CN108138992A

CN108138992A - For the isostatic pressing formed graphite liner of fluidized-bed reactor

Info

Publication number: CN108138992A
Application number: CN201680058765.8A
Authority: CN
Inventors: S·L·金贝尔
Original assignee: SunEdison Inc
Current assignee: Jiangsu Zhongneng Polysilicon Technology Development Co ltd
Priority date: 2015-10-05
Filing date: 2016-10-04
Publication date: 2018-06-08
Anticipated expiration: 2036-10-04
Also published as: CN108138992B; WO2017062356A1

Abstract

A kind of fluidized-bed reactor, including polysilicon preparation liner, which has the tube-shaped tube extended along axis with liner.The pipe includes the inner surface and the outer surface, which limits tube thickness therebetween.The polysilicon liner further includes at least one layer of twister wound around the outer surface of pipe.The twister prevents being radially expanded for pipe.

Description

For the isostatic pressing formed graphite liner of fluidized-bed reactor

Cross-reference to related applications

This application claims the excellent of the U.S. Provisional Patent Application Serial No.62/237,288 submitted on October 5th, 2015 It first weighs, is herein integrally incorporated the disclosure of which as reference.

Technical field

The field of the disclosure is related to the isostatic pressing formed graphite liner for fluidized-bed reactor, and relates more specifically to have For applying the graphite liner of the pre-tensioned twister of radial compression force to liner.

Background technology

Polysilicon is for producing many commercial products --- including such as integrated circuit and photovoltaic (i.e. solar energy) electricity Pond --- important raw and processed materials, polysilicon usually produced using chemical vapor deposition mechanism, and wherein silicon is from heat decomposable silicon Precursor compound is deposited on the silicon particle in fluidized-bed reactor (" FBR ").Suitable thermal decomposition silicon compound includes example Such as silane and the halogenated silanes of such as trichlorosilane.

In the FBR preparation processes being known in the art, decomposable silicon precursor compound (for example, silane) and silicon seed Particle is by continuous feed to reactor.Silicon particle bed is kept using appropriate heating unit under high temperature, and is passed through upwards Gas flowing keep in fluidized state.This bed is referred to as fluid bed.Siliceous deposits is in the seed particles continuously grown, directly Reach critical dimension to them, hereafter separate them to the bottom of reactor, they are as polysilicon product (i.e. " grain herein Shape " polysilicon) it is removed from FBR.

It is different from the conventional FBR for being used to prepare general chemical product, in the fluidized-bed reactor for being used to prepare polysilicon Limitation is encountered in the material selection of component.Reactor linings are continuously contacted with the silicon particle fluidized at high temperature and pressure, and Bear the irregular oscillation as caused by the fluid bed of particle and serious shear stress and the pressure difference and temperature across reactor linings Difference.Desired high material output due to the expectation high-purity of polysilicon, in the case of downtime minimum is exposed to corrosion Property reaction gas and pressure, temperature, shear stress, vibration and the combination of the extreme operating condition of abrasion, for fluid bed liner The material selection of structure is difficult.For these reasons, FBR reactors and reactor linings have by many process variables and The labyrinth that a combination thereof influences.

The FBR liners and inner lining surface contacted with silicon particle is designed to meet mechanical, hot, electricity and chemical-resistance will It asks, to provide silicon that is acceptable compatible and producing high purity grades for high-temperature operation.The problem, however, is that this field In known liner case hardness and roughness be not optimized to provide cause to being contacted by polycrysalline silcon with inner lining surface Corrosion high-resistance.Furthermore compressive resistance, bending strength and the tensile strength of liner known in the art are insufficient to allow for It builds to improve compared with reactor well known in the prior art in the yield of polysilicon and the large-scale FBR of productivity Lining.Specifically, the tensile stress of the outside of the cylindrical shape graphite liner acted in silicon FBR reactors may cause pad to react Device and as technique liner graphite cylinder section axial rift.For the axial compressive force for maintaining sealing and for maintaining technique The radial pressure of purity is there may be axial crack or axially expands existing graphite crackle, is broken so as to cause liner or broken It splits and operation troubles occurs.

Therefore exist to preventing or eliminating the fracture in the FBR liners for preparing polysilicon with high-purity and high production rate Demand.

The background section is intended to may be with the various aspects of the relevant technology of each aspect of the present invention to reader's introduction, this A little aspects are described below and/or require.It is believed that this is discussed for being supplied to reader with background information in favor of more fully understanding Various aspects of the disclosure is helpful.It is therefore to be understood that these contents should be read in the sense that, not as Admission of prior art.

Invention content

In one aspect, a kind of polysilicon fluidized-bed reactor includes annular outer cover and ring lining, the ring lining position Cause to limit interior room between shell and liner in the enclosure.The polysilicon fluidized-bed reactor further includes at least one Feed gas entrance, at least one discharge gas vent and fluidisation region, the fluidisation region are included by ring lining The volume that the diameter on surface and the length from feed gas entry position to discharge gas vent position of ring lining limit.It should Ring lining includes the tube-shaped tube extended along an axis.The pipe includes the inner surface and the outer surface, which limits The tube thickness gone out therebetween.Ring lining further includes at least one layer of twister wound around the outer surface, wherein twister structure It causes to prevent being radially expanded for pipe.

On the other hand, a kind of polysilicon preparation liner includes the tube-shaped tube extended along an axis.The pipe includes interior table Face and outer surface, the inner surface and the outer surface limit tube thickness therebetween.The polysilicon preparation is further included with liner to be surrounded At least one layer of twister of the outer surface winding of pipe.Twister is configured to prevent being radially expanded for pipe.

The various improvement of feature referred in the presence of the above-mentioned various aspects about the disclosure.Other feature can also be incorporated in this In disclosed above-mentioned various aspects.These are improved and additional feature can exist with individualism or in any combination.For example, hereafter The various features of any one diagram embodiment discussion about the disclosure can be incorporated in individually or in any combination In any of above aspect of the disclosure.

Description of the drawings

Fig. 1 is the schematic diagram for the gas stream for entering and leaving fluidized-bed reactor (FBR) system.

Fig. 2 is the sectional view of the FBR sections of the disclosure, and liner and reaction shell is shown.

Fig. 3 is the sectional view on the right side of the first exemplary liner used for FBR systems shown in FIG. 1.

Fig. 4 is the sectional view of the second exemplary liner used for FBR systems shown in FIG. 1.

Fig. 5 is the sectional view of third exemplary liner used for FBR systems shown in FIG. 1.

Fig. 6 is the side view for showing any one of liner shown in Fig. 3-5.

Fig. 7 is the sectional view of the 4th exemplary liner used for FBR systems shown in FIG. 1.

Fig. 8 is the sectional view of the 5th exemplary liner used for FBR systems shown in FIG. 1.

Fig. 9 is the sectional view of the 6th exemplary liner used for FBR systems shown in FIG. 1.

Figure 10 is the side view of any one of the liner shown in Fig. 7-9.

In whole attached drawings, corresponding reference numeral indicates corresponding component.

Specific embodiment

Referring now to fig. 1, an example of a fluidized-bed reactor (FBR) in the scope of the present disclosure is represented as 1. FBR 1 includes reative cell 10 and gas distribution member 2.The source of first gas 5 and the source of second gas 7 are introduced into allocation unit 2 In, corresponding gas is appropriately distributed in the entrance of reative cell 10.Allocation unit 2 helps to divide in entire reative cell 10 Cloth reaction gas, to improve deposition rate of the reaction indoor material on fluidized particles to the maximum extent, while to greatest extent The deposit of lining in ground reduction.As used herein, " first gas " is that have the component different from " second gas " Gas, and vice versa.First gas and second gas can include multiple gases compound, as long as in first gas The quality composition of at least one compound or mole composition are different from the composition of the compound in second gas.Product extraction tube 12 Extend through gas distribution member 2.Product particle can extract from pipe 12 and be transported to product storage element 15.Consumption gas/ It leaves and can be introduced into other processing units 18 in 16 reacted room 10 of discharge gas.In this regard, it should be understood that figure Reactor 1 shown in 1 is illustrative and can use other reactor designs without departing from the scope of the present disclosure.

Referring now to Fig. 2, it shows the reative cell 10 of the FBR 1 according to some aspects of the disclosure, is shown The source of one gas 5, the source of second gas 7, gas distribution member 2, consumption gas 16, reative cell inside 30 and reaction liner 32. The heating equipment 34 of FBR1 can be maintained in the annular interior room 39 formed between reaction liner 32 and the shell 35 of reactor.It is interior Room 39 (or part of it) may include heat-insulating material (not shown), to prevent heat from being lost by shell 35.Used heat insulating material Material can be suitable for any material (including carbon and inorganic material) adiabatic at high temperature as understood by those skilled in the art, And various forms can be taken, including heat-insulating block, blanket or felt.

Pressure in some optional aspects of the disclosure, interior room 39 is equal to or less than the pressure of process gas 5 and 7. These aspects of the disclosure, by control valve come the pressure differential between maintenance process gas 5 and 7 and interior room 39 (that is, pressure Power_{Process gas}Pressure_{Interior room}), to establish flow rate desired for fluidisation.

The some aspects of the unshowned disclosure in fig. 2, heating equipment 34 can be physically contacted and add with liner 32 There may be void space between hot equipment 34 and shell 35.The some other aspects of the unshowned disclosure in fig. 2, heating Equipment 34 can be physically contacted with shell 35 and there may be void space between heating equipment 34 and liner 32.In fig. 2 The other aspect of the unshowned present invention, heating equipment 34 can be physically contacted with shell 35 and liner 32.

Heating equipment 34 is shown as extending less than such as from gas dividing for annular interior room 39 along the axis 33 of FBR1 in fig. 2 The overall length that the outlet of the part of the reaction gas inlet section of neighbouring reative cell 10 with unit 2 to consumption gas 16 measures.So And it will be understood to those skilled in the art that as needed, heating equipment 34 can be selected to extend any suitable length with The purpose of any one of various aspects of the invention is realized, for example, as from the neighbouring reative cell 10 of gas distribution member 2 The part of reaction gas inlet section to consumption gas 16 outlet measure about 1/3rd of the length of annular interior room 39, two / mono-, 2/3rds or substantially all length.Those skilled in the art is readily able to select the surface of heating equipment 34 Product and its ratio with the inner lining surface product needed for the purpose of the volume of reative cell 10 and/or the realization disclosure.Heating equipment 34 Can be resistance heater or one or more induction coils；However, it is possible to it is set without limitation using other types of heating Standby (for example, heating equipment 34 can be the hot gas of such as burning gases).In some optional aspects of the disclosure, gas distribution At least part of the external surface area of unit 2 can be exposed to heating equipment, such as heating equipment 34.

At some optional aspects of the disclosure, liner 32 includes thickness T1 and for example determines in induction coil around liner 32 It is used as heat source in combination with induction heating system (more fully hereinafter describing) in the case of position, high-frequency ac current passes through The induction coil along at least part of the height of liner 32 to provide induced electricity, so as to generate Temperature Distribution.Therefore, reference chart 2, in these areas, liner 32 is heating source and heating equipment 34 is induction coil.

Fig. 3 is the sectional view on the right side of the first exemplary liner 100 used for FBR systems shown in FIG. 1.As such, Liner 32 (being shown in FIG. 1) can be liner 100.In this exemplary embodiment, liner 100 is included along axis 33 (in Fig. 2 In show) extend and with first end 104 and the second end 106 --- first end 104 and the second end 106 define Length L1 therebetween --- isostatic pressed molding graphite-pipe 102.

The graphite monolithic that pipe 102 can be moulded by single isostatic pressed or the isostatic mold combined jointly by two or more The graphite section or ring of system are formed.In some aspects of the disclosure, pipe 102 can be by multiple isostatic molds along its axial length Ring processed is formed, wherein each ring for example by interlocking connection or passes through at least one surface of wherein the first section or ring and second What at least one surface of section or ring was overlapped is connected to by contact or is abutted against position connection.This interlocking assembly advantageously improves pipe 102 mechanical strength.

The method for preparing isostatic pressing formed graphite is well known in the art.In general, isostatic pressing formed graphite molding is by stone Black particle is formed, wherein uniformly applied compaction force in all directions.In any one of various aspects of the disclosure side Face, isostatic pressed molding graphite have in 1.7 grams/cc of (g/cm³) and 1.95g/cm³Between density.Isostatic pressed moulds stone Ink is also comprising the ash for being less than hundred a ten thousandths thousand (1000ppmw) by weight.It is used to form the graphite of isostatic pressed molding graphite Grain can be characterized by grain size or granularity, and plurality of graphite particle shows the average grain diameter less than 100 microns.It is such Grain size is typically less than the grain size for fluidizing polycrysalline silcon, and it is believed that is helped in the case of not bound to any specific theory In the performance of liner of the present invention, including (i) caused by high-pressure molding low porosity, (ii) is due to a large amount of closelypacked Little particle and the chemical reaction with high intensity and reduction, the coefficient of thermal expansion that (iii) matches with coat of silicon carbide.

Pipe 102 further includes drum type inner surface 108 and cylindrical external surface 110, outside drum type inner surface 108 and cylindrical shape Surface 110 defines therebetween tube thickness T2.In the exemplary embodiment, surface 108 and 110 is substantially parallel so that thickness T2 is between end 104 and 106 along length of tube L1 substantial constants.In the exemplary embodiment, thickness T2 about 50mm with Between about 140mm.

In one embodiment, pipe internal surface 108 defines fluidized reaction chamber interior 30.As it is used herein, fluidisation is anti- Room is answered to be defined as fluid bed, wherein silicon particle flows up to suspend in the reactor, and be it by fluidizing gas Middle silicon particle is contacted with heat decomposable silicon compound so that siliceous deposits is on silicon particle and thus generates high-purity polycrystalline silicon The region of particle.Any part that the silicon compound that fluidized reaction room can uitably include fluid bed thermally decomposes wherein and can Include the interior zone of gas distributor 2.

In the exemplary embodiment, liner 100 further includes at least one layer of pre-tensioned twister 112, this is pre-tensioned to twine It is wrapped on the outer surface 110 of pipe 102 around object and is configured to prevent being radially expanded for pipe 102.Twister 112 is by graphite fibre It is made at least one of carbon fiber, and in the form of at least one of band, rope and a plurality of fiber.Twister 112 wraps First end 114 and the second end 116 are included, first end 114 and the second end 116 define therebetween twister length L1. In the exemplary embodiment, the first end 114 of twister is aligned with the first end 104 of pipe, the second end 116 of twister It is aligned with the second end 106 of pipe so that twister length L1 is substantially equal to length of tube L1.

Twister 112 further includes inner surface 118 and outer surface 120, and inner surface 118 and outer surface 120 define therebetween Twister thickness T3.In the exemplary embodiment, surface 118 and 120 is substantially parallel so that thickness T3 is along end 114 and 116 Between twister length L1 substantial constants.In the exemplary embodiment, thickness T3 about 10mm and about 100mm it Between.As such, twister thickness T3 is equal to the overall thickness T1 of liner 100 plus tube thickness T2, overall thickness T1 is less than 150mm.One In a embodiment, tube thickness T2 is more than twister thickness T3.Alternatively, twister thickness T3 is more than tube thickness T2 or thickness T2 It is essentially equal with T3.As shown in figure 3, pipe internal surface 108, tube outer surface 110, twister inner surface 118 and twister appearance Face 120 is all substantially parallel to each other and parallel with axis 33.Either side in various aspects of the disclosure, twister Outer surface 120 is contacted with annular interior room 39,34 or combination of heating equipment.

In the exemplary embodiment, liner 100 further includes the silicon carbide painting for the inner surface 108 for being evenly applied to pipe 102 Layer 122.In the embodiment with coat of silicon carbide 122, coating 122 defines fluidized reaction chamber interior 30 and constructs and position It is ground into machinery of the pipe internal surface 108 from the hard polycrysalline silcon in the diffusion and chamber interior 30 of reactive chemical is protected Damage.Alternatively, liner 100 does not include coat of silicon carbide 122.Coat of silicon carbide 122 has in about 3.05g/cm³To about 3.2g/cm³ Between density.Coat of silicon carbide 122 also include less than each element boron of 1ppmw, sodium, magnesium, aluminium, phosphorus, sulphur, potassium, Calcium, titanium, vanadium, chromium, manganese, iron, copper, zinc, gallium, germanium, arsenic, indium, tin, antimony, tungsten, tellurium, lead and bismuth.Coat of silicon carbide 122 further leads to Substantially zeroed porosity is crossed to characterize.Coat of silicon carbide 122 can also be characterized further by grain size or granularity, wherein more The average grain diameter less than 100 microns is presented in a silicon-carbide particle.As isostatic pressed molding graphite, above-mentioned silicon carbide grain size helps The trend of inner lining surface is worn in reducing polycrysalline silcon, and higher polysilicon purity and mechanical antibody Monoclonal liner are provided.

Coat of silicon carbide 122 can pass through any one of various methods as known in the art --- such as passing through Learn vapor deposition, evaporation, ion sputtering, RF sputterings or DC magnetron sputterings --- and it is applied appropriately to pipe internal surface 108.Carbon SiClx layer 122 is ideally deposited as after pipe internal surface 108 is applied to almost without defect and unstressed.In routine In chemical vapor deposition, by making required precursor gases stream by heated substrate come depositing coating 122.When precursor gases connect When touching hot surface, they are reacted and depositing silicon silicon coating.Base reservoir temperature in the range of about 100-1000 DEG C is typically enough to These coatings 122 are formed in a few minutes to a few hours, this depends on the precursor and thickness of required coating.In the scope of the present disclosure Any various depositing SiC techniques are generated with the dense coating of porosity being substantially zero.

Fig. 4 is the sectional view of the second exemplary liner 200 used for FBR systems 1 (being shown in FIG. 1).It is as such, interior It can be liner 200 to serve as a contrast 32 (being shown in FIG. 1).As shown in figure 4, liner 200 includes the graphite-pipe 202 of isostatic pressed molding, Extend along axis 33 (being shown in FIG. 2) and with first end 204 and the second end 206, first end 204 and second End 206 defines therebetween length L1.Pipe 202 further includes inner surface 208 and outer surface 210, inner surface 208 and outer surface 210 define therebetween tube thickness T4.In the exemplary embodiment, inner surface 208 is arranged essentially parallel to axis 33, and appearance Face 210 includes at least one curved surface so that thickness T4 changes between end 204 and 206 along length of tube L1.For example, thickness T4 It is larger towards end 204 and 206 and smaller at the midpoint 205 along length L1.In the exemplary embodiment, thickness T4 is big Between about 50mm and about 140mm.

Similar to pipe 102 (as shown in Figure 3), graphite monolithic that pipe 202 can be moulded suitably by single isostatic pressed or by two The graphite section or ring that a or more the isostatic pressed combined jointly moulds are formed.In some aspects of the disclosure, pipe 202 can be with It is formed by multiple isostatic presseds molding ring along its axial length, wherein each ring for example by interlocking connection or passes through wherein first At least one surface of section or ring is Chong Die at least one surface of the second section or ring to be connected to by contact or is abutted against position Connection.This interlocking assembly is conducive to increase pipe section alignment and sealing.

As shown in figure 4, liner 200 further includes at least one layer of pre-tensioned twister 212, which surrounds The outer surface 210 of pipe 202 winds and is arranged to prevent being radially expanded for pipe 202.(show in figure 3 similar to twister 112 Go out), twister 212 is made of at least one of graphite fibre and carbon fiber, and in band, rope and a plurality of fiber at least The form of one.Twister 212 includes first end 214 and the second end 216, and first end 214 and the second end 216 are at it Between define twister length L1.In the exemplary embodiment, the first end 214 of twister and the first end 204 of pipe are right Together, the second end 216 of twister is aligned with the second end 206 of pipe so that twister length L1 is substantially equal to length of tube L1。

Twister 212 further includes inner surface 218 and outer surface 220, and inner surface 218 and outer surface 220 define therebetween Twister thickness T5.Specifically, twister 212 includes multilayer, the number of plies is according to length of the scheduled stress curve along twister 212 Spend L1 variations so that the overall thickness T5 variations of twister.In this exemplary embodiment, inner surface 218 includes and outer surface 210 Corresponding at least one curved surface, and the outer surface 220 of twister is arranged essentially parallel to the inner surface 208 of axis 33 and pipe, makes Thickness T5 is obtained between end 214 and 216 along twister length L1 to change.For example, thickness T5 increases along length L1 towards midpoint 215 Reduce greatly and towards end 204 and 206.As such, thus the extra play in nearly 215 attachment of midpoint of twister 212 is configured to The specific location on pipe 202 provides the compression nearby applied in tube end 204 and 206 compared to twister 212 For additional compression.In the exemplary embodiment, thickness T5 is between about 10mm and about 100mm.As such, twister Thickness T5 is equal to the overall thickness T1 of liner 200 plus tube thickness T4, and overall thickness T1 is less than 150mm.

Similar to liner 100, liner 200 further includes the coat of silicon carbide 122 being applied on the inner surface 208 of pipe.Alternatively, Liner 200 does not include coat of silicon carbide 122.Except both graphite-pipe 202 and twister 212 include the length along liner 200 Other than the thickness of variation, liner 200 is substantially similar to liner 100 in operation and composition.

Fig. 5 is the sectional view of third liner 300 being used together for FBR systems 1 (being shown in FIG. 1).As such, liner 32 (being shown in FIG. 1) can be liner 300.As shown in figure 5, liner 300 includes the graphite-pipe 302 of isostatic pressed molding, edge Axis 33 (being shown in FIG. 2) to extend and there is first end 304 and the second end 306, first end 304 and second end Portion 306 defines therebetween length L1.Pipe 302 further includes inner surface 308 and outer surface 310, inner surface 308 and outer surface 310 Define tube thickness T2 therebetween.In the exemplary embodiment, surface 308 and 310 is substantially parallel so that thickness T2 is along end Length of tube L1 substantial constants between 304 and 306.In the exemplary embodiment, thickness T2 is in about 50mm and about 140mm Between.As such, the pipe 302 of liner 300 can be identical with the graphite-pipe 102 used in liner 100.

As shown in figure 5, liner 300 further includes at least one layer of pre-tensioned twister 312, which surrounds The outer surface 310 of pipe 302 winds and is positioned to prevent being radially expanded for pipe 302.Similar to twister 112 and 212 (in Fig. 3 With 4 in show), twister 312 is made of at least one of graphite fibre and carbon fiber, and in band, rope and a plurality of fiber At least one of form.Twister 312 includes first end 314 and the second end 316, first end 314 and second end Portion 316 defines therebetween twister length L1.In the exemplary embodiment, the first end 314 of twister and the first of pipe End 304 is aligned, and the second end 316 of twister is aligned with the second end 306 of pipe so that twister length L1 is substantially etc. In length of tube L1.

Twister 312 further includes inner surface 318 and outer surface 320, and inner surface 318 and outer surface 320 define therebetween Twister thickness T6.Specifically, twister 312 includes multilayer, the number of plies is according to length of the scheduled stress curve along twister 312 Spend L1 variations so that the overall thickness T6 variations of twister.Temperature difference and process condition are in twister 312 and coat of silicon carbide Stress is established between 122.Graphite liner 300 further include due to it is axially loaded to maintain sealing element caused by stress, radially plus It is loaded onto operation pressure and the radial thermal gradient caused by process heat transfer.The number of the suitably entire process conditions of stress curve The stress curve for learning prediction adds the relative thermal expansion of graphite liner 300 and carbon fiber winding object 312 from room temperature to operating temperature.

In the exemplary embodiment, inner surface 318 is arranged essentially parallel to axis 33 and is parallel to pipe surface 308 and 310, and And the outer surface 320 of twister includes at least one curved surface so that thickness T6 becomes between end 314 and 316 along length of tube L1 Change.For example, thickness T6 increases along length L1 towards midpoint 315 and reduces towards end 314 and 316.As such, twister 312 The specific location that is positioned on pipe 302 of the extra play near midpoint 315 provide and exist compared to twister 312 Additional compression for the compression that tube end 304 and 306 is nearby applied.In the exemplary embodiment, thickness T6 is about Between 10mm and about 100mm.As such, twister thickness T6 is equal to the overall thickness T7 of liner 200, overall thickness plus tube thickness T2 T7 is less than 150mm.The twister thickness T6 of liner 300 may be substantially similar to the twister thickness T5 of liner 200.Alternatively, Twister thickness T5 and T6 are different.Similarly, thickness of inner lining T7 is substantially similar to thickness of inner lining T1 and (shows in figures 3 and 4 Go out).Alternatively, thickness of inner lining T7 and T1 are different.

Similar to liner 100 and 200, liner 300 further includes the coat of silicon carbide 122 being applied on the inner surface 308 of pipe. Alternatively, liner 300 does not include coat of silicon carbide 122.

In addition to graphite-pipe 302 includes constant thickness and twister 312 includes the thickness changed along the length of liner 300, Liner 300 is substantially similar to liner 100 and 200 in operation and composition.

Fig. 6 is the side view of any one of the liner 100,200 and 300 shown in Fig. 3-5, show twister 112, 212 and 312 extend along the whole length L1 of pipe 102,202 and 302.

Fig. 7 is the cross-sectional view of the 4th liner 400 used for FBR systems 1 shown in FIG. 1.As such, liner 32 ( Shown in Fig. 1) can be liner 400.In this exemplary embodiment, liner 400 includes prolonging along axis 33 (being shown in FIG. 2) It stretches and with the graphite-pipe of the isostatic pressed of first end 404 and the second end 406 molding for defining therebetween out length L1 402。

Pipe 402 further includes inner surface 408 and outer surface 410, and inner surface 408 and outer surface 410 define therebetween the thickness of pipe Spend T1.In the exemplary embodiment, outer surface 410 includes groove or groove 405 formed therein so that pipe 402 includes position The first flange 407 at first end 404 and the second flange 409 at the second end 406.Groove 405 includes appearance Face 411, outer surface 411 and the outer surface 410 of pipe are radially spaced apart so that each flange 407 and 409 includes thickness T8.In example In property embodiment, surface 408,410 and 411 are substantially parallel so that thickness T8 is between about 10mm and about 100mm.

In the exemplary embodiment, liner 400 further includes at least one layer of pre-tensioned twister 412, this is pre-tensioned to twine It is wound around object around pipe 402 and is configured to strengthen the pipe 402 and reduce it to the maximum extent to be radially expanded.Similar to twister 112 (being shown in FIG. 3), twister 412 are made of at least one of graphite fibre and carbon fiber, and in band, rope and it is more The form of at least one of bar fiber.Twister 412 includes first end 414 and the second end 416,414 He of first end The second end 416 defines therebetween twister length L2.In the exemplary embodiment, twister 412, which is located in, is formed in pipe Outer surface 410 in groove 405 in so that length of tube L1 be more than twister length L2.As such, the first flange 407 and second Flange 409 does not include twister 412.

Twister 412 further includes inner surface 418 and outer surface 420, and inner surface 418 and outer surface 420 define therebetween Twister thickness T8.In the exemplary embodiment, surface 418 and 420 is substantially parallel so that thickness T8 is along end 414 and 416 Between twister length L2 substantial constants.Specifically, twister inner surface 418 contacts fluted external surface 411, and twine It is substantially flush around exterior surface 420 and the outer surface 410 of pipe so that twister thickness is substantially equal to flange 407 and 409 Thickness.In addition, in one embodiment, twister 412 is substantially centered about along the length L1 of pipe 402 so that the first flange 407 and second flange 409 there is the length L3 that is essentially equal.Alternatively, twister 412 according to be conducive to as described herein in It serves as a contrast the predetermined stress curve of 400 operation and is located at any position along the length L1 of pipe 402.

Similar to liner 100,200 and 300 as described above, liner 400 further includes the inner surface 408 for being applied to pipe 402 On coat of silicon carbide 122.Alternatively, liner 400 does not include coating 122.

Fig. 8 is the sectional view of the 5th exemplary liner 500 used for FBR systems 1 (being shown in FIG. 1).Such as Fig. 8 institutes Show, liner 500 includes the graphite-pipe 502 of isostatic pressed molding, extends along axis 33 (being shown in FIG. 2) and with first End 504 and the second end 506, first end 504 and the second end 506 define therebetween length L1.In pipe 502 further includes Surface 508 and outer surface 510, inner surface 508 and outer surface 510 define therebetween tube thickness T9.In the exemplary embodiment, Inner surface 508 is arranged essentially parallel to axis 33, and outer surface 210 includes groove 505, and groove 505 includes at least one curved surface 511 so that thickness T9 changes between end 504 and 506 along length of tube L1.For example, thickness T9 towards end 504 and 506 compared with It is big and smaller in the midpoint along length L1.In the exemplary embodiment, thickness T10 about 10mm and about 100mm it Between.Thickness T10 is substantially similar to liner overall thickness T10 in the majority of cases.

Similar to pipe 102 (as shown in Figure 3), graphite monolithic that pipe 502 can be moulded suitably by single isostatic pressed or by two The graphite section or ring that a or more the isostatic pressed combined jointly moulds are formed.In some aspects of the disclosure, pipe 502 can be with It is formed by multiple isostatic presseds molding ring along its axial length, wherein each ring for example by interlocking connection or passes through wherein first At least one surface of section or ring is Chong Die at least one surface of the second section or ring to be connected to by contact or is abutted against position Connection.This interlocking assembly advantageously improves the mechanical strength of pipe 502.

As shown in figure 8, liner 500 further includes at least one layer of pre-tensioned twister 512, which surrounds Pipe 502 winds and is configured to strengthen the pipe 502 and reduce it to the maximum extent to be radially expanded.(scheming similar to twister 112 Shown in 3), twister 512 is made of at least one of graphite fibre and carbon fiber, and in band, rope and a plurality of fiber The form of at least one.Twister 512 includes first end 514 and the second end 516, first end 514 and the second end 516 define therebetween twister length L2.In the exemplary embodiment, twister 512 is located in the outer surface for being formed in pipe In groove 505 in 510 so that length of tube L1 is more than twister length L2.As such, the pipe appearance near end 504 and 506 Face does not include twister 512.

Twister 512 further includes inner surface 518 and outer surface 520, and inner surface 518 and outer surface 520 define therebetween Twister thickness T10.Specifically, twister 512 includes multilayer, the number of plies is according to scheduled stress curve along twister 512 Length L2 changes so that the overall thickness T10 variations of twister.In this exemplary embodiment, inner surface 518 includes and groove At least one curved surface that outer surface 511 corresponds to and contacts, and the outer surface 520 of twister is arranged essentially parallel to axis 33 and pipe Inner surface 508 so that thickness T10 between end 514 and 516 along twister length L2 change.For example, thickness T10 is along length Degree L2 increases towards midpoint 515 and reduces towards end 514 and 516.As such, twister 512 is attached near midpoint 515 The specific location that layer is configured on pipe 502 is added to provide compared to twister 512 in the neighbouring institute of tube end 504 and 506 Additional compression for the compression of application.In the exemplary embodiment, thickness T10 is between about 10mm and about 100mm. In this exemplary embodiment, twister thickness T8 is substantially similar to twister thickness T10 (being shown in FIG. 7).Alternatively, it twines It is dissimilar around object thickness T10 and twister thickness T8.

Similar to liner 100,200,300 and 400 as described above, liner 500 further includes the inner surface for being applied to pipe 500 Coat of silicon carbide 122 on 508.Alternatively, liner 500 does not include coating 122.

Fig. 9 is the sectional view of the 6th exemplary liner 600 used for FBR systems 1 (being shown in FIG. 1).It is as such, interior It can be liner 600 to serve as a contrast 32 (being shown in FIG. 1).In this exemplary embodiment, liner 600 is included along axis 33 (in fig. 2 Show) extend and with the stone of the isostatic pressed of first end 604 and the second end 606 molding for defining therebetween out length L1 Black pipe 602.

Pipe 602 further includes inner surface 608 and outer surface 610, and inner surface 608 and outer surface 610 define the thickness of pipe therebetween Spend T11.In the exemplary embodiment, outer surface 610 includes groove or groove 605 formed therein so that pipe 602 includes position The first flange 607 at first end 604 and the second flange 608 at the second end 606.Groove 605 includes appearance Face 611, outer surface 611 and the outer surface 610 of pipe are radially spaced apart so that each flange 607 and 609 includes thickness T12.In example In property embodiment, surface 608,610 and 611 are substantially parallel so that thickness T11 between about 50mm and about 140mm simultaneously And thickness T12 is between about 0mm and about 50mm.

In the exemplary embodiment, liner 600 further includes at least one layer of pre-tensioned twister 612, this is pre-tensioned to twine It is wound around object around pipe 602 and is configured to strengthen the pipe 602 and reduce it to the maximum extent to be radially expanded.Similar to twister 112 (being shown in FIG. 3), twister 612 are made of at least one of graphite fibre and carbon fiber, and in a plurality of fiber, The form of band and at least one of rope.Twister 612 includes first end 614 and the second end 616,614 He of first end The second end 616 defines therebetween twister length L2.In the exemplary embodiment, twister 612, which is located in, is formed in pipe Outer surface 610 in groove 605 in so that length of tube L1 be more than twister length L2.As such, the first flange 607 and second Flange 609 does not include twister 612.

Twister 612 further includes inner surface 618 and outer surface 620, and inner surface 618 and outer surface 620 define therebetween Twister thickness T13.Specifically, twister 612 includes multilayer, the number of plies is according to scheduled stress curve along twister 612 Length L2 changes so that the overall thickness T13 variations of twister.Specifically, twister inner surface 618 contacts and substantially parallel It in fluted external surface 611, and winds exterior surface 620 and includes at least one curved surface so that thickness T13 is in end 614 and 616 Between along twister length L2 change.For example, thickness T13 increases along length L2 towards midpoint 615 and towards 614 He of end 616 reduce.Specifically, winding exterior surface 620 extends beyond tube outer surface 610 up to distance D1 so that the total thickness of liner 600 It spends and adds distance D1 for thickness T11.As such, the extra play near midpoint 615 of twister 612 is configured on pipe 602 The specific location provides attached for the compression that twister 612 is nearby applied in twister end 614 and 616 The compression added.In the exemplary embodiment, thickness T11 is between about 50mm and about 140mm, thickness T12 in about 0mm and Between about 70mm, and thickness T11 is less than 150mm plus the twister overall thickness of distance D1.

In addition, in one embodiment, twister 612 is substantially centrally positioned along the length L1 of pipe 602 so that first 607 and second flange 609 of flange has the length L3 being essentially equal.Alternatively, twister 612 is according to being conducive to as being described herein Liner 602 operation predetermined stress curve and be located at any position along the length L1 of pipe 600.

Similar to liner 100,200,300,400 and 500, liner 600 further includes the carbon being applied on the inner surface 608 of pipe SiClx coating 122.Alternatively, liner 600 does not include coating.

Figure 10 is the side view of any one of the liner 400,500 and 600 shown in Fig. 7-9, shows twister 412nd, 512 and 612 extend along the length L2 shorter than the length L1 of pipe 402,502 and 602.In one embodiment, pipe 402,502 It is processed in tube outer surface 410,510 and 610 after manufacturing with the groove 405,505 and 605 in 602.It is alternatively, recessed Slot 405,505 and 605 is formed during production pipe 402,502 and 602 so that groove 405,505 and 605 is not in the later stage It is processed during manufacturing process.

Either side in various aspects of the disclosure, can be by including relative to conventional FBR and related process The use of the liner of static pressure graphite-pipe improves the polysilicon purity of the thermal decomposition process in fluidized-bed reactor (FBR) and production Amount, the isostatic pressing formed graphite pipe have the pre-tensioned twister for applying continuous compression power on graphite-pipe.Liner includes winding Graphite fibre twister on liner outer surface, to apply compressing force on graphite liner and prevent the radial direction of graphite liner swollen It is swollen.Specifically, twister is pre-tensioned to offset the predetermined circumferential tensile stress on liner inner surface.

The liner of the present invention, which is characterized as being under 500 DEG C to 1500 DEG C of operating temperature, especially has following characteristics：(i) base Free of contamination surface in sheet, (ii) high withstand voltage intensity, (iii) have enough hardness to provide the surface of highly corrosion resistant, (iv) The best difference of coefficient of thermal expansion between graphite-pipe and pre-tensioned twister and (v) high heat conductance.

Liner should have sufficiently high mechanical strength, under the high temperature and pressure differential that are presented in disclosed method Trouble-freely work.High mechanical properties are needed to bear by positive pressure being maintained to be compressed axially and the height generated in annular interior room 39 Power, to prevent or prevent fluidizing gas and product silicon migration to pass through liner.In addition, it is also desirable to which high mechanical properties are to bear possibility The high thermal gradient (axial or radial direction) generated due to the high heat-flux requirement of technique.Furthermore, it is necessary to high intensity is interior It is lined with and bears the variation due to technique heat demand, the silicon deposits accumulated in inner liner wall or due to heating system maloperation or tightly Anxious power loss and over time and generate high thermal gradient.

The liner of this embodiment has the drag minimization for being enough to make to transmit heat and makes lengthwise thickness and length along liner The thermal conductivity that the thermal gradient of degree minimizes.Either side in various aspects of the disclosure, the thermal conductivity is at ambient temperature It is at least 50W/mK more than 115 watt/meter Kelvins (W/mK) and at 1500 DEG C.

In terms of using the disclosure of induction heating system, liner can have the electricity for being enough liner is allowed to be used as heating source Resistance rate.In these areas, resistivity is more than 1,100 micrin ohm cms.In terms of other, wherein liner only a part is used as adding Heat source, resistivity are less than 1,600 micrin ohm cms.

In addition, after pre-tensioned twister is wrapped in around pipe, the carbon fibre-reinforced graphite (CFRG) that is newly formed Then Liner Components can be roasted with burn out binder, and will wind fibres again by further material of the dipping rich in carbon It is bonded to each other and is combined with graphite cylinder body.After roasting again, the step of performing purification, final processing and silicon carbide coating.Pipe Roasting process is designed to make not make carbon fiber relaxation or recrystallization with twister, relaxation or recrystallization may offset strong fibre The expected positive benefits of peacekeeping high-tension twister.In addition, the thermal expansion system between twister and the graphite of isostatic pressed molding The difference of number (CTE) is designed in 500 DEG C to 1500 DEG C of operating temperature range minimum.Specifically, the CTE of twister It is designed to resemble or less than graphite-pipe, to prevent or prevent relaxation of the twister under liner operating temperature.

Furthermore compressive resistance, bending strength and the tensile strength of monomer isostatic pressing formed graphite pipe well known in the prior art can Liner of the structure for large size FBR can be insufficient to allow for, compared with reactor well known in the prior art, the large size FBR will Improve production of polysilicon amount and productivity.Specifically, this monolithic isostatic pressing formed graphite liner is born in silicon FBR reactors The rigid structure of tensile stress on its outside.These stress can lead to pad reactor and the graphite cylindrical portion as technique liner The axial rift of section.For the axial compressive force for maintaining sealing and for the radial pressure of process purity to be maintained to be split there may be axial Line axially expands existing graphite crackle, crack or fractured so as to cause liner and operation troubles occurs.It is twined with carbon fiber Around object winding isostatic pressing formed graphite liner outside advantageously reduce or eliminate liner be radially expanded and resulting stress And fracture.

For producing the method for polysilicon

As generally described in Fig. 1, disclosed method includes that the gaseous silicon compound that can be thermally decomposed will be included Feed gas be introduced into reactor.Heat decomposable compound 7 and carrier gas 5 are respective next from its via gas distribution member 2 Source is fed into reactor assembly.Carrier gas 5 can include hydrogen or inert gas, such as argon gas or helium and its mixture.It can heat The silicon compound of decomposition includes that the compound to generate silicon usually can be thermally decomposed.Can from the product outside decomposable process amount of production and The scope of the present disclosure is not departed from, as long as it provides the source of silicon forms polycrysalline silcon to grow polycrysalline silcon. Heat decomposable silicon compound gas includes all containing the gas of silicon that can be deposited by chemical vapor deposition, such as tetrahydro One or more hydrogen atoms of silicon (being commonly referred to as silane), trichlorosilane and wherein silane are taken by the halogen of such as chlorine, bromine, fluorine and iodine Other silicon halides in generation.Heat decomposable compound can be introduced into reactor or gas can be in the case that undiluted With such as hydrogen, argon gas, helium or combination carrier gases dilute.During decomposition, if necessary, in reactor assembly Byproduct hydrogen gas is generated in operation, which can be recovered for use as the thermal decomposition feed gas for additional quantity Carrier gas.

Various gas distribution members 2 design the practice for being well known in the art and being suitable for the disclosure.

Either side in various aspects of the disclosure, first gas 5 may include decomposable silicon precursor compound Source, and second gas 7 may include carrier gas, and wherein first gas 5 and second gas 7 is supplied to different reaction chamber regions. For example, first gas 5 (decomposable silicon precursor compound) can be supplied to the central area of distributor 2, it can be by second Gas 7 (carrier gas) is supplied to around central area, and extracts polysilicon product from reactor via pipe 12.

Feed gas is heated in the reaction chamber, so that at least part silicon in silicon compound passes through chemical vapor deposition Product and deposit on the silicon seed particle in reative cell, silicon particle is thus made to grow into the larger of commonly known as granular polycrystalline silicon Particle.Another part of heat decomposable silicon compound decomposes and forms silicon vapor etc..Suitable heating equipment includes but unlimited In sensing heating and radiant heating, such as resistance radiating element.

As shown in Figure 1, extract granular polycrystalline silicon from product extraction tube 12.It can be as in batch operation intermittently from anti- Device is answered to extract granular polycrystalline silicon；However, continuously extraction grain products are usually more effective.Silicon production is either extracted in batches or continuously Product, it has been found that size of the product particle when being extracted from reactor influences reactor productivity.For example, it has been found that usually The size of the extracted silicon particle of increase causes reactor productivity to improve；If however, allow product particle grow too big, Then the contact in reactor between gas phase and solid phase is likely to reduced, so as to reduce productivity.Therefore, in each side of the disclosure Face, the average diameter of the granular polycrystalline silicon extracted from reactor are about 600 μm to about 2000 μm, about 800 μm to about 1500 μm, Or about 900 μm to about 1300 μm.

When the element for introducing the present invention or the embodiment of the present invention, article " one ", "one", "the" and " described " be intended to Represent there is element as one or more.Term "comprising", " comprising " and " having " are intended to open, it is meant that remove There may be additional element except listed element.

Various changes can be carried out without departing from the scope of the present invention to above-mentioned construction and method, it is therefore, described above The all the elements shown in included in book and attached drawing are intended to be interpreted to be exemplary, and are not intended to carry out on limited significance It explains.

Claims

1. a kind of polysilicon fluidized-bed reactor, including：

Annular outer cover；

Ring lining is located at the inside of the shell so that limit interior room between the shell and the liner；

At least one feed gas entrance；

At least one discharge gas vent；

Fluidize region, diameter and the ring lining including the inner surface by the ring lining from the feeding gas The volume that the length of body entry position to the discharge gas vent position limits,

The ring lining includes：

The tube-shaped tube extended along axis, the pipe include the inner surface and the outer surface, and described the inner surface and the outer surface defines therebetween out Tube thickness；With

Around at least one layer of twister of outer surface winding, the twister prevents being radially expanded for the pipe.

2. fluidized-bed reactor according to claim 1, wherein, the twister is pre-tensioned to offset in the pipe Predetermined circumferential tensile stress on surface.

3. fluidized-bed reactor according to claim 1, wherein, the twister is included in graphite fibre and carbon fiber At least one.

4. fluidized-bed reactor according to claim 1, wherein, the twister includes the band of graphite fibre or carbon fiber At least one of with the rope of graphite fibre or carbon fiber.

5. fluidized-bed reactor according to claim 1, wherein, the tube thickness is along length of tube substantial constant.

6. fluidized-bed reactor according to claim 1, wherein, the tube thickness changes along length of tube.

7. fluidized-bed reactor according to claim 1, wherein, the pipe includes the graphite of isostatic pressed molding.

8. fluidized-bed reactor according to claim 1, wherein, the twister includes multiple layers.

9. fluidized-bed reactor according to claim 8, wherein, the quantity of the multiple layer according to predetermined stress curve and Change along the length of the pipe.

10. fluidized-bed reactor according to claim 1, wherein, the twister includes the inner surface and the outer surface, described The inner surface and the outer surface of twister limits twister thickness therebetween.

11. fluidized-bed reactor according to claim 10, wherein, the length of twister thickness along the pipe is permanent Fixed.

12. fluidized-bed reactor according to claim 10, wherein, the twister thickness becomes along the length of the pipe Change.

13. fluidized-bed reactor according to claim 10, wherein, the interior table of the outer surface of the twister and the pipe Face is arranged essentially parallel to the axis.

14. fluidized-bed reactor according to claim 13, wherein, the appearance of the inner surface of the twister and the pipe Face is bending relative to the axis.

15. fluidized-bed reactor according to claim 10, wherein, the appearance of the inner surface of the twister and the pipe Face is arranged essentially parallel to the axis.

16. fluidized-bed reactor according to claim 1, wherein, the outer surface of the twister is relative to the axis It is bending.

17. fluidized-bed reactor according to claim 1, wherein, the pipe includes first end, the second end and at it Between the length of tube that extends, the twister includes first end, the second end and the twister length extended therebetween.

18. fluidized-bed reactor according to claim 17, wherein, it is long that the length of tube is substantially equal to the twister Degree.

19. fluidized-bed reactor according to claim 17, wherein, the length of tube is longer than the twister length.

20. fluidized-bed reactor according to claim 19, wherein, the pipe includes the first end of the neighbouring pipe The second part of the second end of first part and the neighbouring pipe, the first part and the second part do not have described Twister.

21. fluidized-bed reactor according to claim 19, wherein, pipe range of the twister edge between the end of pipe Degree substantially centrally positions.

22. fluidized-bed reactor according to claim 1 further includes essentially homogeneously outer coated in the twister Silicon carbide on surface.

23. a kind of polysilicon preparation liner, including：

Around at least one layer of twister of outer surface winding, the twister is configured to prevent being radially expanded for the pipe.

24. liner according to claim 23, wherein, the twister includes at least one in graphite fibre and carbon fiber Person.

25. liner according to claim 23, wherein, the twister includes multiple layers, the quantity root of the multiple layer Change according to predetermined stress curve along the length of the pipe.

26. liner according to claim 23, wherein, the length of twister thickness along the pipe is constant.

27. liner according to claim 23, wherein, twister thickness changes along the length of the pipe.

28. liner according to claim 23, wherein, the length of tube is substantially equal to twister length.

29. liner according to claim 23, wherein, the length of tube is longer than twister length.

30. a kind of method for forming polysilicon preparation liner, the method includes：

The tube-shaped tube extended along axis is formed, which includes the inner surface and the outer surface, and described the inner surface and the outer surface limits therebetween Make tube thickness；And

At least one layer of twister is wound around the outer surface, the twister is configured to prevent being radially expanded for the pipe.

31. according to the method for claim 30, wherein, the graphite that formation tube-shaped tube includes being moulded by isostatic pressed forms described Tube-shaped tube.

32. according to the method for claim 30, wherein, wind at least one layer of twister include winding include graphite fibre with At least one layer of twister of at least one of carbon fiber.

33. it according to the method for claim 30, wherein, winds at least one layer of twister and includes winding includes graphite or carbon At least one layer of twister of at least one of the band of fiber and graphite or carbon fiber rope.

34. according to the method for claim 30, further comprise the material rich in carbon is used to impregnate the pipe and the winding At least one of object.

35. according to the method for claim 34, further comprise roasting the pipe again and the twister is debindered to remove Agent.

36. according to the method for claim 30, further comprise at least one layer of coat of silicon carbide being applied to the pipe On inner surface.