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Factors Influencing the Transport of Air‐Borne Bacteria at Openings
Author(s) -
HELDMAN D. R.,
HEDRICK T. I.,
HALL C. W.
Publication year - 1967
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1365-2621.1967.tb01330_32_3.x
Subject(s) - aerosol , turbulence , chemistry , atmospheric sciences , ventilation (architecture) , concentration gradient , airflow , environmental science , analytical chemistry (journal) , thermodynamics , environmental chemistry , physics , organic chemistry
SUMMARY— The factors causing transport of air‐borne microorganisms from a high concentration space to a low concentration space were investigated in an aerosol chamber. The transport of bacterial aerosol through an opening between the compartments of the chamber was expressed in terms of a turbulent transfer coefficient. The experimental transfer coefficients increased significantly as the ventilation rates increased from 20 to 40 ft 3 /min and increased slightly between 40 and 60 ft 3 /min. Results obtained with ventilation rate gradients ranging from − 30 to +30 ft 3 /min indicated that the coefficient was maximum at equal rates. An increase in the opening height from 3 to 9 in. produced a significant decrease in the turbulent transfer coefficient. Temperature gradients ranging from −14 to +12S°F with respect to a reference temperature of 75°F resulted in an increase in the turbulent transfer coefficients from 2.09 to 8.09. The effect of temperatures between 75 and 95°F and corresponding relative humidities between 31 and 60%, on aerosol viability did not account for the entire influence of the temperature gradient on aerosol transport.