Cabinet filter change time detection method and Biohazard Countermeasure for cabinet

摘要

PPROBLEM TO BE SOLVED: To provide a cabinet for biohazard measure which is capable of controlling an exhaust air quantity so as to be kept always constant with good responsiveness for disturbance conditions in an exhaust type (type B) to outdoor upon the cabinet operation, that is, outdoor strong wind such as building wind and monsoon, clogging of HEPA (high-efficiency particulate air) filter and the obstruction of front surface inflow air current due to operators and does not cause the fluctuations of the degree of negative pressure in an installment chamber by keeping the exhaust air amount of the cabinet constant, and to provide a method for detecting the time limit of filter exchange time of the HEPA filter in use. PSOLUTION: The cabinet comprises an air feeding path through which air entering from an operation space and an operation space opening part is sent to a positive pressure chamber via a negative pressure stream path by a fan and clean air is sent into an operation chamber from a positive pressure chamber via an air feeding filter and an exhaust path through which the clean air is sent into an exhaust cylinder from the positive pressure chamber via an exhaust filter. Further, an exhaust air amount detection member and a feeding air amount detection member are disposed on the downstream side of respective HEPA filters of the exhaust path and the air feeding path and the rotation output of a fan motor is controlled based on detection data of the respective air quantity detection members. PCOPYRIGHT: (C)2005,JPO&NCIPI