Heat exchange – Flow passages for two confined fluids – Interdigitated plural first and plural second fluid passages
Patent
1980-07-07
1982-07-13
Richter, Sheldon J.
Heat exchange
Flow passages for two confined fluids
Interdigitated plural first and plural second fluid passages
291573D, 165DIG10, F28F 922, F28F 300, F28D 900
Patent
active
043389988
DESCRIPTION:
BRIEF SUMMARY
DESCRIPTION
TECHNICAL FIELD
This invention relates to a low profile heat exchanger module for use in heat furnaces, steel melting furnaces, gas turbines which use recuperators and the like, and a method for forming the same.
BACKGROUND ART
U.S. Pat. No. 3,759,323 issued to Harry J. Dawson et al describes an important prior art primary surface heat exchanger for use as a recuperator core of a gas turbine. Dawson et al discloses a heat exchanger core made from a multiplicity of thin metal sheets which have been individually corrugated, or folded in a wavy pattern according to the method described in U.S. Pat. No. 3,892,119 issued to Miller et al. A large number of these metal plates are stacked on top of each other and the edges of the sheets are crushed to form the flat sections necessary to encase the assembly and to allow the attachment of suitable manifolding for conveying hot and cold fluids. The necessity for crushing the edges results in blockage, and hence the restriction of fluid flow. In addition, the depth of the corrugations in the unit described by Dawson et al is limited by the need to crush the edges. Deep corrugations or pleats cannot be crushed in an organized or predictable manner without causing severe blockage.
The pattern of the corrugations and the relatively thick crushed edges of the individual sheets described by Dawson et al result in rigidity in all directions in the heat exchanger unit. This may lead to the development of high thermal strains, especially when transient loads are characterized by steep gradients.
A major drawback of the prior art heat exchanger construction has been the presence of high stress concentration factors which have resulted from the need to crush the edges. In some applications the effect has been that of producing a multiplicity of cracks. Another problem has been the failure of the weld to penetrate at certain junctions, which results in a preformed crack. While such stress concentration factors may not be significant when the assembly is preloaded in compression, as intended, and when the transients are not steep, high stresses which lead to premature failures may appear under severe operating conditions and after prolonged periods of operation during which the preload is likely to be relaxed.
DISCLOSURE OF THE INVENTION
The present invention is directed to a low profile heat exchanger module made from one or more compact, single sheet primary surface heat exchanger core units. Each unit is formed from a single sheet of thin material which has been pleated to any depth desired. Before pleating, the longitudinal edges of the thin sheet are serrated to provide fluid entrance ramps that minimize blockage, and the surface of the sheet is embossed to define flow passages and provide a means for directing flow and controlling turbulence.
Other objects, advantages and features of the invention will be more readily apparent from the following detailed description of a preferred embodiment of the invention when taken together with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a portion of a single sheet of heat exchange material employed to form the heat exchange core of the present invention;
FIG. 2 is a plan view of a portion of the single sheet of FIG. 1 after embossing to show a "U" flow concept.
FIG. 2' is a plan view of a portion of the single sheet of FIG. 1 after embossing to show a "Z" flow concept.
FIG. 3 is a view in side elevation of the single sheet of FIG. 2 during the pleating thereof;
FIG. 4 is a diagrammatic illustration of a side view of a pleated assembly of the present invention;
FIG. 5 is a diagrammatic illustration of an end view of a pleated assembly of the present invention;
FIG. 6 is a cross sectional view of the heat exchanger module of the present invention;
FIG. 7 is a diagrammatic illustration of an end view of the heat exchanger of the present invention;
FIG. 8 is a plan view of a portion of a single sheet of heat exchange material of a second embodiment of the present invention
REFERENCES:
patent: 2321110 (1943-06-01), Shipman
patent: 2953110 (1960-09-01), Etheridge
patent: 3148442 (1964-09-01), Gier, Jr.
patent: 3552488 (1971-01-01), Grill et al.
patent: 3759323 (1973-09-01), Dawson et al.
patent: 3866674 (1975-02-01), Tramuta et al.
patent: 3892119 (1975-07-01), Miller et al.
patent: 4116271 (1978-09-01), De Lepeleire
Caterpillar Tractor Co.
Richter Sheldon J.
LandOfFree
Low profile heat exchanger and method of making the same does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Low profile heat exchanger and method of making the same, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Low profile heat exchanger and method of making the same will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-200508