CA2086697A1 - High temperature filter bag support rings - Google Patents
High temperature filter bag support ringsInfo
- Publication number
- CA2086697A1 CA2086697A1 CA 2086697 CA2086697A CA2086697A1 CA 2086697 A1 CA2086697 A1 CA 2086697A1 CA 2086697 CA2086697 CA 2086697 CA 2086697 A CA2086697 A CA 2086697A CA 2086697 A1 CA2086697 A1 CA 2086697A1
- Authority
- CA
- Canada
- Prior art keywords
- support ring
- composite support
- reinforcing element
- filamentary reinforcing
- cylindrical shell
- 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.)
- Abandoned
Links
Landscapes
- Filtering Materials (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A composite support ring designed to maintain a fabric filter bag in a fully opened condition is made by winding a resin-coated yarn onto a mandrel to produce a cylindrical shell of predetermined thickness thereon. After the cylindrical shell has been cured and removed from the mandrel, it is sliced into support rings of suitable thickness. The composite support rings so produced lack an obvious join region, and exhibit no discontinuities in their circumferential mechanical properties.
A composite support ring designed to maintain a fabric filter bag in a fully opened condition is made by winding a resin-coated yarn onto a mandrel to produce a cylindrical shell of predetermined thickness thereon. After the cylindrical shell has been cured and removed from the mandrel, it is sliced into support rings of suitable thickness. The composite support rings so produced lack an obvious join region, and exhibit no discontinuities in their circumferential mechanical properties.
Description
i-~2 ~ ~3æ S ~
- HIGH TEMPERATURE_FI1TE~A~ Syp~O~T RINGS
Back~round of the Invention Field.o~ the._In__ntion The pre~ent invention relates to the cylindrical fiberglass fabric filter bags used to remove particulate matter from gaseous streams. Specifically, the present invention i~
concerned with the provision of composite support rings for use with cylindrical fiberglass fabric filter bags.
Description of the Prior ~rt ~ t present, hot gas filtration units which are used extensively in such settings as ooal-fired boiler~, furnaces and carbon black manu~acturing plants, include fiberglass fabric f ilter bags to f ilter and recycle hot gases produced in connection with their respective processes. Typically, temperatures within hot gas filtration units are between 200 C
.~ (392-F~ and 260-C (500-F). Periodi~ally, the particulate ~ matter filtered from the hot gas ~ust be cleaned from th~
; ~ilter bags to restore the permeabilities o~ the bags to : efficient levels.
Such periodic cleaning involves stopping the flow of ; hot gas into the bag, and shaking the bag to allow any--particulate matter caked ~n its mside surface to drop to the bottom. During this shaking interval, the bag's high lPngth-to-diameter ratio, typically higher than 24, tend~ to cause the bag to buc~le, blocking the pathway ~or the sediment falling to the bottom.
: To prevent buckling during ~haking, sta~nless steel suppo rings are ased circurferentially around the bags at :. .
points along their length. ~he rings are of approx~mat~ly the same diameter as the bags, and are sewn onto the outer ~urfaces of the bags. Often 9 several ring~, sewn at spaced intervals along the length of the bag, are used. In this manner, the rings ensure that the bags will remain open along their entir~
lengths, even while ~eing shaken.
Currently used stainless ~teel rings are manufactured by bending and welding steel wire, typically S mm in diameter, into hoops for specified bag diamet~ers ranging up to 300 ~m (12 inches). The harsh chemical enviro~ment and high temperatures characteri~tic of hot gas filtration units require stainless steel, rather than mild steel, to be used to form the support rings. The requirement of stainless steel makes the support rings more expensive in terms of ~oth material and manufacturing costs. ~
In addition, the weld areas in stainless steel rings may in time become corroded and weakened in the caustic and elevated temperature-environment of the hot gas filtration unit, which may ultimately cause the rings to separate at the weld joint. Human error in the actual welding process can al~o contribute to premature and undesired separation of ~he weld.
When separation takes place, the separated ends of the ring will be able to puncture thP filter bag during shaking, making the replacement of the entire bag necessary~
Clearly, the provision of a seamless support ring, capable of surviving in ths punishing chemical and temperature conditions characteristic o~ hot gas-filtration units, would provide a solution to these problems. Such a support ring is provided by way o~ the present in~ention.
, ' ~
- HIGH TEMPERATURE_FI1TE~A~ Syp~O~T RINGS
Back~round of the Invention Field.o~ the._In__ntion The pre~ent invention relates to the cylindrical fiberglass fabric filter bags used to remove particulate matter from gaseous streams. Specifically, the present invention i~
concerned with the provision of composite support rings for use with cylindrical fiberglass fabric filter bags.
Description of the Prior ~rt ~ t present, hot gas filtration units which are used extensively in such settings as ooal-fired boiler~, furnaces and carbon black manu~acturing plants, include fiberglass fabric f ilter bags to f ilter and recycle hot gases produced in connection with their respective processes. Typically, temperatures within hot gas filtration units are between 200 C
.~ (392-F~ and 260-C (500-F). Periodi~ally, the particulate ~ matter filtered from the hot gas ~ust be cleaned from th~
; ~ilter bags to restore the permeabilities o~ the bags to : efficient levels.
Such periodic cleaning involves stopping the flow of ; hot gas into the bag, and shaking the bag to allow any--particulate matter caked ~n its mside surface to drop to the bottom. During this shaking interval, the bag's high lPngth-to-diameter ratio, typically higher than 24, tend~ to cause the bag to buc~le, blocking the pathway ~or the sediment falling to the bottom.
: To prevent buckling during ~haking, sta~nless steel suppo rings are ased circurferentially around the bags at :. .
points along their length. ~he rings are of approx~mat~ly the same diameter as the bags, and are sewn onto the outer ~urfaces of the bags. Often 9 several ring~, sewn at spaced intervals along the length of the bag, are used. In this manner, the rings ensure that the bags will remain open along their entir~
lengths, even while ~eing shaken.
Currently used stainless ~teel rings are manufactured by bending and welding steel wire, typically S mm in diameter, into hoops for specified bag diamet~ers ranging up to 300 ~m (12 inches). The harsh chemical enviro~ment and high temperatures characteri~tic of hot gas filtration units require stainless steel, rather than mild steel, to be used to form the support rings. The requirement of stainless steel makes the support rings more expensive in terms of ~oth material and manufacturing costs. ~
In addition, the weld areas in stainless steel rings may in time become corroded and weakened in the caustic and elevated temperature-environment of the hot gas filtration unit, which may ultimately cause the rings to separate at the weld joint. Human error in the actual welding process can al~o contribute to premature and undesired separation of ~he weld.
When separation takes place, the separated ends of the ring will be able to puncture thP filter bag during shaking, making the replacement of the entire bag necessary~
Clearly, the provision of a seamless support ring, capable of surviving in ths punishing chemical and temperature conditions characteristic o~ hot gas-filtration units, would provide a solution to these problems. Such a support ring is provided by way o~ the present in~ention.
, ' ~
2~~9~
Summarv o~_~he lnven~iQn The present inventisn is a continuously wound, fiberglass-reinforced phenolic resin ring designed for use as a replacement for the welded 5ta~nle55 steel rings currently being used as support rings for cylindrical fibergla~s fabric filter bags. The high-temperature stability of the phenolic resin and the strength and stiffness of the fibergla~
reinforcement provide the ~upport rings of the present invention with physical properti~-s similar to those of the ~teel rings currently in use, plus the added advantages of light weight, reduced cost and improved performanc~ over a longer useful lifetime.
The present in~ention will now be described in more complete detail below, with frequent reference being made to the accompanying figures identified below.
Brief Description of the Drawin~
Figure 1 shows a typical cylindrical fiberglass fabric filter bag with several support rings sewn to its outer sur~ace.
Figure 2 shows schematically an apparatus with which the composite support rings of the present invention may be manufactured.
Detailed Description of the Preferred Embodiments As shown in Fiqur~ ~, a filter bay 10, such as a cylindrical fiberglass fabric filter bag used in hot gas filtration units, has an opening 12, through which ~he gaseous stream to be filtered enters, and a closed end 14. At se~eral se~r~ 1 nng the le~gth of the filt~'. ba.~ 10~ suppor-t 2~'$~
rings 16, each havlng a diameter ~pproximately equal to that of the ~ilter bag 10, are BeWn, or otherwise attached, to the outside thereo~. In such positions, the 8upport rings 16, which are substantially rigid, keep the filter bag 10 open for its entire length, particularly during the shaking periodically required to cause particulate~matter to settle to the bottom thereof, and prevent the buckling of the filter bag 10 during that shaking.
As previously di6cussed, the 5upport rings of the prior art are manufactured by forming a hoop from a length of steel wire, whose ends are joined to one another by w21ding. The weld point in the prior art has represented a weakness in such support rings, as, under the adverse temperature and chemical conditions present in hot gas filtration units, the weld often corrodes and separates. The separated ends of the prior-art ~upport ring can then puncture ~he filter bag, particularly during the shaking cycle, maXing it necessary to replace the filter bag at a time earlier t~an would in general be desirable.
The support rings 10 of the present invention, as a consequence of the manner in which they are manufactured, do not have a weld point, ~or do they have any single point representing a join region, li~e a weld point. The absence of any discontinuities in circumferential mechanical properties makes the supp~rt rings 10 o~ the present invention ideal replacements for the stainless steel rings o~ the prior art.
The composite support rings of the present invention are developed on a conventional two-axis filament winder by passing a single fiberglass yarn hrough a heated dip tank containing a low viscosity phenolic resin formulation~ and by ~3~ 7 hoop w~nding the yarn over a cylindrical mandr~l to ~chieve the required wall thicknes~.
This process is represented in Figure 2. A reel 20, or other source of fiber, 8uppli~s fi~erglass yarn 22 continuously. ~he yarn 22 i8 directed over and around rollers 24 into a rasin dip tanX 26, which may contain a low viscosity phenolic resin 28. The resin-coated yarn 30 is then ho~p wound over a cylindrical mandrel 32 until the required wall thickness has been achieved on the mandrel 32. The resin-coated yarn 30 thereby forms a cylinder 34 on the mandrel 32.
The cylindrical mandrel 32 is then vacuum-bag cured at 177-C (350-F~ under full YacUUm conditions (30 inches Hg).
Upon completion of the cure, the vacuum bag is removed and the composite cylinder is exposed to a free-standing post cure at 360-C (5~0-F) to enable the phenolic resin to withstand the constant high temperature conditions to which the support rings 16 are exposed. Once the post-cure is completed, the cylinder 34 is removed from the mandrel 32, and is slicPd to produce the composite support rings of the present invention.
The present composite support rings have ~een tested in a production environment, and have been proven to per~orm well through the entire life of the filter bags, which ~ypically is in the range from 12 to 36 months.
Fiberglass yarn 22 is only one example of the filamentary reinforcing elements that may be used in the composite support rings of the present invention. In general, staple yarns, continuous filament yarns, consolidated or spread continuous ~ilament tows, or strips of woven fabric could b~
sed as the reinforcing elements. Materials for the r~inforcing elements may be of fiberglass, carbon fiber, aramid ~i~er.~. ~n~ n~her~
The resins used to coat the reinforcing elements prior to being wound onto the mandrel ~ay be ~elected from thermo~et or thermoplastic resins; ~he phenol~c resin mentloned in the preceding discussion is one of the thermoset res~ns ~hat ~ay be used for this purpose.
It should be readily under~tood that modi~ications to the above would be obvious to anyone skilled in the ar~ without departing from the scope o~ the appended claims.
.,, ~ r. .~ . T~ . ~ __
Summarv o~_~he lnven~iQn The present inventisn is a continuously wound, fiberglass-reinforced phenolic resin ring designed for use as a replacement for the welded 5ta~nle55 steel rings currently being used as support rings for cylindrical fibergla~s fabric filter bags. The high-temperature stability of the phenolic resin and the strength and stiffness of the fibergla~
reinforcement provide the ~upport rings of the present invention with physical properti~-s similar to those of the ~teel rings currently in use, plus the added advantages of light weight, reduced cost and improved performanc~ over a longer useful lifetime.
The present in~ention will now be described in more complete detail below, with frequent reference being made to the accompanying figures identified below.
Brief Description of the Drawin~
Figure 1 shows a typical cylindrical fiberglass fabric filter bag with several support rings sewn to its outer sur~ace.
Figure 2 shows schematically an apparatus with which the composite support rings of the present invention may be manufactured.
Detailed Description of the Preferred Embodiments As shown in Fiqur~ ~, a filter bay 10, such as a cylindrical fiberglass fabric filter bag used in hot gas filtration units, has an opening 12, through which ~he gaseous stream to be filtered enters, and a closed end 14. At se~eral se~r~ 1 nng the le~gth of the filt~'. ba.~ 10~ suppor-t 2~'$~
rings 16, each havlng a diameter ~pproximately equal to that of the ~ilter bag 10, are BeWn, or otherwise attached, to the outside thereo~. In such positions, the 8upport rings 16, which are substantially rigid, keep the filter bag 10 open for its entire length, particularly during the shaking periodically required to cause particulate~matter to settle to the bottom thereof, and prevent the buckling of the filter bag 10 during that shaking.
As previously di6cussed, the 5upport rings of the prior art are manufactured by forming a hoop from a length of steel wire, whose ends are joined to one another by w21ding. The weld point in the prior art has represented a weakness in such support rings, as, under the adverse temperature and chemical conditions present in hot gas filtration units, the weld often corrodes and separates. The separated ends of the prior-art ~upport ring can then puncture ~he filter bag, particularly during the shaking cycle, maXing it necessary to replace the filter bag at a time earlier t~an would in general be desirable.
The support rings 10 of the present invention, as a consequence of the manner in which they are manufactured, do not have a weld point, ~or do they have any single point representing a join region, li~e a weld point. The absence of any discontinuities in circumferential mechanical properties makes the supp~rt rings 10 o~ the present invention ideal replacements for the stainless steel rings o~ the prior art.
The composite support rings of the present invention are developed on a conventional two-axis filament winder by passing a single fiberglass yarn hrough a heated dip tank containing a low viscosity phenolic resin formulation~ and by ~3~ 7 hoop w~nding the yarn over a cylindrical mandr~l to ~chieve the required wall thicknes~.
This process is represented in Figure 2. A reel 20, or other source of fiber, 8uppli~s fi~erglass yarn 22 continuously. ~he yarn 22 i8 directed over and around rollers 24 into a rasin dip tanX 26, which may contain a low viscosity phenolic resin 28. The resin-coated yarn 30 is then ho~p wound over a cylindrical mandrel 32 until the required wall thickness has been achieved on the mandrel 32. The resin-coated yarn 30 thereby forms a cylinder 34 on the mandrel 32.
The cylindrical mandrel 32 is then vacuum-bag cured at 177-C (350-F~ under full YacUUm conditions (30 inches Hg).
Upon completion of the cure, the vacuum bag is removed and the composite cylinder is exposed to a free-standing post cure at 360-C (5~0-F) to enable the phenolic resin to withstand the constant high temperature conditions to which the support rings 16 are exposed. Once the post-cure is completed, the cylinder 34 is removed from the mandrel 32, and is slicPd to produce the composite support rings of the present invention.
The present composite support rings have ~een tested in a production environment, and have been proven to per~orm well through the entire life of the filter bags, which ~ypically is in the range from 12 to 36 months.
Fiberglass yarn 22 is only one example of the filamentary reinforcing elements that may be used in the composite support rings of the present invention. In general, staple yarns, continuous filament yarns, consolidated or spread continuous ~ilament tows, or strips of woven fabric could b~
sed as the reinforcing elements. Materials for the r~inforcing elements may be of fiberglass, carbon fiber, aramid ~i~er.~. ~n~ n~her~
The resins used to coat the reinforcing elements prior to being wound onto the mandrel ~ay be ~elected from thermo~et or thermoplastic resins; ~he phenol~c resin mentloned in the preceding discussion is one of the thermoset res~ns ~hat ~ay be used for this purpose.
It should be readily under~tood that modi~ications to the above would be obvious to anyone skilled in the ar~ without departing from the scope o~ the appended claims.
.,, ~ r. .~ . T~ . ~ __
Claims (14)
1. A composite support ring for use with fabric filter bags, said composite support ring comprising a plurality of substantially circumferential windings of a filamentary reinforcing element, said plurality of windings being embedded in a thermally and chemically resistant polymeric matrix material, said reinforcing element being continuous and extending over more than one circumferential distance of said composite support ring, so that said composite ring may have no obvious join region and may exhibit no discontinuities in its circumferential mechanical properties.
2. A composite support ring as claimed in claim 1 wherein said filamentary reinforcing element is a staple yarn.
3. A composite support ring as claimed in claim 1 wherein said filamentary reinforcing element is a continuous filament yarn.
4. A composite support ring as claimed in claim 1 wherein said filamentary reinforcing element is a continuous filament tow.
5. A composite support ring as claimed in claim 4 wherein said continuous filament tow is consolidated.
6. A composite support ring as claimed in claim 4 wherein said continuous filament tow is spread.
7. A composite support ring as claimed in claim 1 wherein said filamentary reinforcing element is a strip of woven fabric.
8. A composite support ring as claimed in claim 1 wherein said filamentary reinforcing element includes glass fibers.
9. A composite support ring as claimed in claim 1 wherein said filamentary reinforcing element includes carbon fibers.
10. A composite support ring as claimed in claim 1 wherein said filamentary reinforcing element includes aramid fibers.
11. A composite support ring as claimed in claim 1 wherein said polymeric matrix material is a thermoset resin.
12. A composite support ring as claimed in claim 11 wherein said thermoset resin is a phenolic resin.
13. A composite support ring as claimed in claim 1 wherein said polymeric matrix material is a thermoplastic resin.
14. A method for manufacturing a composite support ring for use with fabric filter bags comprising the steps of:
a) providing a length of a filamentary reinforcing element;
b) passing said length of said filamentary reinforcing element through a supply of a liquid thermally and chemically resistant polymeric matrix material to coat said filamentary reinforcing element;
c) winding said coated filamentary reinforcing element onto a mandrel to form a cylindrical shell of predetermined thickness therefrom;
d) curing said cylindrical shell on said mandrel in a rarefied atmosphere;
e) removing said cylindrical shell from said mandrel;
f) curing said cylindrical shell under elevated temperature conditions; and g) slicing said cylindrical shell into a plurality of rings.
a) providing a length of a filamentary reinforcing element;
b) passing said length of said filamentary reinforcing element through a supply of a liquid thermally and chemically resistant polymeric matrix material to coat said filamentary reinforcing element;
c) winding said coated filamentary reinforcing element onto a mandrel to form a cylindrical shell of predetermined thickness therefrom;
d) curing said cylindrical shell on said mandrel in a rarefied atmosphere;
e) removing said cylindrical shell from said mandrel;
f) curing said cylindrical shell under elevated temperature conditions; and g) slicing said cylindrical shell into a plurality of rings.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US86521192A | 1992-04-08 | 1992-04-08 | |
| US865,211 | 1992-04-08 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2086697A1 true CA2086697A1 (en) | 1993-10-09 |
Family
ID=25344958
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2086697 Abandoned CA2086697A1 (en) | 1992-04-08 | 1993-01-05 | High temperature filter bag support rings |
Country Status (5)
| Country | Link |
|---|---|
| AU (1) | AU2853792A (en) |
| BR (1) | BR9301442A (en) |
| CA (1) | CA2086697A1 (en) |
| MX (1) | MX9207624A (en) |
| ZA (1) | ZA929509B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1995027431A1 (en) * | 1994-04-11 | 1995-10-19 | Goyen Controls Co. Pty. Ltd. | Components for and methods of operation of bag house filter/cartridge cleaning systems |
-
1992
- 1992-11-18 AU AU28537/92A patent/AU2853792A/en not_active Abandoned
- 1992-12-08 ZA ZA929509A patent/ZA929509B/en unknown
- 1992-12-30 MX MX9207624A patent/MX9207624A/en unknown
-
1993
- 1993-01-05 CA CA 2086697 patent/CA2086697A1/en not_active Abandoned
- 1993-04-05 BR BR9301442A patent/BR9301442A/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| BR9301442A (en) | 1993-10-13 |
| ZA929509B (en) | 1993-06-15 |
| MX9207624A (en) | 1993-07-01 |
| AU2853792A (en) | 1993-11-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP0083789B1 (en) | Corrugated filter element with external spiral tape support | |
| EP0883429B1 (en) | Coreless non-metallic filter element | |
| AU615487B2 (en) | Soot filter | |
| US4882056A (en) | Fluid filter element with an overlapped wrap | |
| RU2563273C2 (en) | Unpleated tubular depth filter with filtering material of thin fibres | |
| CA1188634A (en) | Ceramic fabric filter | |
| US5552048A (en) | Two pleated filter composite having cushioning layers | |
| US3061107A (en) | Filter cartridge and method of making the same | |
| AU678593B2 (en) | High-efficiency, self-supporting filter elements made from fibers | |
| AU612779B2 (en) | Storage tanks with fabricated support ribs | |
| US4836931A (en) | Reinforced filter tube and method of making the same | |
| US6787031B2 (en) | Filter cartridge with strap and method | |
| US6739459B1 (en) | Filter element including bonded end caps and support core | |
| US20090101567A1 (en) | Method and Apparatus for the Purification of Salty Streams and the Removal of Particulates Therefrom | |
| US20090188856A1 (en) | Externally Centering Filter Element or Cartridge and Housing and System Utilizing the Same | |
| US4341631A (en) | Ultrafiltration and reverse osmosis device comprising plural carbon tubes bonded together | |
| CA2086697A1 (en) | High temperature filter bag support rings | |
| US5954848A (en) | Filter cartridge and method for its manufacture | |
| US6415930B1 (en) | Separator cartridge | |
| US20080072553A1 (en) | Method and apparatus for assembling a filter cartridge | |
| US20180290088A1 (en) | Self-supporting industrial air filter | |
| EP2189206B1 (en) | Filter Element with High Temperature Polymer Retaining Straps and Method of Manufacture | |
| CA1259034A (en) | Filter element | |
| JPH06126111A (en) | Filter element manufacture |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Dead |