THE EFFECT OF REYNOLDS NUMBER OF AIR FLOW DURING THE AIR STERILIZATION PROCESS WITH ULTRAVIOLET GERMICIDAL IRRADIATION LAMP

Abstract

This case study examines the effect that the Reynolds number of air flow has on the population of
live pathogenic microorganisms during the process of air sterilization using ultraviolet germicidal
irradiation (UVGI) lamp in a closed air-duct. With this aim, the first discussion is the mathematical
model which regulates changes to the Reynolds number in terms of the percentage of population
for the following live pathogenic microorganisms: Escherichia coli, Mycobacterium tuberculosis
and Streptococcus pneumoniae, under special condition of flow rate and intensity of UV
irradiation. In conclusion, as the velocity and the Reynolds number of the air flow in the duct
increases, the exposure time of the pathogens to the field of UV-C irradiation decreases, the
effect of UV-C irradiation and the germicide capabilities of the UVGI lamp are reduced.
Consequently, the population of live pathogenic microorganisms increases.