Purification treatment equipment and purification treatment method for blast furnace gas

Abstract

The invention discloses blast furnace gas purification treatment equipment and a purification treatment method thereof. The blast furnace gas purification treatment equipment comprises an absorption tower, a regeneration tower and absorption liquid, the absorption tower comprises an alkali liquor washing chamber, a new water washing chamber and an absorption chamber, and a blast furnace gas discharge channel is arranged at the top of the absorption tower; an alkali liquor spraying mechanism, a structured packing layer D, a blast furnace gas inlet and a washing wastewater outlet are arranged in the alkali liquor washing chamber; a regular packing layer E, an industrial new water spraying mechanism and a semi-washing wastewater discharge port are arranged in the new water washing chamber; a barren liquor spraying mechanism, a structured packing layer F, a semi-rich liquor spraying mechanism A, a structured packing layer G and a rich liquor outlet are arranged in the absorption chamber; the regeneration tower comprises an upper tower and a lower tower; a structured packing layer A, a rich liquid spraying mechanism, a structured packing layer B and a semi-rich liquid cavity are arranged in the upper tower; and a semi-pregnant solution spraying mechanism B, a structured packing layer C, a semi-barren solution cavity and a barren solution cavity are sequentially arranged in the lower tower from top to bottom. According to the invention, deacidification, desulfurization and decarbonization treatment of the blast furnace gas can be realized.

Description

Technical Field

[0001] The present invention relates to the technical field of blast furnace gas purification, and in particular to a blast furnace gas purification treatment device and a purification treatment method thereof. Background Art

[0002] Blast furnace gas, a byproduct of blast furnace ironmaking, undergoes baghouse dust removal and TRT residual pressure power generation before being fed into boilers, coke ovens, hot blast furnaces, and other systems for combustion as fuel. Blast furnace gas recycling is a crucial component of the circular economy for steel companies, significantly reducing production costs while also creating a host of challenges. These include corrosion of gas pipelines and equipment caused by trace amounts of HCl and H₂S in the gas; with the escalation of national environmental protection policies, failure to desulfurize blast furnace gas will result in substandard sulfur emissions from combustion exhaust; and blast furnace gas contains significant amounts of carbon dioxide, making its direct release inconsistent with national carbon emission policy guidelines and trends. Therefore, the development of metallurgical technologies for deacidification, desulfurization, and decarbonization of blast furnace gas is an inevitable development. Summary of the Invention

[0003] The present invention aims to provide a blast furnace gas purification and treatment device to solve the above-mentioned technical problems.

[0004] To achieve the above objectives, the technical solution of the present invention is: a blast furnace gas purification and treatment device comprising an absorption tower, a regeneration tower, and a regenerable absorption liquid circulating between the absorption tower and the regeneration tower, wherein the absorption liquid is divided into four types: rich liquid, semi-rich liquid, semi-lean liquid, and lean liquid, and the concentrations of sulfide and carbon dioxide in the rich liquid, semi-rich liquid, semi-lean liquid, and lean liquid gradually decrease; The absorption tower includes an alkali solution washing chamber, a fresh water washing chamber, and an absorption chamber, which are sequentially connected from bottom to top. A blast furnace gas discharge channel connected to the absorption chamber is provided at the top of the absorption tower; an alkali solution spray mechanism, a structured packing layer D, a blast furnace gas inlet, and a washing wastewater discharge port are sequentially provided in the alkali solution washing chamber from top to bottom, and the blast furnace gas inlet is externally connected to an air inlet channel; the fresh water washing chamber is sequentially provided with a structured packing layer E, an industrial fresh water spray mechanism, and a semi-washing wastewater discharge port from top to bottom, the structured packing layer E is used to remove water and alkali solution from the washed blast furnace gas, and the industrial fresh water nozzle is externally connected to an industrial fresh water delivery pipe; the absorption chamber is sequentially provided with a lean liquid spray mechanism, a structured packing layer F, a semi-rich liquid spray mechanism A, a structured packing layer G, and a rich liquid discharge port from top to bottom, and a structured packing layer H is provided in the blast furnace gas discharge channel, and the structured packing layer H is used to remove fresh water and absorption liquid from the purified blast furnace gas; The regeneration tower includes an upper tower and a lower tower connected from top to bottom. The upper tower is provided with a structured packing layer A, a rich liquid spray mechanism, a structured packing layer B, and a semi-rich liquid chamber in order from top to bottom. The structured packing layer A is used to remove the absorbent in the regeneration gas flow. The top of the upper tower is externally connected to a regeneration gas output channel. The lower tower is provided with a semi-rich liquid spray mechanism B, a structured packing layer C, a semi-lean liquid chamber, and a lean liquid chamber in order from top to bottom. The semi-lean liquid chambers are connected to each other through a heating mechanism. The heating mechanism is used to heat the semi-lean liquid flowing out of the semi-lean liquid chamber to form a lean liquid and regeneration gas flow, which are then transported to the lean liquid chamber. The lean liquid chamber is communicated with the lean liquid spray mechanism, the semi-rich liquid chamber is communicated with the semi-rich liquid spray mechanism B and the semi-rich liquid spray mechanism A respectively, and the rich liquid discharge port is communicated with the rich liquid spray mechanism.

[0005] Preferably, it also includes a first channel, a second channel, and a third channel. The lean liquid chamber is connected to the lean liquid spray mechanism through the first channel, the semi-rich liquid chamber is connected to the semi-rich liquid spray mechanism A and the semi-rich liquid spray mechanism B respectively through the second channel, and the rich liquid discharge outlet is connected to the rich liquid spray mechanism through the third channel. A first heat exchanger is provided between the industrial new water delivery pipe and the first channel to cool the lean liquid in the first channel, a second heat exchanger is provided between the industrial new water delivery pipe and the second channel to cool the semi-rich liquid in the second channel, and a third heat exchanger is provided between the first channel and the third channel to cool the lean liquid in the first channel.

[0006] Preferably, a first partition is provided between the alkali liquid washing chamber and the new water washing chamber, a first air tower is provided on the first partition, and the alkali liquid washing chamber and the new water washing chamber are connected through the first air tower; a second partition is provided between the new water washing chamber and the absorption chamber, a second air tower is provided on the second partition, and the new water washing chamber and the absorption chamber are connected through the second air tower.

[0007] Preferably, the first partition plate and the second partition plate are both arc-shaped partition plates with a high middle portion and low surrounding portions.

[0008] Preferably, a third gas tower is provided at the bottom end of the upper tower corresponding to the position of the semi-rich liquid chamber, and the upper tower and the lower tower are connected through the third gas tower; a fourth gas tower is provided at the lower part of the lower tower corresponding to the position of the semi-lean liquid chamber, and the semi-lean liquid chamber and the lean liquid chamber are connected through the fourth gas tower.

[0009] Preferably, the absorption liquid is a complex alcoholamine liquid.

[0010] Preferably, the heating mechanism includes a delivery pipeline and a heater installed on the delivery pipeline, and the heater heats the semi-lean liquid by introducing steam.

[0011] Preferably, the structured packing layer B and the structured packing layer G are both arranged in a vertical arrangement in plurality.

[0012] Preferably, the washing wastewater outlet is connected to a wastewater treatment system, and the semi-washing wastewater outlet is connected to an alkali solution preparation system.

[0013] The present invention also provides a method for purifying blast furnace gas, comprising any of the above-mentioned blast furnace gas purification equipment, the method comprising the following steps: S1. Blast furnace gas is input into the alkali washing chamber of the absorption tower through the air inlet channel and flows upward. The alkali spraying mechanism sprays alkali liquid to countercurrent with the blast furnace gas, thereby achieving preliminary deacidification, cooling and dust removal treatment of the blast furnace gas. S2, the blast furnace gas in the alkali solution washing chamber flows upward into the fresh water washing chamber, and the industrial fresh water spraying mechanism sprays fresh water to wash the blast furnace gas to achieve further deacidification, cooling and dust removal treatment, and then removes water and alkali solution from the blast furnace gas through the structured packing layer E; The blast furnace gas in S3 and the new water washing chamber continues to flow upward and enters the absorption chamber, and the lean liquid spraying mechanism sprays lean liquid, and the semi-rich liquid spraying mechanism A sprays semi-rich liquid. The blast furnace gas flows upward in the absorption chamber and passes through the semi-rich liquid and the lean liquid in sequence after washing. The sulfide and carbon dioxide in the blast furnace gas are taken away from. Then, the new water and the absorption liquid in the blast furnace gas after purification are removed by the structured packing layer H. Finally, the blast furnace gas is discharged from the blast furnace gas discharge channel at the top of the absorption chamber, completing the deacidification, desulfurization and decarbonization process of the blast furnace gas. Among them, in the absorption chamber, the semi-rich liquid and the lean liquid absorb the sulfide and carbon dioxide in the blast furnace gas and become rich liquid, which flows downward and accumulates at the bottom of the absorption chamber. Then the rich liquid at the bottom of the absorption chamber is sent to the rich liquid spraying mechanism of the upper tower of the regeneration tower, and then the rich liquid is sprayed down through the rich liquid spraying mechanism. The rich liquid is heated by the rising regeneration gas flow and precipitates carbon dioxide and sulfide to become semi-rich liquid and accumulate in the semi-rich liquid cavity at the bottom of the upper tower. The regeneration gas flow continues to flow upward through the structured packing layer A to remove the absorption liquid and then pass through, and the regeneration gas is output The channel is output to the outside for recycling; the semi-rich liquid flows out from the bottom of the upper tower and is pressurized and divided into two paths. One path is sent to the semi-rich liquid spray mechanism A in the middle of the absorption chamber of the absorption tower after being cooled by new water, and the other path is sent to the semi-rich liquid spray mechanism B in the lower tower of the regeneration tower. The semi-rich liquid sprayed by the semi-rich liquid spray mechanism B is heated by the rising regeneration gas flow to precipitate carbon dioxide and sulfide to become semi-lean liquid and accumulate in the semi-lean liquid cavity of the lower tower; then the semi-lean liquid flows to the heating mechanism and is heated to form lean liquid and regeneration gas flow, and then is transported to the lean liquid cavity.

[0014] The present invention has the following beneficial effects: (1) Through the cooperation between the absorption tower and the regeneration tower, the blast furnace gas can be efficiently, fully, safely and reliably deacidified, desulfurized and decarbonized, solving the problem of high corrosiveness of blast furnace gas and substandard exhaust gas emissions after combustion, meeting the national emission requirements for blast furnace gas, and realizing the efficient recycling of the absorption liquid, thus saving resources.

[0015] (2) The absorption tower adopts a segmented absorption mode of semi-rich liquid and lean liquid, and the regeneration tower adopts a segmented regeneration mode of rich liquid and semi-rich liquid, which effectively improves the absorption efficiency while reducing the energy consumption of the entire device.

[0016] (3) The vertical absorption tower structure is adopted to integrate the deacidification, desulfurization and decarbonization processes, saving the investment cost and floor space of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The figure is a simplified flowchart of an embodiment of the present invention.

[0018] Figure markings: 1 absorption tower, 2 alkali solution washing chamber, 3 new water washing chamber, 4 absorption chamber, 5 blast furnace gas discharge channel, 6 alkali solution spraying mechanism, 7 structured packing layer D, 8 blast furnace gas inlet, 9 washing wastewater outlet, 10 air inlet channel, 11 alkali solution input mechanism, 12 structured packing layer E, 13 industrial new water spraying mechanism, 14 semi-washing wastewater outlet, 15 industrial new water delivery pipe, 16 lean liquid spraying mechanism, 17 structured packing layer F, 18 semi-rich liquid spraying mechanism A, 19 structured packing layer G, 20 rich liquid outlet, 21 structured packing layer H, 22 regeneration tower, 221 upper tower, 222 lower tower, 23 structured packing layer Whole packing layer A, 24 rich liquid spraying mechanism, 25 structured packing layer B, 26 semi-rich liquid chamber, 27 semi-rich liquid spraying mechanism B, 28 structured packing layer C, 29 semi-lean liquid chamber, 30 lean liquid chamber, 31 heating mechanism, 311 conveying pipeline, 312 heater, 32 first channel, 33 second channel, 34 third channel, 35 first heat exchanger, 36 second heat exchanger, 37 third heat exchanger, 38 first partition, 39 first gas tower, 40 second partition, 41 second gas tower, 42 third gas tower, 43 fourth gas tower, 44 wastewater treatment system, 45 alkali solution preparation system, 36 regeneration gas output channel, 37 pressurizer. DETAILED DESCRIPTION

[0019] To further illustrate various embodiments, the present invention is provided with accompanying drawings. These drawings form part of the present disclosure and are primarily used to illustrate the embodiments and, in conjunction with the relevant description in the specification, to explain the operating principles of the embodiments. By referring to these drawings, one of ordinary skill in the art will understand other possible embodiments and the advantages of the present invention. The components in the figures are not drawn to scale, and similar reference numerals are generally used to represent similar components.

[0020] In the description of the present invention, unless otherwise specified, "plurality" means two or more; terms such as "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," and "tail" indicate positions or relationships based on those shown in the accompanying drawings. These terms are intended solely to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present invention. Furthermore, terms such as "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0021] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integral connection; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0022] See Figure 1 As shown, as an embodiment of the present invention, a blast furnace gas purification treatment device is provided, comprising an absorption tower 1, a regeneration tower 22, and a regenerable absorption liquid circulating between the absorption tower 1 and the regeneration tower 22. The absorption liquid is divided into four types: rich liquid, semi-rich liquid, semi-lean liquid, and lean liquid. The concentrations of sulfide and carbon dioxide in the rich liquid, semi-rich liquid, semi-lean liquid, and lean liquid gradually decrease. The absorption tower 1 includes an alkali solution washing chamber 2, a fresh water washing chamber 3 and an absorption chamber 4 which are connected in sequence from bottom to top. A blast furnace gas discharge channel 5 which is connected to the absorption chamber 4 is provided on the top of the absorption tower 1. An alkali solution spraying mechanism 6, a structured packing layer D7, a blast furnace gas inlet 8 and a washing wastewater outlet 9 are provided in sequence from top to bottom in the alkali solution washing chamber 2. The blast furnace gas inlet 8 is externally connected to an air inlet channel 10. The alkali solution spraying mechanism 6 is externally connected to an alkali solution input mechanism 11. The fresh water washing chamber 3 is provided in sequence from top to bottom with a structured packing layer E12, an industrial A fresh water spray mechanism 13 and a semi-washed wastewater outlet 14 are provided. Structured packing layer E12 is used to remove water and alkali from the washed blast furnace gas. An industrial fresh water nozzle is externally connected to an industrial fresh water delivery pipe 15. Within the absorption chamber 4, from top to bottom, are arranged a lean liquid spray mechanism 16, a structured packing layer F17, a semi-rich liquid spray mechanism A18, a structured packing layer G19, and a rich liquid outlet 20. A structured packing layer H21 is provided within the blast furnace gas discharge channel 5. This structured packing layer H21 is used to remove fresh water and absorption liquid from the purified blast furnace gas. The regeneration tower 22 includes an upper tower 221 and a lower tower 222 connected to each other. The upper tower 221 is provided with a structured packing layer A23, a rich liquid spraying mechanism 24, a structured packing layer B25, and a semi-rich liquid cavity 26 in order from top to bottom. The structured packing layer A23 is used to remove the absorbent in the regeneration gas flow. The structured packing layer B25 makes the contact between the rich liquid and the regeneration gas flow more complete, so that the rich liquid is heated by the regeneration gas flow to precipitate sulfide and becomes a semi-rich liquid and accumulates in the semi-rich liquid cavity 26 at the bottom of the upper tower 221. The top of the upper tower 221 is externally connected to the regeneration gas output channel 46; the lower tower 222 is provided with a structured packing layer A23, a rich liquid spraying mechanism 24, a structured packing layer B25, and a semi-rich liquid cavity 26. Towards the bottom, a semi-rich liquid spraying mechanism B27, a structured packing layer C28, a semi-lean liquid chamber 29, and a lean liquid chamber 30 are sequentially arranged. The semi-lean liquid chamber 29 and the lean liquid chamber 30 are connected via a heating mechanism 31. The structured packing layer C28 ensures more complete contact between the semi-rich liquid and the regeneration gas flow, so that the semi-rich liquid is heated by the regeneration gas flow to precipitate sulfides and becomes semi-lean liquid, which accumulates in the semi-lean liquid chamber 29 of the lower tower 222. The heating mechanism 31 is used to heat the semi-lean liquid flowing out of the semi-lean liquid chamber 29 to form lean liquid and regeneration gas flow, which are then transported to the lean liquid chamber 30. The regeneration gas flow mainly contains carbon dioxide and sulfides. The lean liquid chamber 30 is communicated with the lean liquid spray mechanism 16, the semi-rich liquid chamber 26 is communicated with the semi-rich liquid spray mechanism B27 and the semi-rich liquid spray mechanism A18 respectively, and the rich liquid discharge port 20 is communicated with the rich liquid spray mechanism 24; specifically, it also includes a first channel 32, a second channel 33, and a third channel 34. The lean liquid chamber 30 is communicated with the lean liquid spray mechanism 16 through the first channel 32, the semi-rich liquid chamber 26 is communicated with the semi-rich liquid spray mechanism A18 and the semi-rich liquid spray mechanism B27 respectively through the second channel 33, and the rich liquid discharge port 20 is communicated with the rich liquid spray mechanism 24 through the third channel 34. A first heat exchanger 35 is provided between the industrial new water delivery pipe 15 and the first channel 32 to cool the lean liquid in the first channel 32, and a second heat exchanger 36 is provided between the industrial new water delivery pipe 15 and the second channel 33 to cool the lean liquid in the first channel 32. The semi-rich liquid in the second channel 33 is cooled so that the cooled semi-rich liquid flows through the second channel 33 to the semi-rich liquid spraying mechanism A18, thereby improving the absorption effect of the semi-rich liquid on sulfides and carbon dioxide in blast furnace gas. A third heat exchanger 37 is provided between the first channel 32 and the third channel 34, so that the rich liquid flowing out from the bottom of the absorption chamber 4 of the absorption tower 1 to the third channel 34 and the lean liquid flowing out from the bottom lean liquid chamber 30 of the regeneration tower 22 to the first channel 32 are heat exchanged, so that the rich liquid is heated, which is conducive to the precipitation of sulfides and carbon dioxide, and the lean liquid is cooled to improve the absorption effect on sulfides and carbon dioxide in blast furnace gas; the setting of the heat exchanger can save the energy of the entire equipment and reduce energy consumption. Pressurizers 47 are respectively installed on the first channel 32, the second channel 33, and the third channel 34.

[0023] The working process of the purification treatment equipment of blast furnace gas of the present invention is as follows: S1, blast furnace gas is input into the alkali solution washing chamber 2 of the absorption tower through the air inlet channel 10 and flows upward. The alkali solution spraying mechanism 6 sprays alkali solution to perform convection with the blast furnace gas, thereby achieving preliminary deacidification (mainly HCL), cooling, and dust removal of the blast furnace gas. The alkali solution is NaOH alkali solution. The structured packing layer D7 is used to increase the contact area between the blast furnace gas and the NaOH alkali solution, thereby improving the removal efficiency of HCL in the blast furnace gas. S2: The blast furnace gas in the alkali solution washing chamber 2 flows upward into the fresh water washing chamber 3. The industrial fresh water spraying mechanism 13 sprays fresh water to wash the blast furnace gas to achieve further deacidification, cooling, and dust removal. HCl and particulate dust in the blast furnace gas are further removed, and the gas temperature is further reduced. The water and alkali solution in the blast furnace gas are then removed through the structured packing layer E12. The blast furnace gas in S3 and the new water washing chamber 3 continues to flow upward into the absorption chamber 4, the lean liquid spraying mechanism 16 sprays the lean liquid, and the semi-rich liquid spraying mechanism A18 sprays the semi-rich liquid. The blast furnace gas flows upward in the absorption chamber 4 and is sequentially washed by the semi-rich liquid and the lean liquid, and the sulfide and carbon dioxide in the blast furnace gas are removed. The blast furnace gas and the semi-rich liquid can fully contact at the structured packing layer G19, so that the blast furnace gas can be fully deacidified and decarbonized. The blast furnace gas that has completed partial deacidification and decarbonization is fully contacted with the lean liquid at the structured packing layer F17, and further deacidification and decarbonization of the blast furnace gas are carried out to ensure the removal effect; then the new water and absorption liquid in the purified blast furnace gas are removed by the structured packing layer H21, and finally the blast furnace gas is discharged from the blast furnace gas discharge channel 5 at the top of the absorption chamber 4, completing the full and efficient deacidification, desulfurization and decarbonization process of the blast furnace gas; Among them, in the absorption chamber 4, the semi-rich liquid and the lean liquid absorb the sulfide and carbon dioxide in the blast furnace gas and become rich liquid, which flows downward and gathers at the bottom of the absorption chamber 4, and then the rich liquid at the bottom of the absorption chamber 4 is sent to the rich liquid spraying mechanism 24 of the upper tower 221 of the regeneration tower 22, and then the rich liquid is sprayed downward through the rich liquid spraying mechanism 24. The rich liquid is heated by the rising regeneration gas flow and precipitates carbon dioxide and sulfide to become semi-rich liquid and accumulates in the semi-rich liquid cavity 26 at the bottom of the upper tower 221. The regeneration gas flow continues to flow upward through the structured packing layer A23 to remove the absorption liquid and then pass through the regeneration gas output channel 46 to be output to the outside for recycling; the semi-rich liquid in the semi-rich liquid cavity 26 at the bottom of the upper tower 221 flows out through the second channel 33 and is pressurized It is then divided into two paths. One path is sent to the semi-rich liquid spraying mechanism A18 in the middle of the absorption chamber 4 of the absorption tower 1 after being cooled by new water, so that the cooled semi-rich liquid can improve the absorption effect of sulfide and carbon dioxide in the blast furnace gas. The other path is sent to the semi-rich liquid spraying mechanism B27 of the lower tower 222 of the regeneration tower 22. The semi-rich liquid sprayed by the semi-rich liquid spraying mechanism B27 is heated by the rising regeneration gas flow to precipitate carbon dioxide and sulfide to become semi-lean liquid and accumulate in the semi-lean liquid chamber 29 of the lower tower 222; then the semi-lean liquid flows to the heating mechanism 31 and is heated to form lean liquid and regeneration gas flow and then transported to the lean liquid chamber 30. The regeneration tower 22 performs multi-stage treatment on the rich liquid and finally treats it into lean liquid, thereby realizing the regeneration and recycling of the absorption liquid.

[0024] In summary, the present invention has the following advantages: (1) Through the cooperation between the absorption tower 1 and the regeneration tower 22, the blast furnace gas can be efficiently, fully, safely and reliably deacidified, desulfurized and decarbonized, solving the problems of high corrosiveness of blast furnace gas and substandard exhaust gas emissions after combustion, meeting the national emission requirements for blast furnace gas, and realizing the efficient recycling of the absorption liquid, thus saving resources.

[0025] (2) The absorption tower 1 adopts a segmented absorption mode of semi-rich liquid and lean liquid, and the regeneration tower 22 adopts a segmented regeneration mode of rich liquid and semi-rich liquid, which effectively improves the absorption efficiency while reducing the energy consumption of the entire device.

[0026] (3) The vertical absorption tower 1 structure is adopted to integrate the deacidification, desulfurization and decarbonization processes, saving the investment cost and floor space of the equipment.

[0027] In this embodiment, a first partition plate 38 is provided between the alkali liquid washing chamber 2 and the new water washing chamber 3, and a first gas tower 39 is provided on the first partition plate 38. The alkali liquid washing chamber 2 and the new water washing chamber 3 are connected through the first gas tower 39. The blast furnace gas in the alkali liquid washing chamber 2 flows upward into the new water washing chamber 3 through the diversion of the first gas tower 39. A second partition plate 40 is provided between the new water washing chamber 3 and the absorption chamber 4. A second gas tower 41 is provided on the second partition plate 40. The new water washing chamber 3 and the absorption chamber 4 are connected through the second gas tower 41. The blast furnace gas in the new water washing chamber 3 flows upward into the absorption chamber 4 through the diversion of the second gas tower 41.

[0028] In this embodiment, the first partition plate 38 and the second partition plate 40 are both arc-shaped partition plates with a high middle portion and low surrounding portions, thereby facilitating the collection and discharge of washing wastewater and rich liquid.

[0029] In this embodiment, a third gas tower 42 is provided at the bottom end of the upper tower 221 at a position corresponding to the semi-rich liquid chamber 26, and the upper tower 221 and the lower tower 222 are connected through the third gas tower 42, and the regenerated gas flow in the semi-lean liquid chamber 29 of the lower tower 222 flows upward through the guide of the third gas tower 42 and enters the lean liquid chamber 30; a fourth gas tower 43 is provided at the lower part of the lower tower 222 at a position corresponding to the semi-lean liquid chamber 29, and the semi-lean liquid chamber 29 and the lean liquid chamber 30 are connected through the fourth gas tower 43, and the regenerated gas flow in the lean liquid chamber 30 flows upward through the guide of the fourth gas tower 43 and enters the semi-lean liquid chamber 29.

[0030] In this embodiment, the absorption liquid is a composite alcohol amine liquid, which has a better absorption effect on sulfide and carbon dioxide in blast furnace gas.

[0031] In this embodiment, the heating mechanism 31 includes a delivery pipe 311 and a heater 312 installed on the delivery pipe 311. The heater 312 heats the semi-lean liquid by introducing steam.

[0032] In this embodiment, structured packing layers B25 and G19 are arranged in a vertical arrangement to provide more complete contact between the gas and liquid. Structured packing layers A23-H are constructed of lightweight stainless steel or aluminum alloy materials, such as wire mesh or folded plates, primarily to increase contact area.

[0033] In this embodiment, the washing wastewater outlet 9 is externally connected to a wastewater treatment system 44 , and the semi-washing wastewater outlet 14 is externally connected to an alkali solution preparation system 45 .

[0034] Regarding the function of absorption chamber 4: Since the sulfide and carbon dioxide content of the blast furnace gas at the upper portion of absorption chamber 4, corresponding to structured packing layer F17, is relatively low, to ensure absorption efficiency, the absorption liquid is selected from the fully regenerated lean liquid in the lean liquid chamber 30 at the bottom of the lower tower 222 of the regeneration tower 22. Since the sulfide and carbon dioxide content of the blast furnace gas at the lower portion of absorption chamber 4, corresponding to structured packing layer G19, is relatively high, a general-quality absorption liquid can effectively absorb the sulfide and carbon dioxide content of the blast furnace gas. Therefore, the absorption liquid here is selected from the semi-rich liquid in the semi-rich liquid chamber 26 at the bottom of the upper tower 221 of the regeneration tower 22, which has undergone preliminary regeneration.

[0035] Functional description of the alkali solution washing chamber 2: Cooling, dust removal and deacidification of blast furnace gas in the alkali solution washing chamber 2 are all indispensable and important links for the subsequent efficient and stable desulfurization and decarbonization process of blast furnace gas.

[0036] Functional description of the new water washing chamber 3: (1) New water washes blast furnace gas to further remove dust and deacidify; (2) Washing water is used to supplement the alkali loss of the alkali input mechanism 11 in the lower section, effectively avoiding the alkali concentration in the alkali input mechanism 11 being too high and oversaturated; (3) Since the quality of the semi-washing wastewater discharged from the semi-washing wastewater outlet 14 is acceptable, it can directly enter the alkali configuration system 45, thereby reducing the facility scale of the washing wastewater treatment system 44 in the lower section; (4) Reduce the entrainment of alkali in the upward flow of blast furnace gas; (5) Reduce the probability of clogging of the upper dehydration filler.

[0037] The present invention also provides a method for purifying blast furnace gas, comprising the above-mentioned blast furnace gas purification equipment, and the purification method comprises the following steps: S1, blast furnace gas is input into the alkali solution washing chamber 2 of the absorption tower 1 through the air inlet channel 10 and flows upward, and the alkali solution spraying mechanism 6 sprays alkali solution to countercurrent with the blast furnace gas, thereby achieving preliminary deacidification, cooling and dust removal treatment of the blast furnace gas; S2, the blast furnace gas in the alkali solution washing chamber 2 flows upward into the fresh water washing chamber 3, and the industrial fresh water spraying mechanism 13 sprays fresh water to wash the blast furnace gas to achieve further deacidification, cooling, and dust removal. Then, the water and alkali solution in the blast furnace gas are removed through the structured packing layer E12; The blast furnace gas in S3 and the new water washing chamber 3 continues to flow upward into the absorption chamber 4, the lean liquid spraying mechanism 16 sprays the lean liquid, and the semi-rich liquid spraying mechanism A18 sprays the semi-rich liquid. The blast furnace gas flows upward in the absorption chamber 4 and is sequentially washed by the semi-rich liquid and the lean liquid, and the sulfide and carbon dioxide in the blast furnace gas are removed. The blast furnace gas and the semi-rich liquid can fully contact at the structured packing layer G19, so that the blast furnace gas can be fully deacidified and decarbonized. The blast furnace gas that has completed partial deacidification and decarbonization is fully contacted with the lean liquid at the structured packing layer F17, and further deacidification and decarbonization of the blast furnace gas are carried out to ensure the removal effect; then the new water and absorption liquid in the purified blast furnace gas are removed by the structured packing layer H21, and finally the blast furnace gas is discharged from the blast furnace gas discharge channel 5 at the top of the absorption chamber 4, completing the full and efficient deacidification, desulfurization and decarbonization process of the blast furnace gas; Among them, in the absorption chamber 4, the semi-rich liquid and the lean liquid absorb the sulfide and carbon dioxide in the blast furnace gas and become rich liquid, which flows downward and accumulates at the bottom of the absorption chamber 4. Then the rich liquid at the bottom of the absorption chamber 4 is sent to the rich liquid spraying mechanism 24 of the upper tower 221 of the regeneration tower 22, and then the rich liquid is sprayed downward through the rich liquid spraying mechanism 24. The rich liquid is heated by the rising regeneration gas flow and precipitates carbon dioxide and sulfide to become semi-rich liquid and accumulates in the semi-rich liquid cavity 26 at the bottom of the upper tower 221. The regeneration gas flow continues to flow upward through the structured packing layer A23 to remove the absorption liquid and then passes through the regeneration gas output channel 46 to be output to the outside for recycling; the semi-rich liquid is discharged from the upper tower 2 The bottom outflow of 21 is divided into two paths after pressurization. One path is sent to the semi-rich liquid spraying mechanism A18 in the middle of the absorption chamber 4 of the absorption tower 1 after being cooled by new water, and the other path is sent to the semi-rich liquid spraying mechanism B27 of the lower tower 222 of the regeneration tower 22. The semi-rich liquid sprayed by the semi-rich liquid spraying mechanism B27 is heated by the rising regeneration gas flow to precipitate carbon dioxide and sulfide to become semi-lean liquid and accumulate in the semi-lean liquid chamber 29 of the lower tower 222; then the semi-lean liquid flows to the heating mechanism 31 and is heated to form lean liquid and regeneration gas flow, and then is transported to the lean liquid chamber 30. The regeneration tower 22 performs multi-stage treatment on the rich liquid and finally treats it into lean liquid, thereby realizing the regeneration and recycling of the absorption liquid.

[0038] In this embodiment, the structural principles of each spray mechanism are the same, and all include a spray pipe and a plurality of spray heads installed on the spray pipe.

[0039] Although the present invention has been particularly shown and described in conjunction with preferred embodiments, it should be understood by those skilled in the art that various changes in form and details made to the present invention without departing from the spirit and scope of the invention as defined in the appended claims fall within the scope of protection of the present invention.

Claims

1. A blast furnace gas purification equipment, characterized by: It includes an absorption tower, a regeneration tower, and a regenerable absorption liquid circulating between the absorption tower and the regeneration tower. The absorption liquid is divided into four types: rich liquid, semi-rich liquid, semi-lean liquid, and lean liquid. The concentrations of sulfide and carbon dioxide in the rich liquid, semi-rich liquid, semi-lean liquid, and lean liquid gradually decrease. The absorption tower includes an alkali solution washing chamber, a fresh water washing chamber, and an absorption chamber, which are sequentially connected from bottom to top. A blast furnace gas discharge channel connected to the absorption chamber is provided at the top of the absorption tower; an alkali solution spray mechanism, a structured packing layer D, a blast furnace gas inlet, and a washing wastewater discharge port are sequentially provided in the alkali solution washing chamber from top to bottom, and the blast furnace gas inlet is externally connected to an air inlet channel; the fresh water washing chamber is sequentially provided with a structured packing layer E, an industrial fresh water spray mechanism, and a semi-washing wastewater discharge port from top to bottom, the structured packing layer E is used to remove water and alkali solution from the washed blast furnace gas, and the industrial fresh water nozzle is externally connected to an industrial fresh water delivery pipe; the absorption chamber is sequentially provided with a lean liquid spray mechanism, a structured packing layer F, a semi-rich liquid spray mechanism A, a structured packing layer G, and a rich liquid discharge port from top to bottom, and a structured packing layer H is provided in the blast furnace gas discharge channel, and the structured packing layer H is used to remove fresh water and absorption liquid from the purified blast furnace gas; The regeneration tower includes an upper tower and a lower tower connected from top to bottom. The upper tower is provided with a structured packing layer A, a rich liquid spray mechanism, a structured packing layer B, and a semi-rich liquid chamber in order from top to bottom. The structured packing layer A is used to remove the absorbent in the regeneration gas flow. The top of the upper tower is externally connected to a regeneration gas output channel. The lower tower is provided with a semi-rich liquid spray mechanism B, a structured packing layer C, a semi-lean liquid chamber, and a lean liquid chamber in order from top to bottom. The semi-lean liquid chambers are connected to each other through a heating mechanism. The heating mechanism is used to heat the semi-lean liquid flowing out of the semi-lean liquid chamber to form a lean liquid and regeneration gas flow, which are then transported to the lean liquid chamber. The lean liquid chamber is communicated with the lean liquid spray mechanism, the semi-rich liquid chamber is communicated with the semi-rich liquid spray mechanism B and the semi-rich liquid spray mechanism A respectively, and the rich liquid discharge port is communicated with the rich liquid spray mechanism.

2. The blast furnace gas purification equipment according to claim 1, characterized in that: It also includes a first channel, a second channel, and a third channel. The lean liquid chamber is connected to the lean liquid spray mechanism through the first channel, and the semi-rich liquid chamber is connected to the semi-rich liquid spray mechanism A and the semi-rich liquid spray mechanism B respectively through the second channel. The rich liquid discharge outlet is connected to the rich liquid spray mechanism through the third channel. A first heat exchanger is provided between the industrial new water delivery pipe and the first channel to cool the lean liquid in the first channel, a second heat exchanger is provided between the industrial new water delivery pipe and the second channel to cool the semi-rich liquid in the second channel, and a third heat exchanger is provided between the first channel and the third channel to cool the lean liquid in the first channel.

3. The blast furnace gas purification equipment according to claim 1, characterized in that: A first partition is provided between the alkali solution washing chamber and the new water washing chamber, a first air tower is provided on the first partition, and the alkali solution washing chamber and the new water washing chamber are connected through the first air tower; a second partition is provided between the new water washing chamber and the absorption chamber, a second air tower is provided on the second partition, and the new water washing chamber and the absorption chamber are connected through the second air tower.

4. The blast furnace gas purification equipment according to claim 3, characterized in that: The first partition plate and the second partition plate are both arc-shaped partition plates with a high middle portion and low surrounding portions.

5. The blast furnace gas purification equipment according to claim 1, characterized in that: A third gas tower is provided at the bottom end of the upper tower corresponding to the position of the semi-rich liquid chamber, and the upper tower and the lower tower are connected through the third gas tower; a fourth gas tower is provided at the lower part of the lower tower corresponding to the position of the semi-lean liquid chamber, and the semi-lean liquid chamber and the lean liquid chamber are connected through the fourth gas tower.

6. The blast furnace gas purification equipment according to claim 1, characterized in that: The absorption liquid is a compound alcohol amine liquid.

7. The blast furnace gas purification equipment according to claim 1, characterized in that: The heating mechanism includes a delivery pipeline and a heater installed on the delivery pipeline. The heater heats the semi-lean liquid by introducing steam.

8. The blast furnace gas purification equipment according to claim 1, characterized in that: There are multiple structured packing layers B and structured packing layers G arranged vertically.

9. The blast furnace gas purification equipment according to claim 1, characterized in that: The washing wastewater outlet is connected to a wastewater treatment system, and the semi-washing wastewater outlet is connected to an alkali solution preparation system.

10. A method for purifying blast furnace gas, characterized in that: The blast furnace gas purification equipment comprising any one of claims 1 to 9, wherein the purification method comprises the following steps: S1. Blast furnace gas is input into the alkali washing chamber of the absorption tower through the air inlet channel and flows upward. The alkali spraying mechanism sprays alkali liquid to countercurrent with the blast furnace gas, thereby achieving preliminary deacidification, cooling and dust removal treatment of the blast furnace gas. S2, the blast furnace gas in the alkali solution washing chamber flows upward into the fresh water washing chamber, and the industrial fresh water spraying mechanism sprays fresh water to wash the blast furnace gas to achieve further deacidification, cooling and dust removal treatment, and then removes water and alkali solution from the blast furnace gas through the structured packing layer E; The blast furnace gas in S3 and the new water washing chamber continues to flow upward and enters the absorption chamber, and the lean liquid spraying mechanism sprays lean liquid, and the semi-rich liquid spraying mechanism A sprays semi-rich liquid. The blast furnace gas flows upward in the absorption chamber and passes through the semi-rich liquid and the lean liquid in sequence after washing. The sulfide and carbon dioxide in the blast furnace gas are taken away from. Then, the new water and the absorption liquid in the blast furnace gas after purification are removed by the structured packing layer H. Finally, the blast furnace gas is discharged from the blast furnace gas discharge channel at the top of the absorption chamber, completing the deacidification, desulfurization and decarbonization process of the blast furnace gas. Among them, in the absorption chamber, the semi-rich liquid and the lean liquid absorb the sulfide and carbon dioxide in the blast furnace gas and become rich liquid, which flows downward and accumulates at the bottom of the absorption chamber. Then the rich liquid at the bottom of the absorption chamber is sent to the rich liquid spraying mechanism of the upper tower of the regeneration tower, and then the rich liquid is sprayed down through the rich liquid spraying mechanism. The rich liquid is heated by the rising regeneration gas flow and precipitates carbon dioxide and sulfide to become semi-rich liquid and accumulate in the semi-rich liquid cavity at the bottom of the upper tower. The regeneration gas flow continues to flow upward through the structured packing layer A to remove the absorption liquid and then pass through, and the regeneration gas is output The channel is output to the outside for recycling; the semi-rich liquid flows out from the bottom of the upper tower and is pressurized and divided into two paths. One path is sent to the semi-rich liquid spray mechanism A in the middle of the absorption chamber of the absorption tower after being cooled by new water, and the other path is sent to the semi-rich liquid spray mechanism B in the lower tower of the regeneration tower. The semi-rich liquid sprayed by the semi-rich liquid spray mechanism B is heated by the rising regeneration gas flow to precipitate carbon dioxide and sulfide to become semi-lean liquid and accumulate in the semi-lean liquid cavity of the lower tower; then the semi-lean liquid flows to the heating mechanism and is heated to form lean liquid and regeneration gas flow, and then is transported to the lean liquid cavity.

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