Supersonic virtual impactor

An apparatus for separating particles from a gas containing said particles said apparatus comprising:

• a housing having an inlet and outlet, said inlet receiving said gas containing said particles;
• supersonic nozzle means for accelerating gas containing said particles to a supersonic velocity and passing it into said inlet;
• a virtual impactor means including a plate having an aperture therein said housing and an interior chamber housing, said interior chamber housing is positioned adjacent said plate so that said aperture is positioned above said interior chamber housing, wherein said supersonic flow strikes said virtual impactor means wherein said nozzle and said impactor cause the forming of a shock wave in front of said virtual impactor means and wherein said particles flow through said aperture of said impactor into said interior chamber and the gas separated from said particles is caused to change direction from the original direction of flow;
• means for introducing an inert gas into said interior chamber thereby maintaining the pressure in said interior chamber at least as great as the pressure behind said shock wave causing a small net flow of gas from said interior chamber through said aperture;
• particle collecting means for collecting said particles in said interior chamber;
• and
• recovery means for recovering the gas separated from said particles wherein the gas separated from said particles exits said housing through said outlet.