Improved operating parameters for the Pitt-3 aerosol generator during resuspension of respirable cotton dust.
Frazer DG; Robinson VA; Jayaraman K; Weber KC; DeLong DS; Glance C
Cotton dust: proceedings of the Tenth Cotton Dust Research Conference, beltwide cotton research conferences, January 8-9, 1986, Las Vegas, Nevada. Jacobs RR, Wakelyn PJ, eds. Memphis TN: The National Cotton Council of America, 1986 Apr; :122-125
A study was conducted to determine whether the output consistency of an acoustically powered particle generator (the Pitt-3) used to produce respirable cotton dust could be improved with respect to time. When the generator speaker was operated at an amplitude of 6 volts (root mean square) and a frequency of 60 hertz (Hz), the output mass concentration of cotton dust fell off rapidly with time. The lowest resonant frequency of the system, at which a minimum in spectral amplitude occurred, was approximately 30Hz. When the generator was operated at 30Hz, the output mass concentration decrease was less over a 6 hour period that the decrease for 40 minutes at 60Hz. During the course of 1 hour experiment, no significant changes in the count distribution of the particles were observed. Mass median diameter of the resuspended cotton dust calculated by the APS particle sizer was 3.5 micrometers, nearly identical to those previously reported. The authors conclude that operating the Pitt-3 system at its lowest resonant frequency (30Hz) greatly increased the stability of the generator with respect to time. In cases where a stable concentration of cotton dust is needed over an extended period of time, it would be better to operate the Pitt-3 generator near its resonant frequency.
Cotton-dust; Aerosol-particles; Dust-particles; Particulates; Respirable-dust; Aerosol-generators; Airborne-particles
Jacobs RR; Wakelyn PJ
Cotton dust: proceedings of the Tenth Cotton Dust Research Conference, beltwide cotton research conferences, January 8-9, 1986, Las Vegas, Nevada