Patents

U. S. Patent for "AHLFLEX Expansion Joint Flexible Seal"
Patent No.: 5,311,715 (May 17, 1994)
Co-Inventor: Neil Raskin V. Swaminathan

Abstract

An expansion joint and flexible seal for refractory lined flues includes a flexible insulating body having a pair of end faces, a pair of lateral faces and a longitudinal dimension. The flexible seal further includes a filter element positioned adjacent to one of the end faces and extending in the longitudinal dimension. The filter element is attached to the insulating body and the assembly may be placed with other seal assemblies in endwise fashion around the periphery of a pair of opposing flue members. A further external pressure seal is provided, mounted to each end of the flue elements.

Inventors: Linck; Ed (Kemah, TX), Raskin; Neil R. (Rancho la Costa, CA), Swaminathan; V. (El Cajon, CA)
Assignee: Pyropower Corporation (San Diego, CA)
Appl. No.: 07/598,250
Filed: October 16, 1990

Claims

What is claimed is:

1. A flue and duct system expansion joint flexible seal comprising: a flexible insulating body having a pair of end faces, a pair of lateral faces and a longitudinal dimension; a filter element positioned adjacent one of said end faces and extending in said longitudinal dimension, said filter element being made from a wire mesh material; and means for securing said filter element to said insulating body.

2. A flue and duct system expansion joint flexible seal comprising: a flexible insulating body having a pair of end faces, a pair of lateral faces and a longitudinal dimension; a filter element positioned adjacent one of said end faces and extending in said longitudinal dimension, said filter element including a wrapping of wire mesh cloth; and means for securing said filter element to said simulating body.

3. A flue and duct system expansion joint flexible seal comprising: a flexible insulating body having a pair of end faces, a pair of lateral faces and a longitudinal dimension; a filter element positioned adjacent one of said end faces and extending in said longitudinal dimension, said filter element including a plurality of wire mesh elements wrapped in a larger wire mesh wrapping; and means for securing said filter element to said insulating body.

4. A flue and duct system expansion joint flexible seal comprising: a flexible insulating body having a pair of end faces, a pair of lateral faces and a longitudinal dimension; a filter element positioned adjacent one of said end faces and extending in said longitudinal dimension; and means for securing said filter element to said insulating body including a wire mesh wrapping around said filter element and said insulating body.

5. The flexible seal of claim 4 wherein said means for securing said filter element to said insulating body further includes a flexible casing that encases said wire mesh wrapping.

6. A flue and duct system expansion joint flexible seal comprising: a flexible insulating body having a pair of end faces, a pair of lateral faces, and a longitudinal dimension; a filter element positioned adjacent one of said end faces and extending in said longitudinal dimension, said filter element including a pair of filter elements positioned on said end faces; and means for securing said filter elements to said insulating body including a tie fastened to said filter elements and extending through said insulating body.

7. A flue and duct system expansion joint flexible seal comprising: a flexible insulating body having a pair of end faces, a pair of lateral faces and a longitudinal dimension, said insulating body including a central insulating core and a pair of simulating side panels providing said lateral faces; a filter element positioned adjacent one of said end faces and extending in said longitudinal dimension, said filter element including a wrapping of wire cloth; and means for securing said filter element to said insulating body.

8. The flexible seal of claim 7 wherein said filter element includes a plurality of wire mesh elements wrapped in a larger wire mesh wrapping.

9. The flexible seal of claim 8 wherein said means for securing said filter element to said insulating body includes a wire mesh wrapping around said filter element and said insulating body.

10. The flexible seal of claim 9 wherein said means for securing said filter element to said insulating body further includes a flexible casing that encases said wire mesh wrapping.

11. The flexible seal of claim 10 further including a second filter element positioned adjacent one of said end faces and extending along said longitudinal dimension.

12. The flexible seal of claim 11 wherein said means for securing said filter element to said insulating body includes a tie fastened to said filter elements and extending through said insulating body.

13. An expansion joint flexible seal comprising: a flexible insulating body made from a ceramic fiber blanket material having a pair of end faces, a pair of lateral faces and a longitudinal dimension, said insulating body including a central insulating core and a pair of insulating side panels providing said lateral faces; a filter element positioned adjacent one o said end faces and extending in said longitudinal dimension, said filter element including a plurality of wire mesh tube elements wrapped in a larger wire mesh wrapping; and means for securing said filter element to said insulating body, said securing means include a wire mesh wrapping around said filter element and said insulating body, and a flexible casing that encases said wire mesh wrapping.

14. The flexible seal of claim 13 further including a second filter element positioned adjacent one of said end faces and extending in said longitudinal dimension.

15. A flue and duct system expansion joint for joining a first flue and a second flue having inner surfaces made from a refractory material, said expansion joint comprising a first flue terminal face, a second flue terminal face, and a flexible seal sandwiched between said first and second flue terminal faces, said flexible seal including a flexible insulating body having a pair of inner and outer end faces oriented generally perpendicularly to said first and second flue terminal faces, a pair of lateral faces generally parallel to and abutting, respectively, said first and second flue terminal faces, and a longitudinal dimension, said flexible seal further including a filter element mounted against said inner end faces of said flexible insulating body, and extending in said longitudinal dimension, said expansion joint further including an external pressure seal mounted to the first and second flues, outwardly from said flexible seal, said flexible seal being mounted to said first flue terminal face by a pin arrangement extending from said first flue terminal face into said flexible seal insulating body.

BACKGROUND OF THE INVENTION

The field of the present invention is expansion joints for ducting and flue systems, and more particularly, nonmetallic flexible expansion joints to provide stress relief in refactory lined flue systems used in high temperature applications such as power generation and related activities.

In power generating or cogeneration plants, including facilities for obtaining usable electrical power or processing steam/hot water from the burning of solid, liquid or gaseous fuel products, hot flue gases generated by the combustion process are typically directed through a series of processing areas to remove particulates and environmentally hazardous components before finally being exhausted from the facility. FIG. 1 illustrates a power generation plant of unique design that includes a furnace having a circulating fluidized bed (CFB) wherein various fuel materials are combusted. The hot flue gases containing combustion by-products are transferred from the furnace through a flue/expansion joint to a cyclone separator. The cyclone separator diverts heavier combustion particulate matter back to the CFB and the fine particulate matter and hot flue gases are directed through a heat exchanger. The fine particulate matter is then diverted to a particulate filter for disposal. Gases emitted from the facility will have most of the combustion by-product emissions, including NO.sub.x, SO.sub.2, CO, particulates, etc., removed therefrom, resulting in an environmentally safe means of power generation.

Nonmetallic flue expansion joints are flexible connectors designed to provide stress relief in flue systems by absorbing movement caused by thermal changes. They also act as vibration isolators, and in some instances, make up for minor misalignment of adjoining flues or equipment. They may be fabricated from a wide variety of nonmetallic materials, including synthetic elastomers, fabrics, insulation materials and other suitable materials depending upon the designs thereof. Since their introduction in the early 1960's, the use of nonmetallic expansion joints has continuously grown. The advent of more rigid emission standards has caused the use of more complex flue work systems. Nonmetallic expansion joints have been used in place of the traditional all metal expansion joints to solve problems caused by the thermal and mechanical stresses generated in these complex systems. Although the major user of the nonmetallic joint continues to be the power generation industry, the use of this product has expanded into many other industries wherein gases are conveyed including pulp and paper plants, refineries, steel mills, foundries, smelters, cement plants, kilns, refuse incineration, marine applications, vapor-heat-dust recovery, food processing, and HVAC (Heating, Ventilating and Air Conditioning).

A typical prior art nonmetallic expansion joint is shown in FIG. 2. The joint includes a pair of angle brackets mounted to the respective ends of a pair of adjoining ducts or flues. A pair of frame members are in turn attached to the angle brackets. The frame members have mounted thereto a flexible pressure seal that extends around the periphery of the expansion joint. The pressure seal may be of the elastomeric type for operation below 400 degrees F or may be of the composite type for operation at temperatures continuously above 400 degrees F. It will be appreciated that the flexible pressure seal allows relative axial, transverse, angular and rotational movement between the respective ducts while preventing the escape of pressurized flue gasses and particulates carried therein. Other nonmetallic expansion joint constructions may be seen in the "Technical Handbook" published by the Ducting Systems Nonmetallic Expansion Joint Division of the Fluid Sealing Association, 2017 Walnut Street, Philadelphia, Pa. 19103 (2nd Edition), the contents of which are fully incorporated herein by this reference.

It is known that nonmetallic expansion joints are prone to failure from the build-up of abrasive particulates carried by the flue gas stream, which can accumulate in the expansion joint in such quantities that they eventually rupture the pressure seal. Moreover, fly ash and other particulates can cause damage to the expansion joint by solidifying to a cementatious state. Also, certain non-cementatious particulates (fly ash) can create a severe, corrosive (acidic) environment when subjected to cooling (below the H.sub.2 SO.sub.4 dew point) during a maintenance outage.

To prevent premature expansion joint failure from the build up of particulate matter therein, baffles have been proposed to help direct particulate matter beyond the expansion joint, as shown in FIG. 2. Other proposals include mounting the flexible pressure seal substantially flush with the interior surface of the duct or flue, as shown in FIG. 3, or mounting an insulation barrier behind a baffle arrangement as shown in FIG. 4. Although these proposals may exhibit varying degrees of effectiveness in minimizing expansion joint failure, the arrangement of FIG. 3 may result in thermal transfer on the inner face of the expansion joint and abrasion from particulates in the gas stream. A greater setback would be desirable. The arrangement of FIG. 4 may result in the insulation barrier rubbing on the baffle under negative pressures. Moreover, the insulation barrier must be fixedly attached to both sides of the joint, which may complicate joint construction and also impart adverse loads on the barrier.

Accordingly, there is an evident need for an expansion joint flexible seal which not only prevents particulate build up, but which is durable, easy to install and will perform satisfactorily despite joint movement. It would be further desirable to provide an expansion joint flexible seal that also performs a sealing function to provide an additional gas sealing barrier. The present invention accomplishes the foregoing objects and advantages. It is therefore an object of the present invention to provide an improved expansion joint and flexible seal therefor.

It is a further object of the present invention to provide an expansion joint having a flexible seal that is not adversely affected by relative joint movement.

It is a further object of the present invention to provide an expansion joint having a modular construction for easier installation.

It is a further object of the present invention to provide an expansion joint and flexible seal therefor providing an additional gas sealing barrier.

SUMMARY OF THE INVENTION

The present invention employs concepts for an expansion joint and flexible seal therefor that accomplish the foregoing objects and advantages. In accordance therewith, an expansion joint may include flexible seal means having flexible insulating body means and filter means positioned adjacent thereto. Additional filter element means may be provided, as well as flexible seal mounting means for easy installation and joint accessibility .

BRIEF DESCRIPTION OF THE DRAWINGS

The objects, advantages and features of this invention will be more clearly perceived from the following detailed description when read in accordance with the accompanying drawing in which:

FIG. 1 is a diagrammatic view of a fluidized circulating bed power generation plant that includes expansion joints in the ducting system thereof;

FIG. 2 is a detailed cross-sectional view of a prior art expansion joint having a baffle system to prevent premature joint failure;

FIG. 3 is a detailed cross-sectional view of another prior art expansion joint having a flush mounted flexible pressure seal also designed to eliminate premature joint failure;

FIG. 4 is a detailed cross-sectional view of still another prior art expansion joint having an insulation barrier and baffle system also designed to minimize premature joint failure;

FIG. 5 is a detailed cross-sectional view of a nonmetallic expansion joint and flexible seal constructed in accordance with the present invention;

FIG. 6 is a detailed isometric view of a flexible seal constructed in accordance with the present invention having a portion broken away for clarity;

FIG. 7 is a plan view of the flexible seal of FIG. 6 having end portions adapted for interlocking with adjacent flexible seal elements; and

FIG. 8 is an exploded detailed cross-sectional view of a nonmetallic expansion joint and flexible seal constructed in accordance with the present invention.

 

U. S. Patent for "Loop Seal Expansion Joint"
Patent No.: 5,383,316
Co-Inventor: James Burke

Abstract

An expansion joint and flexible seal for refractory lined flues includes a baffle system in combination with a filter element and an air purge system for preventing egress of flue particulates. The baffle system is slideably positionable to accommodate relative lateral displacement of the flues.

Inventors: Burke; James (Mesa County, CO), Linck; Ed (Kemah, TX)
Assignee: Pyropower Corporation (San Diego, CA)
Appl. No.: 07/773,217
Filed: October 9, 1991

Claims

What is claimed is:

1. An expansion joint in combination with and joining a first flue and a second flue in adjacent relation at a flue junction, comprising: a sealing chamber extending between the first and second flues, defined by a first side wall mounted to the first flue, a second side wall mounted to the second flue, a flexible outer wall mounted to and extending between said first and second side walls, and an inner wall defined by one of the first and second flues; a baffle plate mounted to one of said first or second side walls and extending toward the other of said first or second side walls; said baffle plate defining a labyrinth passage between the flue junction and said sealing chamber flexible outer wall; and said baffle plate being slideably mounted to said first side wall and said expansion joint further including a second baffle plate spaced radially outwardly from said slideably mounted baffle plate and fixedly mounted to said second side wall.

2. The expansion joint of claim 1 wherein further including an insulation blanket disposed between said baffle plates.

3. The expansion joint of claim 1 wherein said expansion joint further includes an air purge system providing a pressurized fluid between said fixedly mounted baffle plate and said flexible outer wall.

4. An expansion joint in combination with and joining a first flue and a second flue in adjacent relation at a flue junction, comprising: a sealing chamber extending between the first and second flues, defined by a first side wall mounted to the first flue, a second side wall mounted to the second flue, a flexible outer wall mounted to and extending between said first and second side walls, and an inner wall defined by one of said first and second flues, said first and second flues having an interior flow chamber portion for carrying flue material and said expansion joint further including a frustoconical passage extending from said interior flow chamber portion of said first and second flues to said sealing chamber; a baffle plate mounted to one of said first or second side walls and extending toward the other of said first or second side walls; said baffle plate defining a labyrinth passage between the first flue junction and said sealing chamber flexible outer wall; and said baffle plate being slideably mounted for lateral movement with respect to said first or second side walls.

5. The expansion joint of claim 4 wherein the first flue includes an inner conical portion at the flue junction and the second flue includes an outer conical portion at the flue junction, said inner and outer conical portions being adjacently positioned to form said frustoconical passage.

6. An expansion joint in combination with and joining a first flue and a second flue in adjacent relation at a flue junction, comprising: a sealing chamber extending between the first and second flues, defined by a first side wall mounted to the first flue, a second side wall mounted to the second flue, a flexible outer wall mounted to and extending between said first and second side walls, and an inner wall defined by one of said first and second flues; a baffle plate mounted to one of said first or second side walls and extending toward the other of said first or second side walls; said baffle plate defining a labyrinth passage between the flue junction and said sealing chamber flexible outer wall; said baffle plate being slideably mounted for lateral movement with respect to said first or second side walls; and said first flue including an outwardly flared end portion encircling a corresponding inwardly tapered end portion of said second flue, said flared end portion terminating at an annular horizontal flange, and said slideable baffle plate having a lower horizontal flange slideably engaging said annular horizontal flange.

7. The expansion joint of claim 6 wherein said annular horizontal flange extends outwardly to an annular longitudinal flange, and said side wall includes a bracket having a longitudinal leg fixedly mounted to said annular longitudinal flange and a horizontal leg slideably disposed on said baffle plate horizontal flange.

8. The expansion joint of claim 7 wherein said expansion joint further includes an air purge system providing a pressurized fluid into said sealing chamber and through an aperture in said annular horizontal flange to an area of sliding contact between said horizontal flange and said baffle plate horizontal flange and between said baffle plate horizontal flange and said sidewall bracket horizontal leg.

9. An expansion joint in combination with and joining a first flue and a second flue in adjacent relation at a flue junction, comprising: a sealing chamber extending between the first and second flues, defined by a first side wall mounted to the first flue, a second side wall mounted to the second flue, a flexible outer wall mounted to and extending between said first and second side walls, and an inner wall defined by one of the first and second flues; a baffle plate mounted to one of said first or second side walls and extending toward the other of said first or second side walls; said baffle plate defining a labyrinth passage between the flue junction and said sealing chamber flexible outer wall; said baffle plate being slideably mounted for lateral movement with respect to said first or second side walls; and wherein said expansion joint further including a wire mesh filter element positioned in same labyrinth passage and an air purge system providing a pressurized fluid into said labyrinth between said filter and said expansion chamber flexible outer wall.

BACKGROUND OF THE INVENTION

The field of the present invention is expansion joints for ducting and flue systems, and more particularly, nonmetallic flexible expansion joints to provide stress relief in refactory lined flue systems used in high temperature applications such as power generation and related activities.

In power generating or cogeneration plants, including facilities for obtaining useable electrical power or processing steam/hot water from the burning of solid, liquid or gaseous fuel products, hot flue gases generated by the combustion process are typically directed through a series of processing areas to remove particulates and environmentally hazardous components before finally being exhausted from the facility. FIG. 1 illustrates a power generation plant of unique design that includes a furnace having a circulating fluidized bed (CFB) wherein various fuel materials are combusted. The hot flue gases containing combustion by-products are transferred from the furnace through a flue duct/expansion joint to a cyclone separator. The cyclone separator diverts heavier combustion particulate matter back to the CFB, through a loop seal assembly, which lifts the heavy particulates, mixes them with freshly fed fuel, and introduces the mixture to the combustion chamber. The fine particulate matter and hot flue gases are directed through a heat exchanger. The fine particulate matter is then diverted to a particulate filter for disposal. Gases emitted from the facility will have most of the combustion by-product emissions, including NO.sub.x, SO.sub.2, CO, particulates, etc., removed therefrom, resulting in an environmentally safe means of power generation.

Nonmetallic expansion joints are flexible connectors designed to provide stress relief in flue duct systems by absorbing movement caused by thermal changes. They also act as vibration isolators, and in some instances, make up for minor misalignment of adjoining flue ducts and/or equipment. They may be fabricated from a wide variety of nonmetallic materials, including synthetic elastomers, fabrics, insulation materials and other suitable materials depending upon the designs thereof. Since their introduction in the early 1960's, the use of nonmetallic expansion joints has continuously grown. The advent of more rigid emission standards has caused the use of more complex flue work systems. Nonmetallic expansion joints have been used in place of the traditional all metal expansion joints to solve problems caused by the thermal and mechanical stresses generated in these complex systems. Although the major user of the nonmetallic joint continues to be the power generation industry, the use of this product has expanded into many other industries wherein gases are conveyed including pulp and paper plants, refineries, steel mills, foundries, smelters, cement plants, kilns, refuse incineration, marine applications, vapor-heat-dust recovery, food processing, and HVAC (Heating, Ventilating and Air Conditioning).

A typical prior art nonmetallic expansion joint is shown in FIG. 2. The joint includes a pair of angle brackets mounted to the respective ends of a pair of adjoining ducts or flues. A pair of frame members are in turn attached to the angle brackets. The frame members have mounted thereto a flexible pressure seal that extends around the periphery of the expansion joint. The pressure seal may be of the elastomeric type for operation below 400 degrees F or may be of the composite type for operation at temperatures continuously above 400 degrees F. It will be appreciated that the flexible pressure seal allows relative axial, transverse, angular and rotational movement between the respective ducts while preventing the escape of pressurized flue gasses and particulates carried therein. Other nonmetallic expansion joint constructions may be seen in the "Technical Handbook" published by the Ducting Systems Nonmetallic Expansion Joint Division of the Fluid Sealing Association, 2017 Walnut Street, Philadelphia, Pa. 19103 (2nd Edition), the contents of which are fully incorporated herein by this reference.

It is known that nonmetallic expansion joints are prone to failure from the build-up of abrasive particulates carried by the flue gas stream, which can accumulate in the expansion joint in such quantities that they eventually rupture the pressure seal. Moreover, fly ash and other particulates can cause damage to the expansion joint by solidifying to a cementatious state. Also, certain non-cementatious particulates (fly ash) can create a severe, corrosive (acidic) environment when subjected to cooling (below the H.sub.2 SO.sub.4 dew point) during a maintenance outage.

To prevent premature expansion joint failure from the build up of particulate matter therein, baffles have been proposed to help direct particulate matter beyond the expansion joint, as shown in FIG. 2. Other proposals include mounting the flexible pressure seal substantially flush with the interior surface of the duct or flue, as shown in FIG. 3, or mounting an insulation barrier behind a baffle arrangement as shown in FIG. 4. Although these proposals may exhibit varying degrees of effectiveness in minimizing expansion joint failure, the arrangement of FIG. 3 may result in thermal transfer on the inner face of the expansion joint and abrasion from particulates in the gas stream. A greater setback would be desirable. The arrangement of FIG. 4 may result in the insulation barrier rubbing on the baffle under negative pressures. Moreover, the insulation barrier must be fixedly attached to both sides of the joint, which may complicate joint construction and also impart adverse loads on the barrier.

Accordingly, there is an evident need for an expansion joint flexible seal which not only prevents particulate build up, but which is durable, easy to install and will perform satisfactorily despite joint movement. It would be further desirable to provide an expansion joint flexible seal that also performs a sealing function to provide an additional gas sealing barrier.

The present invention accomplishes the foregoing objects and advantages. It is therefore an object of the present invention to provide an improved expansion joint and flexible seal therefor.

It is a further object of the present invention to provide an expansion joint having a flexible seal that is not adversely affected by relative joint movement.

It is a further object of the present invention to provide an expansion joint having a modular construction for easier installation.

It is a further object of the present invention to provide an expansion joint and flexible seal therefor providing an additional gas sealing barrier.

It is a further object of the present invention to provide a loop seal expansion joint for use in joints subject to lateral misalignment.

SUMMARY OF THE INVENTION

The present invention employs concepts for an expansion joint and flexible seal therefor that accomplish the foregoing objects and advantages. In accordance therewith, an expansion joint may include flexible seal means having flexible insulating body means and filter means positioned adjacent thereto. Additional filter element means may be provided, as well as flexible seal mounting means for easy installation and joint accessibility. In a further aspect applicable to joints that must accommodate longitudinal offset movements, a baffle system may be provided in combination with filter element means and an air purge system for preventing egress of flue particulates.

DRAWINGS


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  • Fig1
    Diagrammatic view of a fluidized circulating bed power generation plant that includes expansion joints in the ducting system thereof
  • Fig2
    Detailed cross-sectional view of a prior art expansion joint having a baffle system to prevent premature joint failure
  • Fig3
    Detailed cross-sectional view of another prior art expansion joint having a flush mounted flexible pressure seal also designed to eliminate premature joint failure
  • Fig4
    Detailed cross-sectional view of still another prior art expansion joint having an insulation barrier and baffle system also designed to minimize premature joint failure
  • Fig5
    Detailed cross-sectional view of a nonmetallic expansion joint and flexible seal constructed in accordance with the present invention