| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an inexpensive coarse dust filter capable of extending replacing period. SOLUTION: In order to extend the exchange period by more than six times than that of a washing regeneration type panel type coarse dust filter, a filter area is expanded by more than six times than that of filter plane by using a fold type filter formed by a filter fabric having about 80-95% capturing efficiency, or the exchange period is extended by expanding the filter area by more than six times by increasing a number of folding without providing a separator between the filter fabrics by providing a virgin spare zone obtained by shrinking a folding part at the end part of the folding type filter and by shrinking a clogged part and extending virgin spare folding part by using virgin spare folding part as a use zone after clogging of the use zone. In this way, the exchange period of a post stage main filter is extended too and a total cost is reduced.</p> |
