CN107406976A - Siliceous deposits reactor with sealed bottom arrangement - Google Patents

Abstract

The invention discloses the fluidized bed reactor system for manufacturing high purity silicon coating particles.Container have in shell, the shell to insulating barrier, in the shell to concentric inner casing and be positioned at introversive and defined reaction device room the concentric lining of the inner casing.The inner casing and lining are sealed in their bottom by O-ring sealing arrangement, to prevent the gas in the reactor chamber from entering the space between the inner casing and the lining.Central inlet nozzle produces vertical gas plume in the reactor chamber.

Description

Silicon deposition reactor with bottom seal arrangement

Related Application Cross Reference

This application claims the benefit of US Provisional Application No. 62/099,057, filed December 31, 2014, which is incorporated herein by reference in its entirety.

technical field

The present disclosure relates to a reactor for thermally decomposing a silicon-containing gas in a fluidized bed to produce silicon-coated particles.

Background technique

Thermal decomposition of silicon-containing gases in fluidized beds is an attractive process for the manufacture of polysilicon for the photovoltaic and semiconductor industries due to excellent quality and heat transfer, increased deposition surface and continuous production. Compared to Siemens type reactors, fluidized bed reactors offer significantly higher productivity at a fraction of the energy consumption. Fluidized bed reactors can be continuous and highly automated, thereby significantly reducing labor costs.

One such fluidized bed reactor is described in WO2011063007A2 and shown in FIG. 1 . In this reactor, the inner shell extends generally vertically through the reactor and is generally cylindrical with a generally circular cross-section. A liner, located inwardly of the inner shell, extends generally vertically through the reactor and is also generally cylindrical, having a generally circular cross-section. The liner defines the reactor chamber and protects the inner shell from abrasion by the silicon-coated particles. The liner is constructed of materials selected to avoid contamination by the silicon particles. The liner thus protects the seed particles and product particles in the fluidized bed from contamination by the inner shell and/or vessel wall material.

The inner shell and liner of WO2011063007A2 are separated by a gap such that a cylindrically shaped annular space is provided between said inner shell and said liner. A seal is provided at the bottom of the inner shell to prevent gases and particulate material from entering the space from the reaction chamber.

Because the inner shell and the liner are made of materials with different coefficients of thermal expansion, and because during operation of the reactor, the air pressure in the reaction chamber differs from the air pressure in the space between the inner shell and the liner different, problems may occur.

A particular problem in such systems is failure of the seal between the inner shell and the liner. In such systems, a typical sealing arrangement is a flat gasket between two horizontal flat metal surfaces. This arrangement is problematic because the gaskets are held in place only by friction between the flat surfaces. Fluidized bed reactors generate significant vibrations during operation. As a result, the flat gasket slowly slides out between the two metal flat surfaces with vibrations, and pressure shocks cause components at the bottom of the reactor to move around.

It is also a problem that the inwardly facing edge surface of the flat gasket can come into direct contact with the silicon particles inside the reactor chamber when there are process disturbances. The gasket overheats and is damaged by direct contact with the hot silicon particles. Once the innermost region of the flat gasket is damaged and lost, the hot silicon particles act on the next layer and eventually "burn" through the entire gasket, destroying the integrity of the seal. This also affects product quality. Small pieces of dislodged gasket material enter the reactor chamber and contaminate the silicon particles contained therein.

Therefore, there is a need for a sealing arrangement that will function effectively under the conditions present in a fluidized bed reactor for depositing silicon.

Contents of the invention

A fluidized bed reactor system for producing high purity silicon coated particles is disclosed. The fluidized bed reactor system includes a liner constructed of a material that minimizes particle contamination in the fluidized bed. In this reactor, the inner shell extends generally vertically through the reactor and is generally cylindrical with a generally circular cross-section. A liner, located inwardly of the inner shell, extends generally vertically through the reactor and is also generally cylindrical, having a generally circular cross-section. The liner defines the reactor chamber and protects the inner shell from abrasion due to contact with the silicon-coated particles.

A system includes a vessel having an outer shell, an insulating layer adjacent an inner surface of the outer shell, a generally cylindrical inner shell inwardly of the insulating layer and positioned inwardly of a plurality of heaters. Advantageously, said inner shell is made of superalloy. A generally cylindrical liner is located within the inner shell and provides a cylindrically shaped annular space between the inner shell and the liner. The liner defines a reaction chamber containing a plurality of seed particles and/or silicon-coated particles. The liner may be made of non-polluting materials including, but not limited to, quartz, silicon, low nickel alloys, superalloys, cobalt alloys, silicon nitride, graphite, silicon carbide, molybdenum, or molybdenum alloys.

Bottom end surfaces of the inner shell and liner are supported near the bottom of the reactor. The support assembly includes means arranged to seal the bottom of the space between the inner shell and the liner against the entry of gas and particulate material into the space. The assembly will advantageously comprise one or more O-rings between facing surfaces of adjacent steel reactor components. Each O-ring is contained in an annular channel or groove defined in the horizontal surface of the steel reactor section. The O-ring is located at a radially outward distance from the surface defining the reactor chamber so that it is not touched by hot silicon particles located inside the chamber. As a result, the silicon particles are free from contamination due to contact with the O-ring. The integrity of this O-ring is maintained because the hot particles cannot touch the O-ring and because the steel part will absorb most of the heat and carry it away. Advantageously, O-rings are provided at both upper and lower surfaces of the steel sealing ring located between said inner shell and said liner. The steel seal ring helps dissipate heat. Because each O-ring is seated in an annular groove, the O-ring cannot slip out of position.

The system also includes a reactant gas inlet nozzle, one or more fluidization gas inlets, such as a plurality of fluidization nozzles, and at least one outlet for silicon product removal.

The foregoing will be better understood from the following detailed description with reference to the accompanying drawings.

Description of drawings

Figure 1 is a schematic cross-sectional elevation view of a fluidized bed reactor.

Figure 2 is an enlarged cross-sectional elevational view of a portion of a fluidized bed reactor depicting the outer shell, insulation, inner shell with inner shell expansion means, and liner.

Figure 3 is an enlarged partial cross-sectional elevation view of a portion of the fluidized bed reactor of Figure 2, depicting details of the bottom support system for the inner shell and the liner.

FIG. 4 is a partial cross-sectional view taken along line 4 - 4 of FIG. 3 .

detailed description

Disclosed herein is a fluidized bed reactor system for forming polysilicon by thermally decomposing a silicon-containing gas and depositing silicon on fluidized silicon particles or other seed particles such as silicon dioxide, graphite, or quartz particles.

The silicon-coated particles are grown by thermally decomposing a silicon-containing gas in a reactor chamber and depositing silicon on the particles in a fluidized bed in the chamber. Initially, the deposition is on small seed particles. Deposition is continued until the particles grow to a size suitable for commercial use, after which the grown particles are harvested.

The seed particles may have any desired composition suitable for coating with silicon. Suitable components are those that do not melt or vaporize under the conditions present in the reactor chamber, and do not decompose or undergo chemical reactions. Examples of suitable seed particle components include, but are not limited to, silicon, silicon dioxide, graphite, and quartz.

Silicon is deposited on the particles by decomposing a silicon-containing gas selected from silane (SiH ₄ ), disilane (Si ₂ H ₆ ), higher silanes (Sin H _{2n +2} ), dichloro Silane (SiH ₂ Cl ₂ ), trichlorosilane (SiHCl ₃ ), silicon tetrachloride (SiCl ₄ ), dibromosilane (SiH ₂ Br ₂ ), tribromosilane (SiHBr ₃ ), silicon tetrabromide (SiBr ₄ ), diiodosilane (SiH ₂ I ₂ ), triiodosilane (SiHI ₃ ), silicon tetraiodide (SiI ₄ ), and mixtures thereof. The silicon-containing gas may be mixed with one or more halogen-containing gases defined as chlorine (Cl2), _hydrogen chloride (HCl), bromine (Br2), _hydrogen bromide (HBr), iodine ( Any of I ₂ ), hydrogen iodide (HI), and a mixture thereof. The silicon-containing gas may also be mixed with one or more other gases including hydrogen ( _H2 ) or one or more gases selected from nitrogen ( _N2 ), helium (He), argon ( Ar) and neon (Ne) are inert gases. In a particular embodiment, the silicon-containing gas is silane, and the silane is mixed with hydrogen.

The silicon-containing gas, together with any accompanying hydrogen, halogen-containing gas and/or inert gas, is introduced into the central chamber of the fluidized bed reactor and is thermally decomposed in the chamber to produce silicon, which is deposited in the chamber on the seed crystal particles.

Figure 1 shows the general configuration of a fluidized bed reactor 10 for producing coated particles. The reactor of Figure 1, similar to that of WO2011063007A2, is particularly well suited for the production of silicon by thermal decomposition of silane. The reactor 10 includes a vessel 12 that extends generally vertically from a base 170 to a top 172, has a vertical central axis A1, and may have different cross-sectional dimensions at different heights. The reactor shown in Figure 1 has five zones I-V with different cross-sectional dimensions.

The reactor 10 has an outer shell 80 . One or more heaters 100 are positioned inwardly of housing 80 in zone IV. In some systems, heater 100 is a radiant heater. Reactor 10 may also include an internal bed heater 90 . The insulating layer 130 is positioned along the inner surface of the housing 80 . The insulating layer 130 thermally insulates the housing 80 from the radiant heater 100 .

The inner shell 140 extends vertically through zones II-V of the reactor 10 . The illustrated inner shell is generally cylindrical with a generally circular cross-section. The inner shell may be constructed of any suitable material that can withstand the conditions within reactor 10 and is well suited to the high temperatures utilized to transfer heat into the fluidized bed. Because the pressure inside and outside the inner shell is similar, the inner shell can be thin. In some systems, the inner shell has a thickness of 5-10 mm, such as 6-8 mm.

A liner 150 , which may be removable, is positioned within the inner shell 140 at a small distance from the inner surface 142 of the inner shell 140 . The illustrated liner 150 is generally cylindrical, has a generally circular horizontal cross-section, is concentric with the inner shell 140, and extends generally vertically through regions II-V. The liner 150 has an inner surface 151 that at least partially defines the reactor chamber 15 .

Liner 150 provides containment of the fluidized bed and isolates it from other components of the reactor. In particular, the liner 150 protects the inner shell 140 from abrasion by the silicon-coated particles and seed particles in the fluidized bed and protects the particles from contamination by the inner shell and/or vessel wall material.

Liner 150 is constructed of a material selected to not contaminate the particles, and is preferably made of a material that can withstand temperatures of 1600°F (870°C) and maintain stability. Suitable materials for the liner 150 include, but are not limited to, non-polluting materials including, but not limited to, quartz, silicon, low nickel alloys, superalloys, cobalt alloys, silicon nitride, graphite, silicon carbide, molybdenum, or molybdenum alloys. In certain systems, the liner is constructed of silicon carbide, molybdenum, or a molybdenum alloy. Silicon carbide advantageously has a low coefficient of thermal expansion of 2.2-2.4x 10-6/°F or 3.9-4.0x 10-6/°C.

Figure 2 shows the configuration of the improved reactor system from its shell 80 to its liner 150, including an improved bottom seal. Insulation layer 130 is disposed adjacent housing 80 and is supported between lower seal support ring 220 and upper seal ring 230 . The inner shell 140 is positioned inwardly of the insulating layer 130 and supported by the lower sealing support ring 220 . The inner shell 140 has an outer surface 141 and an inner surface 142 . The illustrated surfaces 141 , 142 are concentric and, except for the divergence of the surfaces at the bottom portion of the inner shell 140 , are generally cylindrical. The liner 150 is positioned inwardly of the inner shell 140 . There is a narrow gap, for example 1.5mm measured laterally, between the inner shell 140 and the liner 150 to allow lateral thermal expansion. Due to said gap, there is an annular space 240 between the bottom seal and the top of the inner shell 140 . In the illustrated embodiment, the side boundaries of the annular space 240 are bounded by two vertically extending concentric surfaces 142, 152, which are cylinders. Together, the various components of the bottom seal assembly provide a seal extending from the inner shell 140 to the liner 150 to block gas from entering the space 240 between the inner shell 140 and the liner 150 through the bottom of the reactor chamber 15 .

Outer shell 80, inner shell 140, and lower seal support ring 220 are each constructed of materials suitable for withstanding temperature gradients associated with heating the fluidized bed and cooling the product. Suitable materials include, without limitation, austenitic stainless steel, high temperature metal alloys such as alloy, alloys, and cobalt alloys (e.g., 41).

A radiant heater (not shown) may be disposed between the insulating layer 130 and the inner case 140 .

The expansion joint system includes an inner shell expansion device 160 extending upwardly from the upper surface of the inner shell 140 . Inner shell expansion device 160 is compressible to allow longitudinal thermal expansion of inner shell 140 during operation of reactor 10 . The device 160 need not provide a hermetic seal.

The illustrated inner shell expansion device 160 extends between the inner shell 140 and the expansion support. The expandable support comprises members 241 , 242 firmly attached to the upper sealing ring 230 . The expansion joint system accommodates uneven expansion of the inner shell 140 and outer shell 80 of the reactor. The illustrated inner shell expansion device 160 is a generally cylindrical spring-type device with an inner diameter similar to that of the inner shell 140 . The inner shell expansion device 160 is configured to exert downward pressure on the inner shell 140 . In some systems, the inner shell expansion device 160 is a helical coil of flat wire or a wave spring, ie, a cylindrical stack of flat wire with waves in the wire.

As the temperature within the reactor increases, the inner shell 140 expands and the inner shell expansion device 160 is pushed up and compressed. Upon cooling, the inner shell 140 contracts and the inner shell expansion device 160 lengthens. The inner shell expansion device 160 also applies pressure to the inner shell 140 . Optionally, an expansion spring 165 may be provided above the liner 150 to accommodate thermal expansion of the liner.

The lower end portions of the inner shell 140 and the liner 150 are supported and sealed such that gas does not flow from the fluidized bed into the annular space 240 between the inner shell and the liner. The liner 150 has an annular bottom surface 154 that is ground smooth and flat to help form a good bottom seal. In the illustrated system, the bottom surface 154 of the liner 150 extends generally horizontally.

Figure 3 shows the bottom seal arrangement of Figure 2 in more detail. In the illustrated arrangement, the liner 150 is supported by the inner shell 140, and one or more gaskets are provided between the liner 150 and the inner shell 140 to provide a hermetic seal. A support member, such as the illustrated lower seal support ring 220 , is annular, attached to the outer shell 80 at a level above the base 170 , extends inwardly from the outer shell 80 in a flange fashion, and supports the inner shell 140 . Lower seal support ring 220 has an outer peripheral surface 260 facing housing 80 and an inner peripheral surface 262 defining a generally vertically extending central opening 264 indicated in FIG. . The inner shell 140 has an upper portion 270 and a lower portion 272 . The illustrated lower portion 272 has a flat bottom surface that rests on the seal support ring 220 . Lower portion 272 includes a radially inwardly projecting flange 274 relative to upper portion 270 having a generally horizontal, upwardly facing flange surface 276 . The liner 150 is supported by the flange surface 276 . In the advantageous arrangement shown in FIG. 3 , the lower part 272 of the inner shell 140 is thicker than the upper part 270 measured horizontally. The greater thickness of lower portion 272 gives inner housing 140 a wider base to seat on seal support ring 220 . Advantageously, the lower portion 272 will be sufficiently thick that the base of the inner shell 140 can define holes to receive bolts or can support pegs to secure the inner shell to the container, for example to the seal support ring 220 . In the illustrated system, the outer surface 141 is flared toward the bottom of the inner shell 140 to provide additional thickness.

In the illustrated system, an annular member is connected to the inner shell 140 to provide support for the liner 150 . The illustrated annular member is a seal ring 280 positioned between the liner 150 and the flange surface 276 by which the seal ring 280 is supported and the liner 150 is supported by the seal ring 280 . Seal ring 280 has an annular top surface 285 and an annular bottom surface 286 that are generally planar and extend generally horizontally. Seal ring 280 also has an annular inner edge surface 282 that defines a generally vertically extending opening 284 indicated in FIG. 4 through seal ring 280 . Seal ring 280 may be ferritic stainless steel, such as grade 410 stainless steel.

The top surface 285 of the seal ring 280 defines at least one annular upwardly opening channel. In the system shown in FIGS. 3-4 , the top surface 285 defines a circular channel 288 . An O-ring 290 , sometimes referred to as an “upper O-ring”, is provided in the annular upwardly opening channel 288 . The O-ring engages surfaces above and below the O-ring to form a seal between those surfaces. Alternatively, multiple channels may be provided in the top surface 285 ; multiple O-rings may be provided between the liner 150 and the seal ring 280 . O-ring 290 may be made of any suitable material. In particular, O-ring 290 may be hollow core stainless steel or may be a perfluoroelastomer material such as DuPont ^™ Perfluoroelastomer (FFKM).

The system may also include an annular intermediate ring 300 best seen in FIG. 3 . The illustrated intermediate ring 300 is positioned between the seal ring 280 and the flange surface 276 , the intermediate ring 300 is supported by the flange surface 276 and the seal ring 280 is supported by the intermediate ring 300 . The illustrated intermediate ring has a top surface 304 that defines at least one annular upwardly opening channel 308 . O-rings 310 , sometimes referred to as “lower O-rings,” are provided in one or more of the annular upwardly-opening channels 308 . The O-ring engages surfaces above and below the O-ring to form a seal between those surfaces. In the embodiment of FIGS. 3-4 , one o-ring 310 is provided in one channel 308 . Alternatively, multiple channels 308 may be provided; multiple O-rings may be provided. O-ring 310 may be made of a polymer such as DuPont ^TM Made of fluoroelastomer or can be a perfluoroelastomer material such as DuPont ^TM Perfluoroelastomer (FFKM).

In the illustrated embodiment, an annular upper gasket 294 is positioned between the seal ring 280 and the liner 150 primarily to protect the O-ring from wear caused by contact with the lower surface 154 of the liner 150 . An annular lower gasket 296 is located between seal ring 280 and flange surface 276 . In particular, annular upper gasket 294 is located between top surface 285 of seal ring 280 and liner 150 ; and annular lower gasket 296 is located between bottom surface 286 of seal ring 280 and flange surface 276 . Such spacers are generally not necessary and can be omitted. However, one or both of spacers 294, 296 may be provided as desired. The gasket can be made of graphite material such as A flexible graphite gasket material that is rigid enough that the gasket does not slide sideways during operation of the reactor. In systems without the upper gasket 294, the lower surface 154 of the liner 150 rests on the top surface 285 of the seal ring 280, and the one or more O-rings 290 are in contact with the liner 150 and the seal ring 280 and between the two. form a seal between them. In systems without lower gasket 296, bottom surface 286 of seal ring 280 rests on top of intermediate ring 300, with one or more O-rings 310 in contact with and between seal ring 280 and intermediate ring 300 Form a seal.

Inlet nozzles 20 are provided for injecting a primary gas through a central passage 22 and a secondary gas through an annular passage 24 around the central passage 22 . Advantageously, the nozzle 20 is positioned such that the silane is injected as a plume 180 near the vertical centerline A1 of the reactor 10 . In a particular arrangement, the central inlet nozzle 20 comprises two substantially cylindrical tubes which are substantially circular in cross-section. The main gas is a silicon-containing gas or a mixture of a silicon-containing gas, hydrogen and/or an inert gas (eg helium, argon). The primary gas may also include a halogen-containing gas. The secondary gas typically has substantially the same composition as the hydrogen and/or inert gases in the primary gas mixture. In a particular arrangement, the primary gas is a mixture of silane and hydrogen and the secondary gas is hydrogen.

The illustrated reactor 10 also includes a plurality of fluidizing gas nozzles 40 . Additional hydrogen and/or inert gas may be delivered into the reactor through the fluidization nozzle 40 to provide sufficient gas flow to fluidize the particles within the reactor bed.

Also provided are sampling nozzles 50 through which product is sampled and one or more pressure nozzles 60 laterally displaced from the central inlet nozzle 20 for monitoring the pressure within the reactor. One or more purge gas/cooling gas nozzles 70 , 72 are located below the fluidization nozzle 40 and extend radially through the shell 80 into the reactor 10 .

The reactor 10 has a seed nozzle 110 through which seed particles can be introduced into the reactor chamber 15 . Reactor 10 also has one or more product outlets 120 for removing silicon-coated particles from reactor chamber 15 .

In operation, a seed particle bed is disposed inside the reactor chamber 15 and is fluidized by gas injected through the single central inlet nozzle 20 and the supplementary fluidization nozzle 40 . The contents of the reactor chamber 15 are heated. The silicon-containing gas decomposes and deposits silicon on the seed particles in the fluidized bed. Cooling gas is introduced into the chamber 15 through cooling gas nozzles 70 , 72 .

It should be recognized that the illustrated reactor is an example only and should not be considered as limiting the scope of the invention. Rather, the scope of the invention is defined by the claims.

Claims (21)

1. siliceous deposits reactor assembly, it is included：

Container, it has substrate, top cover and between the substrate and the top cover outside the generally tubular of general vertical extension Shell；

Generally tubular inner casing, it is located in the shell to the inner casing general vertical extends and by the container support；

Generally tubular lining, it is located in the inner casing to the lining general vertical extends and supported by the inner casing, described Lining has inner surface, and the inner surface at least partly limits the room for being suitable for including many silicon particles in fluid bed；

At least one nozzle, it is used to inject a gas into the room；With

At least one outlet, it is used to remove gas from the room.

2. the system of claim 1, wherein：

The inner casing has upper and bottom section, and the lower part includes the method radially-inwardly protruded relative to the upper part Orchid, wherein the flange has approximate horizontal ledge surface upwardly；And

The lining is supported by the ledge surface.

3. the system of claim 2, it also comprising the sealing ring between the lining and the ledge surface, causes described Sealing ring is supported by the ledge surface and the lining is supported by the sealing ring, and the sealing ring has annular inner rim table Face, the general vertical that the annular inner rim surface is limited through the sealing ring extend opening.

4. the system of claim 3, wherein：

The sealing ring has annular top and annular basal surface；

The top surface of the sealing ring limits at least one annular upward opening raceway groove；And

O-ring at least one annular upward opening raceway groove, it is close between the lining and the sealing ring to provide Envelope.

5. any one of claim 3-4 system, it is also comprising the Upper gasket between the sealing ring and the lining.

6. any one of claim 3-5 system, it is also comprising the underlay between the sealing ring and the ledge surface Piece.

7. the system of claim 6, wherein the lower gasket is located between basal surface and the ledge surface of the sealing ring.

8. any one of claim 3-7 system, it is also comprising the centre between the sealing ring and the ledge surface Ring, wherein the middle ring is supported by the ledge surface and the sealing ring is supported by the middle ring.

9. the system of claim 8, wherein：

The middle ring has annular top, and it limits at least one annular upward opening raceway groove；And

O-ring is located at least one annular upward opening raceway groove.

10. the system of claim 9, it is also comprising the lower gasket between the sealing ring and the O-ring, the O shapes Ring is located at least one annular upward opening raceway groove of the middle ring.

11. siliceous deposits reactor assembly, it is included：

Container, it has substrate, top cover and between the substrate and the top cover outside the generally tubular of general vertical extension Shell；

The inner casing of generally tubular, it is located in the shell to, the inner casing general vertical extension, by the container support, simultaneously With inner surface；

The lining of generally tubular, it is located in the inner casing to, the lining general vertical extension, the lining have with it is described The outer surface that the inner surface of inner casing separates, cause the space that tubulose is limited between the inner casing and the lining, the lining With inner surface, the inner surface at least partly limits the room for being suitable for including many silicon particles in fluid bed, and described Opening position of the lining near the bottom of the lining is sealed to the inner casing by O-ring sealing so that gas can not be from The room enters the space；

At least one nozzle, it is used to inject a gas into the room；With

At least one outlet, it is used to remove gas from the room.

12. the system of claim 11, wherein：

The lining is supported by the inner casing or the support of the annular construction member by being connected with the inner casing；And

The O-ring sealed bundle contains at least one O-ring, and the O-ring is positioned to provide in the lining and the inner casing Between sealing or sealing between the lining and the annular construction member being connected with the inner casing is provided.

13. the system of claim 12, wherein：

The inner casing has upper and bottom section, and the lower part includes the method radially-inwardly protruded relative to the upper part Orchid, wherein the flange has approximate horizontal ledge surface upwardly；And

The lining is supported by the ledge surface.

14. any one of claim 12-13 system, it includes the annular construction member being connected with the inner casing, the annular construction member It is the sealing ring between the lining and the inner casing, wherein the lining is supported by the sealing ring, the sealing ring With annular inner rim surface, the general vertical that the annular inner rim surface is limited through the sealing ring extends opening.

15. the system of claim 14, wherein：

The sealing ring has annular top and annular basal surface；

The top surface of the sealing ring limits at least one annular upward opening raceway groove；And

O-ring is located at least one annular upward opening raceway groove to provide the sealing between the lining and the sealing ring.

16. any one of claim 14-15 system, it is also comprising the upper pad between the sealing ring and the lining Piece.

17. any one of claim 14-16 system, it is also comprising the underlay between the sealing ring and the inner casing Piece.

18. any one of claim 14-17 system, it is also comprising the centre between the sealing ring and the inner casing Ring, wherein the sealing ring is supported by the middle ring.

19. the system of claim 18, wherein：

The middle ring has annular top, and it limits at least one annular upward opening raceway groove；And

The system also includes O-ring, and it is located at least one annular upward opening raceway groove to provide the sealing ring and institute State the sealing between middle ring.

20. the system of claim 19, it is also comprising the lower gasket between the sealing ring and the O-ring, the O shapes Ring is located at least one annular upward opening raceway groove of the middle ring.

21. any one of claim 14-20 system, it is also comprising the O-ring between the inner casing and the sealing ring Sealing.