Cleanable dust filter comprising a zigzag pleated filter pack
A cleanable filter for particulate material, includes a zigzag pleated filter pack, spacers disposed between the pleats in the filter pack and a frame having an upper and lower part covering the respective upper and lower side of the filter pack that contains the ends of the fold lines and two lateral parts covering the opposite sides of the filter pack that contains the ends of the filter medium zigzag folded into a filter pack, the frame thereby leaving the opposite sides of the filter pack that contains alternate fold lines of the pleated filter pack, free for the passage of air. The filter medium in the filter pack includes a pleated sheet of polytetrafluorethylene and the spacers between the pleats consist of corrugated aluminum foils. An earthing element furthermore electrically connects the aluminum foils to each other and to an earth connection on the outside of the filter frame.
1. Cleanable filter ( 1 ) for particulate material comprising a zigzag pleated filter pack ( 2 ), spacers ( 6 ) disposed between the pleats in the filter pack and a frame ( 3 ) having an upper ( 4 ) and lower part covering the respective upper and lower side of said filter pack that contains the ends of the fold lines and two lateral parts covering the opposite sides of said filter pack that contains the ends of the filter medium ( 5 ) zigzag folded into a filter pack, said frame ( 3 ) thereby leaving the opposite sides of the filter pack that contains alternate fold lines of the pleated filter pack, free for the passage of air, characterised in that the filter medium ( 5 ) in the filter pack include a pleated sheet of polytetrafluorethylene (PFTE), in that the spacers ( 6 ) between the pleats consist of corrugated aluminium foils and in that an element ( 7 ) electrically connects the aluminium foils to each other and to an earth connection on the outside of the filter frame ( 3 ).
2. Filter according to claim 1 , wherein the element ( 7 ) electrically connecting the spacers together is an elongate piece of sheet metal extending along the upper or lower side of the filter pack ( 2 ).
3. Filter according to claim 2 , wherein the spacers ( 6 ) between the pleats have ends extending outside the upper or lower side of said filter pack and said elongated element ( 7 ) of sheet metal is pressed against said ends of the spacers.
4. Filter according to claim 2 , wherein said elongate element of sheet metal has a row of projections protruding in between the pleats of the filter pack and into contact with the sides of the spacers.
5. Filter according to claim 1 , wherein the spacers ( 6 ) existing between pleats of the filter pack ( 2 ) all are present in a central region between the opposing sides of the filter pack ( 2 ) that contains alternate folds.
6. Filter according to claim 5 , wherein the spacers ( 6 ) having their free ends turned against one side of the filter pack ( 2 ) that contains alternate fold lines, are thicker than the spacers ( 6 ) having their free ends turned against the opposite side.
7. Filter according to claim 2 , wherein the spacers ( 6 ) existing between pleats of the filter pack ( 2 ) all are present in a central region between the opposing sides of the filter pack ( 2 ) that contains alternate folds.
8. Filter according to claim 3 , wherein the spacers ( 6 ) existing between pleats of the filter pack ( 2 ) all are present in a central region between the opposing sides of the filter pack ( 2 ) that contains alternate folds.
9. Filter according to claim 4 , wherein the spacers ( 6 ) existing between pleats of the filter pack ( 2 ) all are present in a central region between the opposing sides of the filter pack ( 2 ) that contains alternate folds.