Patent ID: 8859931

Claim:
An apparatus for producing nanopowders comprising: a) a plasma torch to generate a plasma flow and to produce a vapour from a reactant material supplied to the plasma torch; and b) a quenching chamber mounted to the plasma torch downstream therefrom and in fluid communication with said plasma torch to receive the vapour from the plasma torch and condense said vapour into the nanopowders, said quenching chamber comprising: i) an upstream hot quench section supplied with a first quench gas preheated to a vapour condensation temperature lower than a melting point of the reactant material, the first quench gas preheated to the vapour condensation temperature being injected into the upstream hot quench section to generate in the quenching chamber a renewable controlled-temperature gaseous condensation front, wherein the vapour condensation temperature of the first, pre-heated quench gas controls at least one physical property of the nanopowders from particle morphology, particle uniformity, particle size and particle size distribution; ii) at least one downstream cold quench section supplied with a second quench gas at a temperature lower than the vapour condensation temperature of the first, preheated quench gas to control a temperature profile along the quenching chamber to improve at least one physical property of the nanopowders from particle morphology, particle size and particle size distribution.