Desulfurization waste liquid recovery system

Abstract

The utility model provides a desulfurization waste liquid recovery system which comprises a spray tower, a sulfur sealing tank, a buffer tank and a separator, the spray tower is connected with a front unit, sulfur-containing desorption gas from the front unit is subjected to gas-liquid separation in the spray tower, the sulfur sealing tank is connected with the spray tower, the buffer tank is connected with the sulfur sealing tank, and the separator is connected with the buffer tank. By arranging the spray tower, the sulfur sealing tank, the buffer tank and the separator, sulfur in the sulfur-containing waste liquid can be recovered, so that the technical problems that a large amount of sulfur-containing waste water is generated in the process of purifying blast furnace gas and preparing sulfur, the treatment difficulty is high, and certain environmental protection pressure is caused are solved.

Description

Technical Field

[0001] The utility model relates to the technical fields of metallurgical gas purification technology and environmental protection, and in particular to a desulfurization waste liquid recovery system. Background Art

[0002] According to relevant technologies, sulfur in blast furnaces is primarily introduced by the charge material, which primarily consists of iron ore, fuel, and a small amount of solvent. Coke accounts for 78% of the sulfur introduced into the blast furnace, while pulverized coal accounts for 14%, for a combined 92%. The vast majority of this sulfur introduced by the charge material is absorbed by the slag and carried out of the blast furnace, accounting for approximately 79%. Blast furnace gas carries out 15% of the sulfur, while molten iron carries out 6%. Hot blast furnaces and heating furnaces are the primary users of blast furnace gas, but excessive sulfur content in their exhaust gases is a major environmental concern. Exhaust gas emissions from hot blast furnaces have been tested, revealing sulfur dioxide levels ranging from 71.8 mg / m³ to 149 mg / m³. The SO2 concentration in the exhaust flue gas falls far short of the ultra-low emission requirement of less than 50 mg / m³ as stipulated in the "Opinions on Promoting the Implementation of Ultra-Low Emissions in the Steel Industry" (Environmental Atmosphere

[2019] No. 35).

[0003] The sulfur components in blast furnace gas primarily include organic sulfur and inorganic sulfur. Inorganic sulfur primarily consists of H₂S and a small amount of SO₂; organic sulfur primarily consists of COS and CS₂, with smaller amounts of methyl mercaptan and thiophene. Organic sulfur accounts for approximately 75%-80% of the total sulfur content, while inorganic sulfur accounts for 20%-25%. The blast furnace gas fine desulfurization process primarily removes COS and H₂S from blast furnace gas.

[0004] After passing through a hydrolysis tower, COS in blast furnace gas is converted to H2S under the action of a catalyst. The gas then enters a desulfurization tower, where an iron oxide desulfurizer absorbs the H2S and oxidizes it into sulfur. The clean blast furnace gas is then delivered to users such as hot blast furnaces. The iron oxide desulfurizer can be used repeatedly through steam desulfurization, and the sulfur-containing desulfurized gas can be used to produce sulfur for sale. When the iron oxide desulfurizer's oxidizing capacity decreases, the iron oxide can be replaced and directly delivered to the sintering plant for use as feedstock. The absorbed sulfur is ultimately converted to SO2 after sintering and combustion, and then removed in the final desulfurization system following the combustion unit.

[0005] Currently, the process of purifying blast furnace gas and producing sulfur produces a large amount of sulfur-containing wastewater, which is difficult to treat and poses a certain environmental pressure. Therefore, providing a technical solution to this problem is an urgent problem that those skilled in the art need to solve. Utility Model Content

[0006] The embodiment of the utility model provides a desulfurization waste liquid recovery system, which can improve the technical problem that a large amount of sulfur-containing wastewater is generated during the purification of blast furnace gas and the production of sulfur, and the treatment is relatively difficult, causing certain environmental pressures.

[0007] The embodiment of the utility model provides a desulfurization waste liquid recovery system, comprising:

[0008] A spray tower, the spray tower is connected to the pre-unit, and the sulfur-containing analytical gas from the pre-unit completes gas-liquid separation in the spray tower;

[0009] a sulfur sealing tank connected to the spray tower;

[0010] a buffer tank connected to the sulfur sealing tank;

[0011] A separator is connected to the buffer tank.

[0012] In one embodiment, the desulfurization waste liquid recovery system further includes a cooling device, and the cooling device includes a water inlet and a water outlet, the water inlet is connected to the buffer tank, and the water outlet is connected to the spray tower.

[0013] In one embodiment, the water inlet is also connected to the separator.

[0014] In one embodiment, a first water pump and a first control valve are further provided between the sulfur sealing tank and the buffer tank.

[0015] In one embodiment, a second water pump and a second control valve are further provided between the buffer tank and the separator.

[0016] In one embodiment, a third water pump and a third control valve are further provided between the cooling device and the spray tower.

[0017] In one embodiment, the pre-unit includes at least two oxidation towers, and the oxidation tower includes a first port and a second port, the first port is connected to a first pipeline and a second pipeline, the first pipeline is connected to an external conveying structure, and the second pipeline is connected to the spray tower; the second port is connected to a third pipeline and a fourth pipeline, the third pipeline is connected to the regeneration gas, and the fourth pipeline is connected to the downstream user; control valves are respectively provided on the first pipeline, the second pipeline, the third pipeline and the fourth pipeline.

[0018] In one embodiment, a stop valve is provided between the separator and the water inlet.

[0019] In one embodiment, the desulfurization waste liquid recovery system further includes a baler, the baler is connected to the separator, and a gate valve is provided between the baler and the separator.

[0020] Beneficial effects of the embodiments of the present utility model:

[0021] In the embodiments of the present invention, by setting up a spray tower, a sulfur sealing tank, a buffer tank and a separator, the sulfur in the sulfur-containing waste liquid can be recovered, thereby improving the technical problem that a large amount of sulfur-containing waste water is generated during the purification of blast furnace gas and the production of sulfur, which is difficult to treat and causes certain environmental pressures. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 This is a schematic structural diagram of a first desulfurization waste liquid recovery system provided by an embodiment of the present utility model;

[0024] Figure 2 This is a schematic flow chart of a second desulfurization waste liquid recovery system provided by an embodiment of the present utility model;

[0025] Figure 3 This is a schematic diagram of the simplified structure of a second desulfurization waste liquid recovery system provided by an embodiment of the present utility model.

[0026] Explanation of the reference numerals: pre-unit A, spray tower 1, sulfur sealing tank 2, buffer tank 3, separator 4, cooling device 5, water inlet 5a, water outlet 5b, first water pump b1, first control valve c1, second water pump b2, second control valve c2, third water pump b3, third control valve c3, oxidation tower 6, first port 6a, second port 6b, first pipeline g1, second pipeline g2, third pipeline g3, fourth pipeline g4, stop valve c4, gate valve c5, baler 7. DETAILED DESCRIPTION

[0027] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention. In the present invention, unless otherwise specified, the directional words used, such as "upper" and "lower", generally refer to the upper and lower parts of the device in actual use or working state, specifically the drawing direction in the accompanying drawings; while "inside" and "outside" refer to the outline of the device.

[0028] See also Figure 1 The present invention provides a desulfurization waste liquid recovery system, comprising a spray tower 1, a sulfur seal tank 2, a buffer tank, and a separator 4. The spray tower 1 is connected to a pre-unit A, and the sulfur-containing desorption gas from the pre-unit A undergoes gas-liquid separation within the spray tower 1. The sulfur seal tank 2 is connected to the spray tower 1, the buffer tank 3 is connected to the sulfur seal tank 2, and the separator 4 is connected to the buffer tank.

[0029] The working principle of this embodiment is that the sulfur-containing waste liquid enters the spray tower 1 to complete gas-liquid separation, the gas flows upward to the downstream user, and the liquid portion enters the sulfur sealing tank 2. The sulfur sealing tank 2 needs to be supplemented with a certain amount of water to prevent sulfur precipitation in the sulfur sealing tank 2. The liquid then enters the buffer tank 3. The liquid in the buffer tank 3 then flows to the separator 4 for pressure filtration to achieve solid-liquid separation. The solid sulfur will be packaged and exported.

[0030] In the embodiment of the present utility model, by providing a spray tower 1, a sulfur sealing tank 2, a buffer tank 3 and a separator 4, it is possible to recover sulfur in the sulfur-containing waste liquid, thereby improving the technical problem that a large amount of sulfur-containing waste water is generated during the purification of blast furnace gas and the production of sulfur, which is difficult to treat and causes certain environmental pressures.

[0031] See also Figure 2 and Figure 3 It should be noted that the pre-unit A can be at least two oxidation towers 6, the oxidation tower 6 includes a first port 6a and a second port 6b, the first port 6a is connected to the first pipeline g1 and the second pipeline g2, the first pipeline g1 is connected to the external conveying structure, and the second pipeline g2 is connected to the spray tower 1; the second port 6b is connected to the third pipeline g3 and the fourth pipeline g4, the third pipeline g3 is connected to the regeneration gas, and the fourth pipeline g4 is connected to the downstream user; control valves are respectively provided on the first pipeline g1, the second pipeline g2, the third pipeline g3 and the fourth pipeline g4.

[0032] The pre-processing unit A may also include a pretreatment unit. This unit converts carbonyl sulfide (COS) in blast furnace gas into hydrogen sulfide through catalytic hydrolysis, generating sulfur-containing desorption gas. During the desorption process, the sulfur-containing desorption gas enters one of the oxidation towers 6 via a first pipeline g1. Oxidation tower 6 is filled with iron oxide as an oxidant for hydrogen sulfide oxidation. The sulfur-containing desorption gas enters oxidation tower 6 for oxidation and adsorption desulfurization. The desulfurized desorption gas is transported to downstream users via a fourth pipeline g4. During the adsorption process, regeneration gas, consisting of steam and hot nitrogen, is introduced into the other oxidation tower 6 via a third pipeline g3. The regeneration gas is then transferred to the spray tower 1 via a second pipeline g2. It is understood that the desorption and adsorption processes can be performed simultaneously in the two oxidation towers 6. That is, while the adsorption process is being performed in one oxidation tower 6, the desorption process can be performed in the other. Control valves can be used to control the desorption and adsorption processes in the two oxidation towers 6 to run simultaneously. Each oxidation tower 6 has a diameter of 2 meters and a height of 10 meters.

[0033] The desorption and adsorption processes are continuous. Within each adsorption and desorption unit, one oxidation tower 6 is always operating for adsorption while the other is desorbing, without any pauses. To ensure unobstructed gas flow, all valves on corresponding pipelines in the corresponding operating phases are in their respective open states. For ease of description, these valves are opened according to the steps or processes, and should not be construed as limiting the use of the present invention.

[0034] See also Figure 2 In one embodiment, a desulfurization waste liquid recovery system further includes a cooling device 5, which includes a water inlet 5a and a water outlet 5b. The water inlet 5a is connected to the buffer tank 3, and the water outlet 5b is connected to the spray tower 1. A third pump b3 and a third control valve c3 are also provided between the cooling device 5 and the spray tower 1.

[0035] It should be noted that the sulfur-containing waste liquid enters the spray tower 1 and is then separated from the gas and liquid before being discharged to downstream users. The sulfur-containing waste liquid is actually in a gaseous state, and is mainly steam carrying a large amount of sulfur, namely, sulfur-containing desorption gas. The gas-liquid separation is completed in the spray tower 1, that is, the desulfurization is completed again, and the clean desorption gas returns to the user system. It should be noted that in the spray tower 1, the sulfur-containing desorption gas ascends, and the acid liquid or water cooled by the cooling device 5 descends. This ascending steam is in full contact with the descending water, which is equivalent to fully washing the sulfur-containing steam, that is, the desulfurization of the desorption gas is completed again, allowing as much sulfur as possible to enter the utilization system. The cooling device 5 can be a cooling tower. The third water pump b3 pumps the liquid in the buffer tank 3 to the cooling device 5 to ensure the normal liquid flow between the buffer tank 3 and the cooling device 5. The third control valve c3 controls the opening and closing of the liquid flow between the buffer tank 3 and the cooling device 5. It is understandable that sulfur will be partially deposited in the buffer tank 3. Therefore, the third water pump b3 can also increase the sulfur concentration in the buffer tank 3, so that the liquid flowing to the separator 4 contains a higher concentration of sulfur, thereby improving the separation efficiency of the separator 4.

[0036] See also Figure 2 In one embodiment, the water inlet 5a is also connected to the separator 4.

[0037] It can be understood that the separator 4 realizes solid-liquid separation through pressure filtration. The water inlet 5a is connected to the separator 4 so that the acidic water after pressure filtration can be redistributed to the cooling tower through the pipeline. On the one hand, it avoids the discharge of acidic water and causes environmental pressure. On the other hand, the sulfur concentration of the acidic water after pressure filtration is low. The acidic water after cooling can achieve more thorough washing of the sulfur-containing steam in the spray tower 1, thereby improving the sulfur recovery effect.

[0038] See also Figure 2 In one embodiment, a first water pump b1 and a first control valve c1 are further provided between the sulfur sealing tank 2 and the buffer tank 3 .

[0039] The first pumping pump b1 pumps the liquid in the sulfur sealing tank 2 to the buffer tank 3 to ensure normal liquid flow between the buffer tank 3 and the sulfur sealing tank 2. The first control valve c1 controls the opening and closing of the liquid flow between the sulfur sealing tank 2 and the buffer tank 3.

[0040] See also Figure 2 In one embodiment, a second water pump b2 and a second control valve c2 are further provided between the buffer tank 3 and the separator 4 .

[0041] The second water pump b2 pumps the liquid in the buffer tank 3 to the separator 4 to ensure normal liquid flow between the buffer tank 3 and the separator 4. The second control valve c2 controls the opening and closing of the liquid flow between the buffer tank 3 and the separator 4.

[0042] See also Figure 2In one embodiment, a stop valve c4 is provided between the separator 4 and the water inlet 5a.

[0043] The stop valve c4 controls the flow of liquid between the separator 4 and the water inlet 5a.

[0044] See also Figure 2 In one embodiment, a desulfurization waste liquid recovery system further includes a baler 7 connected to a separator 4, with a gate valve c5 disposed between the baler 7 and the separator 4. Solid sulfur is fed into the baler 7 through the gate valve c5 for packaging and export.

[0045] The desulfurization waste liquid recovery system of the utility model successfully realizes the recycling of acidic water in the blast furnace gas purification process, which not only solves the difficult problem of acidic water treatment and realizes continuous purification and industrial application, but also constructs a new environmentally friendly, efficient and clean blast furnace gas purification process with good economic, social and environmental benefits.

[0046] The above is a detailed introduction to the embodiments of the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, based on the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the contents of this specification should not be understood as limiting the present invention.

Claims

1. Desulfurization waste liquid recovery system, characterized in that: include: A spray tower, the spray tower is connected to the pre-unit, and the sulfur-containing analytical gas from the pre-unit completes gas-liquid separation in the spray tower; a sulfur sealing tank connected to the spray tower; a buffer tank connected to the sulfur sealing tank; A separator is connected to the buffer tank.

2. The desulfurization waste liquid recovery system according to claim 1, characterized in that: The desulfurization waste liquid recovery system further includes a cooling device, which includes a water inlet and a water outlet. The water inlet is connected to the buffer tank, and the water outlet is connected to the spray tower.

3. The desulfurization waste liquid recovery system according to claim 2, characterized in that: The water inlet is also connected to the separator.

4. The desulfurization waste liquid recovery system according to claim 1, characterized in that: A first water pump and a first control valve are further provided between the sulfur sealing tank and the buffer tank.

5. The desulfurization waste liquid recovery system according to any one of claims 1 to 4, characterized in that: A second water pump and a second control valve are further provided between the buffer tank and the separator.

6. The desulfurization waste liquid recovery system according to claim 2, characterized in that: A third water pump and a third control valve are further provided between the cooling device and the spray tower.

7. The desulfurization waste liquid recovery system according to claim 1, characterized in that: The pre-unit includes at least two oxidation towers, and the oxidation tower includes a first port and a second port, the first port is connected to a first pipeline and a second pipeline, the first pipeline is connected to an external conveying structure, and the second pipeline is connected to the spray tower; the second port is connected to a third pipeline and a fourth pipeline, the third pipeline is connected to the regeneration gas, and the fourth pipeline is connected to the downstream user; control valves are respectively provided on the first pipeline, the second pipeline, the third pipeline and the fourth pipeline.

8. The desulfurization waste liquid recovery system according to claim 3, characterized in that: A stop valve is provided between the separator and the water inlet.

9. The desulfurization waste liquid recovery system according to claim 1, characterized in that: The desulfurization waste liquid recovery system further includes a baler, which is connected to the separator, and a gate valve is provided between the baler and the separator.

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