US5036903A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Graphite tube condensing heat exchanger and method of operating same
Assignee: United Mcgill Corp
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Filing: 1989-11-08
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Granted: 1991-08-06
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Expires: 2009-11-08
Abstract
Abstract The present invention is directed to a method for recovering heat from a gas stream contaminated with water vapor and an acid-forming moiety, said gas having an acid dew point ranging from about 200° F. to 300° F. and a water dew point ranging from about 90.20 F. to 150° F. The inventive method comprises passing the gas stream through a heat exchange fitted with a plurality of generally-parallel tubes through which flow heat exchanging fluid counter-current to the flow of said gas stream in said heat exchanger. The heat exchanging fluid is at a temperature such that the exterior tube temperature is at or below both said dew points, or the temperature of the contaminated gas stream exiting the heat exchanger is at or below both said dew points. The tubes are formed from acid-resistant, resin-impregnated graphite and exhibit a smooth, washable exterior surface. The heat exchanger further is fitted with a pair of side apertured tube sheets through which said tubes penetrate. The ends of the tubes penetrating through the tube sheets are interconnected with non-graphite connectors for establishing a flow path of heat exchange fluid therethrough. The tube sheets house an interior heat-exchange chamber therebetween through which said contaminated gas stream flows.
Inventors
- 👤 James R. Shook
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:17
CPC Classifications
F; F28; F28F; F28F19/00; F28F19/02; F28F21/00; F28F21/02; Y; Y10; Y10S; Y10S165/00; Y10S165/905; Y10S165/921
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
198 words
A method for recovering heat from a gas stream contaminated with water vapor and acid or acid-forming moeity, said gas having an acid dew point ranging from about 200° F. to 300° F. and a water dew point ranging from about 90° F. to 150° F., which comprises: passing said gas stream through a heat exchanger fitted with a plurality of generally-parallel tubes through which flow heat exchanging fluid counter-current to the flow of said gas stream in said heat exchanger, the heat exchanging fluid being at a temperature such that the wall tube temperature or the temperature of said contaminated gas stream exiting said heat exchanger, is at or below either of said dew points, said tubes formed from acid-resistant ceramic material and exhibiting a smooth washable exterior surface; said exchanger fitted with a pair of side apertured tube sheets through which said tubes penetrate, the ends of said tubes being interconnected with connectors for establishing a flow path of heat-exchange fluid therethrough, between said tube sheets is an interior heat-exchange chamber through which said contaminated gas stream flows, said tube sheets being bi-layer lined with an inner epoxy novolac coating and an outer fiber-reinforced fluoroplastic layer.
Claim 2
Independent Claim
198 words
A method for recovering heat from a gas stream contaminated with water vapor and acid or acid-forming moeity, said gas having an acid dew point ranging from about 200° F. to 300° F. and a water dew point ranging from about 90° F. to 150° F., which comprises: passing said gas stream through a heat exchanger fitted with a plurality of generally-parallel tubes through which flow heat exchanging fluid counter-current to the flow of said gas stream in said heat exchanger, the heat exchanging fluid being at a temperature such that the wall tube temperature or the temperature of said contaminated gas stream exiting said heat exchanger, is at or below either of said dew points, said tubes formed from acid-resistant ceramic material and exhibiting a smooth washable exterior surface; said exchanger fitted with a pair of side apertured tube sheets through which said tubes penetrate, the ends of said tubes being interconnected with connectors for establishing a flow path of heat-exchange fluid therethrough, between said tube sheets is an interior heat-exchange chamber through which said contaminated gas stream flows, said tube sheets being bi-layer lined with an inner epoxy novolac coating and an outer fiber-reinforced fluoroplastic layer.
Claim 3
Dependent Claim
17 words
The method of claim 1 wherein said gas stream passed through said heat exchanger comprises flue gas.
Claim 4
Dependent Claim
28 words
The method of claim 1 wherein said acid is selected from the group consisting of sulfuric acid, nitric acid, hydrochloric acid, carbonic acid, hydrofluoric acid, and mixtures thereof.
Claim 5
Dependent Claim
13 words
The method of claim 1 wherein said tubes comprise acid-resistant resin-impregnated graphite tubes.
Claim 6
Dependent Claim
16 words
The method of claim 4 wherein said ends of said tubes are interconnected with non-graphite connectors.
Claim 7
Dependent Claim
24 words
The method of claim 1 wherein said heat exchange fluid flowing through said tubes is selected from the group consisting of water and air.
Claim 8
Dependent Claim
16 words
The method of claim 1 wherein said inner coating comprises a silicon-carbide impregnated epoxy novolak coating.
Claim 9
Dependent Claim
11 words
The method of claim 1 wherein said fiber-reinforcement comprises glass fiber.
Claim 10
Dependent Claim
24 words
The method of claim 1 wherein said fluoroplastic layer is retained by sealing sleeves disposed in said apertures and through which said tubes pass.
Claim 11
Dependent Claim
20 words
The method of claim 1 wherein said fluoroplastic comprises an elastomer derived from the combination of vinylidene fluoride and hexafluoropropylene.
Claim 12
Dependent Claim
24 words
The method of claim 1 wherein said tube sheets are lined with an inner ceramic or porcelain coating and an outer fiber-reinforced fluoroelastomer layer.
Claim 13
Dependent Claim
68 words
The method of claim 5 wherein said non-graphite connectors are U-shaped and contain a bead about each end, each end of said graphite tubes contain a barbed fitting, an elastic sleeve is placed around the abutting of the connector and tube ends and which extends beyond the connector bead and tube barbed fitting, said sleeve having a pair of clamps pressed thereabout adjacent each end of said sleeve.
Claim 14
Independent Claim
136 words
A method for recovering heat from a gas stream contaminated with water vapor and acid or acid-forming moeity, said gas having an acid dew point ranging from about 200° F. to 300° F. and a water dew point ranging from about 90° F. to 150° F., which comprises: passing said gas stream through a heat exchanger fitted with a plurality of generally-parallel tubes through which flow heat exchanging fluid counter-current to the flow of said gas stream in said heat exchanger, the heat exchanging fluid being at a temperature such that the exterior tube temperature or the temperature of said contaminated gas stream exiting said heat exchanger, is at or below both said dew points, each of said tube sheets being bi-layer lined with an inner silicon-carbide impregnated epoxy coating and an outer fiber-reinforced fluoroplastic layer.
Claim 15
Independent Claim
136 words
A method for recovering heat from a gas stream contaminated with water vapor and acid or acid-forming moeity, said gas having an acid dew point ranging from about 200° F. to 300° F. and a water dew point ranging from about 90° F. to 150° F., which comprises: passing said gas stream through a heat exchanger fitted with a plurality of generally-parallel tubes through which flow heat exchanging fluid counter-current to the flow of said gas stream in said heat exchanger, the heat exchanging fluid being at a temperature such that the exterior tube temperature or the temperature of said contaminated gas stream exiting said heat exchanger, is at or below both said dew points, each of said tube sheets being bi-layer lined with an inner silicon-carbide impregnated epoxy coating and an outer fiber-reinforced fluoroplastic layer.
Claim 16
Dependent Claim
20 words
The method of claim 13 wherein said fluoroplastic comprises an elastomer derived from the combination of vinylidene fluoride and hexafluoropropylene.
Claim 17
Dependent Claim
11 words
The method of claim 13 wherein said fiber-reinforcement comprises glass fiber.
Claim 18
Dependent Claim
27 words
The method of claim 13 wherein said fiber-reinforced fluoroplastic layer is retained in place by sealing sleeves disposed in said apertures and through which said tubes pass.
Claim 19
Dependent Claim
21 words
The method of claim 13 wherein said tubes are formed from acid-resistant ceramic material which exhibits a smooth washable exterior surface.
Claim 20
Dependent Claim
16 words
The method of claim 13 wherein said inner coating comprises a silicon-carbide impregnated epoxy novolak coating.
Claim 21
Dependent Claim
13 words
The method of claim 13 wherein said tubes comprise acid-resistant resin-impregnated graphite tubes.
Claim 22
Independent Claim
200 words
A method for recovering heat from a gas stream contaminated with water vapor and acid or acid-forming moiety, said gas having an acid dew point ranging from about 200° F. to 300° F. and a water dew point ranging from about 90° F. to 150° F., which comprises: passing said gas stream through a heat exchanger fitted with a plurality of generally-parallel tubes through which flow heat exchanging fluid counter-current to the flow of said gas stream in said heat exhanger, the heat exchanging fluid being at a temperature such that the wall tube temperature or the temperature of said contaminated gas stream exiting said heat exchanger, is at or below both either of said dew points, said tubes formed from acid-resistant ceramic material and exhibiting a smooth washable exterior surface; said exchanger fitted with a pair of side apertured tube sheets through which said tubes penetrate, the ends of said tubes being interconnected with connectors for establishing a flow path of heat-exchange fluid therethrough, between said tube sheets is an interior heat-exchange chamber through which said contaminated gas stream flows, said tube sheets being bi-layer lined with an inner ceramic or porcelain coating and an outer fiber-reinced fluoroelastic layer.
Claim 23
Independent Claim
200 words
A method for recovering heat from a gas stream contaminated with water vapor and acid or acid-forming moiety, said gas having an acid dew point ranging from about 200° F. to 300° F. and a water dew point ranging from about 90° F. to 150° F., which comprises: passing said gas stream through a heat exchanger fitted with a plurality of generally-parallel tubes through which flow heat exchanging fluid counter-current to the flow of said gas stream in said heat exhanger, the heat exchanging fluid being at a temperature such that the wall tube temperature or the temperature of said contaminated gas stream exiting said heat exchanger, is at or below both either of said dew points, said tubes formed from acid-resistant ceramic material and exhibiting a smooth washable exterior surface; said exchanger fitted with a pair of side apertured tube sheets through which said tubes penetrate, the ends of said tubes being interconnected with connectors for establishing a flow path of heat-exchange fluid therethrough, between said tube sheets is an interior heat-exchange chamber through which said contaminated gas stream flows, said tube sheets being bi-layer lined with an inner ceramic or porcelain coating and an outer fiber-reinced fluoroelastic layer.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-08-05 | 1995-02-04 | 1995-08-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-08-05 | 1999-02-04 | 1999-08-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-08-05 | 2003-02-04 | 2003-08-06 | $7700.00 | Window Closed / Lapsed |