US3868994A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid metal operated heat exchanger
Assignee: United States Atomic Energy Commission
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Filing: 1973-02-26
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Granted: 1975-03-04
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Expires: 1993-02-26
Abstract
Abstract This invention relates to a heat exchanger arrangement of the shell and tube type especially adapted for the use of high temperature liquid metal as a heating medium. The arrangement incorporates a tube bundle comprising a plurality of bayonet tube assemblies through which the liquid metal is circulated in indirect heat exchange relation with vaporizable fluid that flows through the shell. The tube assemblies incorporate a double walled bayonet tube containing a gas space which provides a thermal barrier to minimize heat loss from the heating medium. Various embodiments of evaporator and evaporator-superheater organizations utilizing the heat exchanger arrangement are described.
Inventors
- 👤 John Paul Petrek
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 00:28
CPC Classifications
F; F28; F28D; F28D7/00; F28D7/10; F28D7/12; F22; F22B; F22B1/00; F22B1/02; F22B1/06; F22B1/063
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
255 words
A shell and tube heat exchanger organization in which heating fluid is circulated in heat exchange relation with a fluid to be heated comprising: a. a shell; b. an outer tube having an open end and a closed end housed within said shell; c. an inner tube having a pair of concentrically spaced walls defining an axial passage and a first annulus concentrically spaced therefrom and means for closing one end of said first annulus; d. said inner tube having an external diameter less than that of the internal diameter of said outer tube and extending coaxially into said outer tube from the open end thereof with its leading end axially spaced from the closed end of said outer tube to define a second annulus in fluid communication with said axial passage; e. means to direct a flow of heating fluid through said axial passage and said second annulus; f. means for passing an inert gas into said first annulus; and g. means for circulating fluid to be heated through said shell externally of said outer tube in heat exchange relation therewith; said shell includes means forming a plenum in fluid communication with said axial passage and said second annulus in said inner tube, said plenum containing a body of heating fluid therein and a gas space thereabove and wherein the axial passage through said inner tube extends below the level of said body of heating fluid and said second annulus communicates with said gas space, said plenum having means for venting said gas space.
Claim 2
Dependent Claim
255 words
A shell and tube heat exchanger organization in which heating fluid is circulated in heat exchange relation with a fluid to be heated comprising: a. a shell; b. an outer tube having an open end and a closed end housed within said shell; c. an inner tube having a pair of concentrically spaced walls defining an axial passage and a first annulus concentrically spaced therefrom and means for closing one end of said first annulus; d. said inner tube having an external diameter less than that of the internal diameter of said outer tube and extending coaxially into said outer tube from the open end thereof with its leading end axially spaced from the closed end of said outer tube to define a second annulus in fluid communication with said axial passage; e. means to direct a flow of heating fluid through said axial passage and said second annulus; f. means for passing an inert gas into said first annulus; and g. means for circulating fluid to be heated through said shell externally of said outer tube in heat exchange relation therewith; said shell includes means forming a plenum in fluid communication with said axial passage and said second annulus in said inner tube, said plenum containing a body of heating fluid therein and a gas space thereabove and wherein the axial passage through said inner tube extends below the level of said body of heating fluid and said second annulus communicates with said gas space, said plenum having means for venting said gas space.
Claim 3
Dependent Claim
71 words
An apparatus according to claim 1, wherein said shell is elongated along the vertical axis; said heating fluid is a molten metal; and said fluid to be heated is a vaporizable fluid, and additionally including, means for dividing the interior of said shell into axially spaced high pressure and low pressure regions, said molten metal circulated in said low pressure region and said vaporizable fluid circulated in said high pressure region.
Claim 4
Dependent Claim
120 words
Apparatus according to claim 2 wherein means for forming a plenum divides said low pressure region into axially spaced plenums, said inner and outer tubes define tube assemblies; and the axial passage in said inner tube communicates with one of said plenums and said second annulus communicates with the other of said plenums, and additionally including a. a plurality of elongated shroud tubes enclosing said tube assemblies to define annular fluid passages thereabout; and b. means forming a support plate axially spaced from said main tube sheet in said high pressure region of said shell and forming a vaporizable fluid inlet plenum, said support plate attaching said shroud tubes with their lower ends in communication with said fluid inlet plenum.
Claim 5
Dependent Claim
41 words
An apparatus according to claim 3, wherein said high pressure region is positioned above said low pressure region, said low pressure region axially spaced plenums are divided into a lower inlet plenum intermediate said inlet plenum and said high pressure region.
Claim 6
Dependent Claim
35 words
Apparatus according to claim 3 in which the inner walls of some of said inner tubes extend to reduced depths below the level of molten metal in said plenums than others of said inner tubes.
Claim 7
Dependent Claim
81 words
Apparatus according to claim 3 including: a. a collection space adjacent the upper end of said high pressure region of said shell; b. a vapor outlet from said collection space; and c. inverted, domed baffle means spacedly enclosing said bundle of tube assemblies in concentrically spaced relation from the shell wall and cooperating therewith to form a vapor discharge passage in which the fluid undergoes an abrupt change of direction in flowing from said annular fluid passages to said collection space.
Claim 8
Dependent Claim
40 words
Apparatus according to claim 6 wherein the lower end of said baffle means extends to a position slightly spaced above said third tube sheet for washing the axial length of said shell wall with Fluid at a substantially uniform temperature.
Claim 9
Dependent Claim
65 words
Apparatus according to claim 3 including: a. means dividing the high pressure region of said shell into an evaporator portion and a superheater portion axially spaced therefrom; b. said tube assemblies extending longitudinally through both of said portions; c. means for directing said vaporizable fluid successively through said evaporator portion and said superheater portion; and d. means for withdrawing superheater vapor from said superheater portion.
Claim 10
Dependent Claim
150 words
Apparatus according to claim 8 in which said evaporator portion is disposed intermediate said vaporizable inlet plenum and said superheater portion and said apparatus includes: a. a first annular baffle surrounding said tube assembly bundle in concentrically spaced relation from the wall of said shell, the ends of said baffle terminating short of the lower and upper ends of said high pressure region to define an outer annular passage substantially coextensive with said high pressure region; b. a second annular baffle concentrically spaced from said first baffle and surrounding said tube assembly bundle in said superheater portion to define an interior flow passage containing said tube assemblies and an intermediate flow passage between said interior and said outer flow passages; c. means connecting said outer flow passage, said intermediate flow passage and said interior flow passage in series; and d. means for conducting superheated vapor from said interior flow passage.
Claim 11
Dependent Claim
48 words
Apparatus according to claim 9 including a transverse baffle having its periphery sealingly connected to the inner wall of said first annular baffle, said transverse baffle being disposed intermediate the ends of said annular baffle and separating said evaporator portion of said shell from the superheater portion thereof.
Claim 12
Dependent Claim
102 words
Apparatus for evaporating and superheating a vaporizable fluid by the indirect exchange of heat from a molten metal comprising: a. a pair of structurally similar heat exchangers defined in claim 2 respectively and defining an evaporator and a superheater, b. said means for circulating vaporizable fluid through said apparatus including: i. means for supplying said fluid as a liquid to the high pressure region of said evaporator, ii. means connecting the high pressure regions of said heat exchangers for series flow of vaporizable fluid, and iii. means for withdrawing said fluid as superheated vapor from the high pressure region of said superheater.
Claim 13
Dependent Claim
37 words
Apparatus according to claim 11 including vapor-liquid separating means interposed in said vaporizable fluid circulating means between said heat exchangers, and means for passing liquid from said separating means to the high pressure region of said evaporator.
Claim 14
Dependent Claim
31 words
Apparatus according to claim 12 wherein said molten metal circulating means includes means connecting the low pressure regions of said heat exchangers for series flow from said superheater to said evaporator.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-03 | 1978-09-02 | 1979-03-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-03 | 1982-09-02 | 1983-03-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-03 | 1986-09-02 | 1987-03-04 | $7700.00 | Window Closed / Lapsed |