Silane accident multi-stage condensing device

Abstract

A silane accident multi-stage condensing device comprises an accident mixed gas buffer tank, the accident mixed gas buffer tank is connected with a first-stage condenser through a pipeline, the first-stage condenser is connected with a second-stage condenser and a chlorosilane storage tank through pipelines, the second-stage condenser is connected with a third-stage condenser through a pipeline, and the third-stage condenser is connected with a third-stage condenser through a pipeline. The third-stage condenser is connected with a fourth-stage condenser through a pipeline, and the fourth-stage condenser is connected with a silane storage tank through a pipeline; a non-condensable gas pipeline is connected between the second-stage condenser and the fourth-stage condenser, and non-condensable gas of the second-stage condenser is conveyed into a non-condensable gas storage tank through the pipeline. According to the utility model, silane and chlorosilane in accident gas are separated and recycled through multi-stage condensation, and non-condensable gas is discharged to a torch for treatment, so that materials are recycled, the material cost is reduced, and meanwhile, the workload of the torch is also reduced.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of semiconductor manufacturing, especially relates to a silane accident multistage condensing device. BACKGROUND

[0002] Silane has high flammability and explosiveness in the production and treatment process, and once leaked or improperly treated, it can easily cause serious safety accidents. The traditional silane production and treatment device usually adopts single-stage condensing mode. After the safety valve of each device is triggered, the single-stage condensing makes the silane gas condense into liquid, recovers the mixed liquid, and discharges the gas that cannot be condensed to a flare for treatment. However, the single-stage condensing device has problems such as low condensing efficiency, incomplete condensing, and poor system stability, and cannot effectively respond to sudden accidents that may occur in the silane production process.

[0003] The prior art has the following problems: the condensing efficiency is not high, a large amount of silane gas cannot be fully condensed in a short time, the condenser is easy to be blocked, and the difficulty of system maintenance is increased; the temperature control in the condensing process is not accurate enough, causing a large amount of silane to be discharged to a flare for combustion. Therefore, a multistage condensing device capable of improving the condensing efficiency, enhancing the system stability and safety is needed to solve the above problems. SUMMARY

[0004] The technical problem to be solved by the utility model is to provide a silane accident multistage condensing device, which separates silane and chlorosilane in the accident gas through multistage condensing, recovers and reuses them, discharges the non-condensable gas to a flare for treatment, recovers the materials, reduces the material cost, and also reduces the working load of the flare.

[0005] To solve the above technical problems, the utility model adopts the technical scheme of:

[0006] A silane accident multistage condensing device, comprising an accident mixed gas buffer tank, the accident mixed gas buffer tank is connected with a first-stage condenser through a pipeline, the first-stage condenser is connected with a second-stage condenser and a chlorosilane storage tank through pipelines respectively, the second-stage condenser is connected with a third-stage condenser through a pipeline, the third-stage condenser is connected with a fourth-stage condenser through a pipeline, and the fourth-stage condenser is connected with a silane storage tank through a pipeline.

[0007] A non-condensable gas pipeline is connected between the second-stage condenser and the fourth-stage condenser, and the non-condensable gas of the second-stage condenser is transported into a non-condensable gas storage tank through the pipeline.

[0008] Preferably, the accident mixed gas buffer tank is used for introducing mixed tail gas.

[0009] Preferably, the chlorosilane storage tank is connected with a chlorosilane delivery pump through a pipeline.

[0010] Preferably, the silane storage tank is connected with a silane delivery pump through a pipeline.

[0011] Preferably, the outputs of the secondary, tertiary, and quaternary condensers are connected in parallel via parallel pipes.

[0012] Preferably, the non-condensable gas storage tank is connected to the flare via a pipeline.

[0013] The present invention can achieve the following beneficial effects:

[0014] 1. The mixture of gaseous chlorosilane, silane, and non-condensable gas is cooled in four steps. By gradually cooling down, the temperature change during the condensation process can be controlled more precisely, so that the separated non-condensable gas basically does not contain silane and chlorosilane, and the separation between silane and chlorosilane is also more thorough.

[0015] 2. Silanes and chlorosilanes in the accident gas are recovered and reused through multi-stage condensation separation, while non-condensable gases are discharged to the flare for treatment. This process recovers materials, reduces material costs, and also reduces the workload of the flare.

[0016] 3. The cooling medium of the secondary condenser comes from the low-temperature non-condensable gas of the quaternary condenser, which eliminates the need for the heat exchange medium of the secondary condenser and saves costs. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0018] Figure 1 This is a system structure diagram of the present invention.

[0019] In the diagram: 1. Accident mixed gas buffer tank; 2. Primary condenser; 3. Secondary condenser; 4. Tertiary condenser; 5. Quaternary condenser; 6. Non-condensable gas storage tank; 7. Chlorosilane storage tank; 8. Chlorosilane transfer pump; 9. Silane storage tank; 10. Silane transfer pump. Detailed Implementation

[0020] Preferred solutions include Figure 1 As shown, a multi-stage condensation device for silane accidents includes an accident mixed gas buffer tank 1, which is connected to a first-stage condenser 2 via a pipeline. The first-stage condenser 2 is connected to a second-stage condenser 3 and a chlorosilane storage tank 7 via pipelines. The second-stage condenser 3 is connected to a third-stage condenser 4 via a pipeline. The third-stage condenser 4 is connected to a fourth-stage condenser 5 via a pipeline. The fourth-stage condenser 5 is connected to a silane storage tank 9 via a pipeline.

[0021] A non-condensable gas pipeline connects the secondary condenser 3 and the quaternary condenser 5. The non-condensable gas from the secondary condenser 3 is transported to the non-condensable gas storage tank 6 through the pipeline.

[0022] Specifically, the accident mixed gas buffer tank 1 is used for venting mixed tail gas. The chlorosilane storage tank 7 is connected with the chlorosilane delivery pump 8 through a pipeline. The silane storage tank 9 is connected with the silane delivery pump 10 through a pipeline. The output ends of the secondary condenser 3, the tertiary condenser 4 and the quaternary condenser 5 are connected in parallel through parallel pipelines. The non-condensable gas storage tank 6 is connected with a flare through a pipeline.

[0023] The condenser is a key equipment for converting gaseous substances into liquid state, and its working principle is to separate each material by the different boiling points of each component in the material. The silane accident multi-stage condensing device mainly includes five parts of an accident mixed gas buffer tank, an accident gas condenser, a chlorosilane storage tank, a non-condensable gas storage tank and a silane storage tank. It is composed of multiple components, including the accident mixed gas buffer tank V01, the accident gas condenser E01-E04, the chlorosilane storage tank V02, the non-condensable gas storage tank V04 and the silane storage tank V03. These components are assembled into an integrated whole through connecting pipelines and valves, and jointly complete the separation and condensation process of the accident mixed gas.

[0024] Process step description:

[0025] The production device safety valve jumps, and the accident mixed gas enters the first-stage condenser E01 through the accident mixed gas buffer tank. The mixed gas enters the first-stage condenser E01, which is cooled by circulating water to preliminarily condense chlorosilane in the mixed gas. The condensed chlorosilane liquid enters the chlorosilane storage tank V02, and the mixed gas enters the second-stage condenser E02. The mixed gas enters the second-stage condenser E02, which is cooled by the gaseous non-condensable gas of the fourth-stage condenser E04. The condensed chlorosilane liquid enters the chlorosilane storage tank V02, and the mixed gas enters the third-stage condenser E03. The mixed gas enters the third-stage condenser E03, which is cooled by -15°C refrigerated brine. The condensed chlorosilane liquid enters the chlorosilane storage tank V02, and the separated gaseous silane and a small amount of non-condensable gas enter the fourth-stage condenser E04. The gaseous silane and a part of the non-condensable gas enter the fourth-stage condenser E04, which is cooled by -30°C freon. The condensed silane liquid enters the silane storage tank V03, and the non-condensable gas is cooled by the second-stage condenser E02 and then enters the non-condensable gas storage tank. The non-condensable gas buffer tank discharges the gaseous gas in the buffer tank to the flare system for treatment by pressure control. The liquid-phase materials condensed by the first-stage, second-stage, and third-stage condensers enter the chlorosilane storage tank V02. The chlorosilane storage tank V02 is controlled by liquid level to start the pump P01 to return the materials in the chlorosilane storage tank V02 to the disproportionation rectification raw material tank. The liquid-phase materials condensed by the fourth-stage condenser enter the silane storage tank V03 for temporary storage. The silane storage tank V03 is controlled by liquid level to start the pump P02 to return the materials in the silane storage tank V03 to the disproportionation rectification silane buffer tank. In the silane accident multi-stage condensing device, the gaseous chlorosilane and silane mixed gas is first preliminarily condensed by circulating water to preliminarily condense chlorosilane in the mixed gas. Then, the chlorosilane is separated by the second-stage and third-stage condensers, and the silane and non-condensable gas are separated by the fourth-stage condenser. The refrigeration media used by the condensers are, respectively, circulating water, non-condensable gas of the fourth-stage condenser, -15°C refrigerated brine, and -30°C freon. Most of the accident gas is converted from the gaseous state to the liquid state through the condensers. The separated chlorosilane liquid and silane gas are respectively pumped back to the front-end process as raw materials for use, and the non-condensable gas is sent to the flare for treatment.

[0026] In this process, the chlorosilane and silane discharged in the accident process are recovered and separated, and are recovered to the front-end process for reuse, improving the resource utilization rate and greatly saving the material loss. At the same time, the accident gas within the processing capacity does not need to be directly washed and treated by the flare, saving the processing cost.

[0027] In addition, the heat exchange medium of the second-stage condenser E02 is the non-condensable gas from the fourth-stage condenser E04, which cools the mixed accident gas by low-temperature non-condensable gas, saving the investment of the heat exchange medium of the second-stage condenser and further saving the cost.

[0028] Example 1:

[0029] The device mainly comprises a silane accident multistage condensing device which mainly comprises an accident mixed gas buffer tank, an accident gas condenser, a chlorosilane storage tank, a non-condensable gas storage tank and a silane storage tank.

[0030] The device contains four heat exchangers and four storage tanks, and two pumps, wherein the heat exchanger E01 uses circulating water as medium, the heat exchanger E02 uses low-temperature non-condensable gas collected by the heat exchanger E04 as medium, the heat exchanger E03 uses -15 DEG C frozen brine as heat exchange medium, the heat exchanger E04 uses -30 DEG C freon as heat exchange medium, the storage tank V01 is used for storing accident mixed gas, the storage tank V02 is used for storing condensed liquid chlorosilane, the storage tank V03 is used for storing condensed liquid silane, and the storage tank V04 is used for storing non-condensable gas which cannot be condensed by the heat exchanger E04.

[0031] A silane accident multistage condensing device, and the specific steps include the following:

[0032] The accident mixed gas from the silane production device enters the accident mixed gas buffer tank, the mixed gas is cooled by the first-stage condenser E01, the condensed chlorosilane enters the V02 chlorosilane storage tank for collection, the remaining gas enters the second-stage condenser E02 for cooling, the heat exchange medium of the E01 is circulating water, and the temperature of the circulating water is between 0-30 DEG C. The gas from the first-stage condenser E01 is cooled by the second-stage condenser E02, the condensed chlorosilane enters the V02 chlorosilane storage tank for collection, the remaining gas enters the third-stage condenser E03 for cooling, the heat exchange medium of the E02 is low-temperature non-condensable gas from the fourth-stage condenser E04, and the temperature of the low-temperature non-condensable gas is between 0 DEG C. The gas from the second-stage condenser E02 is cooled by the third-stage condenser E03, the condensed chlorosilane enters the V02 chlorosilane storage tank for collection, the remaining gas enters the fourth-stage condenser E04 for cooling, and the heat exchange medium of the E03 is -15 DEG C frozen brine. The gas from the third-stage condenser E03 is cooled by the fourth-stage condenser E04, the condensed silane enters the V03 silane storage tank for collection, the remaining gas enters the second-stage condenser E02 for cooling of the accident mixed gas, and the heat exchange medium of the E04 is -30 DEG C freon.

[0033] The above-mentioned embodiments are only preferred technical solutions of the utility model, and should not be regarded as limitations of the utility model, and the protection scope of the utility model should be the technical solutions recorded in the claims, including equivalent replacement solutions of the technical features recorded in the claims as the protection scope. That is, equivalent replacement improvements within the scope are also within the protection scope of the utility model.

Claims

1. A silane incident multi-stage condensing apparatus, characterized by: The accident mixed gas buffer tank (1) is connected with the first stage condenser (2) through a pipeline, the first stage condenser (2) is connected with the second stage condenser (3) and the chlorosilane storage tank (7) through pipelines respectively, the second stage condenser (3) is connected with the third stage condenser (4) through a pipeline, the third stage condenser (4) is connected with the fourth stage condenser (5) through a pipeline, and the fourth stage condenser (5) is connected with the silane storage tank (9) through a pipeline. A non-condensable gas pipeline is connected between the second stage condenser (3) and the fourth stage condenser (5), and the non-condensable gas of the second stage condenser (3) is transported into the non-condensable gas storage tank (6) through the pipeline.

2. A silane incident multi-stage condensing device according to claim 1, characterized in that: The accident mixed gas buffer tank (1) is connected with the first stage condenser (2) through a pipeline, the first stage condenser (2) is connected with the second stage condenser (3) and the chlorosilane storage tank (7) through pipelines respectively, the second stage condenser (3) is connected with the third stage condenser (4) through a pipeline, the third stage condenser (4) is connected with the fourth stage condenser (5) through a pipeline, and the fourth stage condenser (5) is connected with the silane storage tank (9) through a pipeline.

3. A silane incident multi-stage condensing device according to claim 1, wherein: The chlorosilane storage tank (7) is connected with the chlorosilane delivery pump (8) through a pipeline.

4. A silane incident multi-stage condensing device as claimed in claim 1, wherein: The silane storage tank (9) is connected with the silane delivery pump (10) through a pipeline.

5. A silane incident multi-stage condensing device as claimed in claim 1, wherein: The output ends of the second stage condenser (3), the third stage condenser (4) and the fourth stage condenser (5) are connected in parallel through parallel pipelines.

6. A silane incident multi-stage condensing device as defined in claim 1, wherein: The non-condensable gas storage tank (6) is connected with a flare through a pipeline.

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