Centrifugal compression method for electronic high-purity gas
Technical Field
The invention relates to the technical field of electronic grade polycrystalline silicon production, in particular to a centrifugal compression method for electronic high-purity gas.
Background
In the field of producing 11N electronic grade polycrystalline silicon, due to market demands, the method has extremely high requirements (11N) on the purity of partial products, and on the basis of the application, the method provides more severe purity requirements on corresponding production, operation, filling and transportation packaging equipment. Due to production requirements, various process gas compressors are subsequently used to produce 11N electronic grade polysilicon, in an effort to deliver high purity hydrogen gas in a pressurized cycle.
The main devices of modern gas in the field of compression delivery are diaphragm compressors, reciprocating compressors and centrifugal compressors. The conveying of high-purity media is limited by the structure, the compression ratio of the diaphragm compressor is high, but the flow rate is low, and the production requirement of a large-batch production process cannot be met. The reciprocating compressor can generate particles due to the friction motion of a piston/cylinder barrel in the operation process, so that the quality/purity of high-purity gas is polluted, and the traditional centrifugal compressor is only applied to the fields of petrochemical industry, conventional fine chemical industry and inorganic chemical industry production at present. The existing centrifugal compressor shaft seal is influenced by the sealing performance, dry gas sealing is adopted, the dry gas sealing introduces gas of a unit, the unit is easy to circularly pollute, and combustible and pyrophoric gas overflows to cause safety accidents.
Therefore, how to provide a centrifugal compression method capable of achieving high-purity electronic grade industrial gas compression is a problem which needs to be solved urgently by the technical personnel in the field.
Disclosure of Invention
In view of the above, the present invention provides a centrifugal compression method for electronic high-purity gas, which aims to solve the above technical problems.
In order to achieve the purpose, the invention adopts the following technical scheme:
a centrifugal compression method for high-purity gas of electrons, the high-purity process gas for electrons enters the interior of a compressor main body through an air inlet of the compressor main body, enters a next-stage impeller channel through an interstage baffle by high-speed rotation of a rotor for gradual pressurization, and is discharged through an air outlet; a primary shaft seal, a secondary shaft seal, a tertiary shaft seal and an isolation shaft seal are symmetrically and sequentially sleeved at two ends of the rotor outwards; two primary shaft seals at two ends of the rotor are communicated through a balance pipe; when the compressor main body works, ultra-high-purity mixed gas is introduced into the first-stage shaft seal, high-purity gas is introduced into the second-stage shaft seal, mixed gas is introduced into the third-stage shaft seal, and inert gas passes through the isolation shaft seal; the ventilation pressure of the first-stage shaft seal is greater than that of the second-stage shaft seal and that of the third-stage shaft seal is greater than that of the isolation shaft seal.
Through the technical scheme, the invention improves the problems of low flow and secondary pollution in the field of high-purity gas process compression and pressure boosting from the details of optimized equipment by adjusting multiple aspects of shaft seal arrangement, gas introduction control, pressure control and the like, ensures the production cleanness of polycrystalline silicon products, and solves the problem that the clean compression of ultra-pure gas cannot be carried out due to the cleanness problem.
Preferably, in the centrifugal compression method for electronic high-purity gas, the rotor is sleeved with a balance disc positioned at the end head of the compressor main body, and the balance disc is positioned between the inner cavity of the compressor main body and the primary shaft seal. For equalizing the internal pressure.
Preferably, in the centrifugal compression method for electronic high-purity gas, the maximum aeration pressure of the primary shaft seal is 0.3MPa, and the maximum inlet flow rate is 20Nm3H is used as the reference value. Can meet the sealing requirement.
Preferably, in the above centrifugal compression method for electronic high purity gas, the maximum leakage pressure of the primary shaft seal is 0.1MPa and the maximum leakage flow rate is 30Nm3H; the maximum leakage pressure of the secondary shaft seal is 0.2MPa, and the maximum leakage flow is 30Nm3H; the maximum leakage pressure of the three-stage shaft seal is 0.1MPa, and the maximum leakage flow is 30Nm3H is used as the reference value. Can meet the sealing requirement.
Preferably, in the above centrifugal compression method for electronic high purity gas, the inter-stage partition plate in contact with the high purity gas inside the compressor main body is connected by bolts; the bolt is axially provided with a through ventilation hole. The ventilation holes are formed, so that the ventilation property of the compressor inner cylinder connecting fastener can be changed, and the problem of dead angles in replacement is solved.
Preferably, in the above-mentioned one centrifugal compression method for electronic high-purity gas, the number of stages of the compressor body is 1 to 12 stages. The flow rate of the compressor can reach 5000-3H, the lifting pressure is 0.1-2.0 MPa.
Preferably, in the above centrifugal compression method for electronic high purity gas, the gas supply system is connected through EP grade metal piping, flanges and unions. The medium in the compressor main body is ensured not to leak and be polluted by the outside during the operation.
Preferably, in the centrifugal compression method for electronic high-purity gas, the surface of the inner flow passage of the compressor main body is polished by a metal polishing processing technology, and the surface roughness Ra is less than or equal to 1.6. The metal polishing technology is processing of grinding and precision grinding after conventional machining, and reduces the surface roughness of a medium flow passage component of the process and meets the use requirement of an electronic grade by mechanical processing and chemical processing methods.
Preferably, in the centrifugal compression method for electronic high-purity gas, the degreasing and rust removal treatment is performed when the structural parts are assembled, and the sealing grease special for high-purity clean gas is applied to the sliding-mounting part of the O-ring for sleeving.
Compared with the prior art, the centrifugal compression method for the electronic high-purity gas has the following beneficial effects that:
1. according to the invention, through the multi-stage arrangement of the shaft seal, the regulation is carried out in multiple aspects such as gas control and pressure control, the problem of low flow and secondary pollution in the field of high-purity gas process compression and pressure boosting is improved from the details of optimized equipment, the production cleanness of polycrystalline silicon products is ensured, and the problem that the clean compression of ultra-pure gas cannot be carried out due to the cleanness problem is solved.
2. The invention reduces the surface roughness of the process medium flow passage component and meets the use requirement of an electronic grade by mechanical processing and chemical processing methods on the basis of the basic structure of the existing centrifugal compressor.
3. The invention changes the tightness or ventilation of the connecting fastener of the compressor inner cylinder, namely the bolt, and improves the problem of replacing dead angles.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.
FIG. 1 is a schematic diagram of the overall apparatus provided by the present invention;
fig. 2 is a schematic structural diagram of a bolt provided by the invention.
Wherein:
1-a compressor body; 2-an air inlet; 3-a rotor; 4-interstage separator; 5-an exhaust port; 6-primary shaft seal; 7-secondary shaft seal; 8-tertiary shaft seal; 9-isolating shaft seal; 10-a balance tube; 11-a balance disc; 12-a bolt; 13-ventilation holes.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Referring to the attached drawings 1 and 2, the embodiment of the invention discloses a centrifugal compression method for electron high-purity gas, wherein the electron high-purity process gas enters the interior of a compressor main body 1 through a gas inlet 2 of the compressor main body 1, passes through an interstage diaphragm 4 by high-speed rotation of a rotor 3, enters a next-stage impeller channel by stage for pressurization, and is discharged through a gas outlet 5; a primary shaft seal 6, a secondary shaft seal 7, a tertiary shaft seal 8 and an isolation shaft seal 9 are symmetrically sleeved at two ends of the rotor 3 in sequence; two primary shaft seals 6 at two ends of the rotor 3 are communicated through a balance pipe 10; when the compressor main body 1 works, ultra-high-purity mixed gas is introduced into the first-stage shaft seal 6, high-purity gas is introduced into the second-stage shaft seal 7, mixed gas is introduced into the third-stage shaft seal 8, and inert gas passes through the isolation shaft seal 9; the ventilation pressure of the primary shaft seal 6 is greater than that of the secondary shaft seal 7 and that of the tertiary shaft seal 8 is greater than that of the isolation shaft seal 9.
In order to further optimize the technical scheme, ultra-high-purity mixed gas is introduced into the primary shaft seal 6, and the ultra-high-purity mixed gas is ultra-high-purity electronic gas, such as hydrogen and silane mixed gas, conveyed in the compressor 1; the introduction of high-purity gas into the secondary shaft seal 7 means that high-purity gas which is easy to prepare, such as high-purity hydrogen, is introduced; mixed gas, mainly nitrogen and the seal gas hydrogen which is connected in series with the secondary shaft seal 7, is introduced into the tertiary shaft seal 8 to form mixed gas.
In order to further optimize the technical scheme, a balance disc 11 positioned at the end head of the compressor main body 1 is sleeved on the rotor 3, and the balance disc 11 is positioned between the inner cavity of the compressor main body 1 and the primary shaft seal 6.
In order to further optimize the technical scheme, the maximum ventilation pressure of the primary shaft seal 6 is 0.3MPa, and the maximum inlet flow is 20Nm3/h。
In order to further optimize the technical scheme, the maximum leakage pressure of the primary shaft seal 6 is 0.1MPa, and the maximum leakage flow is 30Nm3H; the maximum leakage pressure of the secondary shaft seal 7 is 0.2MPa, and the maximum leakage flow is 30Nm3H; the maximum leakage pressure of the tertiary shaft seal 8 is 0.1MPa, and the maximum leakage flow is 30Nm3/h。
In order to further optimize the technical scheme, the interstage diaphragms 4 which are contacted with high-purity gas in the compressor main body 1 are connected by bolts 12; the bolt 12 is axially provided with a ventilation hole 13.
In order to further optimize the above technical solution, the number of stages of the compressor body 1 is 1-12 stages.
In order to further optimize the technical scheme, the gas supply system is connected through an EP-grade metal pipeline, a flange and a movable joint.
In order to further optimize the technical scheme, the surface of the inner flow passage of the compressor main body 1 is polished by a metal polishing processing technology, and the surface roughness Ra is less than or equal to 1.6.
In order to further optimize the technical scheme, the degreasing and rust removal treatment is carried out when all structural parts are assembled.
In order to further optimize the technical scheme, the O-shaped ring sliding part is coated with special sealing grease for high-purity clean gas for sleeving.
The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.