High-temperature flue gas treatment system for industrial silicon electric furnace

Abstract

The invention discloses an industrial silicon electric furnace high-temperature flue gas treatment system which comprises an electric furnace flue gas output end, a bag-type dust collector, a wet desulphurization reactor, a wet denitration reactor, a hydrolysis filtering tank and a chimney. The top end and the bottom end of the bag-type dust collector, the top end and the bottom end of the wet desulphurization reactor, the top end and the bottom end of the wet denitration reactor and the top end and the bottom end of the hydrolysis filtering tank are sequentially communicated between the flue gas output end of the electric furnace and the input end of the chimney through gas conveying pipelines; the top end of the wet desulphurization reactor and the top end of the wet denitration reactor are respectively communicated with a desulfurizer supply end and a denitration agent supply end through two supply pipelines, the hydrolysis filtering tank is used for carrying out secondary dust removal, desulfurization and denitration treatment on flue gas, and the top end of the hydrolysis filtering tank is communicated with an external water source through a water supply pipeline; the bottom end of the wet desulphurization reactor, the bottom end of the wet denitration reactor and the bottom end of the hydrolysis filtering tank are connected in parallel through a sewage discharge pipeline and are communicated with a sewage recovery end, and a fourth electromagnetic valve is mounted on the sewage discharge pipeline at the bottom end of the hydrolysis filtering tank.

Description

Technical Field

[0001] The patent of this invention relates to the field of environmental protection, specifically a high-temperature flue gas treatment system for an industrial silicon electric furnace. Background Art

[0002] With the development of China, the market demand for silicone rubber, silicone resin, silicone oil, high-purity semiconductors and formulated alloys is increasing, and industrial silicon (metallic silicon) is an indispensable material in the production of the above products. A large amount of flue gas containing harmful gases will be generated in the production process of modern industrial silicon. With the continuous improvement of global environmental awareness, China has also proposed environmental protection policies for flue gas emissions to industrial silicon manufacturers;

[0003] The existing industrial silicon flue gas emission treatment is generally composed of three parts: desulfurization, denitrification and dust removal. In daily production, general enterprises only carry out desulfurization, denitrification and dust removal on the flue gas once, while some high-quality enterprises will carry out secondary desulfurization, denitrification and dust removal on the flue gas. However, with the continuous improvement of domestic environmental protection requirements, the increased costs caused by secondary desulfurization, denitrification and dust removal treatment are difficult for general enterprises to afford. For this reason, we have developed a low-cost industrial silicon electric furnace high-temperature flue gas treatment system that can perform secondary treatment of industrial silicon flue gas to meet the needs of general enterprises.

[0004] Invention patent content

[0005] The purpose of this patent is to provide an industrial silicon electric furnace high temperature flue gas treatment system to solve the problems raised in the above background technology.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: an industrial silicon electric furnace high-temperature flue gas treatment system, including an electric furnace flue gas output end, a bag filter, a wet desulfurization reactor, a wet denitrification reactor, a hydrolysis filter tank and a chimney, the electric furnace flue gas output end and the chimney input end are connected in sequence through a gas pipeline to the top and bottom of the bag filter, the top and bottom of the wet desulfurization reactor, the top and bottom of the wet denitrification reactor and the top and bottom of the hydrolysis filter tank, the top of the wet desulfurization reactor and the top of the wet denitrification reactor are respectively connected to the desulfurizer supply end and the denitrification agent supply end through two supply pipelines, the hydrolysis filter tank is used for secondary dust removal, desulfurization and denitrification treatment of the flue gas, the top of the hydrolysis filter tank is connected to an external water source through a water supply pipeline, the bottom of the wet desulfurization reactor, the bottom of the wet denitrification reactor and the bottom of the hydrolysis filter tank are connected in parallel through a sewage pipeline, and are connected to the sewage recovery end, and a fourth solenoid valve is installed on the sewage pipeline located at the bottom of the hydrolysis filter tank.

[0007] Furthermore, a thinning rod connected to the gas pipeline is installed at the bottom end of the inner wall of the hydrolysis filter tank. The thinning rod is a hollow structure, and tiny holes are evenly arranged on the outer periphery.

[0008] Furthermore, a pressure gauge for sensing the pressure inside the hydrolysis filtration tank is installed on the outer wall of the hydrolysis filtration tank.

[0009] Furthermore, a stirring tank is installed on the supply pipeline, and the middle part of the hydrolysis and filtration tank is connected in parallel with the top ends of the two stirring tanks through a water pipeline, and a first delivery pump is arranged on the water pipeline.

[0010] Furthermore, a liquid level sensor is installed in the hydrolysis filter tank located above the input end of the water supply pipeline.

[0011] Furthermore, the supply pipeline located at the bottom of the mixing tank is successively installed with a first electric valve and a second delivery pump, the supply pipeline located at the top of the mixing tank is installed with a second solenoid valve, and the water supply pipeline is installed with a third solenoid valve. The pressure gauge, the driving motor of the mixing tank, the first delivery pump, the liquid level sensor, the first electric valve, the second delivery pump, the second solenoid valve, the third solenoid valve and the fourth solenoid valve are all connected to the central control room through signals.

[0012] The beneficial effects achieved by the present invention are:

[0013] 1. By adding a hydrolysis filter tank to the gas pipeline between the wet denitrification reactor and the chimney, the flue gas from the electric furnace can be treated for secondary dust removal, desulfurization and denitrification, thereby realizing and utilizing the most primitive water resources to treat the flue gas, which can effectively reduce the cost of secondary flue gas treatment.

[0014] 2. By adding thinning rods in the hydrolysis filter tank, the contact area between flue gas and water, the release time and the diffusion rate of flue gas in water are increased, thereby improving the secondary dust removal, desulfurization and denitrification effects of the hydrolysis filter tank on flue gas.

[0015] 3. Through the setting of the water delivery pipeline and the first delivery pump, the water after the secondary dust removal, desulfurization and denitrification treatment can be transported to the wet desulfurization reactor and the wet denitrification reactor for primary desulfurization and denitrification treatment, thereby reducing the water cost. At the same time, the setting of the stirring tank can evenly stir the water and the desulfurization / denitrification agent, thereby diluting the desulfurization / denitrification agent to increase the effect of primary desulfurization and denitrification. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of a high-temperature flue gas treatment system for an industrial silicon electric furnace in an embodiment. DETAILED DESCRIPTION

[0017] The present invention is further described below in conjunction with the accompanying drawings.

[0018] like Figure 1As shown, the invention discloses an industrial silicon electric furnace high temperature flue gas treatment system, comprising: an electric furnace flue gas output end, a bag filter 1, a wet desulfurization reactor 2, a wet denitration reactor 3, a hydrolysis filter tank 4 and a chimney, wherein the top and bottom ends of the bag filter 1, the top and bottom ends of the wet desulfurization reactor 2, the top and bottom ends of the wet denitration reactor 3 and the top and bottom ends of the hydrolysis filter tank 4 are connected in sequence between the electric furnace flue gas output end and the chimney input end through a gas transmission pipeline 5, and the top and bottom ends of the wet desulfurization reactor 2 and the wet denitration reactor 3 are connected in sequence. The top of the nitrate reactor 3 is connected to a desulfurizer supply end and a denitrifier supply end through two supply pipelines 6 respectively. The hydrolysis filter tank 4 is used for secondary dust removal, desulfurization and denitrification treatment of the flue gas. The top of the hydrolysis filter tank 4 is connected to an external water source through a water supply pipeline 41. The bottom of the wet desulfurization reactor 2, the bottom of the wet denitrification reactor 3 and the bottom of the hydrolysis filter tank 4 are connected in parallel through a sewage pipeline 7 and connected to a sewage recovery end. A fourth solenoid valve 71 is installed on the sewage pipeline 7 located at the bottom of the hydrolysis filter tank 4.

[0019] Based on the above structure, Figure 1 As shown, when in use, the high-temperature flue gas output from the flue gas output end of the electric furnace is transported by the gas transmission pipeline 5, passes through the bag filter 1, the wet desulfurization reactor 2, the wet denitration reactor 3 and the hydrolysis filter tank 4 in sequence, thereby performing primary dust removal, primary desulfurization, primary denitration and secondary dust removal, desulfurization and denitration treatment, and is finally discharged from the chimney;

[0020] Specifically, the water injected into the hydrolysis filter tank 4 accounts for 80% of the capacity of the hydrolysis filter tank 4. When the flue gas after the primary dust removal, desulfurization and denitration treatment passes through the hydrolysis filter tank 4, the dust particles in the flue gas are moistened and settled when contacting with water. The flue gas contains sulfide, which reacts with water to generate sulfite or sulfate. The nitrogen dioxide contained in the nitrate in the flue gas, the nitric acid and nitric oxide generated by the water reaction, the sulfite, the sulfate and the dust particles are precipitated in the hydrolysis filter tank 4 and discharged, and the nitric oxide is discharged from the gas pipeline 5 and the chimney in sequence.

[0021] In this process, the desulfurization agent supply end and the denitrification agent supply end respectively transport the liquid desulfurization agent and the liquid denitrification agent to the wet desulfurization reactor 2 and the wet denitrification reactor 3 through two supply pipelines 6, and at the same time, the external water source transports water to the hydrolysis filter tank 4 through the water supply pipeline 41, and the waste liquid discharged from the wet desulfurization reactor 2, the wet denitrification reactor 3 and the hydrolysis filter tank 4 is discharged to the sewage recovery end through the sewage pipeline 7;

[0022] Specifically, when there is a lot of sediment in the hydrolysis filter tank 4, the fourth solenoid valve 71 is opened to discharge the sediment in the hydrolysis filter tank 4 together with the water.

[0023] Further, such as Figure 1As shown, in order to increase the contact degree between flue gas and water, a thinning rod 43 connected to the gas pipeline 5 is installed at the bottom end of the inner wall of the hydrolysis filter tank 4. The thinning rod 43 is a hollow structure, and tiny holes are evenly arranged on the periphery. A one-way valve is provided at the connection between the thinning rod 43 and the gas pipeline 5. The thinning rod 43 will disrupt the flow of flue gas through the tiny holes to form turbulence. The turbulence helps the flue gas and water to mix more fully and increase the contact area between the two. At the same time, due to the presence of tiny holes, the flue gas will encounter more resistance when flowing through the thinning rod 43, thereby slowing down the flow rate, which helps to prolong the contact time between the flue gas and water. In addition, the tiny holes can increase the diffusion rate of pollutants in the flue gas into the water, thereby improving the mass transfer efficiency.

[0024] Preferably, a booster pump (not shown) is installed on the gas pipeline 5 between the wet denitration reactor 3 and the hydrolysis filter tank 4. The provision of the booster pump helps to prevent the flue gas from entering the hydrolysis filter tank 4 due to water pressure.

[0025] Further, such as Figure 1 As shown, in order to monitor the pressure in the hydrolysis filter tank 4 in real time, a pressure gauge 44 for sensing the pressure in the hydrolysis filter tank 4 is installed on the outer wall of the hydrolysis filter tank 4 .

[0026] Further, such as Figure 1 As shown, a stirring tank 61 is installed on the supply pipeline 6, and the middle part of the hydrolysis filter tank 4 is connected in parallel with the top ends of the two stirring tanks 61 through a water delivery pipeline 42, and a first delivery pump 421 is provided on the water delivery pipeline 42;

[0027] Specifically, since the dust particles, sulfur and nitrate content in the flue gas are greatly reduced after the primary dust removal, desulfurization and denitrification, the water in the hydrolysis filter tank 4 is less polluted during the secondary dust removal, desulfurization and denitrification. In order to further reduce the cost, the water in the hydrolysis filter tank 4 is pumped out by the first delivery pump 421 after the secondary filtration of the flue gas, and is respectively delivered to the two stirring tanks 61, the water is fused with the desulfurizer and the denitrifier, and the desulfurizer and the denitrifier are diluted and melted, and then delivered to the wet desulfurization reactor 2 and the wet denitrification reactor 3 for primary desulfurization and denitrification treatment. At the same time, the diluted liquid desulfurizer can better react with sulfur dioxide and sulfur dioxide in the flue gas to generate sulfate precipitates, thereby improving the desulfurization efficiency. The diluted liquid denitrifier can promote the absorption of nitrogen oxides (NOx) and improve the denitrification efficiency, thereby increasing the effect of primary desulfurization and denitrification. At the same time, in the primary desulfurization and denitrification treatment, the wet desulfurization and denitrification both cool the high-temperature flue gas, and also avoid the water transported from the hydrolysis filter tank 4 to the stirring tank 61 as high-temperature water, thereby avoiding the reduction of the primary desulfurization and denitrification effects due to the high-temperature water.

[0028] Further, such as Figure 1As shown, in order to avoid the problem of waterless transportation caused by the water level in the hydrolysis filter tank being lower than the input end of the water supply pipeline, a liquid level sensor 45 is installed in the hydrolysis filter tank 4 located above the input end of the water supply pipeline 42.

[0029] Further, such as Figure 1 As shown, in order to intelligently control the high-temperature flue gas treatment system of the industrial silicon electric furnace, the supply pipeline 6 located at the bottom of the stirring tank 61 is successively installed with a first electric valve 62 for controlling the discharge of the diluted desulfurizer and the desulfurization agent and a second delivery pump 63 for delivering the diluted desulfurizer and the desulfurization agent, and the supply pipeline 6 located at the top of the stirring tank 61 is installed with a second solenoid valve 64 for controlling the supply of the desulfurizer and the desulfurization agent, and the water supply pipeline 41 is installed with a third solenoid valve 411 for controlling the supply and delivery amount of the external water source. Specifically, when the fourth solenoid valve 71 is closed, the third solenoid valve 411 is opened by 50%, and when the fourth solenoid valve 71 is opened, the third solenoid valve 411 is opened by 100%. The pressure gauge 44, the driving motor of the stirring tank 61, the first delivery pump 421, the liquid level sensor 45, the first electric valve 62, the second delivery pump 63, the second solenoid valve 64, the third solenoid valve 411 and the fourth solenoid valve 71 are all connected to the central control room through signals.

[0030] The above are only preferred specific implementation methods of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solution and invention concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. Industrial silicon electric furnace high temperature flue gas treatment system, characterized by: The invention comprises an electric furnace flue gas output end, a bag filter (1), a wet desulfurization reactor (2), a wet denitration reactor (3), a hydrolysis filter tank (4) and a chimney. The top and bottom of the bag filter (1), the top and bottom of the wet desulfurization reactor (2), the top and bottom of the wet denitration reactor (3) and the top and bottom of the hydrolysis filter tank (4) are connected in sequence between the electric furnace flue gas output end and the chimney input end through a gas transmission pipeline (5). The top of the wet desulfurization reactor (2) and the top of the wet denitration reactor (3) are connected through two supply lines. The pipeline (6) is connected with a desulfurization agent supply end and a denitrification agent supply end. The hydrolysis filter tank (4) is used for secondary dust removal, desulfurization and denitrification treatment of flue gas. The top of the hydrolysis filter tank (4) is connected with an external water source through a water supply pipeline (41). The bottom of the wet desulfurization reactor (2), the bottom of the wet denitrification reactor (3) and the bottom of the hydrolysis filter tank (4) are connected in parallel through a sewage pipeline (7) and are connected with a sewage recovery end. A fourth solenoid valve (71) is installed on the sewage pipeline (7) located at the bottom of the hydrolysis filter tank (4).

2. The industrial silicon electric furnace high temperature flue gas treatment system according to claim 1 is characterized in that: A thinning rod (43) connected to the gas pipeline (5) is installed at the bottom end of the inner wall of the hydrolysis filter tank (4); the thinning rod (43) is a hollow structure, and tiny holes are evenly arranged on the outer circumference.

3. The industrial silicon electric furnace high temperature flue gas treatment system according to claim 1 is characterized in that: A pressure gauge (44) for sensing the pressure inside the hydrolysis filter tank (4) is installed on the outer wall of the hydrolysis filter tank (4).

4. The industrial silicon electric furnace high temperature flue gas treatment system according to claim 3 is characterized in that: A stirring tank (61) is installed on the supply pipeline (6), and the middle part of the hydrolysis and filtration tank (4) is connected in parallel with the top ends of the two stirring tanks (61) through a water delivery pipeline (42), and a first delivery pump (421) is provided on the water delivery pipeline (42).

5. The industrial silicon electric furnace high temperature flue gas treatment system according to claim 4 is characterized in that: A liquid level sensor (45) is installed in the hydrolysis filter tank (4) located above the input end of the water delivery pipeline (42).

6. The industrial silicon electric furnace high temperature flue gas treatment system according to claim 5 is characterized in that: The supply pipeline (6) located at the bottom end of the stirring tank (61) is installed with a first electric valve (62) and a second delivery pump (63) in sequence, the supply pipeline (6) located at the top end of the stirring tank (61) is installed with a second electromagnetic valve (64), the water supply pipeline (41) is installed with a third electromagnetic valve (411), and the pressure gauge (44), the driving motor of the stirring tank (61), the first delivery pump (421), the liquid level sensor (45), the first electric valve (62), the second delivery pump (63), the second electromagnetic valve (64) and the third electromagnetic valve (411) are all connected to the central control room through signals.

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