US1851881A - Heat exchanging apparatus - Google Patents

Description

March 29, 1932. R j- WAT-r HEAT ExcHANGING APPARATUS Filed Nov. 3.11930 2 Sheets-Sheet Fuga. G

will/lll mm V/ll//hW/l//l/ mm '/ll/l//A'l March 29, 1932. R. J. wATT 1,851,881

HEAT EXCHANGING APPARATUS Filed Nov. 5, 1930 2 Sheets-Sheet 2 Patented Mar. 29, 1932 UNITED" STATES ROBERT JARDINE WATT, F NORTH FERRIBY, ENGLAND,

HEAT` EXCHANGING APPARATUS Application 'filed November 3, 1930,"Seria1 No. 493,180, and in Great Britain April 4, 1930.

This invention has relation to heat exchanging apparatus and more particularly to cooling apparatus for the abstraction of heat from liquids. Its principal object is to provide an efficient heat exchanger especially a cooler, which can be made of a formation offering the minimum resistance to the flow of fluid and with a surface the whole of which constitutes useful heat exchanging area.

i0 A further object of the invention is to pro-V These and other objects will appear moreVv fully from the following specific description of two embodimentsof the invention. In the accompanying drawings Fig. l is an end elevation of a cooler of stream-line formation, one end plate being removed to reveal the interior;

Fig. 2 is a longitudinal section on the line II-II of Fig. l;

Fig. 3 is a plan View of the inner side of a cooler adapted to form part of a surface;

Fig. 3a is a plan view of the inner side at the opposite end portion of the cooler of Fig 3.

Fig. 4l is a cross section thereof; Fig. 5 is an end elevation of a header employed in the cooler of Figs. 3, 3a., and 4; and

Fig. 6 is a plan View of said header.

In the embodiment of the invention illustrated in Figs. l and 2, plates 1,12 of a streamline contour forming adjacent walls of inlet and outlet headers 3, 3a., l are connected at their peripheries to opposite edges of a corrugated sheet 5 bent to said stream-line contour. The peripheries of said plates l, 2 are crenellated to fit the corrugations. The pcripheries of plates 6, 7 forming the outer wallsl of the headers 3, 3a, 4 are connected to the edges of a smooth metal sheet 8 which is also bent to the same stream-line contour and forms the remaining walls of said headers. The smooth sheet 8 is connected to the corrugated sheet 5 along the crest of each corrugation, producing a series of fluid ducts 9 communicating between the headers 3, 3a. 4. The remaining edges of the sheet 5 and the sheet 8 are connected together in the trailing edge of the stream-line shape. The inlet header 3 is fitted with an inlet pipe l0 for the fluid to be cooled and the outlet header 4 with an outlet or return pipe l1 for the cooled fluid. The whole structure is carried by a tubular support 12 to which the plates 1, 2, 6, 7 are secured where they are penetrated thereby. The various parts may be secured or connected together by welding, brazing, sweating and the like as circum- 7 stances require. If preferred the corrugated and smooth sheets 5, 8 may each be intwo parts joined both at the leading and trailing edges of the stream-line shape.

The cooler as a whole thus has a streamline formation bounded by the smooth 'metal' sheet or skin 8. Accordingly it may4 form part of or be incorporated in an aerofoil,y strut, fairing and the like. In. any case the stream-line formation, in addition toits own advantage of `reducing resistance and drag, ensures that the whole surface of the sheet 8 is air-swept and fully effective as heat exchanging area, the boundary layer effect being reduced to a minimum.4 The efficiency of the heat exchanger is enhanced by the fact that heat is transmitted by conduction from the trough-parts of the corrugated sheet 5 to the exposed face of the smooth sheet 8.

The shapeand size of the duct-s 9 are designed to furnish an aggregate heat exchange area sufficient to ensure the required temperature reduction of the fluid to be cooled in its passage, at a given rate of flow, through said ducts from the inlet header 3 to the out- 95 let header 4. Naturally the precise design of the cooler will depend also upon the nature of the fluid cooled, for example, oil, Water, steam and the like. Provision may bemade for regulating the cooling action loo surface.

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f in said stream-line body and between said partition walls,.and inlet and outlet conl'iectlons either by shrouding or by the inclusion in the inlet pipe lline of a multi-way cock whereby a part or the whole of the fluid which would pass through the cooler may be short circuited to the return pipe line.

The form of cooler illustrated in Figs. 3 to 6 is more particularly designed to occupy a part of a surface which is in a fluid stream, that is, a covering for an aerofoil, nacelle, fuselage, boathull or the like, the cooler being shaped in conformity with said In the example illustrated the smooth sheet 8 constituting the outer or heat transfer wall and the corrugated sheet 5 forming the ducts 9 are of a plane formation. Obviously, however, they can be shaped to form a part or continuation of a surface of any desired kind. To enhance the strength and fluid-tightness of the cooler, the edges 13 of the sheet 8 are folded over the edges of the sheet 5 as shown in Fig. 3 and Fig. 3a. Fig. 4 shows the edges 13 before being so folded. The inlet and outlet headers 3, 3a, 4 each consist of a single-piece, bottomless body fitted respectively with an inlet and outlet pipe 10, 11.. The bottom walls of these headers are provided by the sheet 8 when said header bodies are secured thereto. As before, the adjacent sides 1, 2 of the headers 3, 3a, 4 are connected to the corresponding edges of the corrugated sheet 5, the edges of said sides 1, 2 being crenellated in conformity with the corrugations to permit communication between 'the ducts 9 and the head ers. Tongues 14 are formed at intervals along the sides 1, 2 and, projecting at right angles to said sides into the troughsbetween the ducts, facilitate the making of a good Huid-tight and mechanical Around the other sides. the headers 3, 3a, 4 are provided with a Range 15 over which the edges 13 of the smooth plate 8 are also folded, said edges being finally sealed all around by,

for'example, sweating. The inlet and outletV Y' pipes 10, 11 being arranged at the ends of the headers 3, 3a, 4, said headers are made tapered. as illustrated, a substantially uniform distribution of the fluid to be cooled Y between the ducts 9 being thereby obtained.

In other respects the construction and action of this cooler are similar to those of the cooler of Figs. 1 and 2.

VVhat I claim is 1- i 1. Cooler comprising a smooth sheet metal body of stream-line formation, plates closing thev sides of said stream-line body, partition walls arranged within said body parallel to said vsides to 'divide off header spaces therein, a corrugated sheet metal body arranged withto said header spaces for fluid to be cooled,the crests of the corrugated sheet metal body be- Y ing connected to the smooth sheet metal body connection.

to form a series of fluid-ducts communicating between the header spaces.

2. Cooler comprising a smooth metal sheet, [lat bottomless bodies laid flat upon and secured to one face of said sheet along opposite edges thereof to form inlet and outlet headers, inlet and outlet fluid connections to said headers, and a corrugated metal sheet secured to the same face of said smooth metal sheet between said headers, the crests of the corrugated metal sheet being connected to the face of the smooth sheet to form a series of fluidducts communicating between the headers.

3. Cooler as claimed in claim 2, wherein the headers each consist of a bottomless body of a tapered formation having a crenellated edge for connection to the corrugated metal sheet.

4. Cooler comprising a smooth heat exchanging wall exposed on one face to a cooling fluid, inlet and outlet headers bounded on the outside by transverse walls extending along opposite edges of said heat exchanging wall and on the inside by transverse walls extending `across said heat exchanging wall at a distance from the outside walls, and a corrugated wall secured to the other face of the heat exchanging wall and extending between the inside walls of the headers, the corrugations thereby forming a series of fluid ducts communicating in parallel between said headers.

5. Cooler comprising a smooth heat exchanging wall having one face exposed to a cooling fluid, inlet and outlet headers bounded on the outside by transverse walls secured to opposite edges of the other face of said heat exchanging wall and on the inside by crenellated transverse walls extending across said other-face of the heat exchanging wall at a distance from the outside walls, and a corrugated wall havingthe crests of its corrugations secured to the aforementioned other face of the heat exchanging wall and its corrugated edges secured to the crenellated edges of the inside'walls of the headers, a series of fluid ducts communicating in parallel between said headers being thereby formed.

6. Cooler comprising a cooling wall having a smooth exposed outer face and shaped to form a stream-line body, inlet and outlet headers for fluid to be cooled extending from front to rear of said stream-line body, and a corrugated wall secured to the inner face of said cooling wall and between said headers,

the corrugations formingV a plurality of transverse fluid ducts communicating in parallel between said headers.

Dated this 11th day of October 1930.

i ROBERT JARDINE WATT.

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