Improvement by Partial Replacement of Filter Media in an Air Mat Filter

The air filter is usually used in the form of a filter mat unit or an automatic roll filter. In an automatic roll filter, filter media are replaced by the action of a pressure switch or a timer.This report is concerned with experimental results of the automatic filter, of which media are partially or entirely replaced when the pressure loss reaches the maximum set value.1) In case of partial replacement, dust holding capacity of filter media increases nearly twice as much as that of entire replacement, and the fluctuation of air flow decreases.2) There is no difference between dust collection efficiencies of both systems. However, filtering air velocity changes almost liniarly along the filter length.3) The correlation between partial replacement area and drop of pressure loss is nearly linear too.4) It is favorable from the economical stand-point to make the replacement area as a l possible. And the maximum merit can be achieved when the total length of the filter roll is seven or more times as long as the filtering area.