Experimental Research On Movement And Transport Of Indoor Bio-particles

After the outbreak of Service Acute Respiratory Syndrome(SARS)and the emergence of bird flu, the issue of indoor microbe contamination gradually draws widely and highly attentions of scholars all around the world. It has been proved by the results of enormous researches that the bio-particles containing virus and microbe, etc. can spread through air. Especially in the room or other sealed spaces which are crowded with people, the potential to contact with virus and then be infected is much higher. Thus the research on movement and transport of bio-particles in doors is critical and indispensable.In this thesis, which focused on the indoor movement and spread of bio-particles engendered by respiration, cough and sneeze, both methods of theory analysis and experiments were used. Firstly, the continuous point-source dispersion model and the instantaneous point-source dispersion model were used to analyze the rule of indoor movement and transport of bio-particles engendered by respiration, cough and sneeze. The results showed that in these three conditions, microbe can reach, at least, as far as 10m. Additionally, the concentration of microbe in the downwind side of point-source was directly proportional to the concentration of point-source. Secondly, the experiments were conducted in the large scale chamber, used the Serratia marcescens as a subject, focused on the spread distance of microbe under three conditions of respiration, cough and sneeze, as well as the effect of heat flow boundary condition (human body heat emission) on the distribution of indoor microbe. The results showed that continuous point-source dispersion model and instantaneous point-source dispersion model can be used to describe the transport of indoor microbe qualitatively, and that the heat emission from human body can affect the movement of microbe to some extent.Additionally, the adherence of bio-particles on different materials surface was studied, and the adhesive coefficients on materials surface were calculated according to the results of experiments.