High-Temperature Short-Time Disinfection of Bioaerosols Using Infrared Radiation

摘要

In this work, an IR-HTST bioaerosol disinfection device was developed to address the airflow temperature gradients created by axial heating adopted in previous works. By irradiating an IR-absorbing cloth positioned perpendicularly to the flow direction, high temperatures (e.g. 450 °C) were obtained at the cloth surface and downstream air. Airflow temperatures were axially uniform but less so radially/azimuthally due to the velocity profile at the cloth surface. In lab testing, both E. coli and MS2 virus were inactivated at greater than 4.7-log during constant irradiation of the cloth. When the cloth was heated periodically for half or a third of the time, the inactivation was orders of magnitude less indicating that the residual cloth temperature was not sustained for long enough. HTST treatment at 210 °C was found to reduce the concentration of ambient bacteria bioaerosols by 1 to 2-log depending on particle size although it was less effective against ambient fungi. The results of this work proved that the designed IR system can achieve high temperatures and bioaerosol inactivation and lend new information to the development of practical and predictable HTST systems for real-world applications.