CN1033449C - High-frequency thermal reactor for silicon carbide fibre - Google Patents
High-frequency thermal reactor for silicon carbide fibre Download PDFInfo
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- CN1033449C CN1033449C CN 91109267 CN91109267A CN1033449C CN 1033449 C CN1033449 C CN 1033449C CN 91109267 CN91109267 CN 91109267 CN 91109267 A CN91109267 A CN 91109267A CN 1033449 C CN1033449 C CN 1033449C
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Abstract
The present invention relates to a special device for manufacturing silicon carbide fibers by using a vapor deposition method. In the present invention, a high frequency non-contact heating system is used for replacing a traditional direct current heating system; the device comprises a filament collecting and discharging mechanism, a quartz thermal reactor and a high frequency heating system, wherein reaction gas can be led into the quartz thermal reactor; radio frequency electric waves with high energy can be generated by a radio frequency generator in the high frequency heating system; the radio frequency electric waves with high energy can be directed communicated to coaxial symmetrical coupling cavities in a type of reverse phase excitation, which are sheathed on the quartz thermal reactor; under the excitation of radio frequency current, an axial electromagnetic field with uniform intensity can be formed between the coupling cavities so as to realize heating carrier filaments, and the processes of decomposing and depositing the reaction gas in a type of SiC can be accomplished.
Description
The invention belongs to the specific equipment of the fibrous non-metallic material of preparation, specifically it is to use the thermal reaction apparatus that vapour deposition process is produced silicon carbide fiber.
Silicon carbide fiber is the basic constituent element that is used to prepare the high specific strength high specific stiffness, reaches the good properties at high temperature matrix material.The silicon carbide fiber that particularly adopts carbon fiber to do core has the not characteristic of reflection electromagnetic wave, thereby is widely used in Aeronautics and Astronautics and multiple military field.Thereby cause the great attention of countries in the world.State such as the U.S., West Germany just begins to develop silicon carbide fiber from the seventies, and its main technique principle of producing silicon carbide fiber is to adopt vapour deposition process.So-called vapour deposition process promptly adopts tungsten filament or carbon fiber as carrier, carrier is warmed to 1100～1400 ℃ in the reactor that is full of chlorosilane one class gas, forms carbon filament on the carrier or tungsten filament is the silicon carbide fiber of core thereby make decomposing gas and be deposited on the form of sic.Because the diameter of carrier silk is all about 10 μ m, so the fiber that forms we can say it is silicon carbide fiber basically.As seen basic problem is to solve carrier silk even heating to 1100～1400 ℃ in whole technological process, and in the process of folding and unfolding silk continuously, keeps the stability of these processing condition.The silk material is heated to about 1200 ℃ can a lot of methods.But participate at chlorosilane gas under the condition of reaction, we only need a material itself to have this temperature of reaction, if also there is other thermal barrier simultaneously, deposit its surface with regard to having a large amount of silicon carbide so, and its effective turnover ratio is too low.In other words be exactly that waste is too big.So silk material self direct heating is unique soluble method.At present, this device is monopolized by the U.S., West Germany's a few countries.Recognize that from the present information documents that can obtain vapour deposition process production device that sic adopted adopts the DC heating method basically, promptly, make and itself generate heat to temperature of reaction directly leading to direct current on the carrier.Its corresponding equipment is the flow-through method thermal reactor.Comprise a quartzy thermal reactor that can import reactant gases in the device of this preparation silicon carbide fiber, be elongated tubular product such, the carrier silk passes from the centre.Quartzy thermal reactor two ends are provided with contacts electrode, draw lead from contacts electrode and are connected to direct supply.For guaranteeing to work continuously and the quality of becoming a useful person, folding and unfolding silk mechanism is set at quartzy thermal reactor two ends.During working order, give the two ends contacts electrode with constant voltage, carrier promptly is warmed up to working temperature.The chlorosilane gas that imports from quartzy thermal reactor ventage forms the sic deposition in thermal barrier decomposition on every side and at carrier.Reaction back gas is extracted out from venting port.Adjust processing parameter, along with the running of retractable silk wheel, finished silk can generate continuously.The U.S., West Germany have all produced the commodity of sic with this device at present.Yet, in this production equipment,, to guarantee that at first contacts electrode contacts with silk the good of material, does not fluctuate with the resistance value of guaranteeing reaction zone internal thread material in order to make the constant of carrier silk temperature in the quartzy thermal reactor.Have to adopt mercury electrode for realizing above purpose.It is liquid that mercury becomes at normal temperatures, can keep excellent contact at any time with the silk material in the motion, and realize the sealing of both ends of the surface.Owing to adopt the mercury seal electrode, and operating ambient temperature is higher thereby have a large amount of mercury vapors to expose causes public hazards, must whole device is multiple-sealed for addressing this problem, thereby cost is very high, and use and limited to.More seriously mercury molecule trace infiltrates in the sic crystallization, causes to lack limit, has greatly reduced the quality of silk material.In addition, when the preparation large-diameter fiber, because sedimentation velocity is very fast, fiber outlet and ingress fabric resistor value have than big-difference, thereby make the entry and exit temperature difference reach 200～300 ℃.Thereby make the square root of the variance of finished silk material higher, have influence on a consistence of material physicals.Radio frequency method is produced sic and is in the development stage at present abroad, because comparable document is also can not find out in holding in close confidence of foreign technology at present.
Purpose of the present invention promptly provides a kind of device of radio frequency method production silicon carbide fiber, thereby realizes the heating of contactless property and make the interior temperature of conversion zone even, to eliminate mercury pollution and raising wire quality in the production of major diameter silicon carbide fiber.
Key of the present invention is to have replaced dc resistance method to go to finish heating to the carrier silk with the high-frequency induction method.It is conceived substantially will form an even strong axial magnetic field on the axis of quartzy thermal reactor.When silk material carrier under retractable silk mechanism traction at the uniform velocity by the time reached temperature of reaction by the uniform electromagnetic field heating, from then realizing high-quality vapor deposition processes.For realizing above design, the ratio-frequency heating system architecture comprises three parts, radio frequency generators, radio-frequency (RF) coupler and coaxial cable transmission line.Radio-frequency (RF) coupler can generate an even strong axial magnetic field under the excitation of high-frequency current, its main body coupled resonator is sleeved on the quartzy thermal reactor, and assurance is consistent with the axis of reactor.High-frequency current by radio frequency generators produces reaches radio-frequency (RF) coupler by the coaxial cable that transfers, thereby forms a complete ratio-frequency heating system, realizes the purpose of contactless heating.
Further specify below in conjunction with accompanying drawing and the objective of the invention is how to realize:
The structural representation of 1 device of accompanying drawing
Accompanying drawing 2 is the structured flowchart of radio frequency generators
Accompanying drawing 3 is the electrical schematic diagram of directional coupler
Accompanying drawing 4 is that axial even strength of electromagnetic field forms synoptic diagram
Wherein 1,2 represent retractable silk mechanism.3, the 4 left and right coupled resonators of representing the anti-phase excitation symmetrical coupled of coaxial-type chamber.5,6 represent the high frequency choke device.7, represent quartzy thermal reactor, 7A represents an into hole, and 7B represents the wire vent hole, and 7C represents reaction gas inlet, and 7D represents the gas atmosphere inlet, 7E representative reaction back tail gas outlet./ 2 wavelength lines are gone in 8 representatives.9 represent the equipotential tube.10 represent match box.On behalf of isothermal, 11 regulate line.12 represent the coaxial transmission cable line.13 represent radio frequency generators.13A represents high-frequency oscillator.13A1 represents quartz oscillator.13A2 represents frequency multiplier.13B represents power amplifier.The 13B1 representative promotes circuit.13B2 represents power amplifier.13C represents directional coupler.13D represents supporting power supply.13E representation parameter monitor portion.
As can be seen from Figure 1 produce the arts demand of sic fiber in order to adapt to radio frequency method, the structure of quartzy thermal reactor is compared with flow-through method and has been done bigger improvement design.Quartzy thermal reactor 7 among the present invention is elongated tubular construction.Two ends are shunk sealing part and are left into a hole 7A and wire vent hole 7B.Side faces at both ends is provided with reaction gas inlet 7C and gas atmosphere inlet 7D.The middle part is provided with tail gas venting port 7E.Reactant gases such as trichloromethyl silane import reaction chamber from inlet 7C, and shielding gas such as argon gas be from inlet 7D importing, and shielding gas pressure is greater than normal pressure, play the effect of seal protection less than reaction gas pressure, can not sneak into reaction zone again.Reactant gases enters reaction chamber from two end entrance 7C, finishes reaction back tail gas and discharges venting port 7E discharge from venting port 7E, and according to the needs of actual process, the caliber of quartzy thermal reactor can adopt 17-19mm, the wavelength of its length decision rf wave.The 1.1-1.3 that is generally wavelength doubly.
Produce for guaranteeing stable high-frequency oscillation signal, high-frequency oscillator 13A is made up of quartz oscillator 13A1 and frequency multiplier 13A2 two portions, and the oscillation signal of the 35MHz-42MHz that is sent by quartz oscillator 13A1 is delivered to frequency multiplier 13A
2, the signal after the frequency multiplication is delivered to power amplifier 13B again and is amplified processing.
The effect of directional coupler 13C is, from the signal of the same taking-up incident power of 12 shaft cable transmission lines and reflective power, and this signal delivered to parameter monitoring part 13E.As can be seen from Figure 3, it is by the heart yearn I of cable 12, telefault L, and resistance 81,82, the capacity divider summation current transformer that capacitor C 1, C2 form constitutes the crust ground connection of coaxial wire 12.Take R in the design
1=R
2Induction reactance is much larger than R
1, R
2
Radio-frequency (RF) coupler is the important component part in the ratio-frequency heating system, is again one of key of the present invention.Its effect is to form a stable even strong axial magnetic field under the effect of high-frequency current.Its design relation is to the success or failure and the quality of sic fiber process.For reaching the purpose of invention, mainly comprise following a few part in the structure of radio-frequency (RF) coupler: (a) the anti-phase excitation formula of a coaxial-type symmetry (left side, right) strap (3,4), when high-frequency current adopts direct manifold type to be fed to length is a terminal shortcircuit into/4, and on the coaxial line of the other end open circuit coupling cavity time, a certain transient voltage value will distribute shown in Fig. 5 a, and will shown in Figure 58, distribute through going into/2 lagging voltage values, if two cavity adjustment distances make its midfeather less than go into/4, and suitably adjust phase place and will between two cavitys, form a uniform axial magnetic field.Its maximum value and cavity central axes, if pass through a filament on the axis this moment, then this root filament then can be heated to working temperature by the higher frequency electromagnetic field immediately, so coupled resonator is one of key part of the present invention.There is garden shape perforate at its end face center, is sleeved on the outside of quartzy thermal reactor 7 by it.Thereby on the axis of the middle part of quartzy thermal reactor 7, form even heat district.(b) so because the end face of left and right coupled resonator is that short dot also is that the electric current maximum point can form stronger high-frequency induction magnetic field, if inappropriate processing then can form the higher frequency electromagnetic field and leak, not only can make fiber by the time produce heat effect, also can make unstable working condition.Thereby on the end face of left and right coupled resonator (3,4), be equipped with choke (5,6), its length for go into/8, (c) being connected with and going into/2 wavelength lines 8 of left and right coupled resonator (3,4), to guarantee its fixed current phhase difference.(d) when carrier was carbon filament, change in resistance was bigger, for making the fiber homogeneous heating in the reaction zone, was provided with the isothermal that is made of shape-variable metal flexible cord frame in the reaction zone between left and right sides coupled resonator (3,4) and regulated line 11.Suitably adjust wire-shaped and can guarantee that electromagnetic field rationally distributes in the reaction zone.(e), for the potential difference that guarantees the reaction zone two-end-point is stable, put a metal equipotential tube 9 simultaneously at left and right sides coupled resonator (3,4) region intermediate for preventing electromagnetic radiation.(f) because the output impedance of radio frequency generators 13 is about 50 Ω.And coupled resonator input resistance is not 50 Ω, and direct connection closes and has influence on coupling, and its resistance change is big when particularly adopting carbon fiber to do carrier, thereby a match box 10 will be set between them.Specifically be connected coaxial line transmission cable 12 and go into/2 wavelength lines 8 between.The structure of match box 10 is a capacitor C
3, C
4, inductance L
1The pin network of forming.
Supporting power supply 13D mainly is operating voltage and an electric current of supplying with the each several part circuit, and parameter monitoring part 13E is all types of instrument and corresponding change-over circuit, to monitor each positional parameter.Show that back prompting operator adjusts the each several part working order.Or adopt microcomputer to detect automatically, regulate and control, all belong to general automatic technology, at this enumeration no longer.
By the device that above design concept is made, can adopt tungsten filament or carbon filament as carrier, the carrier silk starts radio frequency generators through the good axis coinciding of retractable silk institutional adjustment, and adjusts power output according to working temperature, can feed reactant gases and shielding gas.The carrier silk is warmed up to 1200 ℃-1400 ℃ immediately in reaction zone under the high-frequency electromagnetic field action, along with the continuous operation of folding and unfolding silk mechanism, the sic uniform deposition promptly generates synthetic silicon carbide fiber product on carrier.
The present invention realizes the ratio-frequency heating method to silicon carbide fiber first.Production unit by the sic fiber of the design's manufacturing has passed through continuous 1 year trial production.Result's proof utilizes the coaxial symmetric form coupled resonator under the anti-phase excitation of high-frequency current can generate very even and stable axial magnetic field, its heating properties reaches the processing requirement that vapour deposition process generates the sic fiber, realize non-contact type direct heating carrier silk first, temperature deviation is less than 5% in the reaction zone, electric conversion efficiency is higher than 40%, and successfully pulled out straight through being the sic fiber of 100 μ m, continuous fibers length reaches more than the 500m, but wire 100-120m per hour, the highest non-stop run can reach 12 hours, meets production requirement fully.This mode of production has reduced micro-detrimental impurity and has infiltrated, the stable physical property of its fiber, reach more than the 3200HPa according to its on average anti-intensity of test, modulus in tension is greater than 400GPa, reach advanced world standards, particularly thoroughly eliminate the evil of mercury, saved attached environmental protection equipment, greatly reduced production cost.Thereby the present invention is once great breakthrough in sic fiber production apparatus field, and fiber is pushed away to expand to use very significant meaning.
Claims (7)
1. high-frequency thermal reactor for silicon carbide fibre; comprise in the device that folding and unfolding is a mechanism (1; 2); can import heating system three parts of the quartzy thermal reactor (7) and the carrier silk of reactant gases; wherein carrier silk heating system is by radio frequency generators (13); coaxial cable transmission line (12) and radio-frequency (RF) coupler three parts are formed; the radio-frequency (RF) coupler main body is sleeved on the quartzy thermal reactor (7); quartzy thermal reactor (7) is elongated tubular construction; two ends are shunk sealing part and are left into a hole (7A) and wire vent hole (7B); the side, two ends is provided with reaction gas inlet (7C) and gas atmosphere inlet (7D); the middle part is provided with venting port (7E); coaxial transmission cable (12) is connected between radio-frequency (RF) coupler and the radio frequency generators (13), it is characterized in that:
A. comprise anti-phase excitation formula symmetrical coupled chamber (3,4) in the radio-frequency (RF) coupler structure, be arranged on the high frequency choke device (5,6) at two ends, symmetrical coupled chamber (3,4), go into/2 wavelength lines (8) for one that connects symmetrical coupled chamber (3,4), be assemblied in the isothermal that constitutes by the deformable metal frame between the left and right coupled resonator (3,4) and regulate line (11) and equipotential metal cylinder (9).
B. set up an impedance area match box (10) between coaxial wire (12) and going into/2 wavelength lines (8).
2. according to the device of the said manufacturing silicon carbide fiber of claim 1, it is characterized in that:
A. the axial length of choke (5,6) for go into/8, be positioned at coupled resonator (34) two ends, be enclosed within on the quartzy thermal reactor (7).
B. impedance matching case (10) is a capacitor C
3, C
4Inductance L
1The pin network of forming.
3. according to the device of the said manufacturing silicon carbide fiber of claim 2, the pipe diameter that it is characterized in that quartzy thermal reactor (7) is 17-19mm, and quartzy thermal reactor (7) length is 1.1-1.3 times of rf wave wavelength.
4. according to the device of the said manufacturing silicon carbide fiber of claim 1, it is characterized in that radio frequency generators (13) structure is made up of high-frequency oscillator (13A), power amplifier (13B), directional coupler (13C), supporting power supply (13D) and parameter monitoring part (13E), rf wave through power amplifier output passes through coaxial cable transmission line (12) direct connection to radio-frequency (RF) coupler, and directional coupler (13C) is delivered to parameter controlling section (13E) from incident power and reflected power signal that transmission line takes out.
5. according to the device of the said manufacturing silicon carbide fiber of claim 4, it is characterized in that high-frequency oscillator (13A) is made up of quartz oscillator (13A1) and frequency multiplier (13A2), be connected to power amplifier (13B) again after the oscillation signal of the 35MHz-42MHz that is sent by quartz oscillator (13A1) is delivered to frequency multiplier (13A2) frequency multiplication.
6. according to the device of the said manufacturing silicon carbide fiber of claim 4, it is characterized in that power amplifier (13B) forms by promoting circuit (13B1) and power amplifier (13B2) two portions, wherein promote the amplifying circuit formation that circuit (13B1) can adopt FU-46 type electron tube to form, the input terminus of power amplifier (13B2) will be delivered to after the frequency-doubled signal amplification, power amplification circuit (13B2) can adopt sintering metal tetrode FU-100 to form, oscillating structure is the square chest type single tuned circuit, wherein resonant capacitance adopts the vacuum adjustable condenser, anode voltage 3KV, anode working current 500-700mA, grid bias-80V, screen grid voltage 350V.
7. according to the device of the said manufacturing silicon carbide fiber of claim 4, it is characterized in that heart yearn (1), the telefault L of directional coupler (13C) by transmission coaxial-cable (12), resistance R 1, R2, capacitor C 1, the capacity divider summation current transformer that C2 formed constitute coaxial wire crust ground connection.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 91109267 CN1033449C (en) | 1991-10-05 | 1991-10-05 | High-frequency thermal reactor for silicon carbide fibre |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 91109267 CN1033449C (en) | 1991-10-05 | 1991-10-05 | High-frequency thermal reactor for silicon carbide fibre |
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| Publication Number | Publication Date |
|---|---|
| CN1071398A CN1071398A (en) | 1993-04-28 |
| CN1033449C true CN1033449C (en) | 1996-12-04 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN 91109267 Expired - Fee Related CN1033449C (en) | 1991-10-05 | 1991-10-05 | High-frequency thermal reactor for silicon carbide fibre |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1314191C (en) * | 2002-12-03 | 2007-05-02 | 夏义峰 | Inductive coupling plasma self-excitation radio frequency generator with power control |
Families Citing this family (7)
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|---|---|---|---|---|
| CN1060236C (en) * | 1998-06-15 | 2001-01-03 | 陈新谋 | Technique for making graphitized fibre and its special equipment |
| CN100403856C (en) * | 2002-05-31 | 2008-07-16 | 陈新谋 | Radio frequency focusing heating device for heating parallel arranged dispersd fiber bundle |
| CN100339523C (en) * | 2004-05-11 | 2007-09-26 | 陈新谋 | Microwave thermal reaction device for carbonizing pre-oxidized fiber, and processing technique |
| CN101121577B (en) * | 2007-05-28 | 2010-12-01 | 魏永芬 | Method and device for realizing double-component coat on SiC fibre surface |
| CN106399977B (en) * | 2016-02-22 | 2022-03-25 | 河北陆元新材料科技有限公司 | Production system of coating silicon carbide composite fiber |
| CN107955999B (en) * | 2017-12-11 | 2020-07-14 | 湖南顶立科技有限公司 | Silicon carbide fiber cracking chamber and silicon carbide fiber cracking system |
| CN112481601A (en) * | 2020-11-26 | 2021-03-12 | 中国科学院金属研究所 | Device and method for preparing tungsten-boron radiation-proof fiber by CVD method |
-
1991
- 1991-10-05 CN CN 91109267 patent/CN1033449C/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1314191C (en) * | 2002-12-03 | 2007-05-02 | 夏义峰 | Inductive coupling plasma self-excitation radio frequency generator with power control |
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| Publication number | Publication date |
|---|---|
| CN1071398A (en) | 1993-04-28 |
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