Silane recovery system

Abstract

The utility model provides a kind of silane recovery system, wherein precooling system is used to carry out precooling and condensation to tail gas containing silane, and silane rinsing pipeline sends non-condensable gas in precooling system into rinsing system. Liquid silane after condensation is heated and pressurized by silane jacket heating kettle connected with precooling system, and then the heated and pressurized silane gas is purified by rectification separation system communicated with silane jacket heating kettle, and the purified liquid silane enters product tank area, realizing efficient recovery, purification and reuse of silane gas and improving the recovery rate of silane gas, reducing production cost.

Description

Technical Field

[0001] This utility model relates to the field of silane recovery technology, and in particular to a silane recovery system. Background Technology

[0002] Silanes are silicon-containing substances that can be used to manufacture high-purity polycrystalline silicon, monocrystalline silicon, amorphous silicon, metal silicides, silicon nitride, silicon carbide, silicon oxide, and other silicon-containing materials. Due to their high purity and ability to be precisely controlled, they have become an important specialty gas that cannot be replaced by many other silicon sources. They are widely used in the microelectronics industry and are gradually expanding into various fields such as steel, machinery, chemicals, and optics.

[0003] Currently, silane gas production mainly employs disproportionation distillation, involving complex separation and purification processes to obtain high-purity products. However, existing technologies have significant shortcomings in silane gas recovery: whether it's the exhaust gas after filling at the filling station, the replacement gas from aging or substandard tubular containers, or the process tail gas carrying silane in the production system, all are treated using crude methods such as direct flare incineration or scrubbing neutralization. This treatment mode not only leads to a large waste of valuable silane resources and increases production costs but also causes serious environmental pollution. Furthermore, existing recovery technologies are inefficient and cannot guarantee purity, failing to meet the stringent requirements of high-purity silanes from high-end industries such as semiconductors and photovoltaics. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model provides a silane recovery system. To achieve the above objectives, this utility model adopts the following technical solution: A silane recovery system includes a precooling system for precooling and condensing tail gas containing silane and preheating the condensed liquid silane. One end of the precooling system is equipped with a silane scrubbing pipeline that sends non-condensable gas from the precooling system into the scrubbing system. The other end of the precooling system is connected to one end of a silane jacketed heating vessel, which heats and pressurizes the condensed and preheated liquid silane. The other end of the silane jacketed heating vessel is connected to a distillation separation system, and the other end of the distillation separation system is connected to the tail gas pipeline.

[0005] The precooling system includes a silane precooler and a liquid nitrogen condenser. The silane precooler is connected to a silane jacketed heating vessel, a tail gas pipeline, and a liquid nitrogen condenser, respectively. The liquid nitrogen condenser is connected to a silane scrubbing pipeline. The non-condensable gas in the liquid nitrogen condenser is transported to the silane scrubbing pipeline.

[0006] The distillation separation system includes a distillation unit and a purification unit, which are respectively connected to the exhaust gas pipeline.

[0007] The distillation mechanism includes a distillation column and a first heat exchanger. One end of the distillation column is connected to a silane jacketed heating vessel, the top of the distillation column is connected to the first heat exchanger, and the other end is connected to a tail gas pipeline.

[0008] The purification mechanism includes a purification tower and a second heat exchanger. The second heat exchanger is connected to the bottom pipeline of the purification tower and enters the tail gas pipeline. At the other end, the purified liquid silane enters the liquid phase silane storage tank through the heat exchanger assembly.

[0009] The top of the refining tower is connected to the second heat exchanger, and the bottom of the refining tower is connected to the tail gas pipeline. The gas passes through the silane precooler and the liquid nitrogen condenser in sequence. The condensed liquid silane is heated and pressurized by the silane precooler and the silane jacketed heating kettle before entering the distillation tower.

[0010] The finished product tank area includes a heat exchanger group and a liquid phase silane storage tank, and the silane-containing tail gas in the finished product tank area enters the tail gas pipeline.

[0011] Compared with the prior art, the present invention has the following beneficial effects: In this invention, a silane precooler precools the tail gas containing silane while simultaneously heating the liquid silane, reducing the subsequent consumption of liquid nitrogen and the heat source in the jacketed reactor. A liquid nitrogen condenser utilizes the low-temperature properties of liquid nitrogen to condense and recover the silane gas, and transfers the non-condensable gases from the condenser to the silane scrubbing pipeline. The condensed and preheated liquid silane is then transferred to a silane jacketed heating reactor, which heats and pressurizes the recovered liquid silane. The recovered silane gas is pressurized to a suitable pressure by the silane jacketed heating reactor before entering the distillation separation unit for purification, achieving efficient purification and recovery of the silane gas, reducing production costs, and significantly minimizing environmental impact. Attached Figure Description

[0012] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of the structure of this utility model; In the above attached figures: 1. Precooling system; 11. Silane precooler; 12. Liquid nitrogen condenser; 2. Silane rinsing pipeline; 3. Silane jacketed heating vessel; 4. Distillation separation system; 411. Distillation column; 412. First heat exchanger; 421. Refining column; 422. Second heat exchanger; 5. Tail gas pipeline; 6. Finished product tank area; 61. Heat exchanger group; 62. Liquid phase silane storage tank. Detailed Implementation

[0013] To better understand the purpose, structure, and function of this utility model, the silane recovery system of this utility model will be described in further detail below with reference to the accompanying drawings.

[0014] A silane recovery system includes a precooling system 1 for precooling and condensing tail gas containing silane. One end of the precooling system 1 is equipped with a silane scrubbing line 2, which introduces non-condensable gases from the precooling system 1 into the scrubbing system and preheats the condensed liquid silane. The other end of the precooling system 1 is connected to one end of a silane jacketed heating vessel 3, which heats and pressurizes the condensed and preheated liquid silane. The other end of the silane jacketed heating vessel 3 is connected to a distillation separation system 4, one end of which is connected to a tail gas pipeline 5. By connecting the precooling system 1, the silane jacketed heating vessel 3, the distillation separation system 4, and the finished product tank area 6 in series, and using the scrubbing line to scrub the non-condensable gases from the precooling system 1, the system solves the problems of high energy consumption due to dispersed equipment and pollution caused by direct discharge of non-condensable gases from the precooling system 1 in traditional processes.

[0015] Furthermore, the precooling system 1 includes a silane precooler 11 and a liquid nitrogen condenser 12. The silane precooler 11 is connected to the silane jacketed heating vessel 3, the tail gas pipeline 5, and the liquid nitrogen condenser 12, respectively. The liquid nitrogen condenser 12 is also connected to the silane scrubbing pipeline 2, and the non-condensable gas in the liquid nitrogen condenser 12 is transported to the silane scrubbing pipeline 2. The silane precooler 11 precools the tail gas containing silane and simultaneously heats the liquid silane, reducing the subsequent consumption of liquid nitrogen and the heat source of the silane jacketed vessel. The liquid nitrogen condenser 12 utilizes the low-temperature characteristics of liquid nitrogen to condense and recover the silane gas.

[0016] Furthermore, the distillation separation system 4 includes a distillation unit and a purification unit, which are respectively connected to the exhaust gas pipeline 5. The exhaust gas pipeline 5 is connected to the precooling system 1 for recycling.

[0017] Furthermore, the distillation mechanism includes a distillation column 411 and a first heat exchanger 412. One end of the distillation column 411 is connected to the silane jacketed heating vessel 3, the top of the distillation column 411 is connected to the first heat exchanger 412, and the other end of the first heat exchanger 412 is connected to the tail gas pipeline 5. By connecting the top of the distillation column 411 to the first heat exchanger 412, the light components at the top of the distillation column 411 can be efficiently recovered, reducing the energy consumption of the recovery system.

[0018] Furthermore, the refining mechanism includes a refining tower 421 and a second heat exchanger 422, with the second heat exchanger 422 connected to the bottom pipe of the refining tower 421 and entering the exhaust gas pipeline 5. Step-by-step purification and energy recovery are achieved through sequential connection with the refining tower. Furthermore, the top of the purification column 421 is connected to the second heat exchanger 422, and the bottom of the purification column 421 is connected to the tail gas pipeline 5. The gas passes sequentially through the silane precooler 11 and the liquid nitrogen condenser 12. The condensed liquid silane is then heated and pressurized by the silane precooler 11 and the silane jacketed heating vessel 3 before entering the distillation column 411. The distillation column 411 further purifies the silane in the recovered tail gas, improving recovery efficiency and reducing energy consumption. Furthermore, the finished product tank area 6 includes a heat exchanger group 61 and a liquid phase silane storage tank 62. Multiple heat exchangers in the heat exchanger group 61 are connected to the liquid phase silane storage tank 62 to form the finished product tank area. Silane in the tail gas of the tank area is recovered through the tail gas pipeline 5. At the same time, multiple heat exchangers in the heat exchanger group 61 perform temperature control to reduce safety hazards caused by temperature during the transfer and filling process.

[0019] The above embodiments are merely preferred technical solutions of this utility model and should not be considered as limitations on this utility model. The embodiments and features described in this application can be arbitrarily combined without conflict. The protection scope of this utility model should be defined as the technical solution described in the claims, including equivalent substitutions of the technical features described in the claims. That is, equivalent substitutions and improvements within this scope are also within the protection scope of this utility model.

Claims

1. A silane recovery system characterized by: The system includes a precooling system (1), which is used to precool and condense the tail gas containing silane and preheat the condensed liquid silane. One end of the precooling system (1) is equipped with a silane scrubbing pipeline (2), which sends the non-condensable gas in the precooling system (1) into the scrubbing system. The other end of the precooling system (1) is connected to one end of a silane jacketed heating vessel (3), which heats and pressurizes the condensed and preheated liquid silane. The other end of the silane jacketed heating vessel (3) is connected to a distillation separation system (4), and one end of the distillation separation system (4) is connected to a tail gas pipeline (5).

2. The silane recovery system of claim 1, wherein: The precooling system (1) includes a silane precooler (11) and a liquid nitrogen condenser (12). The silane precooler (11) is connected to the silane jacketed heating vessel (3), the tail gas pipeline (5) and the liquid nitrogen condenser (12) respectively, and the liquid nitrogen condenser (12) is connected to the silane scrubbing pipeline (2). The non-condensable gas in the liquid nitrogen condenser (12) is transported to the silane scrubbing pipeline (2).

3. The silane recovery system of claim 1, wherein: The distillation separation system (4) includes a distillation unit and a refining unit, which are respectively connected to the tail gas pipeline (5).

4. The silane recovery system of claim 3, wherein: The distillation mechanism includes a distillation column (411) and a first heat exchanger (412). One end of the distillation column (411) is connected to a silane jacketed heating vessel (3), the top of the distillation column (411) is connected to the first heat exchanger (412), and the other end of the first heat exchanger (412) is connected to the tail gas pipeline (5).

5. The silane recovery system of claim 3, wherein: The refining mechanism includes a refining tower (421) and a second heat exchanger (422), and the second heat exchanger (422) is connected to the bottom pipe of the refining tower (421) and enters the exhaust gas pipeline (5).

6. The silane recovery system of claim 5, wherein: The top of the refining tower (421) is connected to the second heat exchanger (422), and the bottom of the refining tower (421) is connected to the tail gas pipeline (5). The gas passes through the silane precooler (11) and the liquid nitrogen condenser (12) in sequence. The condensed liquid silane is heated and pressurized by the silane precooler (11) and the silane jacketed heating kettle (3) before entering the distillation tower (411).

7. The silane recovery system of claim 1, wherein: It also includes a finished product tank area (6), which includes a heat exchanger group (61) and a liquid phase silane storage tank (62). The silane-containing tail gas in the finished product tank area (6) enters the tail gas pipeline (5).

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