Cascade desulfurization system for flue gas of coke dry quenching furnace

Abstract

The utility model relates to the technical field of flue gas desulfurization, in particular to a cascade flue gas desulfurization system for a coke dry quenching furnace, which comprises a circulating stock bin, a desulfurizing agent bin, a precooler, a primary dust remover, a secondary dust remover, a first flue gas pipeline for providing diffused gas and coke discharging gas, and a second flue gas pipeline for providing coke loading gas, the first flue gas pipeline is sequentially connected with the precooler and the first-stage dust remover, the second flue gas pipeline is connected with the second-stage dust remover, outlets of the first-stage dust remover and the desulfurizing agent bin are respectively converged into the second flue gas pipeline, and the second-stage dust remover is connected to a feeding hole of the circulating stock bin through a branch pipeline; and a discharge port of the circulating stock bin is connected and converged to the second flue gas pipeline through a branch pipeline. According to the device disclosed by the utility model, the diffused gas and the coke exhaust gas with higher sulfur content are firstly treated for the first time, are converged with the coke loading gas with lower sulfur content and then are treated for the second time, so that high-sulfur and low-sulfur flue gas separation treatment is realized, the effective capture rate of a desulfurizing agent on sulfur dioxide in the flue gas is improved, and the utilization rate of the desulfurizing agent is maximized.

Description

Technical Field

[0001] The utility model relates to the technical field of flue gas desulfurization, in particular to a coke dry quenching furnace flue gas cascade desulfurization system. Background Art

[0002] The flue gas desulfurization system of coke dry quenching furnace is mainly used to treat the flue gas containing SO2 generated in the coke production process. By adopting specific desulfurization technology and process, the SO2 content in the flue gas is reduced to meet the environmental emission requirements. For example, the flue gas desulfurization treatment equipment of coke dry quenching with Chinese patent publication number CN217092895U is equipped with a primary and secondary dust removal device and a desulfurizer feeding device. The primary dust removal device is used to separate the coke powder in the flue gas, and the secondary dust removal device includes a second bag filter, which is used to separate the desulfurization by-products in the flue gas. The main desulfurization reaction is that the desulfurizer is sprayed into the flue gas pipeline to react with the flue gas, and then attached to the filter bag to continue the reaction. The separation of coke powder and desulfurization by-products obtained by two-stage dust removal can realize resource reuse; the unreacted desulfurizer is attached to the filter bag of the second bag filter, and the flue gas contacts the unreacted desulfurizer when passing through the filter bag, realizing secondary desulfurization and improving the desulfurization effect.

[0003] However, the existing desulfurization technology is limited by the high sulfur content of dry coke quenching (generally the exhaust gas concentration is 200-400 mg / m 3 , the concentration of the emitted gas is 1500-2000mg / m 3 ), and considering production safety, the flue gas entering the dust collector needs to be pre-cooled. The direct injection method of desulfurizer faces high sulfur conditions, and the actual reaction efficiency of the temperature is not high when the temperature is ≤100°C. In order to improve the reaction efficiency, the length of the flue gas pipeline cannot be extended indefinitely. The amount of desulfurizer sprayed during actual use is large, and the operation economy is not high. For this reason, the utility model proposes a coke dry quenching furnace flue gas cascade desulfurization system. Utility Model Content

[0004] In order to solve the above technical problems, the utility model provides a coke dry quenching furnace flue gas cascade desulfurization system, which diverts the dry quenching furnace flue gas, realizes the separation and treatment of high-sulfur and low-sulfur flue gas, improves the effective capture rate of sulfur dioxide in the flue gas by the desulfurizer, and at the same time, recycles the incompletely reacted desulfurizer for a second time to maximize the utilization rate of the desulfurizer.

[0005] The coke dry quenching furnace flue gas cascade desulfurization system in the present scheme comprises a circulating silo, a desulfurizer silo, a precooler, a primary dust collector, a secondary dust collector, a first flue gas duct for providing exhaust gas and exhaust coke gas, and a second flue gas duct for providing coke-loaded gas, wherein the first flue gas duct is connected in sequence to the precooler and the primary dust collector to precool the exhaust gas and exhaust coke gas in the first flue gas duct and then transport them to the primary dust collector, the second flue gas duct is connected to the secondary dust collector, wherein the outlets of the primary dust collector and the desulfurizer silo are respectively connected and merged into the second flue gas duct through branch pipes, the secondary dust collector is connected to the feed port of the circulating silo through a branch pipe, and the discharge port of the circulating silo is connected and merged into the second flue gas duct through a branch pipe.

[0006] The technical solution further defined in the utility model is:

[0007] Furthermore, it also includes a desulfurization ash silo equipped with a desulfurization ash silo feed valve, wherein the desulfurization ash silo feed valve is connected to the outlet of the secondary dust collector through a branch pipeline, and / or is connected to the branch pipeline from the secondary dust collector to the feed port of the circulation silo.

[0008] Furthermore, a circulating material feeder and a circulating material silo Roots blower are also installed on the branch pipe connected to the circulating material silo and merging into the second flue gas duct.

[0009] Furthermore, a desulfurizer feeder and a desulfurizer bin Roots blower are also installed on the branch pipe connected to the desulfurizer bin and merging into the second flue gas duct.

[0010] Furthermore, it also includes a coke powder bin, and the outlet of the precooler and / or the primary dust collector is connected to the coke powder bin through a bin pump and a branch pipeline.

[0011] Furthermore, a silo pump is installed on the branch pipeline connecting the secondary dust collector to the feeding port of the circulating silo.

[0012] Furthermore, it also includes an induced draft fan connected to the secondary dust collector to discharge the secondary treated gas.

[0013] The beneficial effects of the utility model are as follows: the utility model diverts the dry quenching furnace flue gas through the first flue gas duct and the second flue gas duct, realizes the separation and treatment of high-sulfur and low-sulfur flue gases, treats the vented gas and coke exhaust gas with higher sulfur content once, and then merges with the coke loading gas with lower sulfur content for a second treatment, thereby improving the effective capture rate of sulfur dioxide in the flue gas by the desulfurizer, and at the same time, reusing the incompletely reacted desulfurizer for a second time, thereby maximizing the utilization rate of the desulfurizer, effectively improving the desulfurization efficiency and reducing the amount of the desulfurizer used. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of a coke dry quenching furnace flue gas cascade desulfurization system in an embodiment of the utility model;

[0015] Among them: 1. Circulating silo; 2. Circulating silo feed valve; 3. Desulfurizer silo; 4. Desulfurizer ash silo feed valve; 5. Desulfurizer ash silo; 6. Circulating material feeder; 7. Roots blower for circulating silo; 8. Desulfurizer feeder; 9. Roots blower for desulfurizer silo; 10. Precooler; 11. Coke powder silo; 12. Primary dust collector; 13. Silo pump; 14. Secondary dust collector; 15. Induced draft fan; 16. First flue gas duct; 17. Second flue gas duct. DETAILED DESCRIPTION

[0016] The coke dry quenching furnace flue gas cascade desulfurization system provided in this embodiment is as follows: Figure 1 As shown, it consists of a circulating material bin 1, a circulating material bin feed valve 2, a desulfurizer bin 3, a desulfurizer ash bin feed valve 4, a desulfurizer ash bin 5, a circulating material feeder 6, a circulating material bin Roots blower 7, a desulfurizer feeder 8, a desulfurizer bin Roots blower 9, a precooler 10, a coke powder bin 11, a primary dust collector 12, a secondary dust collector 14, an induced draft fan 15, a first flue gas duct 16, a second flue gas duct 17, a plurality of bin pumps 13 and a plurality of branch pipes.

[0017] Specifically, in this embodiment, the flue gas of the coke dry quenching furnace includes coke-loading gas, venting gas and exhaust gas, wherein the venting gas and exhaust gas with relatively high sulfur content are provided by the first flue gas duct 16, and the coke-loading gas with relatively low sulfur content is provided by the second flue gas duct 17. The first flue gas duct 16 is connected to the precooler 10 and the primary dust collector 12 in sequence, and the second flue gas duct 17 is connected to the secondary dust collector 14. The outlet of the primary dust collector 12 is connected to the second flue gas duct 17 through a branch pipeline. The secondary dust collector 14 is also connected to the feed port of the circulating silo 1 through a silo pump 13 and a branch pipeline. The feed port of the circulating silo 1 is equipped with a circulating silo feed valve 2. At the same time, the discharge port of the circulating silo 1 is connected to the second flue gas duct 17 through the circulating material feeder 6, the circulating silo Roots blower 7 and the branch pipeline, and the outlet of the desulfurizer silo 3 is also connected to the second flue gas duct 17 through the desulfurizer feeder 8, the desulfurizer silo Roots blower 9 and the branch pipeline.

[0018] The desulfurization ash bin 5 in this embodiment is equipped with a desulfurization ash bin feed valve 4, which is connected to the branch pipe from the secondary dust collector 14 to the feed port of the circulating silo 1. The desulfurization ash produced after treatment by the secondary dust collector 14 can be transported to the circulating silo 1 and the desulfurization ash bin 5 via the bin pump 13 and the branch pipe. When it is detected that the desulfurization ash has effective unreacted components, the circulating silo feed valve 2 is opened. When there are no effective unreacted components, the desulfurization ash bin feed valve 4 is opened to enter the desulfurization ash bin 5 for external discharge.

[0019] In this embodiment, qualified flue gas processed by the primary dust collector 12 and the secondary dust collector 14 in sequence is discharged along with the induced draft fan 15 connected to the secondary dust collector 14, and the bottom of the primary dust collector 12 and the precooler 10 are connected to the coke powder bin 11 through their own bin pumps 13 and branch pipes.

[0020] It should be noted that when the present embodiment is in operation, the coke gas and the vented gas from the dry quenching furnace are collectively connected to the precooler 10 to prevent the high-temperature gas from affecting the primary dust collector 12. At the same time, the settled dust in the precooler 10 is transported to the coke powder bin 11 through the bin pump 13, and the mixed gas after cooling enters the primary dust collector 12. The primary dust collector 12 uses a filter bag to filter the dust, and the filtered coke powder is transported to the coke powder bin 11 through the bin pump 13; the circulating material in the circulating material bin 1 passes through the circulating material feeder 6, and is transported to the coke gas flue gas duct (i.e., the second flue gas duct 17) through the circulating material silo Roots blower 7 to pre-react with the coke gas. The pre-reacted coke gas is mixed with the exhaust gas and the vented gas after the primary dust removal. The desulfurizer in the desulfurizer bin 3 passes through the desulfurizer feeder 8, The desulfurization ash is transported to the mixed flue gas duct (i.e., the second flue gas duct 17) through the Roots blower 9 in the desulfurizer bin for sufficient reaction. The mixed flue gas enters the secondary dust collector 14. After the desulfurizer mixture is partially reacted, the desulfurized ash forms a powder layer on the surface of the filter bag and continues to contact with the flue gas to further improve the desulfurization reaction efficiency. The desulfurization reactants are sprayed through the bag and partially fall into the ash hopper of the dust collector. They are transported to the circulating silo 1 and the desulfurized ash silo 5 through the silo pump 13. By tracking and testing the effective unreacted components in the desulfurized ash, if it can still be used, it is transported to the circulating silo 1 through the circulating silo feed valve 2. At this time, the desulfurized ash feed valve 4 is closed. Otherwise, it is transported to the desulfurized ash silo 5 through the desulfurized ash feed valve 4 for external discharge. After the flue gas is processed by the secondary dust collector 14, it is discharged to the chimney through the induced draft fan 15.

[0021] In this embodiment, highly active calcium hydroxide is selected as the desulfurizer according to the temperature range. The key technical indicators of the desulfurizer are as follows: Ca(OH)2 content ≥85%, water content ≤2wt%, particle size distribution (325 mesh sieving rate) ≥85%, bulk density 0.40-0.65g / mL, BET specific surface area ≥40m 2 / g.

[0022] Table 1 Comparison of data between conventional direct injection method and this embodiment

[0023]

[0024] Refer to Table 1 above, the actual calcium-sulfur ratio of the flue gas without diversion treatment and direct injection of desulfurizer is 2.4-2.6, and the reaction efficiency is about 45%. After the flue gas diversion treatment of the utility model, the unreacted desulfurizer is recycled at the same time, the outlet emission is stable, the calcium-sulfur ratio can be effectively increased to about 1.4, the reaction efficiency is about 86%, and the desulfurizer usage is reduced by about 40%.

[0025] In addition to the above embodiments, the present invention may also have other implementation modes; any technical solutions formed by equivalent replacement or equivalent transformation shall fall within the protection scope required by the present invention.

Claims

1. A coke dry quenching furnace flue gas cascade desulfurization system, characterized in that: The invention comprises a circulating silo (1), a desulfurizing agent silo (3), a precooler (10), a primary dust collector (12), a secondary dust collector (14), a first flue gas duct (16) for providing exhaust gas and exhaust coke gas, and a second flue gas duct (17) for providing coke gas, wherein the first flue gas duct (16) is connected to the precooler (10) and the primary dust collector (12) in sequence, so as to precool the exhaust gas and exhaust coke gas in the first flue gas duct (16) and then transport them to the primary dust collector (12), the second flue gas duct (17) is connected to the secondary dust collector (14), wherein the outlets of the primary dust collector (12) and the desulfurizing agent silo (3) are respectively connected to the second flue gas duct (17) through branch pipes, the secondary dust collector (14) is connected to the feed port of the circulating silo (1) through a branch pipe, and the discharge port of the circulating silo (1) is connected to the second flue gas duct (17) through a branch pipe.

2. The coke dry quenching furnace flue gas cascade desulfurization system according to claim 1 is characterized in that: It also includes a desulfurization ash bin (5) equipped with a desulfurization ash bin feed valve (4), wherein the desulfurization ash bin feed valve (4) is connected to the outlet of the secondary dust collector (14) via a branch pipeline, and / or is connected to the branch pipeline from the secondary dust collector (14) to the feed port of the circulation silo (1).

3. The coke dry quenching furnace flue gas cascade desulfurization system according to claim 1 is characterized in that: The secondary dust collector (14) is connected to the feed port of the circulating silo (1) via a branch pipeline and a circulating silo feed valve (2).

4. The coke dry quenching furnace flue gas cascade desulfurization system according to claim 1, characterized in that: A circulating material feeder (6) and a circulating material silo Roots blower (7) are also installed on the branch pipe connected to the circulating material silo (1) and merging into the second flue gas pipe (17).

5. The coke dry quenching furnace flue gas cascade desulfurization system according to claim 1, characterized in that: A desulfurizer feeder (8) and a desulfurizer bin Roots blower (9) are also installed on the branch pipe of the desulfurizer bin (3) that is connected to the second flue gas pipe (17).

6. The coke dry quenching furnace flue gas cascade desulfurization system according to claim 1, characterized in that: It also includes a coke powder bin (11), and the outlet of the precooler (10) and / or the primary dust collector (12) is connected to the coke powder bin (11) via a bin pump (13) and a branch pipeline.

7. The coke dry quenching furnace flue gas cascade desulfurization system according to claim 1, characterized in that: A silo pump (13) is installed on the branch pipeline connecting the secondary dust collector (14) to the feed port of the circulating silo (1).

8. The coke dry quenching furnace flue gas cascade desulfurization system according to claim 1, characterized in that: It also includes an induced draft fan (15) connected to the secondary dust collector (14) to discharge the secondary treated gas.

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