| 摘要 |
Method and apparatus for forming a filter element especially useful for filtering noxious and radioactive gases. The element is composed of a ribbon of sheet filter material folded into reverse pleats. Bands or straps of flexible material are fixed to the crests of the folds in the sheet, at each side thereof, and extend longitudinally thereof, in laterally spaced relation. Transverse cuts are made in these strips at intervals regularly spaced along the pleated ribbon. Each cut is between two contiguous crests. The cuts made on one side are offset with respect to those on the other side. The pleated ribbon is then reversely folded at and along each line, to form a filter element of zigzag form. This element is then mounted within a casing having a passageway therethrough for gas to be filtered, to obturate the passageway by sealing the end and side termini of the element to the walls of the casing. |
