Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Shrouded probe performance: Variable flow operation and effect of free stream turbulence

Journal Article · · Aerosol Science and Technology
;  [1]
  1. Texas A&M Univ., College Station, TX (United States)
Performance of a shrouded aerosol sampling probe, operated in accordance with the variable flow protocol of EPA Methods 5 and 17, was compared with its performance in a fixed flow rate mode. The effect of free stream turbulence intensity on the transmission ratio of the shrouded probe was also evaluated. This study shows that the sampling flow rate through a shrouded probe can be varied in proportion to the stack velocity, and representative samples can be obtained. This variable sampling flow rate protocol is appropriate to nonnuclear stacks and to nuclear stacks that have the potential to emit significant quantities of radioactive aerosol particles. A shrouded probe, designed for nominal conditions of 57 L/min at a stack velocity of 12 m/s was tested in a wind tunnel over a range of free stream velocities of 6-24 m/s. When the flow rate through the shrouded probe was varied proportionally with the free stream velocity, the transmission ratio (ratio of aerosol concentration at the probe exit plane to the aerosol concentration in the free stream of the stack or duct) of 10-{mu}m aerodynamic diameter (AD) particles varied between 0.97 and 1.04. In comparison, sampling at a fixed flow rate over the same range of free stream velocities resulted in transmission ratios of 0.88-1.32. 21 refs., 8 figs., 1 tab.
Sponsoring Organization:
USDOE
OSTI ID:
460054
Journal Information:
Aerosol Science and Technology, Journal Name: Aerosol Science and Technology Journal Issue: 2 Vol. 26; ISSN ASTYDQ; ISSN 0278-6826
Country of Publication:
United States
Language:
English