Patent US6409851B1 successfully refreshed from Google Patents.
US6409851B1
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Microwave plasma chemical synthesis of ultrafine powders
Assignee: Materials Modification Inc
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Filing: 1999-03-05
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Granted: 2002-06-25
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Expires: 2019-03-05
Abstract
Abstract The present invention relates to the production of ultrafine powders using a microwave plasma apparatus and chemical synthesis technique. Microwaves generated by a magnetron ( 1 ) are passed through waveguides ( 2 ) before they arrive at the head of a plasmatron ( 3 ). These high energy microwaves ionize a plasma gas, thus releasing large amounts of energy. The energy thus released is utilized to initiate and sustain chemical reactions between the desired elements being pumped in a spiral pattern into the plasmatron ( 3 ). The reaction products are quenched rapidly in a reactor column ( 4 ) into ultrafine powders.
Inventors
- 👤 Krupashankara M. Sethuram
- 👤 Raja Kalyanaraman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:47
CPC Classifications
H; H05; H05B; H05B6/00; H05B6/64; H05B6/80; H05B6/806; B; B01; B01J; B01J19/00; B01J19/08; B01J19/12; B01J19/122; B01J19/126; B22; B22F; B22F1/00; B22F1/05; B22F1/054; B22F3/00; B22F3/10; B22F3/105; B22F9/00; B22F9/16; B22F9/30; B22F9/305; B82; B82Y; B82Y30/00; C; C01; C01B; C01B13/00; C01B13/14; C01B13/20; C01B13/22; C01B13/28; C01B21/00; C01B21/06; C01B21/072; C01B21/0722; C01B21/0724; C01B32/00; C01B32/90; C01G; C01G23/00; C01G23/04; C01G23/047; C01G23/07; H01; H01J; H01J37/00; H01J37/32; H01J37/32009; H01J37/32192; H01J37/32431; H01J37/3244; H05B6/70; H05H; H05H1/00; H05H1/24; H05H1/46; H05H1/461; H05H1/463; B01J2219/00; B01J2219/00049; B01J2219/00051; B01J2219/00074; B01J2219/00087; B01J2219/00094; B01J2219/08; B01J2219/0873; B01J2219/0881; B01J2219/0883; B01J2219/0894; B01J2219/12; B01J2219/1203; B01J2219/1206; B01J2219/1209; B01J2219/1221; B01J2219/1224; B01J2219/1227; B01J2219/1248; B01J2219/1269; B22F2999/00; C01P; C01P2004/00; C01P2004/50; C01P2004/51; C01P2004/60; C01P2004/62; C01P2004/64; H01J2237/00; H01J2237/32; H01J2237/33; H01J2237/339
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
81 words
An apparatus for the microwave synthesis of materials, comprising: a microwave generator; a waveguide through which a microwave generated by said microwave generator passes into a plasma zone positioned such that a plasma is capable of heating reactants to form reaction products; a plasma gas inlet offset at an angle so that plasma gas passing through the inlet enters the plasma zone in a spiral-shaped pattern; and a reaction products collector downstream from said plasma zone for collecting the reaction products.
Claim 2
Independent Claim
81 words
An apparatus for the microwave synthesis of materials, comprising: a microwave generator; a waveguide through which a microwave generated by said microwave generator passes into a plasma zone positioned such that a plasma is capable of heating reactants to form reaction products; a plasma gas inlet offset at an angle so that plasma gas passing through the inlet enters the plasma zone in a spiral-shaped pattern; and a reaction products collector downstream from said plasma zone for collecting the reaction products.
Claim 3
Dependent Claim
48 words
The apparatus of claim 1 , wherein said plasma zone comprises a microwave damper at a side of the plasma zone away from the waveguide for damping microwaves that have passed through the plasma zone to thereby reduce the power of a reflected microwave by at least 60%.
Claim 4
Dependent Claim
16 words
The apparatus of claim 2 , wherein the microwave damper is a water cooled glass tube.
Claim 5
Dependent Claim
16 words
The apparatus of claim 2 , wherein the microwave damper is a water cooled metal tube.
Claim 6
Dependent Claim
16 words
The apparatus of claim 2 , wherein the microwave damper is a water cooled rectangular tube.
Claim 7
Dependent Claim
28 words
The apparatus of claim 1 , comprising a column located between the plasma zone and the reaction products collector for cooling the reaction products leaving the plasma zone.
Claim 8
Dependent Claim
13 words
The apparatus of claim 6 , wherein the column is 8-12 inches long.
Claim 9
Dependent Claim
13 words
The apparatus of claim 1 , comprising a plurality of plasma gas inlets.
Claim 10
Dependent Claim
18 words
The apparatus of claim 1 , wherein the plasma gas inlet is offset at an angle between 5-30°.
Claim 11
Dependent Claim
15 words
The apparatus of claim 1 , wherein the plasma gas inlet is offset at 15°.
Claim 12
Independent Claim
94 words
An apparatus for the microwave synthesis of materials, comprising: a microwave generator; a waveguide through which a microwave generated by said microwave generator passes into a plasma zone positioned such that a plasma is capable of heating reactants to form reaction products; a microwave damper at a side of the plasma zone away from the waveguide for damping microwaves that have passed through the plasma zone to thereby reduce the power of a reflected microwave by at least 60%; and a reaction products collector downstream from said plasma zone for collecting the reaction products.
Claim 13
Independent Claim
94 words
An apparatus for the microwave synthesis of materials, comprising: a microwave generator; a waveguide through which a microwave generated by said microwave generator passes into a plasma zone positioned such that a plasma is capable of heating reactants to form reaction products; a microwave damper at a side of the plasma zone away from the waveguide for damping microwaves that have passed through the plasma zone to thereby reduce the power of a reflected microwave by at least 60%; and a reaction products collector downstream from said plasma zone for collecting the reaction products.
Claim 14
Independent Claim
94 words
A method for the microwave synthesis of materials, said method comprising: introducing a plasma gas into a microwave applicator; introducing at least one reactant into the microwave applicator; generating a microwave in a microwave generator; directing the microwave into the microwave applicator containing the plasma gas to create a heated plasma in a plasma zone; absorbing the microwave to reduce the microwave reflection off of a surface of the microwave applicator by at least 60%; and causing a reaction in the plasma zone thereby converting the at least one reactant into a reaction product.
Claim 15
Independent Claim
94 words
A method for the microwave synthesis of materials, said method comprising: introducing a plasma gas into a microwave applicator; introducing at least one reactant into the microwave applicator; generating a microwave in a microwave generator; directing the microwave into the microwave applicator containing the plasma gas to create a heated plasma in a plasma zone; absorbing the microwave to reduce the microwave reflection off of a surface of the microwave applicator by at least 60%; and causing a reaction in the plasma zone thereby converting the at least one reactant into a reaction product.
Claim 16
Dependent Claim
21 words
The method of claim 12 , further comprising: introducing the plasma gas into the microwave applicator in a spiral shaped pattern.
Claim 17
Dependent Claim
27 words
The method of claim 12 , further comprising: introducing the plasma gas into the microwave applicator at an oblique angle to thereby produce a spiral shaped pattern.
Claim 18
Dependent Claim
15 words
The method of claim 12 , wherein at least one reactant is a powder material.
Claim 19
Dependent Claim
16 words
The method of claim 13 , wherein at least one reactant is a reactant chemical vapor.
References Cited (Backward Citations)
US4022872A
Cited
US4353885A
Cited
US4423303A
Cited
US4924061A
Cited
US5384306A
Cited
US5389585A
Cited
US5403375A
Cited
US5407458A
Cited
US5734143A
Cited
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