Low-emission silane tail gas treatment system

Abstract

The invention discloses a low-emission silane tail gas treatment system, and mainly relates to the field of silane tail gas treatment. Comprising a tail gas absorption tower and an alkali liquor regeneration tank, the tail gas absorption tower treats received tail gas S1, generates S2 after alkali liquor reaction and absorption and then sends the S2 into the alkali liquor tank, S3 and S4 are formed in the alkali liquor tank, S3 is pumped into the tail gas absorption tower, a stream S4 is pumped into the alkali liquor regeneration tank, a material S5 is sent into the alkali liquor regeneration tank, and a stream S7 is further pumped into the alkali liquor regeneration tank. S4, S5 and S7 are mixed and reacted in the alkali liquor regeneration tank to generate a stream S8, the stream S8 is pumped into the filter press, the stream S8 generates a stream S6 and a stream S9 under the action of the filter press, and the stream S6 is fed into the alkali liquor tank to complete cyclic utilization. The method has the beneficial effects that the slaked lime and the waste alkali liquid are mixed and reacted to generate the alkali liquid again for tail gas treatment, so that the waste alkali liquid is recycled, the discharge of the waste alkali liquid is effectively reduced, the waste of water resources during the treatment of the waste alkali liquid is reduced, and meanwhile, the concentration of the alkali liquid is ensured, so that the tail gas treatment quality is ensured.

Description

Technical Field

[0001] The invention relates to the field of silane tail gas treatment, in particular to a low-emission silane tail gas treatment system. Background Art

[0002] Silane tail gas has high temperature, low concentration, high content of toxic and harmful components, is corrosive, and easy to burn and explode. Therefore, the industry often needs to treat the discharged silane tail gas. The more commonly used methods are: Alkali washing method: silane waste gas is transported into the alkali washing tower through a pipeline for acid-base neutralization treatment and discharged after meeting the national emission standards. This method can effectively remove the acidic components in silane waste gas.

[0003] The existing alkali washing treatment equipment includes a tail gas absorption tower and an alkali washing tank. The tail gas in the tail gas absorption tower is alkali washed by the alkali washing tank for treatment and then discharged. The defects of the prior art are: the utilization rate of sodium hydroxide alkali solution is relatively low. Basically, the concentration of the sodium hydroxide alkali solution in the initial circulation is about 3%-15%, but only about 50% can be used. The concentration of the remaining alkali solution is not enough to effectively absorb the tail gas, which will greatly reduce the absorption effect of the tail gas, and the treatment quality of the tail gas cannot be effectively guaranteed. It is easy to cause the tail gas emission to fail to meet the standard, and the use effect is not ideal, which affects the treatment and discharge of the tail gas.

[0004] In addition, the existing technology does not reuse the waste alkali liquid absorbed by the tail gas treatment, but needs to be discharged through sewage treatment, which also requires a large amount of funds to treat in order to meet the discharge standards, making the overall treatment cost high and the practicality poor. Summary of the invention

[0005] The object of the present invention is to provide a low-emission silane tail gas treatment system, which treats tail gas by regenerating alkali liquid after mixing slaked lime with waste alkali liquid, thereby realizing the recycling of waste alkali liquid, effectively reducing the discharge of waste alkali liquid, reducing the waste of water resources during the treatment of waste alkali liquid, and at the same time ensuring the concentration of alkali liquid, thereby ensuring the quality of tail gas treatment.

[0006] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0007] A low-emission silane tail gas treatment system comprises a tail gas absorption tower, an alkali liquid tank, an alkali liquid regeneration tank, and a material tank. The tail gas absorption tower is used to receive tail gas S1 for treatment. The alkali liquid reacts and absorbs to generate stream S2, which is then sent to the alkali liquid tank. The substances in the alkali liquid tank react to form streams S3 and S4. The stream S3 is pumped into the tail gas absorption tower under the action of a circulation pump. The stream S4 is pumped into the alkali liquid regeneration tank under the action of a circulation pump. The material tank sends a material S5 for reaction into the alkali liquid regeneration tank. Stream S7 is also pumped into the alkali liquid regeneration tank by a water pump. After the mixed reaction of stream S4, material S5 and stream S7 in the alkali liquid regeneration tank, they are returned to the alkali liquid regeneration tank through a filter press pump to repeat the reaction or fully react to generate stream S8. The stream S8 is pumped into the filter press by the filter press. After passing through the filter press, the stream S8 returns to the alkali liquid regeneration tank again to repeat the reaction or fully react to generate stream S6 and stream S9. The stream S6 is sent to the alkali liquid tank to complete the recycling.

[0008] Furthermore, both the alkali solution tank and the alkali solution regeneration tank are provided with a stirring device.

[0009] Furthermore, the stirring device comprises a liquid spraying pipe, the liquid outlet of the liquid spraying pipe is oriented toward the tangent direction of the tank body, so that the liquid in the tank body flows in a spiral shape under the action of the flow stream sprayed by the liquid spraying pipe.

[0010] Furthermore, a coil heat exchanger is also provided in the alkali liquid tank and the alkali liquid regeneration tank.

[0011] Furthermore, it also includes an automatic feeding system, which includes a weighing sensor used in conjunction with the material tank, an analysis sensor used in conjunction with the alkali solution regeneration tank, and a calculation module for controlling the amount of the pumped-in stream S7.

[0012] Furthermore, the received tail gas S1 is a silane-containing tail gas, the streams S2, S3 and S4 are all absorbed alkali solution, the material S5 is slaked lime, the stream S6 is a recycled alkali solution, the stream S7 is water, the stream S8 is a waste alkali solution, and the stream S9 is a sodium silicate solid.

[0013] Compared with the prior art, the beneficial effects of the present invention are:

[0014] The present invention adds slaked lime and water into the waste alkali liquid tank, so that the sodium silicate solution in the waste alkali liquid reacts with calcium hydroxide to generate sodium hydroxide alkali liquid, and the obtained sodium hydroxide alkali liquid is transported back to the alkali liquid tank, thereby realizing the recycling of the waste alkali liquid. On the one hand, after the recycled alkali liquid is transported back to the alkali liquid tank, the effective concentration of the alkali liquid in the alkali liquid tank can be increased, so that the alkali liquid is always in a concentration range with good tail gas treatment effect, thereby avoiding the incomplete absorption of tail gas caused by the decrease of the effective concentration after the alkali liquid is consumed, ensuring the treatment quality of the tail gas, and ensuring the emission standard of the tail gas treatment. At the same time, after most of the waste alkali liquid is converted into alkali liquid, the discharge volume of the waste alkali liquid is also greatly reduced, and there is no need to treat a large amount of waste alkali liquid, thereby reducing the capital consumption required for treating the waste alkali liquid, and reducing the water resource consumption for treating the waste alkali liquid, thereby effectively reducing the overall cost consumption and having better practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Attached Figure 1 It is a structural schematic diagram of the present invention.

[0016] Attached Figure 2 It is a schematic diagram of the internal structure of the alkali liquid tank and the alkali liquid regeneration tank of the present invention.

[0017] Numbers shown in the accompanying drawings:

[0018] 1. Tail gas absorption tower; 2. Alkali liquid tank; 3. Alkali liquid regeneration tank; 4. Material tank; 5. Circulation pump; 6. Filter press pump; 7. Filter press; 8. Liquid spray pipe; 9. Coil heat exchanger; 10. Weighing sensor; 11. Analytical sensor; 12. Calculation module. DETAILED DESCRIPTION

[0019] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the application equally.

[0020] The present invention discloses a low-emission silane tail gas treatment system, the main structure of which includes a tail gas absorption tower 1, an alkali liquid tank 2, an alkali liquid regeneration tank 3, and a material tank 4. The tail gas absorption tower 1 is used to process the received tail gas S1 into a stream S2 and then send it into the alkali liquid tank 2. The substances in the alkali liquid tank 2 react to form streams S3 and S4. The stream S3 is pumped into the tail gas absorption tower 1 under the action of a circulation pump 5. The stream S4 is pumped into the alkali liquid regeneration tank 3 under the action of the circulation pump 5. The material tank 4 sends the material S5 for reaction into the alkali liquid regeneration tank 3. The alkali liquid Stream S7 is also pumped into the regeneration tank 3 by a water pump. After the mixed reaction of stream S4, material S5 and stream S7 in the alkali solution regeneration tank 3, they are returned to the alkali solution regeneration tank 3 through the filter press pump 6 to repeat the reaction so that the reaction is sufficient. After the sufficient reaction is completed, stream S8 is generated and pumped into the filter press 7. After the action of the filter press 7, stream S8 returns to the alkali solution regeneration tank 3 to repeat the reaction so that the reaction is sufficient. After the sufficient reaction is completed, stream S6 and stream S9 are generated. The stream S6 is sent to the alkali solution tank 2 to complete the recycling, and stream S9 is discharged from the system.

[0021] Preferably, both the alkali liquid tank 2 and the alkali liquid regeneration tank 3 are provided with a stirring device, and the stirring device includes a liquid spray pipe 8, and the liquid outlet of the liquid spray pipe 8 is oriented in the tangential direction of the tank body, so that the liquid in the tank body flows in a spiral shape under the action of the flow stream sprayed from the liquid spray pipe 8, thereby achieving stirring of the liquid in the tank body, abandoning the traditional mechanical stirring structure, and avoiding leakage and fire of unreacted silane at the sealing point of the stirring shaft, making the system safer.

[0022] Preferably, a coil heat exchanger 9 is also provided in the alkali liquid tank 2 and the alkali liquid regeneration tank 3. The part of the coil heat exchanger 9 inside the tank body can play a certain turbulent role, so that the stirring effect is better, and can also exchange the heat of the reaction inside the two tank bodies. In addition, during the initial operation, steam can also be introduced into the coil heat exchanger 9 of the alkali liquid tank 2 to increase the alkali liquid temperature, so as to achieve a better exhaust gas absorption effect.

[0023] Preferably, an automatic feeding system is also included, which includes a weighing sensor 10 used in conjunction with the material tank 4, an analytical sensor 11 used in conjunction with the alkali solution regeneration tank 3, and a calculation module 12 for controlling the amount of pumped stream S7. The sodium silicate concentration in the portion of liquid pumped back from the filter press pump 6 to the alkali solution regeneration tank 3 for repeated reaction is detected and analyzed by the analytical sensor 11, and then the concentration and amount of clean water added are controlled by the calculation module 12 according to a pre-set program, and the weight of slaked lime added from the material tank 4 to the alkali solution regeneration tank 3 is controlled by the weighing sensor 10, thereby realizing automated recovery inspection, which is more intelligent and labor-saving.

[0024] Preferably, the received tail gas S1 is a silane-containing tail gas, and the streams S2, S3 and S4 are all absorption alkali liquids, wherein the stream S4 is the absorption alkali liquid after the sodium silicate concentration in the alkali liquid tank 2 reaches the regeneration standard, the material S5 is slaked lime, the stream S6 is the recycled alkali liquid, the stream S7 is water, the stream S8 is the waste alkali liquid, and the stream S9 is the sodium silicate solid.

[0025] Embodiment: A low-emission silane tail gas treatment system comprises a tail gas absorption tower 1, an alkali liquid tank 2, an alkali liquid regeneration tank 3, and a material tank 4. The alkali liquid tank 2 and the alkali liquid regeneration tank 3 are both provided with a liquid spray pipe 8 and a coil heat exchanger 9. The liquid outlet of the liquid spray pipe 8 faces the tangent direction of the tank body, so that the liquid in the tank body flows in a spiral shape under the action of the stream sprayed by the liquid spray pipe 8. The tail gas absorption tower 1 is used to process the received tail gas S1 into a stream S2 and then send it into the alkali liquid tank 2. The received tail gas S1 is a silane-containing tail gas. After the substances in the alkali liquid tank 2 react, streams S3 and S4 are formed. The streams S2, S3, and S4 are all absorbed alkali liquids, and stream S4 is alkali liquid. After the sodium silicate concentration in tank 2 reaches the regeneration standard, it is transported to the alkali solution regeneration tank 3. It is an intermittent process. The stream S3 is pumped into the tail gas absorption tower 1 under the action of the circulating pump 5. The stream S4 is pumped into the alkali solution regeneration tank 3 under the action of the circulating pump 5. The material tank 4 sends the material S5 for reaction into the alkali solution regeneration tank 3. The material S5 is slaked lime. The material tank 4 is provided with a weighing sensor 10. The alkali solution regeneration tank 3 also pumps stream S7 into the stream S7 through a water pump. The stream S7 is water, and the amount of the stream S7 pumped into the stream S7 is controlled by the calculation module 12. The stream S4, the material S5, and the stream S7 are mixed and reacted in the alkali solution regeneration tank 3 and then returned to the alkali solution through the filter press pump 6. The alkali solution regeneration tank 3 is provided with an analysis sensor 11, which analyzes the liquid that returns to the alkali solution regeneration tank 3 for repeated reaction, detects the concentration of sodium silicate therein, and automatically calculates the amount of slaked lime and clean water to be added according to the detected sodium silicate concentration, thereby automatically adding the required amount of slaked lime and clean water to the alkali solution regeneration tank 3 by using the weighing sensor 10 and the calculation module 12, and after the above-mentioned circulating liquid and the reaction liquid in the alkali solution regeneration tank 3 are fully reacted, a stream S8 is generated, and the diversion process is realized by switching the manual valve of the pump body, and the stream S8 is the waste alkali solution, and the stream S8 is pumped into the filter press 7 under the action of the filter press pump 6, and the After the action of the filter press 7, stream S8 returns to the alkali solution regeneration tank 3 to repeat the reaction. After the slaked lime is added to the waste alkali solution, the alkali solution in the alkali solution regeneration tank 3 after the reaction will contain solids such as calcium silicate or slightly excess slaked lime that has not reacted or insoluble matter in the slaked lime. Therefore, stream S8 needs to be filtered through the filter press 7 by the filter press pump 6 and only returns to the alkali solution regeneration tank 3 to filter out the solids. After the sufficient reaction is completed and the solids are filtered, streams S6 and S9 are generated. The diversion operation is also achieved by switching the manual valve of the pump body. The stream S6 is sent to the alkali solution tank 2 for recycling. The stream S6 is the recycled alkali solution, and the stream S9 is the sodium silicate solid.

[0026] The present invention realizes the recycling and reuse of waste alkali liquid. On the one hand, after the recycled alkali liquid is transported back to the alkali liquid tank 2, the effective concentration of the alkali liquid in the alkali liquid tank 2 can be increased, so that it is always in the concentration range with good exhaust gas treatment effect, avoiding the reduction of effective concentration after the alkali liquid is consumed, resulting in incomplete absorption of exhaust gas, ensuring the treatment quality of exhaust gas, and ensuring the emission standard of exhaust gas treatment. At the same time, after most of the waste alkali liquid is converted into alkali liquid, the discharge volume of the waste alkali liquid is also greatly reduced, and there is no need to treat a large amount of waste alkali liquid, which also reduces the capital consumption required for treating the waste alkali liquid, effectively reduces the overall cost consumption, and has better practicality.

Claims

1. A low emission silane tail gas treatment system, characterized in that: The invention comprises a tail gas absorption tower (1), an alkali liquid tank (2), an alkali liquid regeneration tank (3), and a material tank (4). The tail gas absorption tower (1) is used to receive tail gas S1 for treatment. After the alkali liquid reacts and absorbs, a stream S2 is generated and then sent to the alkali liquid tank (2). After the substances in the alkali liquid tank (2) react, streams S3 and S4 are formed. The stream S3 is pumped into the tail gas absorption tower (1) under the action of a circulation pump (5). The stream S4 is pumped into the alkali liquid regeneration tank (3) under the action of the circulation pump (5). The material tank (4) sends a material S5 for reaction into the alkali liquid regeneration tank (3). The liquid regeneration tank (3) also pumps stream S7 into the liquid regeneration tank (3) through a water pump. After the stream S4, material S5, and stream S7 are mixed and reacted in the alkali liquid regeneration tank (3), they are returned to the alkali liquid regeneration tank (3) through a filter press pump (6) to repeat the reaction or fully react to generate stream S8. The stream S8 is pumped into the filter press (7) under the action of the filter press pump (6). After the stream S8 passes through the filter press (7), it returns to the alkali liquid regeneration tank (3) to repeat the reaction or fully react to generate stream S6 and stream S9. The stream S6 is sent to the alkali liquid tank (2) to complete the recycling.

2. A low emission silane tail gas treatment system according to claim 1, characterized in that: The alkali solution tank (2) and the alkali solution regeneration tank (3) are both provided with stirring devices.

3. A low emission silane tail gas treatment system according to claim 2, characterized in that: The stirring device comprises a liquid spraying pipe (8), the liquid outlet of the liquid spraying pipe (8) is oriented towards the tangent direction of the tank body, so that the liquid in the tank body flows in a spiral shape under the action of the flow stream sprayed by the liquid spraying pipe (8).

4. A low emission silane tail gas treatment system according to claim 1, characterized in that: A coil heat exchanger (9) is also provided in the alkali liquid tank (2) and the alkali liquid regeneration tank (3).

5. A low emission silane tail gas treatment system according to claim 1, characterized in that: It also includes an automatic feeding system, which includes a weighing sensor (10) used in conjunction with the material tank (4), an analysis sensor (11) used in conjunction with the alkali solution regeneration tank (3), and a calculation module (12) for controlling the amount of the pumped-in stream S7.

6. A low emission silane tail gas treatment system according to claim 1, characterized in that: The received tail gas S1 is a silane-containing tail gas, the streams S2, S3 and S4 are all absorbed alkali solution, the material S5 is slaked lime, the stream S6 is a recycled alkali solution, the stream S7 is water, the stream S8 is a waste alkali solution, and the stream S9 is a sodium silicate solid.

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