Patent ID: 8236078
Filing Date: 2012-08-07
Classification: A47L,B01D,Y10S

Abstract:
1. A filter bag, comprising: a first filter material layer including an inflow opening; a second filter material layer having edges along which the second filter layer is joined to the first filter material layer to form an inside space; a pre-filter comprising a flat, multi-layer filter insert arranged in the inside space and having sections connected, respectively, to the first and second material layers, the filter insert having at least two outer layers having a higher permeability for air than the first and second filter material layers and defining an intermediate area there-between, wherein one of the outer layers includes at least one opening on a side facing the inflow opening, and at a distance from the inflow opening, so that dust-laden air can flow into the intermediate area, and wherein the intermediate area includes one of a center layer or an intermediate space for dust collection.