High efficiency filter esp. for polluted air - has fan between two filter units pref. comprising two filters each

摘要

Appts. for treating fluids comprises a first or upstream filter unit contg. at least one high-efficiency filter, and a second downstream filter unit contg. a solid matrix filter medium and also a high-efficiency filter on the discharge side; the pump or blower is mounted between the first and second filter units. With this arrangement, it is found that increased life of the various components is obtd. in partic. the redn. in the quantity of particles impinging upon the blower reduces wear of the blower. The locating of the blower between the first and second units lead to greater efficiency than if it is located either upstream or downstream of the entire set of filters.