BAG FILTRATION ELEMENT WITH FILTER BAG AND METHOD OF ITS ATTACHMENT TO TUBE PLATE Russian patent published in 2013 - IPC B01D46/00 

FIELD: process engineering.

SUBSTANCE: invention relates to chemical equipment, particularly, to bag filter filtration elements for gas cleaning. Bag filtration element has converging neck with bulge at its front edge to ensure maximum filtration area. It comprises filtration bad consisting of three types of materials. First of them is intended for prefiltering and made from, at least, one layer of nonwoven material produced by needle-punching of polyether- or polypropylene-based fibers or mixes thereof. Second is intended for final filtration and consists of several nonwoven material-based web layers produced by settling ultrafine fibers from polypropylene and/or polysulfone and/or PVC. Third material makes bearing and protective surface for materials of second group and is made from one layer of airtight fibrous web. Note here that all layers of the bag are sewed to make a bag with common lengthwise seam while filtration element rear part is stitched and loop is sewed in for yoke attachment. Properties of materials along airflow may relate so that first type of materials features fiber diameter of 0.33 or 0.17 of mix thereof, or is composed of other fibers, including processing their edges by calender. Second type of materials consists of several layers with equal-diameter fibers or of several fiber layers. Diameter of said fibers decreases at every next layer along the flow. Third type of material represents a bearing net of one layer of airtight polypropylene web. Said bag filtration element is attached to tube plate at two points so that its front neck makes tight joint with tube plate by pipe at tube plate and said neck with bulged along front edge with loose ring. Length of said loose ring corresponds to tube plate pipe length. All said elements as-assembled make wedge-like joint resisting mechanical effects and pressure variations. Filtration element neck is squeezed between tube plate and loose ring. Bag filtration element rear part may be attached to supporting grate. Bag filtration element rear part may be attached to supporting grate by plastic yoke.

EFFECT: higher filter capacity, mechanical strength, resistance against pressure and temperature variations.

6 cl, 2 dwg