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US4343352A Expired / Lapsed US ⏱️ 0.0 years remaining

Heat exchanger for gases

Assignee: Norsk Viftefabrikk AS
•
Filing: 1980-04-09
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Granted: 1982-08-10
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Expires: 2000-04-09
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Abstract

Abstract Heat exchanger for gases, comprising a vertical shaft with upward flow of gas between rows of staggered horizontally disposed sets of tubes, downwardly restricted by a gas penetrable bottom (2) and upwardly by the uppermost set of tubes, and over its entire vertical length containing a granular material (7) which is kept in motion by the essentially vertically upward gas stream. The heat exchanger is characterized therein that the ratio between the diagonal free opening a and the horizontal free opening b between the tubes (4) in the set of tubes lies within the range 0.45:1-0.9:1 for controlling and restricting the vertical movement of the grains in the heat exchanger, thereby obtaining an approximately continuous temperature gradient in the gas-grain mixture over the entire height of the heat exchanger.

Inventors

  • 👤 Ole K. Bockman
  • 👤 Kjell Rydland

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 09:53
CPC Classifications
F; F28; F28D; F28D13/00

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 127 words
Heat exchanger for gases, constructed as a vertical shaft with upward gas flow between rows of staggered, horizontally disposed sets of tubes, downwardly restricted by a gas-penetrable bottom (2) and upwardly by the uppermost set of tubes, and over its entire vertical length containing a granular material (7) which is kept in motion by means of the essentially vertically upward flow of gas, characterized in that the ratio between the diagonal free opening a and the horizontal free opening b between the tubes (4) in the set of tubes is within the range 0.45:1-0.9:1 for controlling and restricting the vertical movement of the grains in the heat exchanger, thereby obtaining an approximately continuous temperature gradient in the gas-grain mixture over the entire height of the heat exchanger.
Claim 2
Dependent Claim 127 words
Heat exchanger for gases, constructed as a vertical shaft with upward gas flow between rows of staggered, horizontally disposed sets of tubes, downwardly restricted by a gas-penetrable bottom (2) and upwardly by the uppermost set of tubes, and over its entire vertical length containing a granular material (7) which is kept in motion by means of the essentially vertically upward flow of gas, characterized in that the ratio between the diagonal free opening a and the horizontal free opening b between the tubes (4) in the set of tubes is within the range 0.45:1-0.9:1 for controlling and restricting the vertical movement of the grains in the heat exchanger, thereby obtaining an approximately continuous temperature gradient in the gas-grain mixture over the entire height of the heat exchanger.
Claim 3
Dependent Claim 42 words
A heat exchanger as claimed in claim 1, wherein the net gas velocity through the free flow cross-section of the exchanger is within the range of transition for pneumatic transportaion of the grains and corresponding to 30-100 times the minimum fluidizing velocity.
Claim 4
Dependent Claim 36 words
A heat exchanger as claimed in claim 1 or 2, characterized in that the sets of tubes for heat transfer are completely or partly in the form of tubes provided with fins and having circular cross-section.

References Cited (Backward Citations)

GB699151A Cited
US2640333A Cited
US3048153A Cited
US2919559A Cited
NO123737B Cited
GB1395900A Cited
US3912002A Cited
US3814176A Cited
NO751444L Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1985-08-09 1986-02-08 1986-08-10 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1989-08-09 1990-02-08 1990-08-10 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1993-08-09 1994-02-08 1994-08-10 $7700.00 Window Closed / Lapsed

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