A shrouded aerosol sampling probe: Waste Isolation Pilot Plant

Technical Report · Mon Aug 01 04:00:00 EDT 1988

OSTI ID:6706428

McFarland, A R; Ortiz, C A; Moore, M E; DeOtte, Jr, R E; Somasundaram, S

A new device has been developed for sampling aerosol particles from moving air streams--a shrouded probe. In the design reported herein, a 30 mm diameter sampling probe is located concentrically within a 105 mm diameter cylindrically-shaped shroud. The flow rate through the sampling probe is a constant value of 170 l/min. The dynamic pressure of the external air stream forces flow through the region between the shroud and the internal probe. The velocity of the main air stream, U/sub o/, is reduced in the shroud such that the velocity just upstream of the probe, U/sub s/, is 0.40 that of U/sub o/. By reducing the main air stream velocity, the aerosol losses on the internal walls of the probe inlet are considerably reduced. For a typical isokinetic probe sampling at 170 l/min in an air stream with a velocity of 14 m/s, the wall losses of 10 ..mu..m aerodynamic diameter particles are 39% of the total aspirated aerosol; whereas, the wall losses in the shrouded probe are 13%. Also, by reducing the velocity of the air stream in the shroud, anisokinetic effects can be substantially reduced. Wind tunnel experiments with 10 ..mu..m diameter particles over the range of free stream velocities of 2.0 to 14 m/s show the transmission ratio (ratio of aerosol transmitted through the probe to aerosol concentration in the free stream) to be within the range of 0.93 to 1.11. These data are for a constant flow rate of 170 l/min through the probe. 19 refs., 7 figs.

• Research Organization: Westinghouse Electric Corp., Carlsbad, NM (USA). Waste Isolation Div.; Texas A and M Univ., College Station (USA). Dept. of Mechanical Engineering
• DOE Contract Number: AC04-86AL31950
• OSTI ID: 6706428
• Report Number(s): DOE/WIPP-88-027; ON: DE89002764
• Country of Publication: United States
• Language: English

Related Subjects

440300* -- Miscellaneous Instruments-- (-1989)
47 OTHER INSTRUMENTATION
500300 -- Environment
Atmospheric-- Radioactive Materials Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
AEROSOLS
AIR FLOW
COLLOIDS
DESIGN
DISPERSIONS
FLOW RATE
FLUID FLOW
GAS FLOW
MANAGEMENT
OPERATION
PROBES
SAMPLING
SOLS
TESTING
WASTE MANAGEMENT