Aerosol generation for stable, low-concentration delivery

摘要

A feed aerosol comprising detectable particles is injected into a mix-enhancing swirler. Diluting gas is also injected into the mix-enhancing swirler and mixed with the feed aerosol in a swirling motion to form an aerosol with a particle concentration no greater than 1,000 particles per liter. The aerosol is then injected into a mixing chamber, where the aerosol is mixed and dried; the inner diameter of the mixing chamber is at least twice as great as that of the swirl chamber. The aerosol is then emitted through a flow straightener that removes swirl from the flow of the aerosol and passed through a delivery conduit, where the particles are detected and counted; and the particle count is compared with a target count. The respective flows of feed aerosol and diluting gas can then be increased or decreased based on a comparison of the particle count with the target count.

主权项

1. A method for generating a stable, low-concentration aerosol, comprising:
generating a flow of a feed aerosol comprising detectable particles; injecting the flow of feed aerosol into a mix-enhancing swirler; injecting a flow of a diluting gas into the mix-enhancing swirler and mixing with the feed aerosol in a swirling motion in a swirl chamber of the mix-enhancing swirler to form a low-concentration aerosol with a particle concentration of no greater than 1,000 particles per liter; injecting the low-concentration aerosol from the mix-enhancing swirler into an inlet of a substantially cylindrical mixing chamber; mixing and drying the low-concentration aerosol in the mixing chamber; emitting the low-concentration aerosol from an outlet of the mixing chamber through a flow straightener that removes swirl from the flow of the low-concentration aerosol; passing the low-concentration aerosol from the flow straightener through a delivery conduit; detecting and counting the particles in the delivery conduit to produce a particle count; comparing the particle count with a target count; if the particle count is less than the target count, increasing the flow of feed aerosol and decreasing the flow of diluting gas into the mix-enhancing swirler; and if the particle count is greater than the target count, decreasing the flow of feed aerosol and increasing the flow of diluting gas into the mix-enhancing swirler, wherein the mixing chamber has an inner diameter, measured orthogonally to a flow path from the inlet to the outlet, that is at least twice as great as an inner diameter of the swirl chamber of the mix-enhancing swirler.