AU5994480A - Filter bag retaining system with removable thimble extension - Google Patents

Filter bag retaining system with removable thimble extension

Info

Publication number
AU5994480A
AU5994480A AU59944/80A AU5994480A AU5994480A AU 5994480 A AU5994480 A AU 5994480A AU 59944/80 A AU59944/80 A AU 59944/80A AU 5994480 A AU5994480 A AU 5994480A AU 5994480 A AU5994480 A AU 5994480A
Authority
AU
Australia
Prior art keywords
thimble
extension
filter bag
wall
aperture
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
AU59944/80A
Other versions
AU540011B2 (en
Inventor
H.G. Peterson
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
JOY ENVIRONMENTAL EQUIPMENT Co
Original Assignee
Joy Manufacturing Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US06/027,181 external-priority patent/US4219343A/en
Application filed by Joy Manufacturing Co filed Critical Joy Manufacturing Co
Publication of AU5994480A publication Critical patent/AU5994480A/en
Application granted granted Critical
Publication of AU540011B2 publication Critical patent/AU540011B2/en
Assigned to JOY ENVIRONMENTAL EQUIPMENT COMPANY reassignment JOY ENVIRONMENTAL EQUIPMENT COMPANY Alteration of Name(s) in Register under S187 Assignors: JOY MANUFACTURING COMPANY
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Landscapes

  • Filtering Of Dispersed Particles In Gases (AREA)

Description

FILTER BAG RETAINING SYSTEM WITH REMOVABLE THIMBLE EXTENSION
Background of the Invention
As is known, baghouses are used extensively in power generating stations and the like for air pollution control. In a baghouse of this type, dust-laden air enters a plenum chamber and then flows upwardly through apertures in an upper wall of the plenum chamber and into a plurality of vertically-elongated tubular filter bags which separate the dust from the air as it flows through the fabric walls of the bags. The bottom of each filter bag is open and is secured to the periphery of a thimble which extends upwardly from the upper wall of the plenum chamber and surrounds an associated one of the aforesaid apertures. In the usual case, the bottom of the thimble is essentially flush with the upper wall of the plenum chamber.
When gas in the plenum chamber exits through the aperture and the thimble into the filter bag, part of the gas approaches along the center line of the exit path through the aperture; however another part comes toward the aperture radially along the underside of the upper wall of the plenum from all directions. The part approaching along the underside of the upper wall has momentum toward the center of the aperture with the result that this portion of the entering air may not be fully turned into alignment with the bag axis. As a result, it will strike the fabric of the filter bag at a greater angle of incidence. Particles carried by the gas stream will then strike a grazing blow on the fabric and increase wear rate. The problem of bag wear due to the incidence of air entering the thimble in a sideways or radial direction can be alleviated by extending the thimble beneath the upper wall of the plenum chamber in order that the entire cross section of the airstrearn, when it intersects the bottom of the bag, will be essentially parallel to the longitudinal axis of the bag. In the past, thimble extensions of this type have normally comprised an integral part of the thimble itself; and, consequently, were formed from sheet metal of the same gage or thickness as the main portion of the thimble which must be heavy enough to withstand the pull of the bag, handling stresses and welding requirements. Summary of the Invention
The present invention resides in the discovery that an effective thimble extension can be provided which is not an integral part of the thimble itself, which is of lighter gage than the main body of the thimble, and which can be readily inserted or dropped into the thimble and retained in place without the need of any auxiliary fastening elements. The upper end of the thimble extension is flared outwardly; and this flared portion rests on a shoulder formed in the upper portion of the main body of the thimble. In addition to being lightweight, the extension can be readily removed from the thimble in the event that, under certain operating conditions, it may not be required.
The above and other objects and features of the invention will become apparent from the following detailed description taken in connection with the accompanying drawings which form a part of this specification, and in which: Figure 1 is a schematic cross-sectional view of a baghouse with which the present invention may be used;
Figure 2 is an illustration of one of the filter bags used in the baghouse of Fig. 1, showing its connection to a thimble at the bottom of the filter and to a tensioning device at the top; and
Figure 3 is a broken-away cross-sectional view of the thimble incorporating the removable thimble extension of the invention.
With reference now to the drawings, and particularly to Fig. 1, the baghouse shown includes a pair of gas- filtering chambers 10 and 12 each provided with a lower, stepped bottom wall 14. Formed in each bottom wall 14 is a plurality of openings or apertures 16 which are provided with a surrounding thimble, about to be described. Secured to each of the thimbles is the bottom periphery of an enlarged filter bag 18 which extends throughout the entire length of an associated one of the gas-filtering chambers 10 or 12. Beneath each of the walls 14 is a hopper 20 or 22 which collects particulate materials separated from the entering gas stream and is provided at its lower end with a discharge opening 24. During a gas-filtering operation, dust-laden air enters the baghouse through a gas inlet chamber 26 and then passes through openings 28 into the respective ones of hoppers 20 and 22. In the hopper, the gas stream reverses its direction of movement and flows upwardly into the filter bags 18. Each of the filter bags is formed from a porous fabric material which permits the gas to pass therethrough while retaining the particulate material on the inner surface of the filter. After passing through the bag filters, the gas then flows through valves 30 to a gas outlet chamber 32. By manipulating the valves 30, as well as valves 34, the direction of airflow through the chambers 10 and 12 can be reversed, whereby the dust adhering to the inner periphery of each of the filters 18 can be blown downwardly into the hoppers 20 and 22. The manner in which each bag 18 is suspended within an associated one of the chambers 10 or 12 is shown in Fig. 2. At the top, each bag is secured around its periphery to a bell 36 connected through a stainless steel tensioning device, not shown, to an upper support member 40. The bottom of the elongated filter bag is secured to an annular thimble 42 which surrounds an associated opening or aperture in the wall 14. The improved thimble assembly of the invention is shown in Fig. 3. The thimble itself has an upper enlarged diameter portion including a curved lip 40 connected through section 42 to a tapered portion 44 which connects with the main annular body 46 of the thimble. At the bottom of the thimble is a second lip 48 and a recessed portion 50 which fits into a corresponding aperture 16 in the floor wall 14. Inserted into the thimble is a thimble extension 52 comprising a tubular member, formed of relatively thin sheet metal and having at its upper periphery a flanged, inclined section 54 which is of such diameter as to rest on the inclined portion 44 of the main thimble body. As a result, the extension 52 may simply be dropped into the thimble or removed, depending upon requirements, with the inclined portion 54 resting on inclined portion 44. It has been found that the extension 52 will remain in place without the need for any auxiliary fastening elements, notwithstanding the fact that air will flow upwardly through the extension and the thimble itself. As was explained above, air in the plenum chamber 20 or 22 will approach the bottom of the thimble not only along the axis of the filter bag but also along the underside of the floor wall 14 as illustrated by the arrows 56. If the extension 52 is not inserted into the thimble, the air flowing at right angles to the axis of the thimble must make an essentially right angle turn in passing upwardly through the thimble and the filter and in so doing will strike the side of the filter bag. The particulate material entrained within the airstream will then cause excessive wear on the fabric of the filter bag. By using the extension, however, air flowing along the underside of the floor 14 must now flow downwardly and then upwardly through the extension 52 as illustrated by the arrows 58; and while some of this air will impinge on the sides of the extension 52, the extension, being formed from metal, will not experience any deleterious effects.
Although the invention has been shown in connection with a certain specific embodiment, it will be readily apparent to those skilled in the art that various changes in form and arrangement of parts may be made to suit requirements without departing from the spirit and scope of the invention.

Claims (4)

Claims
1. In apparatus for filtering particulate matter from a gaseous stream including a plenum having a wall with at least one aperture therein, a thimble secured to said wall and surrounding said aperture, a vertically-extending tubular filter bag secured to said thimble and in flowthrough communication with said plenum, and a removable annular insert fitted into the interior of said thimble and having a portion which extends beneath the body of the thimble, whereby gas flowing along said wall must flow downwardly and then upwardly through said thimble extension before passing into said filter bag.
2. The apparatus of claim 1, wherein said thimble has an inwardly-inclined flange formed in its upper peripheral portion, and an outwardly-flared flange portion at the upper periphery of said thimble extension which rests on said first-mentioned flange.
3. The apparatus of claim 1, wherein said extension is in close abutting relationship with the inner periphery of said thimble.
4. The apparatus of claim 3, wherein said extension is retained within said thimble by its own weight without the use of auxiliary fastening elements.
AU59944/80A 1979-04-04 1980-04-02 Filter bag retaining system with removable thimble extension Ceased AU540011B2 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US027181 1979-04-04
US06/027,181 US4219343A (en) 1979-04-04 1979-04-04 Filter bag retaining system with removable thimble extension
PCT/US1980/000351 WO1980002115A1 (en) 1979-04-04 1980-04-02 Filter bag retaining system with removable thimble extension

Publications (2)

Publication Number Publication Date
AU5994480A true AU5994480A (en) 1980-10-22
AU540011B2 AU540011B2 (en) 1984-10-25

Family

ID=26702169

Family Applications (1)

Application Number Title Priority Date Filing Date
AU59944/80A Ceased AU540011B2 (en) 1979-04-04 1980-04-02 Filter bag retaining system with removable thimble extension

Country Status (1)

Country Link
AU (1) AU540011B2 (en)

Also Published As

Publication number Publication date
AU540011B2 (en) 1984-10-25

Similar Documents

Publication Publication Date Title
US3372532A (en) Dry separator
US4219343A (en) Filter bag retaining system with removable thimble extension
EP1059993B1 (en) Cleaning apparatus
US4585466A (en) Cyclone separators
US4526678A (en) Apparatus and method for separating large from small particles suspended in a gas stream
US4900345A (en) Separator for use in installations for conveying objects over distances by means of a flow of air
US4654059A (en) Multistage rotary dust collector
US2918139A (en) Centrifugal separator
US4420314A (en) Gas-solids separator
US4477339A (en) Cyclone classifier
US4600410A (en) Process and apparatus for separating particulate matter from a gaseous medium
US3829165A (en) Anti-stoppage apparatus and method for air conveying systems
JPH0316822Y2 (en)
US2604956A (en) Cyclone separator
US3820307A (en) Apparatus for scrubbing waste gases
US2708033A (en) Fractionator
US5398813A (en) Dry fluid substance loading device
US4246014A (en) Bag filter thimble
US3867116A (en) Separator
AU5994480A (en) Filter bag retaining system with removable thimble extension
US2453951A (en) Dust collector
US1260407A (en) Pulverizing apparatus.
GB2136325A (en) Improvements In or Relating To Cyclone Separators
US3440806A (en) Separator tube cap
GB1401331A (en) Grader for fine-grained material