conveyor is connected to the ash discharge pipe, which is equipped with a pneumatic three-way discharge valve, a normal pneumatic double-layer flap valve and an emergency pneumatic double-layer flap valve; The water-cooled chain conveyor normally discharges ash to the intermediate ash bin through a pneumatic three-way discharge valve, a normal pneumatic double-layer flap valve and a bucket elevator, and the intermediate ash bin is fed into the converter; The water-cooled chain conveyor discharges ash to the coarse ash bin through a pneumatic three-way discharge valve and an emergency pneumatic double-layer flap valve. The coarse ash bin is transported out of the coarse ash through a vacuum suction vehicle or pneumatically transported to the intermediate ash bin through a bin pump.

5. The third generation converter primary dry dust removal system according to claim 1 is characterized in that: The cyclone heat recovery device is equipped with a cyclone device and a heat recovery device. The raw gas can effectively separate coarse dust particles and enhance heat exchange after the cyclone. The outlet of the cyclone heat recovery device is connected to the raw gas pipe.

6. The third generation converter primary dry dust removal system according to claim 1 or 5, characterized in that: The side wall of the raw coal gas pipe is connected to a nitrogen dilution pipe, on which a pneumatic shut-off valve is provided.

7. The third generation converter primary dry dust removal system according to claim 1 is characterized in that: The high temperature resistant explosion-proof ultra-clean dust collectors are used in combination of 2 or more. The inlet of each dust collector is connected to the raw gas pipe, the outlet of each dust collector is connected to the clean gas pipe, the ash outlet of each dust collector is transported to the fine ash bin through the ash collecting pipe, each dust collector is equipped with an explosion relief valve, and each high temperature resistant explosion-proof ultra-clean dust collector is connected to the cooling replacement fan through a pipeline.

8. The third generation converter primary dry dust removal system according to claim 1 or 7, characterized in that: A vibrator is provided on one side of the high temperature resistant explosion-proof ultra-clean dust collector, and a heating coil is provided inside the dust collector.

9. The third generation converter primary dry dust removal system according to claim 1 is characterized in that: A muffler is provided on the pipeline between the gas axial flow fan and the gas switching station, a recovery cup valve is provided on the pipeline for qualified gas output from the gas switching station, and a venting cup valve is provided on the pipeline for unqualified gas output from the gas switching station.

10. The third generation converter primary dry dust removal system according to claim 1 or 2 or 3 or 5 or 7 or 9, characterized in that: A nitrogen ejector and a purge pipe are provided on one side of the vent chimney. The medium-pressure nitrogen transported by the nitrogen ejector is ≥1.2MPa, and the transport medium of the purge pipe is low-pressure nitrogen or saturated steam, and the pressure of the low-pressure nitrogen or saturated steam is ≥0.6MPa.

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