Plasma production of ultra-fine ceramic carbides
AssigneeIdaho Research Foundation, Inc.
InventorsPatrick R. Taylor, Shahid A. Pirzada
Life of this patent
Estimating the term…
Abstract
An apparatus and method for the synthesis of ultra-free (submicron) ceramic carbides in a thermal plasma torch reactor using primarily silica, boron oxide, titanium dioxide or other oxides as metal sources and methane as a reductant. A plasma torch operated with both argon and helium as plasma gases and having methane as a primary carrier gas is connected to the plasma reactor for providing the heat necessary to carry out the reaction. A collection chamber with both interior and exterior cooling is connected to the reactor for quenching of the reactants. Cooling is provided to the torch, the reactor and the collection using coils, baffles and jackets.
Claims17
An apparatus for producing relatively uniform sized ultrafine pure ceramic carbides comprising:
- (a) a plasma torch for heat treating materials, said plasma torch producing a plume hot enough to vaporize particulate feed and disassociate gases included in said materials;
- (b) a reactor chamber for receiving said plasma torch plume and for receiving and heat treating materials to be heat treated, said reactor chamber having a plurality of separate reactor chamber zones and means for independently controlling temperatures in said plurality of separate reactor chamber zones, the temperatures of said plurality of separate reactor chamber zones decreasing from a first reactor temperature zone including the plasma torch to a final reactor temperature zone including a collector;
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- (c) a collection chamber including a heat exchanger, said heat exchanger at least partially disposed in the interior of the collection chamber, for rapid cooling of said materials heat treated by said reactor chamber by heat exchange with a circulating fluid passing through said heat exchange to prevent re-oxidation of said materials and for collecting said materials, said collection chamber removing sufficient thermal energy from said gases and solids to prevent re-oxidation.
In an apparatus having a plasma torch for heating materials selected to produce a desired reaction product, to a temperature sufficient to initiate a reaction, and a reaction chamber for providing a reaction zone in which the materials are heated by the plasma torch, a collection chamber being disposed at an end of said reaction chamber, wherein said collection chamber is made of stainless steel and is intensely fluid cooled, the improvement comprising:
- a fluid cooled cooling means surrounding said collection chamber and at least partially disposed in an interior of said collection chamber for removing sufficient thermal energy from the materials to prevent re-oxidation of the reaction product.
An apparatus for producing relatively uniform sized ultra-fine pure ceramic carbides comprising:
- (a) a plasma torch for heat treating materials, said plasma torch producing a plume hot enough to vaporize particulate feed and disassociate gases included in said
- (b) a reactor chamber for receiving said plasma torch plasma torch plume and for receiving and heat treating materials to be heat treated, said reactor chamber having a plurality of separate reactor chamber zones, multiple ports along said plurality of separate reactor chamber zones for taking samples of said particulate feed and said gases, and means for independently controlling temperatures in said plurality of separate reactor chamber zones, the temperatures of said plurality of separate reactor chamber zones decreasing from a first reactor temperature zone including the plasma torch to a final reactor temperature zone including a collector;
- and
- (c) a collection chamber including a heat exchanger, said heat exchanger at least partially disposed in the interior of the collection chamber, for rapid cooling of said materials heat treated by said reactor chamber by heat exchange with a circulating fluid passing through said heat exchanger to prevent re-oxidation of said materials and for collecting said materials, said collection chamber removing sufficient thermal energy from said gases and solids to prevent re-oxidation.
Dependencies are inferred from the claim text.