GB2050199A - Filter bag-mounting arrangement - Google Patents

Abstract

A gas filter housing has a clear gas chamber separated from a dirty gas chamber by a plate 4 containing apertures into which filter bags (14) and venturi nozzles (24) are mounted. Each filter bag has flexible ring (13) comprising an outer groove (23) having a diameter to permit it to removably embrace the edge of the aperture. The venturi nozzle 24 has an annular shoulder (26), whose diameter is less than the diameter of the aperture but greater than the internal diameter of ring (13), and flanges (28) which engage the interior of the ring and thus hold the bag mouth within the aperture. The bags and nozzles may be inserted in the apertures from either the clean or dirty gas chambers. <IMAGE>

Description

SPECIFICATION Filter arrangement The present invention relates to gas separation devices and more particularly to a filter arrangement adapted to be connected to an apertured plate member.

The prior art includes a variety of filter arrangements adapted to be releasably connected to an apertured plate member. Typically, each arrangement includes a tubular filter having one end connected to an apertured support plate member, a basket or cage disposed within the filter to prevent inadvertent collapse or failure of the filter, and a venturi proximate the end of the filter adapted to direct and channel pulsed gases into the filter during filter cleaning operations. These arrangements have usually required the use of tools to install and remove and generally have only been accessible from one side of the support plate.

According to the present invention there is an arrangement for mounting a tubular filter and venturi in a bag house of the type that includes a plenum chamber having a plate with apertures into which said filter and venturi are mounted, said arrangement being characterized in that said tubular filter has a flexible ring comprising an outer collar having a diameter to removably embrace said aperture; in that said venturi has a housing which includes an outwardly projecting annual shoulder and in that said annular shoulder has a diameter that is less than the diameter of said aperture but greater than the diameter of said collar to permit insertion or withdrawal of said venturi housing from either side of said plate after removal of said flexible ring and collar from said aperture.

Preferably the collar includes a ridge having a diameter greater than the diameter of said aperture and an external groove having a diameter to removably receive the marginal edge of said aperture.

The filter arrangement includes a flexible ring member connected with one end of a tubular filter and adapted to embrace the marginal edge of the plate aperture to removably secure the filter to the plate. A filter cage or support arrangement is provided within the filter which is connected with a venturi housing cooperating with the ring member and extending therethrough into the interior of the filter. The venturi housing includes an outwardly protruding annular shoulder carried by the ring member to support the housing within the filter, and a recessed throat portion generally adjacent the shoulder to accommodate manipulative flexure of the filter and ring member by a workman attendant to installation and removal of the filter arrangement.

To secure the filter arrangement to the plate, the recessed throat portion of the housing is first generally aligned with the plate in the plate aperture. This provides access to the marginal edge of the aperture such that a workman can manipulate the filter and ring member from either side of the plate to connect the filter to the plate. Thereafter, the entire arrangement is secured to the plate by drawing the housing through the ring member until the annular shoulder of the housing is engaged on the ring member. Conversely, to remove the filter arrangement from the plate, this process is reversed.

From the foregoing, it can be seen that the invention provides a convenient and easily maintained filter arrangement which permits rapid repair or replacement of the filter medium in a gas filtration system, it being understood that various changes can be made in the arrangement, form and construction of the apparatus disclosed herein without departing from the scope and spirit of the invention.

In the accompanying drawings: Figure 1 is a side elevation of a bag house, partially in a section, embodying the invention; Figure 2 is an enlarged isometric view, partially in section, showing part of one filter arrangement mounted on the plate member as shown in Fig. 1; and Figures 3, 4, 5 and 6 sequentially illustrate one method of installing the filter arrangement on the plate member.

As shown in Fig. 1, the gas cleaning arrangement embodying the present invention includes a filter housing or bag house 1 having a dirty gas inlet 2 and a clean gas outlet 3. The bag house 1 includes a transversely extending apertured plate or venturi sheet 4 which divides the bag house 1 into a dirty gas cleaning chamber 5 and a clean gas take-off chamber or plenum chamber 6. The venturi sheet 4 supports a plurality of tubular filter arrangement 7 within the dirty gas chamber 5 such that when dirty gas is directed through the inlet 2 into the cleaning chamber 5, it passes through the filter arrangements 7 and leaves the filter housing 1 through the plenum chamber 6 and clean gas outlet 3.Particulate material separated from the dirty gas and deposited on the exterior of each filter is collected in a hopper 8 positioned below the dirty gas chamber 5, and this material is in turn removed from the hopper through the discharge outlet 9 as is well known in the art. To accommodate cleaning of the filters, the filter housing includes a valve controlled reverse flow flushing arrangement 10. As shown schematically in Fig. 1, the flushing arrangement 10 includes an inlet pipe 11 connected to a source of compressed air and having air injection nozzles 12 positioned above each of the filter arrangements 7 to inject jets or pulses of air into each filter during filter cleaning operations.

Each of the filter arrangements 7 includes a flexible ring member 13 connected to one end of a gas permeable tubular filter bag 14 and adapted to embrace the marginal edge 15 of the plate aperture 16. The filter bag 14, which is preferably of a fabric or cloth-like material, is folded back upon itself and secured by stitching 17 or the like (schematically shown by dotted lines in Fig. 2) to provide a filter cuff 18 entraining and thus securing the ring member 13 to the filter bag.

The ring member includes a flexible back-up band member 19 and a flexible collar 20 surroundingly engaging the outer face of the band member. The back-up band member 19 has an outer diameter slightly less than the diameter of the plate aperture 16 and serves as a back-up member outwardly urging the collar 20 into sealing engagement with the marginal edge 15 of the aperture, it being understood that the band member 19 can be made from any one of several flexible, springlike metallic or plastic materials. The flexible collar 20 is of a channel-like cross-sectional configuration having a pair of axially spaced peripheral ridges 21 and 22 of a diameter slightly greater than the diameter of the plate aperture 16 and defining an external groove 23 adapted to removably receive the marginal edge 15 to form a yielding seal between the ring member 13 and the plate 4.Preferably, the ridges 21 and 22 are formed by folding a fabric upon itself as disclosed in U.S. Patent No. 3,747,305; however, various other arrangements providing axially spaced ridges in the outer face of the ring member to define the external groove can be used.

As noted above, the filter arrangement includes an elongated tubular venturi housing 24 extending through the ring member 13 and into the interior of the filter bag 14 to channel or direct pulsed air from a respective nozzle 12 into the filter during cleaning operations. The venturi housing, which may be made of metal, or thermoplastic, hard rubber or similar material, includes and inwardly recessed throat portion 25, an outwardly protruding or flared annular shoulder 26 at one end of the throat portion, and an outwardly protruding or flared attachment flange 27 at the other end of the throat portion.

The shoulder 26 axially outwardly overlies and is supported by the band 19 and includes a plurality of outwardly radiating plate-like flanges 28 spaced equidistant about the periphery of the housing 24. The outer edges 29 of the flanges 28 are slightly axially inwardly tapered or chamfered so as to engage the inner face of ring member and filter in pressfit wedging relation to align and secure the housing 24 within the filter bag. Additionally, it should be particularly noted that the invention acommodates removal of the housing and thus the filter arrangement from either side of the plate 4 by providing that the outermost diameter of the shoulder 26, which is substantially the same as the diameter of the band 19, be slightly less than the diameter of the plate aperture 16.

As shown in Fig. 2, supporting cage or basket 30 is provided within the filter 14. The basket 30, which is generally coextensive with the filter, is carried by the attachment flange 27 and preferably is rigidly secured to it by welding "W" or the like.

The outer diameter of the attachment flange 27 is substantially the same diameter and contiguous with the interior of the filter bag 14. This arrangement effectively limits induced gas flow during pulsing or filter cleaning operations in the annular region generally indicated at 31 in Fig. 2 between the venturi housing 24 and the cuff 18, thereby effectively abating bleed-through of particulate ma-r terial into the filter. Similarly, by extending the cuff 18 such that it is generally coextensive with the housing 24, the arrangement further reduces particulate bleed-through since the double thickness of filter material folded upon itself is relatively impervious to gas flow with respect to the remainder of the filter.

Figs. 3-6 illustrate one method by which the filter arrangement 7 is secured to the apertured plate 4. As shown in Fig. 3, the recessed throat portion 25 is first generally aligned with the plate 4, and then the flexible ring member 13 is manipulated in the plate aperture until it embraces the marginal edge 15 to secure the filter 14 to the plate. Thereafter, the venturi housing 24 is drawn or lowered through the ring member until the shoulder 26 is engaged on the ring member.

As noted in the foregoing, this process is reversed to remove the ring member and thus the filter arrangement.

Claims (11)

1. An arrangement for mounting a tubular filter and venturi in a bag house of the type that includes a plenum chamber having a plate with apertures into which said filter and venturi are mounted, said arrangement being characterized in that said tubular filter has a flexible ring comprising an outer collar having a diameter to removably embrace said. aper- ture; in that said venturi has a housing which includes an outwardly projecting annular shoulder and in that said annular shoulder has a diameter that is less than the diameter of said aperture but greater than the diameter of said collar to permit insertion or withdrawal of said venturi housing from either side of said plate after removal of said flexible ring and collar from said aperture.

2. An arrangement according to claim 1, characterized in that said collar includes a ridge having a diameter greater than the diameter of said aperture and an external groove having a diameter to removably receive the marginal edge of said aperture.

3. An arrangement according to claim 1 or 2 characterized in that said annular shoul der includes outwardly protruding flange structure removably engaging an inner surface of said ring in pressfit wedging relation.

4. An arrangement according to claim 3 characterized in that said flange structure comprises a plurality of outwardly radiating plate portions spaced substantially equidistant about the periphery of the venturi housing.

5. An arrangement according to any of claims 1 to 4 characterized in that said flexi ble ring comprises a portion of said tubular filter that is folded back upon itself to define an annular space containing a flexible band.

6. An arrangement according to any of claims 1 to 5 characterized by said venturi housing being of an elongated tubular configuration having a throat portion, and axially outwardly flared end portions, one of said end portions providing said annular shoulder and the other of said end portions providing an attachment portion for carrying a filter support.

7. An arrangement according to claim 6 characterized by said filter support being an elongated tubular basket generally contiguous with the interior of the filter and having one end rigidly secured to said attachment portion.

8. An arrangement according to claim 7 characterized in that said attachment portion has an outer diameter substantially the same as the diameter of the interior of the filter and generally contiguous therewith.

9. An arrangement according to any of claims 5 to 8 characterized in that said tubular filter folded back portion forms a flexible tubular cuff extending axially a distance to span said throat portion between said annular shoulder and attachment portion.

10. An arrangement according to any of claims 5 to 9 characterized in that said flexible band member has an outer diameter substantially the same as the outermost diameter of said annular shoulder; said collar surroundingly engages the outer face of said band member; with said collar having a channel-like cross-section defined by two axially spaced peripheral ridges having a diameter slightly greater than the diameter of said plate aperture.

11. An arrangement for mounting a tubular filter and venturi in a bag house substantially as hereinbefore particularly described and as illustrated in the accompanying drawings.