Energy-saving rectification system for electronic-grade silane gas production

Abstract

The utility model discloses an energy-saving rectification system for electronic-grade silane gas production. The energy-saving rectification system comprises a stripping tower condenser arranged on a stripping tower, and a trichlorosilane evaporator connected with a trichlorosilane tower, the trichlorosilane tower is respectively connected with a stripping tower reboiler arranged on the stripping tower and a dichlorosilane reboiler arranged on the dichlorosilane tower, the trichlorosilane tower is connected with a trichlorosilane return tank through a trichlorosilane air cooler, and the trichlorosilane return tank is respectively connected with the trichlorosilane tower and the dichlorosilane tower; the dichlorosilane tower is provided with a dichlorosilane air cooler, the dichlorosilane air cooler is connected with a dichlorosilane return tank, and the dichlorosilane return tank is respectively connected to the dichlorosilane tower and the second reactor feeding preheater; a discharge preheater of the first reactor is connected to a trichlorosilane tower, a discharge port of the second reactor is connected with a silane tower, and the silane tower is respectively connected with a dichlorosilane tower and a post-stripping tower. Therefore, efficient production of the electronic-grade silane gas is realized.

Description

Technical Field

[0001] The utility model relates to the field of machinery, in particular to an energy-saving distillation system for producing electronic-grade silane gas. Background Art

[0002] Silane gas is mainly used in applications such as polysilicon production, solar cell preparation, and flat panel display manufacturing. Electronic-grade silane gas has very strict requirements on its purity.

[0003] In the process of realizing the utility model, it is found that the existing methods of producing chlorosilane or other methods of producing silane gas are not energy-saving distillation systems for producing electronic-grade silane gas. Utility Model Content

[0004] In view of this, the energy-saving distillation system provided by the embodiment of the utility model can efficiently produce electronic-grade silane gas and achieve energy conservation, emission reduction and cost reduction.

[0005] To achieve the above-mentioned purpose, according to an embodiment of the utility model, an energy-saving distillation system for producing electronic-grade silane gas is provided, comprising: a stripping tower, a trichlorosilane tower, a stripping tower condenser, a trichlorosilane evaporator, a dichlorosilane reboiler, a stripping tower reboiler, a dichlorosilane tower, a trichlorosilane air cooler, a trichlorosilane reflux tank, a dichlorosilane air cooler, a dichlorosilane reflux tank, a second reactor feed preheater, a second reactor, a first reactor feed cooler, a first reactor, a first reactor discharge preheater, a silane tower and a post-stripping tower;

[0006] The stripping tower is equipped with a stripping tower condenser and a trichlorosilane evaporator connected to the trichlorosilane tower; the trichlorosilane tower is respectively connected to the stripping tower reboiler installed on the stripping tower and the dichlorosilane reboiler installed on the dichlorosilane tower, and the trichlorosilane tower is connected to the trichlorosilane reflux tank through a trichlorosilane air cooler, and the trichlorosilane reflux tank is respectively connected to the trichlorosilane tower and the dichlorosilane tower; the dichlorosilane tower is equipped with a dichlorosilane air cooler, and the dichlorosilane air cooler is connected to the dichlorosilane reflux tank The dichlorosilane reflux tank is connected to the dichlorosilane tower and the second reactor feed preheater respectively, the second reactor feed preheater is connected to the second reactor and the first reactor feed cooler, and the first reactor feed cooler is connected to the first reactor; the discharge port of the first reactor is connected to the first reactor discharge preheater, and the first reactor discharge preheater is connected to the trichlorosilane tower; and the discharge port of the second reactor is connected to the silane tower, and the silane tower is connected to the dichlorosilane tower and the post-stripping tower respectively.

[0007] Optionally, it includes: a dichlorosilane tower reflux pump, a second reactor feed pump, a dichlorosilane cryogenic pump and a mixer; wherein the dichlorosilane reflux tank is connected to the dichlorosilane tower through the dichlorosilane tower reflux pump, and the dichlorosilane reflux tank is connected to the second reactor feed preheater after being mixed with the dichlorosilane cryogenic pump through the mixer through the second reactor feed pump.

[0008] Optionally, it includes: a trichlorosilane reboiler; wherein the trichlorosilane reboiler is installed in a trichlorosilane tower to control the pressure of the trichlorosilane tower, and the heat source of the trichlorosilane reboiler comes from a heat carrier.

[0009] Optionally, it includes: a trichlorosilane tower kettle pump and a silicon tetrachloride air cooler; wherein the trichlorosilane tower is connected to the first reactor discharge preheater through the trichlorosilane tower kettle pump, and the first reactor discharge preheater is connected to the silicon tetrachloride air cooler.

[0010] Optionally, it includes: a dichlorosilane cryogenic cooler, a dichlorosilane cryogenic tank and a mixer; wherein the dichlorosilane tower is equipped with a dichlorosilane cryogenic cooler, the dichlorosilane tower is connected to the dichlorosilane cryogenic tank through the dichlorosilane cryogenic cooler, and the dichlorosilane reflux tank and the dichlorosilane cryogenic tank are connected to the second reactor feed preheater after the mixer.

[0011] Optionally, the method comprises: the dichlorosilane reflux tank is connected to the dichlorosilane tower via a dichlorosilane tower reflux pump, and the dichlorosilane tower bottom is connected to the second reactor feed preheater via a dichlorosilane tower bottom pump.

[0012] Optionally, it includes: a silane tower reboiler; wherein the silane tower reboiler is installed in the silane tower to control the pressure of the silane tower, and the heat source of the silane tower reboiler comes from a heat carrier.

[0013] Optionally, it includes: a silane tower condenser; wherein the silane tower condenser is installed on the top of the silane tower to control the temperature of the silane tower.

[0014] Optionally, the silane tower condenser is connected to an adsorption column, and the adsorption column is connected to a post-stripping tower.

[0015] Optionally, it includes: a post-stripping tower evaporator and a post-stripping tower condenser; wherein the post-stripping tower condenser is installed at the top of the post-stripping tower to control the temperature of the post-stripping tower; and the post-stripping tower evaporator is installed at the bottom of the post-stripping tower to control the pressure of the post-stripping tower.

[0016] One embodiment of the above utility model has the following advantages or beneficial effects: the energy-saving distillation system for electronic-grade silane gas production provided by the utility model can adjust the trichlorosilane tower so that the top gas phase can be used as the heat exchange medium of the stripping tower and the tower kettle reboiler of the dichlorosilane tower, while reducing the load of the top heat exchanger of the trichlorosilane tower, saving the use of heat medium of the stripping tower and the tower kettle of the dichlorosilane tower, and realizing energy saving and emission reduction; through the efficient disproportionation resin, after two-step disproportionation, high-purity silane gas is separated in the silane tower, and electronic-grade silane gas is produced through the post-stripping tower. At the same time, in the coupled distillation part, multiple heat recovery through each heat exchanger can effectively reduce the supply of external heat sources, greatly reduce the initial investment cost and production operation cost. Among them, coupled distillation refers to the distillation process in which two or more distillation towers in multi-component distillation are connected by hot materials to provide each other with the required bottom steam or top reflux.

[0017] The further effects of the above-mentioned non-conventional optional manner will be described below in conjunction with the specific implementation manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are used to better understand the present invention and do not constitute an improper limitation on the present invention.

[0019] Figure 1 It is a structural schematic diagram of an energy-saving distillation system for producing electronic-grade silane gas according to an embodiment of the utility model. DETAILED DESCRIPTION

[0020] The following is a description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, including various details of the embodiments of the present invention to facilitate understanding, which should be considered as merely exemplary. Therefore, it should be recognized by those of ordinary skill in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the present invention. Similarly, for the sake of clarity and conciseness, the description of well-known functions and structures is omitted in the following description.

[0021] At least one embodiment of the present utility model provides an energy-saving distillation system for producing electronic grade silane gas, such as Figure 1As shown, the energy-saving distillation system for producing electronic-grade silane gas can include a stripping tower 1, a trichlorosilane tower 2, a stripping tower condenser 7, a trichlorosilane evaporator 8, a dichlorosilane reboiler 13, a stripping tower reboiler 6, a dichlorosilane tower 3, a trichlorosilane air cooler 10, a trichlorosilane reflux tank 31, a dichlorosilane air cooler 14, a dichlorosilane reflux tank 32, a second reactor feed preheater 16, a second reactor 35, a first reactor feed cooler 17, a first reactor 34, a first reactor discharge preheater 12, a silane tower 4 and a post-stripping tower 5. Among them, the chemical formula of silane is SIH4, abbreviated as MS, which is the final product of the whole system. The chemical formula of trichlorosilane is SIHCL3, abbreviated as TCS, a kind of chlorosilane, a product of cold hydrogenation, used for disproportionation to generate light chlorosilane and silane. The chemical formula of dichlorosilane is SIH2CL2, abbreviated as DCS, a type of chlorosilane and an intermediate product in the system.

[0022] In the embodiment, the stripping tower 1 is equipped with a stripping tower condenser 7, a trichlorosilane evaporator 8 connected to the trichlorosilane tower 2, and the bottom material of the stripping tower 1 is transported to the trichlorosilane evaporator 8 through the stripping tower bottom pump 22, and the trichlorosilane evaporator 8 is connected to the trichlorosilane tower 2. The trichlorosilane tower 2 is respectively connected to the stripping tower reboiler 6 installed on the stripping tower 1 and the dichlorosilane reboiler 13 installed on the dichlorosilane tower 3, and the trichlorosilane tower 2 is connected to the trichlorosilane reflux tank 31 through the trichlorosilane air cooler 10, and the trichlorosilane reflux tank 31 is respectively connected to the trichlorosilane tower 2 and the dichlorosilane tower 3. The dichlorosilane tower 3 is equipped with a dichlorosilane air cooler 14, and the dichlorosilane air cooler 14 is connected to the dichlorosilane reflux tank 32, and the dichlorosilane reflux tank 32 is respectively connected to the dichlorosilane tower 3 and the second reactor feed preheater 16, and the second reactor feed preheater 16 is connected to the second reactor 35 and the first reactor feed cooler 17, and the first reactor feed cooler 17 is connected to the first reactor 34. The discharge port of the first reactor 34 is connected to the first reactor discharge preheater 12, and the first reactor discharge preheater 12 is connected to the trichlorosilane tower 2. And, the discharge port of the second reactor 35 is connected to the silane tower 4, and the silane tower 4 is respectively connected to the dichlorosilane tower 3 and the post-stripping tower 5.

[0023] Therefore, the energy-saving distillation system for electronic-grade silane gas production described in the utility model can allow the mixed chlorosilane from cold hydrogenation production to enter the stripping tower 1 for light removal treatment, and the mixed chlorosilane (mainly STC / TCS) in the bottom of the stripping tower 1 is pumped to the trichlorosilane evaporator 8 by the stripping tower bottom pump 22, and is heated and vaporized by the heat carrier and sent to the trichlorosilane tower 2 for separation. Preferably, the mixed chlorosilane in the bottom of the stripping tower 1 is pumped to the trichlorosilane evaporator 8 by the stripping tower bottom pump 22. In another preferred embodiment, the stripping tower 1 can control the temperature at -30 to -40°C through the stripping tower condenser 7 to recover the chlorosilane, and the non-condensable gas is sent to the waste gas for treatment. Among them, heat recovery is to recover and reuse the waste heat discharged to the outside during the operation of the distillation tower bottom through a heat exchanger as a heat source for part of the material.

[0024] The gas phase at the top of the trichlorosilane tower 2 enters the stripping tower reboiler 6 and the dichlorosilane reboiler 13 as heat carriers to control the pressure of the stripping tower 1 and the dichlorosilane tower 3, and the remaining part is cooled by the trichlorosilane air cooler 10, and the liquid phase DCS / TCS is collected in the trichlorosilane reflux tank 31. A part of the material in the trichlorosilane reflux tank 31 is transported to the trichlorosilane tower 2 as the reflux of the trichlorosilane tower 2, and the other part is transported to the dichlorosilane tower 3 as the feed of the dichlorosilane tower 3. The STC (silicon tetrachloride chemical formula is SICL4, abbreviated as STC, a kind of chlorosilane, a by-product in the cold hydrogenation product and an intermediate product of this system, which is separated by this system and returned to hydrogenation for recycling.) in the bottom of the trichlorosilane tower 2 is transported to the first reactor discharge preheater 12 for heat recovery, and can participate in the circulation reaction again after heating the discharge of the first reactor 34. Preferably, the pressure of the dichlorosilane tower 3 can be controlled at 0.4-0.6 MPag through the dichlorosilane reboiler 13, and the heat source can come from the gaseous chlorosilane at the top of the trichlorosilane tower 2.

[0025] The top material of the dichlorosilane tower 3 is condensed by the dichlorosilane air cooler 14 and collected in the dichlorosilane reflux tank 32. A part of the material in the dichlorosilane reflux tank 32 is transported to the dichlorosilane tower 3 as reflux, and the other part is transported to the reactor 2 for chlorosilane disproportionation reaction. Among them, chlorosilane disproportionation refers to TCS (trichlorosilane chemical formula is SIHCL3, abbreviated as TCS) through disproportionation reaction to generate STC (silicon tetrachloride chemical formula is SICL4, abbreviated as STC) and DCS (dichlorosilane chemical formula is SIH2CL2, abbreviated as DCS), DCS through disproportionation reaction to generate TCS and MCS (monochlorotrihydrogen silicon chemical formula is SIH3CL, abbreviated as MCS, a kind of chlorosilane, an intermediate product in the system.), MCS through disproportionation reaction to generate MS (silane chemical formula is SIH4, abbreviated as MS) and DCS.

[0026] The bottom TCS of dichlorosilane tower 3 is transported to the second reactor feed preheater 16 for heat recovery, cooled to the required temperature of the first reactor 34 through the first reactor feed cooler 17, and enters the first reactor 34 for chlorosilane disproportionation reaction. The discharge of the first reactor 34 is transported to the first reactor discharge preheater 12 for heat exchange with the bottom material of trichlorosilane tower 2, and then sent to trichlorosilane tower 2 for chlorosilane separation. Preferably, the discharge of the first reactor 34 is pumped to the first reactor discharge preheater 12 through the first reactor discharge pump 30, and the first reactor discharge pump 30 can be used or not according to the working conditions of the downstream system.

[0027] The discharge from the second reactor 35 enters the silane tower 4 through a pressure difference for silane separation, and the mixed chlorosilane (including STC / TCS / DCS / MCS) in the bottom of the silane tower 4 is sent to the dichlorosilane tower 3 through a pressure difference for re-separation. In addition, the silane gas at the top of the silane tower 4 is transported to the post-stripping tower 5 for dehydrogenation.

[0028] In addition, the first reactor 34 and the second reactor 35 use a high-efficiency resin for disproportionation of chlorosilane. If there is a more cost-effective resin or other disproportionation material, it can also be used instead.

[0029] Preferably, the waste gas from the top of the stripping tower 1 can be recycled. In this system, an adsorption column for removing boron, phosphorus or other impurities from chlorosilane can be added before feeding the stripping tower 1 or before feeding the silane tower 4, and then combined with the adsorption column of the silane tower 4, the quality of the silane gas can be made purer.

[0030] Some embodiments worth mentioning are energy-saving distillation systems for the production of electronic grade silane gas, such as Figure 1 As shown, the dichlorosilane reflux tank 32 is connected to the dichlorosilane tower 3 through the dichlorosilane tower reflux pump 26, and the dichlorosilane tower 3 bottom is connected to the second reactor feed preheater 16 through the dichlorosilane tower bottom pump 29. Further, the energy-saving distillation system for electronic grade silane gas production includes a second reactor feed pump 27, a dichlorosilane cryogenic pump 28 and a mixer 37, the dichlorosilane reflux tank 32 is connected to the mixer 37 through the second reactor feed pump 27, and the mixer 37 is connected to the dichlorosilane cryogenic pump 28.

[0031] For example: part of the material in the dichlorosilane reflux tank 32 is pumped to the dichlorosilane tower 3 as reflux by the dichlorosilane tower reflux pump 26, and the other part is pressurized by the second reactor feed pump 27 and mixed with the deep-cold material pumped by the dichlorosilane deep-cold pump 28 through the mixer 37 and then sent to the second reactor feed preheater 16, and after being heated by the material in the bottom of the dichlorosilane tower 3, it enters the second reactor 35 for chlorosilane disproportionation reaction.

[0032] Furthermore, the energy-saving distillation system for the production of electronic-grade silane gas includes a dichlorosilane tower bottom pump 29. The TCS in the bottom of the dichlorosilane tower 3 is pumped to the second reactor feed preheater 16 for heat recovery through the dichlorosilane tower bottom pump 29 to heat the DCS / MCS mixture from the mixer. After heat recovery, the mixture is cooled to the required temperature of the first reactor 34 through the first reactor feed cooler 17 and enters the first reactor 34 for chlorosilane disproportionation reaction.

[0033] In other embodiments, the pressure of the stripping tower 1 is controlled at 0.3-0.4 Mpag by the stripping tower reboiler 6 (the heat source is the gaseous chlorosilane at the top of the trichlorosilane tower 2).

[0034] As other embodiments of the utility model, the energy-saving distillation system for the production of electronic-grade silane gas includes: a trichlorosilane tower reflux pump 23 and a dichlorosilane tower feed pump 24. In the embodiment, the trichlorosilane reflux tank 31 is connected to the trichlorosilane tower 2 through the trichlorosilane tower reflux pump 23, and the trichlorosilane reflux tank 31 is connected to the dichlorosilane tower 3 through the dichlorosilane tower feed pump 24. Therefore, a part of the material of the trichlorosilane reflux tank 31 is pumped to the trichlorosilane tower 2 through the trichlorosilane tower reflux pump 23 as the reflux of the trichlorosilane tower 2, and a part is pumped to the dichlorosilane tower 3 through the dichlorosilane tower feed pump 24 as the feed of the dichlorosilane tower 3.

[0035] It is worth noting that the dichlorosilane tower feed pump 24 may not be provided, and a stream of the discharge from the trichlorosilane tower reflux pump 23 may be separated as the feed for the dichlorosilane tower 3 .

[0036] As a preferred embodiment of the utility model, the energy-saving distillation system for producing electronic-grade silane gas further comprises a trichlorosilane reboiler 9. In the embodiment, the trichlorosilane reboiler 9 is installed in the trichlorosilane tower 2 to control the pressure of the trichlorosilane tower 2, and the heat source of the trichlorosilane reboiler 9 comes from a heat carrier. For example: the pressure of the trichlorosilane tower 2 is controlled at 0.8-1 Mpag by the trichlorosilane reboiler 9.

[0037] In some embodiments, it is worth noting that an energy-saving distillation system for producing electronic grade silane gas, such as Figure 1 As shown, it includes a silane tower reboiler 18. The silane tower reboiler 18 is installed on the silane tower 4 to control the pressure of the silane tower 4. The heat source of the silane tower reboiler 18 comes from a heat carrier. For example: the pressure of the silane tower 4 is controlled at 2-3 Mpag by the silane tower reboiler 18.

[0038] In some further embodiments of the present invention, Figure 1As shown, the energy-saving distillation system for producing electronic-grade silane gas includes: a silane tower condenser 19, which is installed on the top of the silane tower 4 and is used to control the temperature of the silane tower 4. For example: the temperature is controlled at -30 to -40°C by the silane tower condenser 19 to recover chlorosilane.

[0039] Furthermore, the silane tower condenser 19 is connected to an adsorption column 36, and the adsorption column 36 is connected to the post-stripping tower 5, and silane is sent to the adsorption column 36 for impurity removal. The adsorption column is loaded with a specific molecular sieve or resin to adsorb and remove impurities in the material. For example: After the silane gas at the top of the silane tower 4 passes through the adsorption column 36 for impurity removal, it enters the post-stripping tower 5 through the pressure difference for dehydrogenation, and the electronic grade silane gas extracted from the side line of the post-stripping tower 5 is sent to the downstream for storage or reaction, and the tower kettle of the post-stripping tower 5 ensures the quality of the silane gas by intermittent waste discharge.

[0040] It is worth noting that the position of the adsorption column can be adjusted, and an adsorption column can be added at the discharge of the post-stripping tower 5 to ensure the quality of the silane gas. In this system, the adsorption column after the silane tower 4 is mainly used for boron and phosphorus adsorption, and other element adsorption columns can also be used, and resins, molecular sieves or other more efficient adsorption materials can be used.

[0041] In some other embodiments, the energy-saving distillation system for producing electronic-grade silane gas includes: a post-stripping tower evaporator 20 and a post-stripping tower condenser 21. The post-stripping tower condenser 21 is installed at the top of the post-stripping tower 5 to control the temperature of the post-stripping tower 5; and the post-stripping tower evaporator 20 is installed at the bottom of the post-stripping tower 5 to control the pressure of the post-stripping tower 5. For example: the pressure of the post-stripping tower 5 is controlled at 2 to 3 Mpag by the post-stripping tower evaporator 20, and the temperature of the post-stripping tower condenser 21 is controlled at -30 to -40 ° C to recover silane, and the silane containing a small amount of hydrogen is sent to the downstream to participate in the reaction.

[0042] There are other embodiments, such as Figure 1 As shown, the energy-saving distillation system for the production of electronic-grade silane gas also includes: a trichlorosilane tower bottom pump 25 and a silicon tetrachloride air cooler 11. Among them, the trichlorosilane tower 2 is connected to the first reactor discharge preheater 12 through the trichlorosilane tower bottom pump 25, and the first reactor discharge preheater 12 is connected to the silicon tetrachloride air cooler 11. For example, the tower bottom STC of the trichlorosilane tower 2 is pumped to the first reactor discharge preheater 12 by the trichlorosilane tower bottom pump 25 for heat recovery to heat the discharge of the first reactor 34, and the STC of the tower bottom of the trichlorosilane tower 2 is cooled to the required temperature for hydrogenation by the silicon tetrachloride air cooler 11, and then participates in the circulation reaction.

[0043] It is worth noting that the trichlorosilane tower kettle pump 25 can be used or not according to the working conditions of the downstream system.

[0044] In some other embodiments of the present invention, Figure 1 As shown, the energy-saving distillation system for the production of electronic-grade silane gas includes a dichlorosilane cryogenic unit 15, a dichlorosilane cryogenic tank 33 and a mixer 37. The dichlorosilane tower 3 is connected to the dichlorosilane cryogenic tank 33 through the dichlorosilane cryogenic unit 15, and the dichlorosilane reflux tank 32 and the dichlorosilane cryogenic tank 33 are connected to the second reactor feed preheater 16 after the mixer 37. In the embodiment, the top material of the dichlorosilane tower 3 is partially condensed by the dichlorosilane air cooler 14, and the partially condensed material (mostly DCS) is collected in the dichlorosilane reflux tank 32, and the non-condensable gas (mainly MCS and SIH4) is collected in the dichlorosilane cryogenic tank 33 after being cryogenically cooled by the dichlorosilane cryogenic unit 15.

[0045] It is worth noting that the dichlorosilane deep cooler 15 can be combined with the dichlorosilane air cooler 14, using the same coolant for cooling, and the corresponding parameters can be adjusted.

[0046] In addition, the energy-saving distillation system for producing electronic-grade silane gas may use heat transfer oil, steam or other heating media as heat carriers for use in, for example, trichlorosilane evaporator 8, trichlorosilane reboiler 9, and silane tower reboiler 18.

[0047] The trichlorosilane air cooler 10, silicon tetrachloride air cooler 11, dichlorosilane air cooler 14, and first reactor feed cooler 17 in the energy-saving distillation system for producing electronic-grade silane gas can use dry air coolers, wet air coolers, composite air coolers or other coolers to cool chlorosilane.

[0048] It should be noted that the energy-saving distillation system for electronic-grade silane gas production adjusts the trichlorosilane tower 2 so that the top gas phase is used as the heat exchange medium of the stripping tower 1 and the tower kettle of the dichlorosilane tower 3, while reducing the load of the top heat exchanger of the trichlorosilane tower 2, saving the use of external heat sources of the stripping tower 1 and the tower kettle of the dichlorosilane tower 3, saving energy and reducing emissions. Through two-step disproportionation of efficient disproportionation resin, high-purity silane gas is separated in the silane tower 4, and enters the rear stripping tower 5 after passing through the efficient adsorption column to produce electronic-grade silane gas. At the same time, in the three-tower coupling distillation part of the stripping tower 1, the trichlorosilane tower 2, and the dichlorosilane tower 3, after multiple heat exchanger heat recovery (for example, the tower kettle material of the trichlorosilane tower 2 is heat-recovered to heat the outlet material of the first reactor 34, and the tower kettle material of the dichlorosilane tower 3 is heat-recovered to heat the material entering the second reactor 35), the external heat source supply can also be effectively reduced. Electronic grade silane gas can be continuously produced in large quantities through the stripping tower 1, trichlorosilane tower 2, dichlorosilane tower 3, silane tower 4 and post-stripping tower 5, as well as the first reactor 34 and the second reactor 35 through heat recovery and impurity adsorption.

[0049] The cooling method in the energy-saving distillation system for electronic-grade silane gas production can be adjusted according to user needs, and various methods such as oil cooling and methanol water cooling can be used according to actual working conditions. The overall specifications, dimensions, and internal filler types and quantities of the equipment can be adjusted according to actual working conditions.

[0050] Each device in the energy-saving distillation system for the production of electronic-grade silane gas can be equipped with instruments, and the number and type of each type of instrument involved are adjusted according to the actual situation of the user. Valves are arranged on the connecting pipelines of each device in the energy-saving distillation system for the production of electronic-grade silane gas, and there is no limitation on the valve form, valve number, valve control, etc. on each pipeline, and they can be selected and set according to the actual situation.

[0051] All connection forms in the energy-saving distillation system for producing electronic-grade silane gas should preferably be welded. If it is not a special component, flange connection or other more reliable connection methods can be used to ensure the reliability of the connection, which can effectively avoid the occurrence of safety accidents.

[0052] Unless otherwise clearly specified and limited, the terms "installed", "connected", "connected" and the like may refer to fixed connection, detachable connection, or integral connection. For those skilled in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0053] The above specific implementations do not constitute a limitation on the protection scope of the present utility model. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions may occur depending on design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present utility model shall be included in the protection scope of the present utility model.

Claims

1. An energy-saving distillation system for the production of electronic grade silane gas, characterized in that: include: Stripping tower, trichlorosilane tower, stripping tower condenser, trichlorosilane evaporator, dichlorosilane reboiler, stripping tower reboiler, dichlorosilane tower, trichlorosilane air cooler, trichlorosilane reflux tank, dichlorosilane air cooler, dichlorosilane reflux tank, second reactor feed preheater, second reactor, first reactor feed cooler, first reactor, first reactor discharge preheater, silane tower and post-stripping tower; The stripping tower is equipped with a stripping tower condenser and a trichlorosilane evaporator connected to a trichlorosilane tower; the trichlorosilane tower is respectively connected to a stripping tower reboiler installed on the stripping tower and a dichlorosilane reboiler installed on a dichlorosilane tower, and the trichlorosilane tower is connected to a trichlorosilane reflux tank through a trichlorosilane air cooler, and the trichlorosilane reflux tank is respectively connected to the trichlorosilane tower and the dichlorosilane tower; The dichlorosilane tower is equipped with a dichlorosilane air cooler, and the dichlorosilane air cooler is connected to a dichlorosilane reflux tank, the dichlorosilane reflux tank is respectively connected to the dichlorosilane tower and a second reactor feed preheater, the second reactor feed preheater is connected to the second reactor and the first reactor feed cooler, and the first reactor feed cooler is connected to the first reactor; The discharge port of the first reactor is connected to the discharge preheater of the first reactor, and the discharge preheater of the first reactor is connected to the trichlorosilane tower; and the discharge port of the second reactor is connected to the silane tower, and the silane tower is respectively connected to the dichlorosilane tower and the post-stripping tower.

2. The energy-saving distillation system for producing electronic-grade silane gas according to claim 1, characterized in that: include: Reflux pump for dichlorosilane tower, feed pump for second reactor, dichlorosilane cryogenic pump and mixer; The dichlorosilane reflux tank is connected to the dichlorosilane tower through a dichlorosilane tower reflux pump, and the dichlorosilane reflux tank is connected to the second reactor feed preheater after being mixed with the dichlorosilane cryogenic pump through a mixer via a second reactor feed pump.

3. The energy-saving distillation system for producing electronic-grade silane gas according to claim 1, characterized in that: Includes: trichlorosilane reboiler; The trichlorosilane reboiler is installed in the trichlorosilane tower to control the pressure of the trichlorosilane tower, and the heat source of the trichlorosilane reboiler comes from the heat carrier.

4. The energy-saving distillation system for producing electronic-grade silane gas according to claim 1, characterized in that: Including: trichlorosilane tower kettle pump and silicon tetrachloride air cooler; The trichlorosilane tower is connected to the first reactor discharge preheater through the trichlorosilane tower kettle pump, and the first reactor discharge preheater is connected to the silicon tetrachloride air cooler.

5. The energy-saving distillation system for producing electronic-grade silane gas according to claim 1, characterized in that: include: Dichlorosilane cryogenic coolers, dichlorosilane cryogenic tanks and mixers; Among them, the dichlorosilane tower is equipped with a dichlorosilane cryogenic cooler, the dichlorosilane tower is connected to the dichlorosilane cryogenic tank through the dichlorosilane cryogenic cooler, and the dichlorosilane reflux tank and the dichlorosilane cryogenic tank are connected to the second reactor feed preheater after a mixer.

6. The energy-saving distillation system for producing electronic-grade silane gas according to claim 1, characterized in that: include: The dichlorosilane reflux tank is connected to the dichlorosilane tower through a dichlorosilane tower reflux pump, and the dichlorosilane tower bottom is connected to the second reactor feed preheater through a dichlorosilane tower bottom pump.

7. The energy-saving distillation system for producing electronic-grade silane gas according to claim 1, characterized in that: include: Silane tower reboiler; The silane tower reboiler is installed in the silane tower to control the pressure of the silane tower, and the heat source of the silane tower reboiler comes from a heat carrier.

8. The energy-saving distillation system for producing electronic-grade silane gas according to claim 1, characterized in that: include: Silane tower condenser; Wherein, the silane tower condenser is installed at the top of the silane tower and is used to control the temperature of the silane tower.

9. The energy-saving distillation system for producing electronic-grade silane gas according to claim 8, characterized in that: include: The silane tower condenser is connected to an adsorption column, and the adsorption column is connected to a post-stripping tower.

10. The energy-saving distillation system for producing electronic-grade silane gas according to any one of claims 1 to 9, characterized in that: Including: post-stripping tower evaporator and post-stripping tower condenser; The post-stripping tower condenser is installed at the top of the post-stripping tower to control the temperature of the post-stripping tower; and the post-stripping tower evaporator is installed at the bottom of the post-stripping tower to control the pressure of the post-stripping tower.

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