A device for treating smelting flue gas purification waste acid

Abstract

The utility model relates to a kind of smelting flue gas purification waste acid treatment device, purpose is to solve overflow weir and its pipeline frequent acid mud blockage, uneven liquid distribution technical problem.Technical scheme is as follows:it includes inclined plate settling tank filter press, 2# filtrate storage tank, gas cooling tower filter press, inclined plate settling tank is connected with inclined plate settling tank filter press, inclined plate settling tank filter press is connected with 2# filtrate storage tank, 2# filtrate storage tank is connected high-level tank, high-level tank is connected overflow weir, gas cooling tower filter press is located in gas cooling tower side, gas cooling tower is connected to cooling tower filter press, cooling tower filter press is connected 2# filtrate storage tank by 2# three-way valve one end, and other end is connected gas cooling tower, cooling tower filter press is connected bin, 1# three-way valve is arranged between inclined plate settling tank and inclined plate settling tank filter press, 1# three-way valve third mouth is connected gas cooling tower filter press.The utility model can keep overflow weir pipeline smooth liquid uniform, improve gas cooling tower cooling effect, prevent metal loss.

Description

Technical Field

[0001] This utility model belongs to the field of flue gas purification technology, specifically relating to a waste acid treatment device for smelting flue gas purification. Background Technology

[0002] In the process of producing sulfuric acid from smelting flue gas, the purification process often employs a dilute acid scrubbing technique. Flue gas from the electrostatic precipitator system sequentially passes through a primary power wave, a gas cooling tower, and a secondary power wave to achieve purification and temperature reduction. Part of the circulating acid from the primary power wave enters the SO2 desorption tower. The desorbed liquid enters the inclined plate settling tank, and the underflow is periodically pumped into a filter press. The filter press residue is returned to the silo, while the filtrate and the overflow from the inclined plate settling tank flow together into the filtrate storage tank. Part of this filtrate is pumped into the waste acid treatment system, and the rest is pumped to a high-level tank flowing towards the overflow weir system. The gas cooling tower is equipped with a plate heat exchanger, using cooling water to indirectly exchange heat with the circulating acid and remove heat from the system.

[0003] In actual production, the unstable operation of the electrostatic precipitator leads to a high content of soot in the flue gas, an increase in the content of heavy metal sludge in the primary power wave circulating acid solution, and poor performance of the inclined plate settling tank. This results in turbid acid solution being transported to the overflow weir system in the high-level tank, causing frequent blockage of the overflow weir and its pipes by sludge, uneven liquid distribution, and ultimately, high-temperature burnout and leakage of the FRP flue. Simultaneously, the increase in sludge in the circulating liquid of the gas cooling tower causes blockage of the acid distributor, packing, and plate heat exchanger channels within the tower, affecting the flue gas cooling effect and thus impacting the acid balance in the dry absorption process. Furthermore, the increase in sludge on the acid side of the plate heat exchanger, coupled with scaling due to high hardness on the water side, blocks the heat exchange channels, increasing the frequency of heat exchanger cleaning, which is time-consuming, labor-intensive, and impacts production. Moreover, the high-hardness circulating water often needs to be replaced with fresh water to reduce its hardness, wasting water resources. Utility Model Content

[0004] The purpose of this invention is to solve the above-mentioned technical problems and provide a device for purifying smelting flue gas and treating waste acid.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0006] A waste acid treatment device for smelting flue gas purification includes a secondary power wave, a gas cooling tower, a primary power wave, a dilute acid desorption tower, an inclined plate settling tank, a filtrate storage tank, and a waste acid and wastewater treatment process. The outlet of the secondary power wave is connected to the inlet of the gas cooling tower, the outlet of the gas cooling tower is connected to the inlet of the primary power wave, the outlet of the primary power wave is connected to the inlet of the dilute acid desorption tower, the outlet of the dilute acid desorption tower is connected to the inlet of the inclined plate settling tank, the overflow port of the inclined plate settling tank is connected to the inlet of the filtrate storage tank, and the outlet of the filtrate storage tank is connected to the inlet of the waste acid and wastewater treatment process.

[0007] It also includes an inclined plate settling tank filter press, a No. 2 filtrate storage tank, a gas cooling tower filter press, a No. 1 three-way valve, and a No. 2 three-way valve. The outlet of the inclined plate settling tank is connected to the inlet of the inclined plate settling tank filter press. The outlet of the inclined plate settling tank filter press is connected to the inlet of the No. 2 filtrate storage tank. The outlet of the No. 2 filtrate storage tank is connected to the inlet of the high-level tank via a transfer pump. The outlet of the high-level tank is connected to the inlet of the overflow weir. The gas cooling tower filter press is located next to the gas cooling tower. The bottom of the gas cooling tower is connected to the inlet of the cooling tower filter press via a mud pump. The filtrate outlet of the cooling tower filter press is connected to the inlet of the No. 2 filtrate storage tank at one end and to the inlet of the gas cooling tower at the other end via the No. 2 three-way valve. The filter residue outlet of the cooling tower filter press is connected to the silo. The No. 1 three-way valve is located on the pipeline between the inclined plate settling tank and the inclined plate settling tank filter press. The third port of the No. 1 three-way valve is connected to the inlet of the gas cooling tower filter press.

[0008] Furthermore, it also includes a plate heat exchanger and a circulating water hardening device, wherein the heat exchange interface of the plate heat exchanger is connected to the heat exchange port of the gas cooling tower, and the circulating water hardening device is connected to the water-side circulating water port of the plate heat exchanger.

[0009] Compared with the prior art, the beneficial effects of this utility model are:

[0010] 1. This utility model has the advantages of keeping the overflow weir pipe unobstructed and the liquid distribution uniform, improving the cooling effect of the gas cooling tower, preventing metal loss, and saving water resources;

[0011] 2. In this utility model, the overflow liquid of the inclined plate settling tank and the liquid output of the filter press are stored separately. The clear liquid from the filter press is used for the overflow weir of the high-level tank, which ensures that the liquid distribution of the overflow weir is smooth and uniform, and protects the flue pipe wall.

[0012] 3. The gas cooling tower filter press of this utility model is added next to the gas cooling tower, which not only avoids the acid sludge from clogging the acid separator, packing and plate heat exchanger channels in the tower and improves the flue gas cooling effect, but also the filter residue return bin of the filter press effectively prevents the loss of metal in the residue.

[0013] 4. The plate heat exchanger of this utility model is equipped with a hardness removal device for circulating cooling water, which effectively avoids water-side blockage caused by scaling. This not only enhances the heat exchange effect and reduces the flue gas temperature, but also saves a lot of fresh water.

[0014] 5. The gas cooling tower filter press of this utility model can be used as a backup filter press for the inclined plate settling tank. It can continuously separate the solid and liquid of the sludge at the bottom of the inclined plate settling tank, greatly reduce the mud content of the original filtrate storage tank, and fully recover non-ferrous metals such as copper, gold and silver.

[0015] 6. The liquid output from the gas cooling tower filter press of this utility model can be used as the backup liquid for the No. 2 filtrate storage tank, which can ensure that the liquid in the No. 2 filtrate storage tank is always clean and sufficient and supplied to the overflow weir system, so that the overflow weir maintains uniform liquid distribution. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of this utility model;

[0017] In the diagram: 1-Secondary dynamic wave; 2-Gas cooling tower; 3-Primary dynamic wave; 4-Dilute acid desorption tower; 5-Inclined plate settling tank; 6-Filtrate storage tank; 7-Sewage and acid treatment process; 8-Inclined plate settling tank filter press; 9-2# Filtrate storage tank; 10-High-level tank; 11-Overflow weir; 12-Gas cooling tower filter press; 13-Plate heat exchanger; 14-Circulating water hardening device; 15-1# Three-way valve; 16-2# Three-way valve. Detailed Implementation

[0018] The present invention will be further described below with reference to the embodiments and accompanying drawings.

[0019] like Figure 1 As shown, a smelting flue gas purification and waste acid treatment device includes a secondary power wave 1, a gas cooling tower 2, a primary power wave 3, a dilute acid desorption tower 4, an inclined plate settling tank 5, a filtrate storage tank 6, and a waste acid and wastewater treatment process 7. The outlet of the secondary power wave 1 is connected to the inlet of the gas cooling tower 2, the outlet of the gas cooling tower 2 is connected to the inlet of the primary power wave 3, the outlet of the primary power wave 3 is connected to the inlet of the dilute acid desorption tower 4, the outlet of the dilute acid desorption tower 4 is connected to the inlet of the inclined plate settling tank 5, the overflow port of the inclined plate settling tank 5 is connected to the inlet of the filtrate storage tank 6, and the outlet of the filtrate storage tank 6 is connected to the inlet of the waste acid and wastewater treatment process 7.

[0020] It also includes an inclined plate settling tank filter press 8, a No. 2 filtrate storage tank 9, a gas cooling tower filter press 12, a No. 1 three-way valve 15, a No. 2 three-way valve 16, a plate heat exchanger 13, and a circulating water hardening device 14. The outlet of the inclined plate settling tank 5 is connected to the inlet of the inclined plate settling tank filter press 8. The overflow liquid of the inclined plate settling tank 5 and the effluent of the inclined plate settling tank filter press 8 are stored separately. The clear liquid from the filter press is used for the overflow weir of the high-level tank, ensuring smooth and uniform liquid distribution of the overflow weir and protecting the flue pipe wall. The outlet of the inclined plate settling tank filter press 8 is connected to the inlet of the No. 2 filtrate storage tank 9. The outlet of the No. 2 filtrate storage tank 9 is connected to the inlet of the high-level tank 10 through a transfer pump. The outlet of the high-level tank 10 is connected to the inlet of the overflow weir 11. The gas cooling tower filter press 12 is located next to the gas cooling tower 2. The bottom of tower 2 is connected to the inlet of cooling tower filter press 12 via a mud pump. The filtrate outlet of cooling tower filter press 12 is connected to the inlet of filtrate storage tank 9 via a 2# three-way valve 16 at one end and to the inlet of gas cooling tower 2 at the other end. The filter residue outlet of cooling tower filter press 12 is connected to a silo. A 1# three-way valve 15 is installed on the pipeline between inclined plate settling tank 5 and inclined plate settling tank filter press 8. The third port of the 1# three-way valve 15 is connected to the inlet of gas cooling tower filter press 12. The heat exchange interface of plate heat exchanger 13 is connected to the heat exchange port of gas cooling tower 2. The circulating water hardening device 14 is connected to the water-side circulating water port of plate heat exchanger 13, which effectively avoids water-side blockage caused by scaling, not only enhancing the heat exchange effect and reducing the flue gas temperature, but also saving a lot of fresh water.

[0021] The experimental data obtained from the small-scale test in this embodiment are compared with those of traditional processes and existing advanced processes as follows:

[0022]

[0023] The experimental results show that this invention is significantly superior to existing technologies in terms of anti-clogging performance (overflow weir, acid separator), resource recovery rate (metal, water resources) and energy consumption control (water consumption, electricity consumption). In particular, the integrated design of dynamic switching of dual filter presses and circulating water hardening solves the problem of low system reliability caused by acid sludge blockage, while improving resource utilization.

[0024] When this utility model is in use, the flue gas from the electrostatic precipitator system passes through the secondary power wave 1, gas cooling tower 2, primary power wave 3, dilute acid desorption tower 4, and inclined plate settling tank 5 in sequence. Then, the #1 three-way valve 15 is switched to connect to the inclined plate settling tank filter press 8. The overflow liquid from the inclined plate settling tank 5 enters the original filtrate storage tank 6 and is pumped to the waste acid wastewater process 7 for subsequent treatment. The effluent from the inclined plate settling tank 5 flows into the inclined plate settling tank filter press 8. After being treated by it, the clear liquid from the inclined plate settling tank filter press 8 flows into the #2 filtrate storage tank 9. The liquid in the #2 filtrate storage tank 9 is pumped to the high-level tank 10 and flows to the overflow weir 11 system.

[0025] Meanwhile, the liquid in the gas cooling tower 2 is pumped to the gas cooling tower filter press 12 by the mud pump at the bottom. The liquid output from the gas cooling tower filter press 12 flows back to the gas cooling tower 2 through the No. 2 three-way valve 16. The slag produced by the gas cooling tower filter press 12 contains valuable metals such as copper, gold and silver, and is returned to the silo for reuse in the furnace.

[0026] Since there is less acid sludge in gas cooling tower 2 than in inclined plate settling tank 5, in order to make full use of gas cooling tower filter press 12, when inclined plate settling tank filter press 8 is full, within 3-5 hours of its unloading, switch the #1 three-way valve 15 to connect to gas cooling tower filter press 12. The material from inclined plate settling tank 5 enters gas cooling tower filter press 12 through the #1 three-way valve 15. During this period, gas cooling tower 2 stops feeding. After the inclined plate settling tank filter press 8 finishes unloading, switch the #1 three-way valve 15 back to inclined plate settling tank filter press 8, and gas cooling tower 2 resumes feeding.

[0027] Within 3-5 hours after the inclined plate settling tank filter press 8 stops being full, the No. 2 filtrate storage tank 9 will have no liquid inlet. When there is no liquid in the No. 2 filtrate storage tank 9, the liquid level in the high-level tank 10 may become low, which will affect the liquid distribution of the overflow weir 11. To solve the above problem, the No. 2 three-way valve 16 is switched to connect to the No. 2 filtrate storage tank 9. At this time, the liquid outlet of the gas cooling tower filter press 12 stops flowing back to the gas cooling tower 2, and instead replenishes the No. 2 filtrate storage tank 9 with liquid. After the inclined plate settling tank filter press 8 finishes unloading, the No. 2 three-way valve 16 is switched to connect to the gas cooling tower 2, and the No. 1 three-way valve 15 is switched to connect to the inclined plate settling tank filter press 8 to replenish the No. 2 filtrate storage tank 9 with liquid.

[0028] Additionally, a circulating water hardening device 14 is connected to the water-side circulating water return port of the plate heat exchanger 13 in the gas cooling tower 2, which can reduce the hardness of the circulating water and reduce scaling.

Claims

1. A smelting flue gas purification waste acid treatment device, comprising a secondary power wave (1), a gas cooling tower (2), a primary power wave (3), a dilute acid desorption tower (4), an inclined plate settling tank (5), a filtrate storage tank (6), and a waste acid and wastewater treatment process (7), wherein the outlet of the secondary power wave (1) is connected to the inlet of the gas cooling tower (2), the outlet of the gas cooling tower (2) is connected to the inlet of the primary power wave (3), the outlet of the primary power wave (3) is connected to the inlet of the dilute acid desorption tower (4), the outlet of the dilute acid desorption tower (4) is connected to the inlet of the inclined plate settling tank (5), the overflow port of the inclined plate settling tank (5) is connected to the inlet of the filtrate storage tank (6), and the outlet of the filtrate storage tank (6) is connected to the inlet of the waste acid and wastewater treatment process (7); Its features are, It also includes an inclined plate settling tank filter press (8), a No. 2 filtrate storage tank (9), a gas cooling tower filter press (12), a No. 1 three-way valve (15), and a No. 2 three-way valve (16). The outlet of the inclined plate settling tank (5) is connected to the inlet of the inclined plate settling tank filter press (8), and the outlet of the inclined plate settling tank filter press (8) is connected to the inlet of the No. 2 filtrate storage tank (9). The outlet of the No. 2 filtrate storage tank (9) is connected to the inlet of the high-level tank (10) through a transfer pump. The outlet of the high-level tank (10) is connected to the inlet of the overflow weir (11). The gas cooling tower filter press (12) is installed in the gas cooling tower (2). Next to it, the bottom of the gas cooling tower (2) is connected to the inlet of the cooling tower filter press (12) via a mud pump. The filtrate outlet of the cooling tower filter press (12) is connected to the inlet of the filtrate storage tank (9) at one end via a 2# three-way valve (16), and the other end is connected to the inlet of the gas cooling tower (2). The filter residue outlet of the cooling tower filter press (12) is connected to the silo. The 1# three-way valve (15) is installed on the pipeline between the inclined plate settling tank (5) and the inclined plate settling tank filter press (8). The third port of the 1# three-way valve (15) is connected to the inlet of the gas cooling tower filter press (12).

2. The smelting flue gas purification and waste acid treatment device according to claim 1, characterized in that, It also includes a plate heat exchanger (13) and a circulating water hardening device (14), wherein the heat exchange interface of the plate heat exchanger (13) is connected to the heat exchange port of the gas cooling tower (2), and the circulating water hardening device (14) is connected to the water-side circulating water port of the plate heat exchanger (13).

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