Suspendable Filter Bag System

Abstract

A bag house filter bag is suspended vertically from a separable hanger. The filter bag has a closure at the top, which is constructed by a series of tucks and folds. The closure also provides a support loop for engagement with the hanger. The filter bag is constructed mainly of woven fabric formed into a cylinder. The folding and stitching pattern of the fabric at the top end enables the bag to transition from linear at the site of the support loop to cylindrical with an even distribution of stress on the fabric. The hanger includes a cross member and a surrounding tube to reduce specific stress on the fabric. The hanger has a removable joint opening clasp at one end of the cross member to enable rapid insertion and removal of the hanger from within the suspension tube without contact, removal or other disturbance of the filter bag.

1 . A filter bag, comprising:
 a substantially-cylindrical, vertically-disposed, air-filtering bag composed of woven fabric having a top, sides and a bottom including an opening at the bottom for receiving unfiltered air, and an installed diameter; and   a closure at the top of the bag comprising a lateral fold of gathered fabric forming a fabric loop which is open at opposite ends.   
     
     
         2 . The filter bag of  claim 1  wherein the fabric loop is formed by the attachment of a top edge of the bag fabric to the remainder of the bag below the fold at a lateral seam. 
     
     
         3 . The filter bag of  claim 2  wherein a portion of the bag at the top includes vertical pleats. 
     
     
         4 . The filter bag of  claim 3  wherein the gathered fabric is has a series of tucks formed by a plurality of stitched vertical pleats all of the same width and length. 
     
     
         5 . The filter bag of  claim 4  wherein the length of the stitching which forms the tucks is approximately equal to the circumference of the loop, said stitching terminating at the lateral seam. 
     
     
         6 . The filter bag of  claim 1  wherein the length of the loop is approximately equal to the installed diameter of the bag. 
     
     
         7 . A substantially triangular hanger for suspending a bag, said hanger having an apex at the top and side arms which terminate at a cross member at the bottom and further including a releasable joint at an intersection of the cross member and one of the side arms comprising two perpendicularly oriented engaged hooks. 
     
     
         8 . The filter bag of  claim 2  including a hanger having a cross member which passes through the loop. 
     
     
         9 . The filter bag of  claim 8  wherein the hanger is substantially triangular including an apex at the top and side arms which terminate at ends of the cross member at the bottom. 
     
     
         10 . The filter bag of  claim 9  further including a tube which surrounds the cross member. 
     
     
         11 . The filter bag of  claim 10  wherein one arm of the hanger is connected to an end of the cross member by a releasable hook and catch joint such that the hanger cross member can be selectively removed from or reconnected to the loop. 
     
     
         12 . The filter bag of  claim 2  wherein the attachment of the top edge of the bag fabric is by stitching. 
     
     
         13 . The filter bag of  claim 1  further including a longitudinal stitched seam joining side edges of the bag fabric. 
     
     
         14 . The filter bag of  claim 13  further including a plurality of vertically-spaced rigid rings fastened to the sides of the bag to maintain its cylindrical shape. 
     
     
         15 . The filter bag of  claim 14  wherein a top portion of the longitudinal seam lies along the outside of the loop midway between its ends. 
     
     
         16 . The filter bag of  claim 10  wherein the top edge of the bag fabric is attached along the lateral seam and forms adjacent supplementary interior and exterior angles between sides of the bag at the seam when the bag is suspended from the hanger tube. 
     
     
         17 . The filter bag of  claim 1  wherein the unfiltered air is flue gas. 
     
     
         18 . The filter bag of  claim 7  wherein the static structure is a portion of a flue gas bag house. 
     
     
         19 . The filter bag of  claim 10  wherein the length of the tube is at least equal to the length of the loop. 
     
     
         20 . The filter bag of  claim 11  wherein said hook and catch joint comprises two hooks, a first hook integral with the end of the first arm and a second hook perpendicular to the first hook and integral with the end of the cross member.