Patent ID: 8449657

Claim:
A continuous droplet generator comprising: an outer housing defining a working liquid reservoir configured to maintain a working liquid; at least one heater configured to change the phase of the working liquid; and an evaporation-condensation tube positioned at least partially within the outer housing, wherein the evaporation-condensation tube comprises: a gas inlet configured to receive a particle-containing gas flow; a gas outlet configured to export generated condensed droplets; a wall; an outer wall surface configured to be in contact with the working liquid; and an inner wall surface configured to be in contact with the particle-containing gas flow; wherein the continuous droplet generator is operable to transport vapor to the particle-containing gas flow through the evaporation-condensation tube by diffusion and vapor pressure difference, thereby increasing a relative humidity of the particle-containing gas flow to grow particles within the particle-containing gas flow by nuclei heterogeneous condensation.