Patent ID: 8062396

Claim:
An apparatus for collecting dust that comprises: a space for collecting dust and a space for discharging air wherein the spaces are separated by a bulkhead, a plurality of pleated-type filters installed in the space for collecting dust, wherein the pleated-type filter comprises a cylindrical inner member having a plurality of holes in its cylindrical structure, and a main body of a pleated-type filter formed by a filtering cloth, wherein the filtering cloth having a sheet-like shape is folded so as to form a pleated cylindrical body that has pleats directed in the longitudinal direction of the cylindrical body, wherein the pleated cylindrical body is disposed around the cylindrical inner member, wherein a ratio of the apertures of the pleats (P/H) that is defined by the intervals (P) between the crests of adjacent pleats of the main body and the heights (H) of its pleats ranges from 0.1 to 0.3, and wherein the value of the ratio of the apertures of the pleats (P/H) is determined based on the relationship between the area for installing the main bodies of the pleated-type filters and the ratio of the apertures of the pleats (P/H), by using a resistance to a ventilation of the contaminated filtering cloth that corresponds to a coefficient of resistance that is caused by a filtering cloth and residual dust that cannot be shaken off from the filter and a jet device for shaking off dust from the filters by means of jets for cleaning the filters installed in the space for discharging air, wherein an amount of the air discharged by the jets is set at a range from 1.3 to 1.5 (NL/m 2 ).