Ultra-low emission equipment and method for primary flue gas particulate matter in converter

Abstract

The present invention discloses an ultra-low emission device and method for primary flue gas particulate matter of a converter. The ultra-low emission device and method for primary flue gas particulate matter of a converter comprises an evaporative cooler (2), an electrostatic precipitator (4), a gas cooler (8) and a switching station (9) connected in sequence. The gas cooler (8) contains a single-medium injection device (81) and a dual-medium injection device (82). The switching station (9) is connected to a transmission pipeline and a gas tank (17) in sequence. The switching station (9) is also connected to an emission pipeline and a venting chimney (15) in sequence. A dehydrator (14) is provided on the emission pipeline. The ultra-low emission device and method for primary flue gas particulate matter of a converter can reduce the dust content of recovered and vented gas to 10 mg / Nm 3 The following can meet the increasingly stringent dust emission standards and eliminate the emitted flue gas at the same time.

Description

Technical Field

[0001] The invention relates to ultra-low emission equipment for primary flue gas particles of a converter, and also relates to an ultra-low emission method for primary flue gas particles of a converter. Background Art

[0002] The increasingly severe environmental situation has brought us great challenges and opportunities. The 2019 Central Economic Work Conference required that this year's "pollution prevention and control battle" should hold its ground, consolidate its achievements, and focus on winning the battle to protect blue skies.

[0003] The existing primary gas dust removal in converter steelmaking in my country adopts OG wet method, semi-dry method, and LT dry method. From the perspective of dust content in flue gas discharged into the atmosphere, the conventional LT dry method has an absolute advantage. It can reduce the dust content in flue gas to 20mg / Nm 3 However, the dust removal limit of this conventional dry process system is 20mg / Nm 3 . Summary of the invention

[0004] In order to further reduce the dust content of steelmaking primary gas, the present invention provides a converter primary flue gas particulate ultra-low emission device and method, which can reduce the dust content of recovered and released gas to 10mg / Nm 3 The following can meet the increasingly stringent dust emission standards and eliminate the emitted flue gas at the same time.

[0005] The technical solution adopted by the present invention to solve its technical problems is: a converter primary flue gas particulate matter ultra-low emission equipment, including an evaporative cooler, an electrostatic precipitator, a gas cooler and a switching station connected in sequence, the gas cooler contains a single-medium injection device and a dual-medium injection device, the switching station is connected in sequence to a transmission pipeline and a gas tank, the switching station is also connected in sequence to an emission pipeline and a discharge chimney, and a dehydrator is provided on the emission pipeline.

[0006] The converter primary flue gas particulate matter ultra-low emission equipment also includes a water-cooling flue and a vaporization cooling flue, and the water-cooling flue, the vaporization cooling flue and the evaporative cooler are connected in sequence.

[0007] The electrostatic precipitator is connected to the coal gas cooler through an air supply pipeline, on which an axial flow fan and a muffler are arranged in sequence.

[0008] The coal gas cooler contains two single-medium injection devices, and the first single-medium injection device, the second single-medium injection device and the double-medium injection device are arranged in sequence from top to bottom.

[0009] The dual-medium spraying device comprises an external-mixed dual-medium atomizing long spray gun and an external-mixed dual-medium atomizing short spray gun which are alternately arranged along the circumference of the coal gas cooler.

[0010] The external mixed dual-medium atomizing long spray gun can spray out umbrella-shaped aerosol, and the external mixed dual-medium atomizing short spray gun can spray out umbrella-shaped aerosol. A stainless steel demister is provided on the upper part of the gas cooler.

[0011] One end of the external mixing dual medium atomizing long spray gun is connected and fixed to the side wall of the gas cooler. The external mixing dual medium atomizing long spray gun is arranged along the diameter direction of the gas cooler. The length of the external mixing dual medium atomizing long spray gun is 60% to 80% of the radius of the gas cooler.

[0012] One end of the external mixing dual-medium atomizing short spray gun is connected and fixed to the side wall of the gas cooler. The external mixing dual-medium atomizing short spray gun is arranged along the diameter direction of the gas cooler. The length of the external mixing dual-medium atomizing short spray gun is 30% to 40% of the radius of the gas cooler.

[0013] The dehydrator is a vertical dehydrator, the inlet of the dehydrator is located at the upper part of the dehydrator, and the outlet of the dehydrator is located at the lower part of the dehydrator.

[0014] A method for ultra-low emission of primary flue gas particles from a converter, wherein the method adopts the above-mentioned ultra-low emission equipment for primary flue gas particles from a converter, and the method comprises the following steps:

[0015] Step 1, converter flue gas enters the evaporative cooler for cooling;

[0016] Step 2, the converter flue gas enters the electrostatic precipitator for dust removal;

[0017] Step 3, dispersing converter flue gas or recovering converter flue gas;

[0018] In the process of dispersing the converter flue gas, the converter flue gas passes through the gas cooler, the switching station and the dehydrator in sequence and then enters the dispersing chimney, and the dual-medium injection device simultaneously sprays water mist and nitrogen in the gas cooler;

[0019] In the process of recovering converter flue gas, the converter flue gas passes through a gas cooler and a switching station in sequence and then enters a gas cabinet, and a single-medium injection device injects a water flow in the gas cooler.

[0020] The beneficial effects of the present invention are:

[0021] 1. The gas cooler is placed before the switching station, and the recovered and released gas are cooled, cleaned and finely dusted by the gas cooler.

[0022] 2. The gas cooler is equipped with three layers of spray guns. Two layers of spray guns are conventionally designed for cooling the flue gas during the recovery process, and the other layer of spray guns is an atomizing spray gun for the release process; it can ensure that the dust content of the recovered and released gas is ≤10mg / Nm 3 .

[0023] 3. In addition to the three-layer spray gun arrangement, the coal gas cooler is also equipped with a demister on the top of the coal cooler to remove mechanical water from the flue gas during operation and reduce the "white smoke" emitted from the chimney.

[0024] 4. A vertical cyclone dehydrator is designed between the vent cup valve and the vent chimney. The flue gas enters from the top and exits from the bottom. A cyclone is installed at the top of the vertical cyclone dehydrator. The saturated water entrained in the flue gas when passing through the gas cooler is removed again by utilizing the flow rate and centrifugal force of the flue gas, thereby achieving the whitening effect.

[0025] 5. The placement of the gas cooler in front will reduce the size of the discharge cup valve and the recovery cup valve of the switching station, reduce the diameter of the discharge gas pipeline, further reduce investment, and achieve a better goal. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings in the specification, which constitute a part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0027] Figure 1 It is a structural schematic diagram of the ultra-low emission equipment of primary flue gas particulate matter of the converter according to the present invention.

[0028] Figure 2 It is a schematic diagram of the gas cooler at the single-medium injection device and the dual-medium injection device.

[0029] Figure 3 yes Figure 2 Cross-sectional view along AA direction.

[0030] Figure 4 It is a schematic diagram of a vertical dehydrator.

[0031] 1. Injection device; 2. Evaporative cooler; 3. Coarse dust bin; 4. Electrostatic precipitator; 5. Fine dust bin; 6. Axial flow fan; 7. Muffler; 8. Gas cooler; 9. Switching station; 10. Recovery cup valve; 11. Electric eye valve; 12. Electric sealing butterfly valve; 13. Discharge cup valve; 14. Dehydrator; 15. Discharge chimney; 16. Ignition head; 17. Gas holder; 18. Converter; 19. Water-cooled flue; 20. Vaporization cooling flue;

[0032] 81. Single-medium spray device; 82. Dual-medium spray device; 83. External-mixed dual-medium atomizing long spray gun; 84. External-mixed dual-medium atomizing short spray gun. DETAILED DESCRIPTION

[0033] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0034] A converter primary flue gas particulate matter ultra-low emission device comprises an evaporative cooler 2, an electrostatic precipitator 4, a gas cooler 8 and a switching station 9 connected in sequence, the gas cooler 8 contains a single medium injection device 81 and a dual medium injection device 82, the switching station 9 is connected in sequence to a delivery pipeline and a gas tank 17, and the switching station 9 is also connected in sequence to an emission pipeline and a venting chimney 15, and the emission pipeline is provided with a dehydrator 14, such as Figure 1 shown.

[0035] A single-medium injection device 81 and a dual-medium injection device 82 are arranged in the gas cooler 8. The single-medium injection device 81 is a conventional design for cooling the flue gas during the recovery process, and the dual-medium injection device 82 is an atomizing spray gun for the dispersion process; it can ensure that the dust content of the recovered and dispersed gas is ≤10mg / Nm 3 A demister is provided at the top of the gas cooler 8, and a dehydrator 14 is provided before the venting chimney 15 to remove mechanical water from the flue gas during operation and reduce the "white flue gas" from the venting chimney.

[0036] In this embodiment, the converter primary flue gas particulate matter ultra-low emission device further includes a water-cooling flue 19 and a vaporization cooling flue 20, and the water-cooling flue 19, the vaporization cooling flue 20 and the evaporative cooler 2 are connected in sequence. The flue gas (about 1500°C) generated by the converter 18 will pass through the water-cooling flue 19 and the vaporization cooling flue 20 in sequence and then enter the evaporative cooler 2, and the top of the evaporative cooler 2 is provided with an injection device 1.

[0037] In this embodiment, the electrostatic precipitator 4 is connected to the gas cooler 8 through an air supply pipe, and an axial flow fan 6 and a muffler 7 are sequentially arranged on the air supply pipe. A coarse dust bin 3 is arranged below the evaporative cooler 2, and a fine dust bin 5 is arranged below the electrostatic precipitator 4. The structure of the switching station 9 is similar to that of a tee. The inlet of the switching station 9 is connected to the outlet of the gas cooler 8, the first outlet of the switching station 9 is sequentially connected to the delivery pipeline and the gas tank 17, and the second outlet of the switching station 9 is sequentially connected to the discharge pipeline and the venting chimney 15. The recovery cup valve 10, the electric eye valve 11 and the electric sealing butterfly valve 12 are sequentially arranged on the delivery pipeline, and the venting cup valve 13 is arranged on the discharge pipeline. An ignition head 16 is arranged at the top of the venting chimney 15.

[0038] In this embodiment, the gas cooler 8 contains two single-medium injection devices 81, and the first single-medium injection device 81, the second single-medium injection device 81 and the dual-medium injection device 82 are sequentially arranged from top to bottom. Figure 2 In the three-layer injection device, the first single-medium injection device 81 and the second single-medium injection device 82 are conventionally designed for cooling the flue gas during the recovery process, and the dual-medium injection device 82 is an atomizing spray gun for the dispersion process; it can ensure that the amount of gas dust recovered and dispersed is ≤10mg / Nm 3 .

[0039] In this embodiment, the single-medium spray device 81 is an existing spray gun capable of spraying water, and the dual-medium spray device 82 includes a plurality of externally mixed dual-medium atomizing long spray guns 83 and externally mixed dual-medium atomizing short spray guns 84 uniformly and alternately arranged along the circumference of the gas cooler 8. The nozzle of the externally mixed dual-medium atomizing long spray gun 83 can spray out an umbrella-shaped aerosol (containing two fluid media, namely, gas and droplets of fine particle size), and the nozzle of the externally mixed dual-medium atomizing short spray gun 84 can spray out an umbrella-shaped aerosol (containing two fluid media, namely, gas and droplets of fine particle size). A folding plate-type stainless steel demister is provided at the upper part of the gas cooler 8, that is, the stainless steel demister, the first single-medium spray device 81, the second single-medium spray device 81 and the dual-medium spray device 82 are arranged in sequence from top to bottom.

[0040] In this embodiment, one end of the external mixing dual-medium atomizing long spray gun 83 is connected and fixed to the side wall of the gas cooler 8, and the other end of the external mixing dual-medium atomizing long spray gun 83 can spray gas and fine water mist. The external mixing dual-medium atomizing long spray gun 83 is arranged along the diameter direction of the gas cooler 8, and the length of the external mixing dual-medium atomizing long spray gun 83 is 60% to 80% of the radius of the gas cooler 8. Figure 3 shown.

[0041] In this embodiment, one end of the external mixing dual-medium atomizing short spray gun 84 is connected and fixed to the side wall of the gas cooler 8, and the other end of the external mixing dual-medium atomizing short spray gun 84 can spray gas and fine water mist. The external mixing dual-medium atomizing short spray gun 84 is arranged along the diameter direction of the gas cooler 8, and the length of the external mixing dual-medium atomizing short spray gun 84 is 30% to 40% of the radius of the gas cooler 8. Figure 3 shown.

[0042] In this embodiment, the dehydrator 14 is a vertical dehydrator, such as a vertical cyclone dehydrator, the inlet of the dehydrator 14 is located at the upper part of the dehydrator 14, and the outlet of the dehydrator 14 is located at the lower part of the dehydrator 14, such as Figure 1 and Figure 4 As shown, the dehydrator 14 can be an existing commercial product. The components of the converter primary flue gas particulate matter ultra-low emission equipment of the present invention can all adopt products in the technology.

[0043] The working process of the converter primary flue gas particulate matter ultra-low emission equipment is introduced below.

[0044] The flue gas generated by the converter 18 passes through the water-cooling flue 19, the vaporization cooling flue 20, the evaporative cooler 2, and the electrostatic precipitator 4 in sequence before entering the coal gas cooler 8.

[0045] When the converter flue gas is released, the converter flue gas passes through the gas cooler 8, the switching station 9 and the dehydrator 14 in sequence and then enters the release chimney 15. The converter flue gas will not enter the gas cabinet 17. The dual-medium injection device 82 is in the open state, and the single-medium injection device 81 is in the closed state. The dual-medium injection device 82 simultaneously sprays water mist and nitrogen in the gas cooler 8 to further cool the converter flue gas that has been finely dedusted by the electrostatic precipitator 4. At the same time, the fine water mist sprayed by the dual-medium injection device 82 convectively collides with the fine dust particles in the converter flue gas, and the quality and heat are exchanged, which can make the fine dust particles nucleate with the water mist, become larger, and freely fall into the return water under the action of gravity, so as to achieve a further dust removal effect; in addition, during the release period, the converter flue gas is reduced to about 100°C, so that the flue gas reaches an unsaturated state, and the condensed water precipitated during the release is reduced, and the white mist is reduced. The dehydrator 14 dehydrates the wet flue gas in the emission process, thereby further achieving the effect of eliminating the whiteness of the emitted flue gas.

[0046] When the converter flue gas is recovered, the converter flue gas passes through the gas cooler 8 and the switching station 9 in turn and then enters the gas cabinet 17. The converter flue gas will not enter the dehydrator 14 and the venting chimney 15. The dual-medium injection device 82 is in a closed state, and the single-medium injection device 81 is in an open state. The single-medium injection device 81 sprays water, and the heat and mass exchange between the flue gas and the water sprayed by the spray gun reaches the recovery temperature. Finally, the recovered and vented gas are flushed, cooled and finely dusted by the gas cooler to ensure that the dust content is ≤10mg / Nm 3 .

[0047] The following is a method for ultra-low emission of primary flue gas particles from a converter. The method for ultra-low emission of primary flue gas particles from a converter adopts the above-mentioned ultra-low emission equipment for primary flue gas particles from a converter. The method for ultra-low emission of primary flue gas particles from a converter comprises the following steps:

[0048] Step 1, converter flue gas enters evaporative cooler 2 for cooling;

[0049] Step 2, the converter flue gas enters the electrostatic precipitator 4 for dust removal;

[0050] Step 3, dispersing converter flue gas or recovering converter flue gas;

[0051] In the process of dispersing the converter flue gas, the converter flue gas passes through the gas cooler 8, the switching station 9 and the dehydrator 14 in sequence and then enters the dispersing chimney 15. The converter flue gas will not enter the gas cabinet 17. The dual-medium injection device 82 is in an open state, and the single-medium injection device 81 is in a closed state. The dual-medium injection device 82 simultaneously sprays water mist and nitrogen in the gas cooler 8 to spray the converter flue gas. The temperature of the converter flue gas at the outlet of the gas cooler 8 is 100°C.

[0052] Specifically, the externally mixed dual-medium atomizing long spray gun 83 includes a water spray pipe and an air jet pipe, and the externally mixed dual-medium atomizing short spray gun 84 also includes a water spray pipe and an air jet pipe. The water source used by the externally mixed dual-medium atomizing long spray gun 83 and the externally mixed dual-medium atomizing short spray gun 84 is industrial new water, and the gas source used by the externally mixed dual-medium atomizing long spray gun 83 and the externally mixed dual-medium atomizing short spray gun 84 is nitrogen, and the pressure of the gas source is 0.6MPa. The pressure in the water spray pipe of the externally mixed dual-medium atomizing long spray gun 83 and the water spray pipe of the externally mixed dual-medium atomizing short spray gun 84 are both 0.5MPa to 0.6MPa, and the gas-water ratio of the gas-water mixture sprayed by the externally mixed dual-medium atomizing long spray gun 83 and the externally mixed dual-medium atomizing short spray gun 84 is 160:1 to 200:1.

[0053] In the process of recovering the converter flue gas, the converter flue gas passes through the gas cooler 8 and the switching station 9 in sequence and then enters the gas cabinet 17. The converter flue gas will not enter the dehydrator 14 and the discharge chimney 15. The dual-medium injection device 82 is in a closed state, and the single-medium injection device 81 is in an open state. The single-medium injection device 81 sprays water in the gas cooler 8 to spray the converter flue gas.

[0054] The above is only a specific embodiment of the present invention, and cannot be used to limit the scope of the invention. Therefore, the replacement of equivalent components, or equivalent changes and modifications made according to the protection scope of the present invention, should still fall within the scope of this patent. In addition, the technical features of the present invention can be freely combined with each other, with technical features and technical solutions, and with technical solutions.

Claims

1. A method for ultra-low emission of particulate matter in primary flue gas of a converter, characterized in that: The converter primary flue gas particulate matter ultra-low emission method adopts converter primary flue gas particulate matter ultra-low emission equipment; The converter primary flue gas particulate matter ultra-low emission equipment comprises an evaporative cooler (2), an electrostatic precipitator (4), a gas cooler (8) and a switching station (9) which are connected in sequence, the gas cooler (8) contains a single-medium injection device (81) and a dual-medium injection device (82), the switching station (9) is connected in sequence to a delivery pipeline and a gas tank (17), and the switching station (9) is also connected in sequence to an emission pipeline and a venting chimney (15), and the emission pipeline is provided with a dehydrator (14); The dual-medium spraying device (82) comprises an external-mix dual-medium atomizing long spray gun (83) and an external-mix dual-medium atomizing short spray gun (84) which are alternately arranged along the circumference of the coal gas cooler (8); The external mixed dual-medium atomizing long spray gun (83) can spray out umbrella-shaped aerosol, and the external mixed dual-medium atomizing short spray gun (84) can spray out gas and umbrella-shaped aerosol. A stainless steel demister is provided at the upper part of the coal gas cooler (8); The method for ultra-low emission of particulate matter in primary flue gas of a converter comprises the following steps: Step 1, converter flue gas enters evaporative cooler (2) for cooling; Step 2, the converter flue gas enters the electrostatic precipitator (4) for dust removal; Step 3, dispersing converter flue gas or recovering converter flue gas; In the process of dispersing the converter flue gas, the converter flue gas passes through the coal gas cooler (8), the switching station (9) and the dehydrator (14) in sequence and then enters the dispersing chimney (15), and the dual-medium injection device (82) simultaneously injects water mist and nitrogen in the coal gas cooler (8); The externally mixed dual-medium atomizing long spray gun (83) comprises a water spray pipe and an air jet pipe, and the externally mixed dual-medium atomizing short spray gun (84) also comprises a water spray pipe and an air jet pipe. The water source used by the externally mixed dual-medium atomizing long spray gun (83) and the externally mixed dual-medium atomizing short spray gun (84) is both industrial fresh water. The gas source used by the externally mixed dual-medium atomizing long spray gun (83) and the externally mixed dual-medium atomizing short spray gun (84) is both nitrogen gas, and the pressure of the gas source is 0.6 MPa. The pressure in the water spray pipe of the externally mixed dual-medium atomizing long spray gun (83) and the water spray pipe of the externally mixed dual-medium atomizing short spray gun (84) is both 0.5 MPa to 0.6 MPa. The gas-water ratio of the gas-water mixture sprayed by the externally mixed dual-medium atomizing long spray gun (83) and the externally mixed dual-medium atomizing short spray gun (84) is 160:1 to 200:

1. In the process of recovering converter flue gas, the converter flue gas passes through a gas cooler (8) and a switching station (9) in sequence and then enters a gas cabinet (17), and a single medium injection device (81) injects a water flow in the gas cooler (8).

2. The method for ultra-low emission of particulate matter in primary flue gas of a converter according to claim 1, characterized in that: The converter primary flue gas particulate matter ultra-low emission equipment also includes a water-cooling flue (19) and a vaporization cooling flue (20), and the water-cooling flue (19), the vaporization cooling flue (20) and the evaporative cooler (2) are connected in sequence.

3. The method for ultra-low emission of particulate matter in primary flue gas of a converter according to claim 1, characterized in that: The electric dust collector (4) and the coal gas cooler (8) are connected via an air supply pipeline, on which an axial flow fan (6) and a muffler (7) are sequentially arranged.

4. The method for ultra-low emission of particulate matter in primary flue gas of a converter according to claim 1, characterized in that: The coal gas cooler (8) contains two single-medium injection devices (81), wherein the first single-medium injection device (81), the second single-medium injection device (81) and the dual-medium injection device (82) are sequentially arranged at intervals from top to bottom.

5. The ultra-low emission method of primary flue gas particulate matter from converter according to claim 1, characterized in that: One end of the external mixing dual-medium atomizing long spray gun (83) is connected and fixed to the side wall of the coal gas cooler (8). The external mixing dual-medium atomizing long spray gun (83) is arranged along the diameter direction of the coal gas cooler (8). The length of the external mixing dual-medium atomizing long spray gun (83) is 60% to 80% of the radius of the coal gas cooler (8).

6. The ultra-low emission method of primary flue gas particulate matter from converter according to claim 1, characterized in that: One end of the external mixing dual-medium atomizing short spray gun (84) is connected and fixed to the side wall of the coal gas cooler (8), and the external mixing dual-medium atomizing short spray gun (84) is arranged along the diameter direction of the coal gas cooler (8), and the length of the external mixing dual-medium atomizing short spray gun (84) is 30% to 40% of the radius of the coal gas cooler (8).

7. The method for ultra-low emission of particulate matter in primary flue gas of a converter according to claim 1, characterized in that: The dehydrator (14) is a vertical dehydrator, the inlet of the dehydrator (14) is located at the upper part of the dehydrator (14), and the outlet of the dehydrator (14) is located at the lower part of the dehydrator (14).

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