High efficiency virtual impactor

Patent · Tue Nov 17 04:00:00 EST 1981

OSTI ID:5684836

Loo, B W

Environmental monitoring of atmospheric air is facilitated by a single stage virtual impactor for separating an inlet flow having particulate contaminants into a coarse particle flow and a fine particle flow to enable collection of such particles on different filters for separate analysis. An inlet particle acceleration nozzle and coarse particle collection probe member having a virtual impaction opening are aligned along a single axis and spaced apart to define a flow separation region at which the fine particle flow is drawn radially outward into a chamber while the coarse particle flow enters the virtual impaction opening. Symmetrical outlet means for the chamber provide flow symmetry at the separation region to assure precise separation of particles about a cutpoint size and to minimize losses by wall impaction and gravitational settling. Impulse defocusing means in the probe member provides uniform coarse particle deposition on the filter to aid analysis. Particle losses of less than 1% for particles in the 0 to 20 micron range may be realized.

• Assignee: Department of Energy
• Patent Number(s): US 4301002
• OSTI ID: 5684836
• Country of Publication: United States
• Language: English

Related Subjects

500200* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
AEROSOLS
AIR POLLUTION MONITORS
COLLOIDS
DESIGN
DISPERSIONS
EFFICIENCY
EQUIPMENT
FILTERS
FILTRATION
FLUID FLOW
GAS FLOW
MEASURING INSTRUMENTS
MONITORS
NOZZLES
PARTICLE SIZE
PARTICLES
SEPARATION PROCESSES
SIZE
SOLS