ABSTRACT
Objective To develop a micro-circumstance airtight cabin for in the study of biological aerosols detection with such functions as airflow control and temperature and humidity detection .Methods Wind speed sensors , temperature and humidity sensors , electrical control valves , high efficiency filters and the vacuum pump formed the micro-circumstance regulating system .The techniques of airflow direction control , temperature compensation , air pressure control and aerosol uniformity distribution were used .Numerical simulation of aerosol concentration distribution in the airtight cabin was achieved using Fluent software .The bioaerosol concentration in different locations was tested by experiments .Results The micro-circumstance airtight cabin consisted of an airtight cabin and a control cabin .The control cabin used a single-chip microprocessor to provide air supply and exhaust air to the airtight cabin in a seaparate exhaust mode and cyclic ventilation mode.It worked under a negative pressure condition .Through numerical simulation,the aerosols were distributed through-out the cabin after five minutes of generation and the bottom airflow arrived at the top .The distribution of aerosol concentra-tion was approximately uniform .Conclusion The micro-circumstance airtight cabin is suited to various bioaerosols testing research thanks to its negative pressure working without bioaerosol leakage .
ABSTRACT
According as partial dog's physiological parameter observing in airtight cabin under normal air pressure, when the oxygen concentration is normal or low, tentatively estimate the important effect of oxygen concentration on dog's circulatory system and respiratory system, and then ascertain the vital significance of micro-circumstance regulating system to improving personnel's physiological function in cockpits and passengers' cabins of armoured vehicles, naval vessels, aircrafts, etc. Micro-circumstance regulating system under the conditions of airtight cabin is designed, a single-chip microprocessor 89C51, oxygen and carbon dioxide concentration transducers form its nucleus primarily, the function involve automatically monitoring and feedbackly regulating oxygen and carbon dioxide concentration all the time.