CA1241882A - Erosion resistant waterwall - Google Patents
Erosion resistant waterwallInfo
- Publication number
- CA1241882A CA1241882A CA000486941A CA486941A CA1241882A CA 1241882 A CA1241882 A CA 1241882A CA 000486941 A CA000486941 A CA 000486941A CA 486941 A CA486941 A CA 486941A CA 1241882 A CA1241882 A CA 1241882A
- Authority
- CA
- Canada
- Prior art keywords
- waterwall
- tubes
- diameter
- stud members
- exposed
- 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.)
- Expired
Links
Landscapes
- Revetment (AREA)
Abstract
EROSION RESISTANT WATERWALL
Abstract of the Disclosure An erosion resistant waterwall in which a plurality of erosion resistant stud members are attached to the exposed surface of a waterwall consisting of a plurality of spaced water tubes connected together by continuous fins. The size of the stud members relative to the tubes are such that a plurality of the stud members extend around the periphery of each exposed tubes surface in a spaced relationship in a direction perpendicular to the axis of each tube.
The stud members may be in the form of steel balls or small rod members attached to the exposed surface, and a ceramic sleeve can extend around the rod members.
Abstract of the Disclosure An erosion resistant waterwall in which a plurality of erosion resistant stud members are attached to the exposed surface of a waterwall consisting of a plurality of spaced water tubes connected together by continuous fins. The size of the stud members relative to the tubes are such that a plurality of the stud members extend around the periphery of each exposed tubes surface in a spaced relationship in a direction perpendicular to the axis of each tube.
The stud members may be in the form of steel balls or small rod members attached to the exposed surface, and a ceramic sleeve can extend around the rod members.
Description
ERoSIQN RESISTANT ~TERhALL
Back~round of the Invention This invention relates to a waterwall and, re particularly, to a waterwall that has been provided with a surface that is resistant to erosion caused by particulate material.
Most erosion in industrial processes occurs where large volu~es of abrasive particles such as coal, catalyst, sand, shale, limestone, etc. change direction of flow via elbows, tees, separators, swirl vanes and the like. The erosion occurs as a result of low angle impingement by large volumes of the abrasive particles which move at varyir~
velocities.
Several systems have been devised to resist this type of erosion. For example, monolithic, cement or phosphate bonded castable (and plastic) refractories held by steel anchors on about two or four~inch staggered centers, on a hexagonal steel grid have been utilized to resist the above erosion. Also, a considerable thickness, up to several inches of the above m~ntioned refractories, have been installed on V-bar or S-bar anc~ors, and if the erosion is exceptionally severe a prefired refractory is used which is usually bolted to the steel structure.
~ kYwever, the use of these refractories increase the thermal resistance which, in rnany systems, seriously affects heat absorption rates to the tubular surfaces in fluidized bed boilers, for example.
It has been discovered that a s-teel support system is more erosion resistant than most of the monolithic cement-bonded, castable refractories discussed above that are tradtionally used in studded anchor wall syste~ls. ~owever, if the tube enclosure walls were simply designed with a greater thickness of steel, the weight and cost increase could be prohibitive.
Summary of the Invention Accordingly the present invention seeks to provide a waterwall that is erosion resistant yet does not affect the heat absorption rates of the waterwall.
Still fur-ther the present inven-tion seeks to provide an erosion resistant waterwall of the above type which does not prohibitively increase the weight and cost of the system.
The present invention also seeks to provide an erosion resistant waterwall in which the metal surface thickness is selectively increased in localized, erosion prone areas of the waterwall as required.
Toward the fulfillment of these and objects the waterwall of the present invention features the use of a plurality of erosion resistant stud members a-ttached -to the exposed surface of the waterwall and disposed along the waterwall in a spaced relationship. The size of the stud members relative to the waterwall tubes are such that a plurality of the stud members ex-tend around the periphery at each exposed tube surEace in a direction perpendicular to the axis of each -tube.
In one aspect of -the invention a plurality of erosion resistant stud members are welded to the exposed surface of the structure, each stud member comprising a cylindri,cal member with a projecting portion extending from the cylindrical member having ~2~
a diameter less than that of the cylindrical member for melting duriny the weldingO A ceramic sleeve extends around the cylindrical member and the projecting portion, the size of -the stud members relative to the tubes being such that a plurality of tne stud members extend around the periphery of each exposed tube surface in a spaced relationship.
In another aspect of the invention a plurality of erosion resistant studs extends around the exposed surface of -the structure in a spaced relationship, each stud comprising a rod member with a weldable member projecting from an end surface of the rod member and welded to the exposed surface of the structure. The length and diameter of the weldable member is such that, after welding, the melted portion of the weldable member extends over substantially the entire surface area of the exposed tube surface corresponding to the end surface of the rod member.
Brief Description of the Drawings The above brief description, as well as further objects, features and advantages of the present invention will be more fully appreciated by reference -to -the following detailed descrip-tion of the presently preferred bu-t nonetheless illustrative embodiment in accordance wi-th the present invention when taken in conjunc-tion with the accompanying drawings in which:
F'igure 1 is a partial, front elevational view of a conventional waterwall before being treated according to the present invention:
Figure 2 is a cross-sectional view taken along the line 2 2 of Figure 1 and depicting a portion of the waterwall surface after being treated according to the present invention;
Figure 3 is a view similar to Figure 1 but depicting an alter-nate embodiment of the present invention;
Figures 4 and 5 are a top plan view and a front elevational view, respectively, of one of the stud members utilized in the embodiment of Figure 3;
Figure 6 is a view similar to Figure 2 but showing another alternative embodiment invention;
Figure 7 is a top plan view of the stud member utilized in the embodiment of Figure 6; and Figure 8 is a vertical cross-sectional view taken of the stud member of Figure 7 before it is welded to the waterwall to form the assembly shown in Figure 6.
Description of the Preferred Embodiments Referring to Figure 1 of the drawings the reference numeral 10 refers in general to a conventional waterwall before it has been modified according to the present invention. The waterwall is formed by a plurality of spaced, parallel water tubes 12 extending for the length of the wall. A pair of continuous fins 14 extend from diametrically opposed surfaces of each tube 12. Each fin 14 is welded along its edge portion to the corresponding surfaces of the adjacent tubes 12 to form a gas tight structure.
A portion of the surface of the waterwall 10 tha-t is exposed to heated particulate material is depicted in Figure 2 in connection with a tube 12 and the two fins 14 extending thereErom. According to the present invention, a plurality of stud members, in the form of steel balls 16, are disposed in a spaced relationship along the exposed surfaces of the tube 12 and the fins 140 The si~e of the steel balls 16 relative to the tubes 12 are such that a plurality of the balls extend around the periphery of each tube surface in a spaced relationship in a direction perpendicular to the axis of the tube. The balls 16 are attached to the outer surface of the tube 12 and the fins 14 by welding in a conventional manner.
According to the embodiment of Figures 3-5l the stud members are in the form of solid rod portions 18 which extend around the outer exposed surface of the tube 12 and the fins 14. ~ projection 20 is formed on the lower surface of each rod member 18, as shown in Figure 5, which melts during the process of welding the rod mem-bers to the exposed surfaces of the tube 12 and fins 14.
According to the embodiment of Figures 6~ the stud members are formed by an inner, rod-like member 22 surrounded by a ceramic sleeve 24. A portion 22a of the inner member 22 projects down~
wardly from the ceramic sleeve 24 for melting during welding of the stud member to the exposed surface of the tube 12 and the fins 14.
The inner members 22 thus functions to anchor the ceramic sleeves down in the position shown in Figure 6 and, in addition, provides steel to weld the stud member, including the ceramic sleeve 24 to the outer exposed surface of the tube 12 and the fins 14.
It is understood that, with exception of the ceramic sleeve in the embodiment of Figure 6, the stud members in each of the foregoing embodiments are preferably made of steel which is welded to the exposed surfaces of the waterwall 10 as described.
Although only one tube 12 and its corresponding fins 14 have been shown in Fi~ures 2, 3 and 6, it is understood that the stud members can extend over the entire exposed surface of the waterwall 10 as needed.
According to a preferred embodiment the diameter of each tube is at least five times greater than the diameter of the stud mem-bers and the spacing between adjacent stud members is between one-fourth of an inch to one inch. For example, the diameter of a tube 12 can be three inches while the diameter of each stud member is one-half inch, it being understood that these dimensions can vary with different designs.
The arrangement of the.present invention enjoys several advan-tages. For example, the irregular shape formed by the stud membersin each of foregoing embodiments disrupts the abrasive particulate flow and lowers the erosive potential when the particles impact with each other or are deflected away from the underlying struc-ture. The closely spaced stud members may also serve as traps for the particulate material which protects the underlying steel in the areas of severe erosive activity.
All of the foregoing is achieved without significantly reducing the heat absorption rates of the waterwall and is ideally suited for field repairs and installation in areas with obvious high ero-sion rates. It is understood that, according to present invention,if heat transfer is not a factor the spaces between the stud mem-bers may be filled with a moderately erosion resistant alumina-phosphate bonded monolith which can be replaced if necessary during annual outages.
Other modificationsl changes, and substitutions are intended in the foregoing disclosure and in some instancs some features of the invention will-be employed without a corresponding use of other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the spirit and scope of the invention herein.
Back~round of the Invention This invention relates to a waterwall and, re particularly, to a waterwall that has been provided with a surface that is resistant to erosion caused by particulate material.
Most erosion in industrial processes occurs where large volu~es of abrasive particles such as coal, catalyst, sand, shale, limestone, etc. change direction of flow via elbows, tees, separators, swirl vanes and the like. The erosion occurs as a result of low angle impingement by large volumes of the abrasive particles which move at varyir~
velocities.
Several systems have been devised to resist this type of erosion. For example, monolithic, cement or phosphate bonded castable (and plastic) refractories held by steel anchors on about two or four~inch staggered centers, on a hexagonal steel grid have been utilized to resist the above erosion. Also, a considerable thickness, up to several inches of the above m~ntioned refractories, have been installed on V-bar or S-bar anc~ors, and if the erosion is exceptionally severe a prefired refractory is used which is usually bolted to the steel structure.
~ kYwever, the use of these refractories increase the thermal resistance which, in rnany systems, seriously affects heat absorption rates to the tubular surfaces in fluidized bed boilers, for example.
It has been discovered that a s-teel support system is more erosion resistant than most of the monolithic cement-bonded, castable refractories discussed above that are tradtionally used in studded anchor wall syste~ls. ~owever, if the tube enclosure walls were simply designed with a greater thickness of steel, the weight and cost increase could be prohibitive.
Summary of the Invention Accordingly the present invention seeks to provide a waterwall that is erosion resistant yet does not affect the heat absorption rates of the waterwall.
Still fur-ther the present inven-tion seeks to provide an erosion resistant waterwall of the above type which does not prohibitively increase the weight and cost of the system.
The present invention also seeks to provide an erosion resistant waterwall in which the metal surface thickness is selectively increased in localized, erosion prone areas of the waterwall as required.
Toward the fulfillment of these and objects the waterwall of the present invention features the use of a plurality of erosion resistant stud members a-ttached -to the exposed surface of the waterwall and disposed along the waterwall in a spaced relationship. The size of the stud members relative to the waterwall tubes are such that a plurality of the stud members ex-tend around the periphery at each exposed tube surEace in a direction perpendicular to the axis of each -tube.
In one aspect of -the invention a plurality of erosion resistant stud members are welded to the exposed surface of the structure, each stud member comprising a cylindri,cal member with a projecting portion extending from the cylindrical member having ~2~
a diameter less than that of the cylindrical member for melting duriny the weldingO A ceramic sleeve extends around the cylindrical member and the projecting portion, the size of -the stud members relative to the tubes being such that a plurality of tne stud members extend around the periphery of each exposed tube surface in a spaced relationship.
In another aspect of the invention a plurality of erosion resistant studs extends around the exposed surface of -the structure in a spaced relationship, each stud comprising a rod member with a weldable member projecting from an end surface of the rod member and welded to the exposed surface of the structure. The length and diameter of the weldable member is such that, after welding, the melted portion of the weldable member extends over substantially the entire surface area of the exposed tube surface corresponding to the end surface of the rod member.
Brief Description of the Drawings The above brief description, as well as further objects, features and advantages of the present invention will be more fully appreciated by reference -to -the following detailed descrip-tion of the presently preferred bu-t nonetheless illustrative embodiment in accordance wi-th the present invention when taken in conjunc-tion with the accompanying drawings in which:
F'igure 1 is a partial, front elevational view of a conventional waterwall before being treated according to the present invention:
Figure 2 is a cross-sectional view taken along the line 2 2 of Figure 1 and depicting a portion of the waterwall surface after being treated according to the present invention;
Figure 3 is a view similar to Figure 1 but depicting an alter-nate embodiment of the present invention;
Figures 4 and 5 are a top plan view and a front elevational view, respectively, of one of the stud members utilized in the embodiment of Figure 3;
Figure 6 is a view similar to Figure 2 but showing another alternative embodiment invention;
Figure 7 is a top plan view of the stud member utilized in the embodiment of Figure 6; and Figure 8 is a vertical cross-sectional view taken of the stud member of Figure 7 before it is welded to the waterwall to form the assembly shown in Figure 6.
Description of the Preferred Embodiments Referring to Figure 1 of the drawings the reference numeral 10 refers in general to a conventional waterwall before it has been modified according to the present invention. The waterwall is formed by a plurality of spaced, parallel water tubes 12 extending for the length of the wall. A pair of continuous fins 14 extend from diametrically opposed surfaces of each tube 12. Each fin 14 is welded along its edge portion to the corresponding surfaces of the adjacent tubes 12 to form a gas tight structure.
A portion of the surface of the waterwall 10 tha-t is exposed to heated particulate material is depicted in Figure 2 in connection with a tube 12 and the two fins 14 extending thereErom. According to the present invention, a plurality of stud members, in the form of steel balls 16, are disposed in a spaced relationship along the exposed surfaces of the tube 12 and the fins 140 The si~e of the steel balls 16 relative to the tubes 12 are such that a plurality of the balls extend around the periphery of each tube surface in a spaced relationship in a direction perpendicular to the axis of the tube. The balls 16 are attached to the outer surface of the tube 12 and the fins 14 by welding in a conventional manner.
According to the embodiment of Figures 3-5l the stud members are in the form of solid rod portions 18 which extend around the outer exposed surface of the tube 12 and the fins 14. ~ projection 20 is formed on the lower surface of each rod member 18, as shown in Figure 5, which melts during the process of welding the rod mem-bers to the exposed surfaces of the tube 12 and fins 14.
According to the embodiment of Figures 6~ the stud members are formed by an inner, rod-like member 22 surrounded by a ceramic sleeve 24. A portion 22a of the inner member 22 projects down~
wardly from the ceramic sleeve 24 for melting during welding of the stud member to the exposed surface of the tube 12 and the fins 14.
The inner members 22 thus functions to anchor the ceramic sleeves down in the position shown in Figure 6 and, in addition, provides steel to weld the stud member, including the ceramic sleeve 24 to the outer exposed surface of the tube 12 and the fins 14.
It is understood that, with exception of the ceramic sleeve in the embodiment of Figure 6, the stud members in each of the foregoing embodiments are preferably made of steel which is welded to the exposed surfaces of the waterwall 10 as described.
Although only one tube 12 and its corresponding fins 14 have been shown in Fi~ures 2, 3 and 6, it is understood that the stud members can extend over the entire exposed surface of the waterwall 10 as needed.
According to a preferred embodiment the diameter of each tube is at least five times greater than the diameter of the stud mem-bers and the spacing between adjacent stud members is between one-fourth of an inch to one inch. For example, the diameter of a tube 12 can be three inches while the diameter of each stud member is one-half inch, it being understood that these dimensions can vary with different designs.
The arrangement of the.present invention enjoys several advan-tages. For example, the irregular shape formed by the stud membersin each of foregoing embodiments disrupts the abrasive particulate flow and lowers the erosive potential when the particles impact with each other or are deflected away from the underlying struc-ture. The closely spaced stud members may also serve as traps for the particulate material which protects the underlying steel in the areas of severe erosive activity.
All of the foregoing is achieved without significantly reducing the heat absorption rates of the waterwall and is ideally suited for field repairs and installation in areas with obvious high ero-sion rates. It is understood that, according to present invention,if heat transfer is not a factor the spaces between the stud mem-bers may be filled with a moderately erosion resistant alumina-phosphate bonded monolith which can be replaced if necessary during annual outages.
Other modificationsl changes, and substitutions are intended in the foregoing disclosure and in some instancs some features of the invention will-be employed without a corresponding use of other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the spirit and scope of the invention herein.
Claims (8)
1. A waterwall comprising a plurality of water tubes extending in a spaced, parallel relationship; a plurality of continuous fins extending between adjacent tubes for the length thereof and connected to the outer surfaces of said tubes for forming a gas-tight structure, one surface of which is exposed to erosion-causing particulate material; and a plurality of erosion resistant stud members welded to said exposed surface of said structure, each stud member comprising a cylindrical member, a projecting portion extending from said cylindrical member and having a diameter less than that of said cylindrical member for melting during said welding, and a ceramic sleeve extending around said cylindrical member and said projecting portion; the size of said stud members relative to said tubes being such that a plurality of said stud members extend around the periphery of each exposed tube surface in a spaced relationship.
2. The waterwall of claim 1 wherein said stud members extend in spaced rows with the stud members of each row being staggered relative to the stud members in adjacent rows.
3. The waterwall of claim 1 wherein the diameter of each of said tubes is at least five times greater than the diameter of said stud members.
4. The waterwall of claim 1 wherein the diameter of each of said tubes is approximately three inches and the diameter of each of said stud members is approximately one-half inch.
5. A waterwall comprising a plurality of water tubes extending in a spaced parallel relationship; a plurality of continuous fins extending between adjacent tubes for the length thereof and connected to the outer surfaces of said tubes for forming a gas-tight structure, one surface of which is exposed directly to erosion-causing particulate material; and a plurality of erosion resistant studs extending around the exposed surface of said structure in a spaced relationship, each stud comprising a rod member, and a weldable member projecting from an end surface of said rod member and welded to said exposed surface of said structure, the length and diameter of said weldable member being such that, after welding, the melted portion of said weldable member extends over substantially the entire surface area of said exposed tube surface corresponding to said end surface of said rod member.
6. The waterwall of claim 5 wherein said studs extend in spaced rows, with the studs of each row being staggered relative to the studs in adjacent rows.
7. The waterwall of claim 5 wherein the diameter of each of said tubes is at least five times greater than the diameter of said studs.
8. The waterwall of claim 5 wherein the diameter of each of said tubes is approximately three inches and the diameter of each of said studs is approximately one-half inch.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000486941A CA1241882A (en) | 1985-07-17 | 1985-07-17 | Erosion resistant waterwall |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000486941A CA1241882A (en) | 1985-07-17 | 1985-07-17 | Erosion resistant waterwall |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1241882A true CA1241882A (en) | 1988-09-13 |
Family
ID=4130995
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000486941A Expired CA1241882A (en) | 1985-07-17 | 1985-07-17 | Erosion resistant waterwall |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1241882A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113007737A (en) * | 2021-03-02 | 2021-06-22 | 华北电力大学 | Waste heat boiler water wall tube bank recycling technology for garbage power station |
-
1985
- 1985-07-17 CA CA000486941A patent/CA1241882A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113007737A (en) * | 2021-03-02 | 2021-06-22 | 华北电力大学 | Waste heat boiler water wall tube bank recycling technology for garbage power station |
| CN113007737B (en) * | 2021-03-02 | 2022-10-18 | 华北电力大学 | Waste heat boiler water wall tube bank recycling technology for garbage power station |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4554967A (en) | Erosion resistant waterwall | |
| US5116394A (en) | Cyclone separator roof | |
| US4715809A (en) | Fluidized bed having modified surfaces in the heat extractor | |
| KR100702298B1 (en) | Wall protection from downward flowing solids | |
| JPH0529509B2 (en) | ||
| US4635713A (en) | Erosion resistant waterwall | |
| CA1241882A (en) | Erosion resistant waterwall | |
| EP0209626B1 (en) | Erosion resistant waterwall | |
| CN210320009U (en) | Energy-saving anti-abrasion structure for circulating fluidized bed boiler | |
| CN106402850B (en) | The heat-transfer pipe of fluid-bed combustion boiler | |
| CN210291851U (en) | Anti-accumulation metal wear-resistant plate for circulating fluidized bed boiler | |
| KR100363990B1 (en) | Cyclone refractory system | |
| JP6361196B2 (en) | Piping support | |
| JPS6233206A (en) | Corrosion-resistant water-cooled wall | |
| CA2585610C (en) | A fluidized bed boiler and a grate element for the same | |
| CN210979821U (en) | Wear-resistant finned tube for fluidized bed boiler | |
| CN220397497U (en) | Castable anti-drop device | |
| CN210320010U (en) | Comb-shaped guide plate for preventing abrasion of water wall pipe of circulating fluidized bed boiler | |
| CN212719828U (en) | Wear-resistant structure of boiler combustion protection belt | |
| CN220017423U (en) | Water cooling wall protection device for boiler ash cooling hopper | |
| JP2001041416A (en) | Fluidized bed boiler | |
| KR102305299B1 (en) | A fluidized bed reaction chamber comprising a tubular waterwall structure | |
| CN211084120U (en) | Wear-resisting boiler water-cooling wall | |
| WO1997003322A1 (en) | Erosion resistant wall assembly | |
| CN85105967A (en) | Erosion resistant waterwall |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |