Fast mixing condensation nucleus counter
AssigneeCalifornia Institute of Technology
InventorsRichard C. Flagan, Jian Wang
Life of this patent
Estimating the term…
Abstract
A fast mixing condensation nucleus counter useful for detecting particles entrained in a sample gas stream is provided. The fast mixing condensation nucleus counter comprises a detector and a mixing condensation device having a mixing chamber adapted to allow gas to flow from an inlet to an outlet, wherein the outlet directs the gas flow to the detector. The mixing chamber has an inlet for introducing vapor-laden gas into the chamber and at least one nozzle for introducing a sample gas having particles entrained therein into the chamber. The inlet and nozzle are arranged such that the vapor-laden gas and sample gas mix turbulently. The mixing chamber is configured such that the particles flow through the mixing chamber at a substantially uniform relative velocity.
Claims28
A fast mixing condensation nucleus counter for detecting particles entrained in a sample gas stream, said counter comprising:
- a mixing condensation device having:
- a mixing chamber;
- an inlet for introducing a vapor-laden gas flow to the chamber;
- an outlet for extracting the mixture from the chamber
- at least one nozzle for introducing a sample gas flow to the chamber in mixing proximity to the vapor-laden gas flow such that the particles flow through the chamber from said at least one nozzle to the outlet;
- wherein the inlet and said at least one nozzle are arranged such that the vapor-laden gas flow and the sample gas flow interact to create a turbulent flow of a mixture thereof within the chamber at a Reynolds number of less than about 2200;
- and
- the mixing chamber defines a volume sufficiently small to ensure that the particles move from said at least one nozzle to said outlet at a substantially uniform relative velocity without forming recirculation currents;
- and
- a particle detector for receiving the mixture from the outlet and sensing a characteristic of said mixture.
A fast mixing condensation nucleus counter for detecting particles entrained in a sample gas stream, said counter comprising:
- a mixing condensation device having:
- a mixing chamber;
- an inlet for introducing a vapor-laden gas flow to the chamber;
- an outlet for extracting the vapor-laden gas flow from the chamber;
- at least one nozzle for introducing a sample gas flow to the chamber in mixing proximity to the vapor-laden gas flow such that the particles flow through the chamber from said at least one nozzle to the outlet;
- wherein the mixing chamber has a cross section and wherein the inlet has a diameter substantially the same as the cross section of the inner cavity;
- and
- wherein the inlet and said at least one nozzle are arranged such that the vapor-laden gas flow and the sample gas flow interact such that the kinetic energies of the flows are dissipated within the mixing chamber to create a turbulent flow of a mixture thereof even at a Reynolds number of less than about 2200 such that adjacent particles within said gas flow move through said chamber substantially together and substantially without forming recirculation currents;
- and
- a particle detector for receiving the particles from the outlet and sensing a characteristic of said particles.
Dependencies are inferred from the claim text.