CHEMICAL FILTER, ITS USE METHOD, CLEAN ROOM, SEMICONDUCTOR PRODUCTION APPARATUS AND FAN FILTER

摘要

PROBLEM TO BE SOLVED: To easily discriminate and predict the life of a filter by constituting a parallel flow type filter in which the air passing the filter flows approximately parallel along the surfaces of the filter media constituting the filter of the plural filter media varying in the length of the direction where the air flows. ;SOLUTION: The chemical filter which is used for a clean room, semiconductor production apparatus, etc., and removes the gaseous contaminants in the air is formed by providing the filter with two kinds of varying length portions of long filter medium portions 4 and short filter medium portion portions 5 at the length of the filter media in the air flow direction. The method of predicting the life of the parallel flow type filter includes a method of periodically measuring the concentration of the contaminants downstream of the long filter medium portions 4 and downstream of the short filter medium portions 5 and making discrimination that the filter is nearly the end of its life where a difference arises at their concentration level. Also, the downstream side in the filter of the short filter medium portions 5 is provided with a space 3 and a filter medium holding frame is disposed in this space 3 so as to come into contact with the downstream portions of the filter media within the outside frame of the filter.;COPYRIGHT: (C)2001,JPO