Tail gas treatment system in trichlorosilane production process
By linking a three-stage tail gas absorption system with a plate and frame filter press, the problem of low tail gas treatment efficiency in the production of trichlorosilane is solved, achieving efficient absorption and recycling of the clarified liquid, simplifying the equipment structure, and reducing operating costs and environmental pollution.
Patent Information
- Application Number
- CN202423266384.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-30
- Publication Date
- 2025-12-16
- Estimated Expiration
- 2034-12-30
AI Technical Summary
The current trichlorosilane production process has low tail gas treatment efficiency, resulting in high salt content in wastewater that cannot be reused. In addition, traditional process equipment occupies a large area, has high operating costs, and pollutes the environment.
A three-stage tail gas absorption system and a plate and frame filter press are used in combination. Through the linkage of multi-stage absorption towers and plate and frame filter presses, the high efficiency of hydrogen chloride and silicon dioxide in the tail gas is achieved, and a clear liquid is prepared for storage. Combined with an alkaline tank, the pH is adjusted to improve the number of filtration cycles and efficiency.
It improves exhaust gas treatment efficiency, reduces production costs, reduces waste emissions, enables the recycling of clarified liquid, simplifies equipment structure, and reduces environmental pollution.
Smart Images
Figure CN223668960U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to trichlorosilane tail gas treatment equipment technical field, concretely relates to a trichlorosilane production process tail gas treatment system. BACKGROUND
[0002] In the production process of trichlorosilane (i.e. trichlorosilane), equipment maintenance or replacement and emergency process will have tail gas, this part of tail gas contains a small amount of trichlorosilane, silicon tetrachloride, dichlorosilane and other components, when this part of tail gas is not treated directly into tail gas washing tower, will first hydrolyze, the hydrolysis product is mainly hydrogen chloride and silicon dioxide, the traditional treatment process is, directly using primary washing tower to absorb, when the concentration of each component in the primary washing tower reaches a certain value, is discharged to the sewage treatment system to the sewage station, carries out pressure filtration and neutralization treatment.But, the salt content in the wastewater treated in this way is relatively high and cannot be reused, needs to enter the evaporation system again for evaporation treatment, and then the condensed water discharged from the evaporation system is reused, but the solid salt discharged therein can only be treated as solid waste. Such a treatment method not only leads to low trichlorosilane tail gas treatment efficiency, but also produces more waste gas or waste residue and other three wastes.
[0003] At the same time, a variety of equipment is needed in the traditional treatment process, which not only occupies a large area and has high running cost, but also pollutes the environment if the tail gas is not fully treated.
[0004] Based on this, the utility model provides a trichlorosilane production process tail gas treatment system, which can improve the absorption efficiency of hydrogen chloride and silicon dioxide in trichlorosilane tail gas by using multi-stage absorption tower and plate and frame filter press, and can also prepare clear liquid for storage, and the whole system of the utility model is simple in equipment and convenient in operation, which is beneficial to improve the production efficiency of trichlorosilane. UTILITY MODEL CONTENTS
[0005] In order to solve the above technical problems, the present application provides a trichlorosilane production process tail gas treatment system, which has high stability and superior performance, can solve the problem of low tail gas treatment efficiency of existing trichlorosilane production equipment, can also improve the absorption efficiency of hydrogen chloride and silicon dioxide in trichlorosilane tail gas, and can prepare clear liquid for storage, has the characteristics of simple design and efficient operation.
[0006] In order to achieve the above technical purpose, the utility model adopts the following technical scheme:
[0007] A trichlorosilane production process tail gas treatment system, specifically a three-stage tail gas absorption system, comprising a primary tail gas absorption tower, a secondary tail gas absorption tower, a tertiary tail gas absorption tower, a plate and frame filter press, a lye tank and a hydrochloric acid product tank.
[0008] The primary tail gas absorption tower is provided with two discharge ends and one feeding end, namely a first discharge end, a second discharge end and a first feeding end; the first discharge end of the primary tail gas absorption tower is connected with the feeding end of the secondary tail gas absorption tower through a first discharge pipe; the discharge end of the secondary tail gas absorption tower is connected with the feeding end of the tertiary tail gas absorption tower through a second discharge pipe;
[0009] The second discharge end of the primary tail gas absorption tower is connected with the feeding end of the plate-frame filter press through a filter press feeding pipe;
[0010] The plate-frame filter press is connected with a filter press discharge pipe at the discharge end; the terminal end of the filter press discharge pipe is connected with the first feeding end of the primary tail gas absorption tower.
[0011] Further, the filter press discharge pipe is further provided with a first bypass pipe, the terminal end of the first bypass pipe being connected with the inlet end of the hydrochloric acid product tank; the filter press discharge pipe is further provided with a second bypass pipe, the terminal end of the second bypass pipe being connected with the inlet end of the lye pool; the outlet end of the lye pool is connected with the side wall of the filter press feeding pipe through a third discharge pipe.
[0012] Further, the lye pool contains lye, which is convenient for adjusting the pH value of the material in the plate-frame filter press.
[0013] Further, the filter press feeding pipe is provided with a flushing pump and a first valve.
[0014] Further preferably, the first valve is located on the filter press feeding pipe on the right side of the flushing pump.
[0015] Further, the filter press discharge pipe is provided with a second valve; the first bypass pipe is provided with a third valve, the second bypass pipe is provided with a fourth valve, and the third discharge pipe is provided with a fifth valve.
[0016] Further, the connection between the third discharge pipe and the filter press feeding pipe is located close to the filter press feeding pipe, i.e. the connection between the third discharge pipe and the filter press feeding pipe is located on the pipeline between the connection between the filter press feeding pipe and the feeding end of the plate-frame filter press and the first valve.
[0017] Further, the connections between the first bypass pipe and the filter press discharge pipe and between the second bypass pipe and the filter press discharge pipe are both located close to the filter press feeding pipe, i.e. the connections between the first bypass pipe and the filter press discharge pipe and between the second bypass pipe and the filter press discharge pipe are both located on the pipeline between the connection between the filter press discharge pipe and the discharge end of the plate-frame filter press and the second valve.
[0018] Further, the first discharge pipe is further provided with a sixth valve, and the second discharge pipe is further provided with a seventh valve.
[0019] Further, the secondary tail gas absorption tower is also connected with the primary tail gas absorption tower through a first back feeding pipe, and a first back feeding valve is arranged on the first back feeding pipe.
[0020] Further, the first valve, the second valve, the third valve, the fourth valve, the fifth valve, the sixth valve, the seventh valve, the first back feeding valve and the second back feeding valve are all manual valves.
[0021] Compared with the prior art, the utility model has the advantages that:
[0022] 1. The utility model discloses a multistage absorption tower and a plate and frame filter are combined, the fluid material in the tail gas absorption tower is removed by the plate and frame filter, and the clear liquid after deslagging by the plate and frame filter is returned to the tail gas absorption tower, so that the impurities in the tail gas are removed.
[0023] 2. The utility model discloses that the lye pool is connected with the plate and frame filter, the alkalinity of the material in the plate and frame filter is adjusted through the lye pool, the filtering cycle number and the use efficiency of the plate and frame filter are improved, the absorption efficiency of hydrogen chloride and silicon dioxide in the trichlorosilane tail gas is improved, and the utility model has the characteristics of simple design and efficient operation.
[0024] 3. The utility model discloses that byproduct hydrochloric acid is produced and recycled in the operation process, compared with the traditional process, the waste water can be converted into the byproduct hydrochloric acid, the production cost is reduced, and the pollution to the environment is reduced to the minimum. DRAWINGS
[0025] Figure 1 It is the structure schematic diagram of tail gas treatment system in the trichlorosilane production process of example 1.
[0026] In the drawing: 1, primary tail gas absorption tower, 2, secondary tail gas absorption tower, 21, sixth valve, 22, first back feeding valve, 3, tertiary tail gas absorption tower, 31, seventh valve, 32, second back feeding valve, 4, plate and frame filter, 5, lye pool, 6, filter press feeding pipe, 61, flushing pump, 62, first valve, 7, filter press discharge pipe, 71, second valve, 8, second discharge pipe, 81, fifth valve, 9, second bypass pipe, 91, fourth valve, 10, hydrochloric acid finished product tank, 11, first bypass pipe, 12, third valve. CONCRETE IMPLEMENTATION
[0027] The utility model is further explained in connection with the embodiment and the drawing, but is not the limitation to the utility model.
[0028] In the description of the utility model, it is necessary to explain that, for the direction word, if there are terms "upper", "lower", "top", "bottom", "inner", "outer" and the like indicate the direction and position relationship as the direction or position relationship shown in the drawing, only for the convenience of describing the application and simplifying the description, and not indicating or implying that the device or element indicated must have a specific direction, be constructed and operated in a specific direction, and cannot be understood as limiting the specific protection scope of the application.
[0029] It should be noted that the terms "first", "second", "third", "1#", "2#" and the like in the specification and claims of the present application are used to distinguish similar objects, and do not necessarily indicate a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the application described herein.
[0030] Embodiment 1
[0031] As Figure 1 shown, a tail gas treatment system in trichlorosilane production process, specifically a three-stage tail gas absorption system, comprising a first-stage tail gas absorption tower 1, a second-stage tail gas absorption tower 2, a third-stage tail gas absorption tower 3, a plate and frame filter press 4, a lye tank 5 and a hydrochloric acid product tank 10;
[0032] The first-stage tail gas absorption tower 1 is provided with two discharge ends and one feeding end, which are a first discharge end, a second discharge end and a first feeding end; the first discharge end of the first-stage tail gas absorption tower 1 is connected with the feeding end of the second-stage tail gas absorption tower 2 through a first discharge pipe, and the discharge end of the second-stage tail gas absorption tower 2 is connected with the feeding end of the third-stage tail gas absorption tower 3 through a second discharge pipe;
[0033] The second discharge end of the first-stage tail gas absorption tower 1 is connected with the feeding end of the plate and frame filter press 4 through a filter press feeding pipe 6;
[0034] The discharge end of the plate and frame filter press 4 is connected with a filter press discharge pipe 7, and the tail end of the filter press discharge pipe 7 is connected with the first feeding end of the first-stage tail gas absorption tower 1.
[0035] Further, the filter press discharge pipe 7 is also provided with a first bypass pipe 11, and the tail end of the first bypass pipe 11 is connected with the inlet end of the hydrochloric acid product tank 10; the filter press discharge pipe 7 is also provided with a second bypass pipe 9, and the tail end of the second bypass pipe 9 is connected with the inlet end of the lye tank 5; the outlet end of the lye tank 5 is connected with the side wall of the filter press feeding pipe 6 through a third discharge pipe 8.
[0036] The lye tank 5 stores lye, which is convenient for adjusting the pH value of the material in the plate and frame filter press 4.
[0037] Further, the filter press feed pipe 6 is provided with a flushing pump 61 and a first valve 62, and in the embodiment, the first valve 62 is located on the right side of the flushing pump 61 on the filter press feed pipe 6; the filter press discharge pipe 7 is provided with a second valve 71; the first bypass pipe 11 is provided with a third valve 12, the second bypass pipe 9 is provided with a fourth valve 91, and the third discharge pipe 8 is provided with a fifth valve 81.
[0038] Further, the connection between the third discharge pipe 8 and the filter press feed pipe 6 is located close to the filter press feed pipe 6, that is, the connection between the third discharge pipe 8 and the filter press feed pipe 6 is located on the pipeline between the filter press feed pipe 6 and the filter press feed end of the plate-and-frame filter press 4 and between the first valve 62;
[0039] The connection between the first bypass pipe 11 and the filter press discharge pipe 7 and the connection between the second bypass pipe 9 and the filter press discharge pipe 7 are both located close to the filter press feed pipe 6, that is, the connection between the first bypass pipe 11 and the filter press discharge pipe 7 and the connection between the second bypass pipe 9 and the filter press discharge pipe 7 are both located on the pipeline between the filter press discharge pipe 7 and the filter press discharge end of the plate-and-frame filter press 4 and between the second valve 71.
[0040] Further preferably, the first discharge pipe is further provided with a sixth valve 21, and the second discharge pipe is further provided with a seventh valve 31.
[0041] The second-stage tail gas absorption tower 2 is further connected with the first-stage tail gas absorption tower 1 through a first return pipe, and the first return pipe is provided with a first return valve 22; the third-stage tail gas absorption tower 3 is further connected with the second-stage tail gas absorption tower 2 through a second return pipe, and the second return pipe is provided with a second return valve 32.
[0042] Among them, the first valve 62, the second valve 71, the third valve 12, the fourth valve 91, the fifth valve 81, the sixth valve 21, the seventh valve 31, the first return valve 22, and the second return valve 32 are all manual valves.
[0043] The operation mode of the utility model is:
[0044] 1) Before the system operates, the flushing pump 61, the first valve 62, the second valve 71, the third valve 12, the fourth valve 91, the fifth valve 81, the sixth valve 21, the seventh valve 31, the first return valve 22, and the second return valve 32 are all in a closed state;
[0045] When running, the tail gas (containing a small amount of trichlorosilane, silicon tetrachloride, dichlorosilane and other components) generated in the production of trichlorosilane, equipment maintenance or replacement and emergency process of the trichlorosilane production equipment is introduced into the first-stage tail gas absorption tower 1 through the pipeline for first-stage treatment, and hydrochloric acid and silicon dioxide are generated after treatment. After the first-stage tail gas absorption tower 1 is treated, the sixth valve 21 and the seventh valve 31 are opened, and the tail gas not completely absorbed is introduced into the second-stage tail gas absorption tower 2 and the third-stage tail gas absorption tower 3 through the pipeline in turn for second-stage treatment and third-stage treatment. After treatment, hydrochloric acid and silicon dioxide are also generated.
[0046] 2) As the first-stage tail gas absorption tower 1, the second-stage tail gas absorption tower 2 and the third-stage tail gas absorption tower 3 run, the generated hydrochloric acid and silicon dioxide will continuously accumulate; when the amount of silicon dioxide generated in the first-stage tail gas absorption tower 1 reaches a certain degree, the flushing pump 61 and the first valve 62 are opened, and part of the fluid material in the first-stage tail gas absorption tower 1 is transported to the plate and frame filter press 4 by the flushing pump 61 through the filter press feeding pipe 6 for deslagging, and then the second valve 71 is opened. The clear liquid after deslagging in the plate and frame filter press 4 is returned to the first-stage tail gas absorption tower 1 through the filter press discharge pipe 7 for reuse.
[0047] 3) During the operation of the first-stage tail gas absorption tower 1, when the concentration of hydrochloric acid in the first-stage tail gas absorption tower 1 reaches 30%, the second valve 71 is closed and the third valve 12 is opened, and the clear liquid after deslagging in the plate and frame filter press 4 is transported to the hydrochloric acid finished product tank 10 through the first bypass pipe 11.
[0048] 4) When the plate and frame filter press 4 accumulates too much acid during the deslagging process, the acid filter cake appears, the fifth valve 81 is opened, and the alkali liquid in the alkali liquid pool 5 is introduced into the plate and frame filter press 4 through the third discharge pipe 8 to neutralize the filter cake to neutral; in addition, the fourth valve 91 can be opened, and the excess alkali liquid in the plate and frame filter press 4 is returned to the alkali liquid pool 5 through the second bypass pipe 9 for continuous circulation.
[0049] When the whole system stops running, the filter cake in the plate and frame filter press 4 can be replaced with neutral filter cake and dried with air, and the dried filter cake is sent to the solid waste storage for storage.
[0050] 5) During the operation of the system, when the liquid level of the first-stage tail gas absorption tower 1 is lowered, the first return valve 22 and the second return valve 32 can also be opened, the liquid level in the second-stage tail gas absorption tower 2 is moved to the first-stage tail gas absorption tower 1, and the liquid level in the third-stage tail gas absorption tower 3 is moved to the second-stage tail gas absorption tower 2, and water can also be added to the third-stage tail gas absorption tower 3 to balance the liquid levels in the first-stage tail gas absorption tower 1, the second-stage tail gas absorption tower 2 and the third-stage tail gas absorption tower 3.
[0051] The above embodiment is an example of the embodiment of the present application, and the embodiment of the present application is not limited by the above embodiment, and any change, modification, replacement, combination, simplification, which does not deviate from the spirit and principle of the present application, should be an equivalent replacement mode, and all are included in the protection scope of the present application.
Claims
1. A system for treating tail gas in a trichlorosilane production process, characterized by, The first-stage tail gas absorption tower, the second-stage tail gas absorption tower, the third-stage tail gas absorption tower, the plate-frame filter press, the lye pool and the hydrochloric acid product tank are connected in series. The first-stage tail gas absorption tower is provided with two discharge ends and one feeding end, namely a first discharge end, a second discharge end and a first feeding end. The first discharge end of the first-stage tail gas absorption tower is connected with the feeding end of the second-stage tail gas absorption tower through a first discharge pipe. The second discharge end of the first-stage tail gas absorption tower is connected with the feeding end of the plate-frame filter press through a filter press feeding pipe.
2. The tail gas treatment system in a trichlorosilane production process according to claim 1, wherein The plate-frame filter press is provided with a filter press discharge pipe connected with the first feeding end of the first-stage tail gas absorption tower.
3. The tail gas treatment system in a trichlorosilane production process according to claim 1, wherein The filter press discharge pipe is further provided with a first bypass pipe connected with the inlet end of the hydrochloric acid product tank, and a second bypass pipe connected with the inlet end of the lye pool.
4. The tail gas treatment system in a trichlorosilane production process according to claim 1, wherein The filter press feeding pipe is provided with a flushing pump and a first valve.
5. The tail gas treatment system in a trichlorosilane production process according to claim 1, wherein The filter press discharge pipe is provided with a second valve, the first bypass pipe is provided with a third valve, the second bypass pipe is provided with a fourth valve, and the third discharge pipe is provided with a fifth valve.
6. The tail gas treatment system in a trichlorosilane production process according to claim 1, wherein The third discharge pipe is connected with the filter press feeding pipe at a position close to the filter press feeding pipe.
7. The tail gas treatment system in a trichlorosilane production process according to claim 1, wherein The first bypass pipe and the second bypass pipe are connected with the filter press discharge pipe at positions close to the filter press feeding pipe.
8. The tail gas treatment system in a trichlorosilane production process according to claim 1, wherein The first discharge pipe is further provided with a sixth valve, and the second discharge pipe is further provided with a seventh valve. The second-stage tail gas absorption tower is further connected with the first-stage tail gas absorption tower through a first return pipe provided with a first return valve, and the third-stage tail gas absorption tower is further connected with the second-stage tail gas absorption tower through a second return pipe provided with a second return valve.