Heat exchanger

Abstract

 A heat exchanger comprising a number of basic elements (1) which are formed integral and which are each formed by a number of tubular members (2) the ends of which adjoin rectangular end walls (3). Connection members (6,7) are provided near the longitudinal edges of the two end walls which are situated one behind the other when viewed in the longitudinal direction, while connection members (9) formed complementarily are provided near the other longitudinal edges of said end walls.

Description

[0001] The invention relates to a heat exchanger comprising a number of spaced-apart tubular members for the passage of fluid.

[0002] Conventionally, these heat exchangers are manufactured from a large number of separate tubular members which are fixed with their ends in tube plates. The manufacture of such a heat exchanger is labour- consuming.

[0003] It is the object of the invention to provide a heat exchanger which can be constructed in a simple manner from elements which are simple to manufacture.

[0004] According to the invention this can be achieved in that the heat exchanger is constructed by means of a number of basic elements which are each formed integral and each comprise a number of tubular members extending between substantially rectangular end walls, in which connection members are provided near the two longitudinal edges of the end walls which, viewed in the longitudinal direction of the tubular members, are situated one behind the other, and connection members which are formed complementarily with respect to said connection members are provided near the other longitudinal edges.

[0005] Such basic elements can be manufactured simply and efficaciously by injection moulding or the like from any suitable material, for example, a synthetic resin or a metal. These basic elements can be manufactured in particular from high-grade thermoplastic synthetic resins, for example, aromatic polycarbonate, modified polyphenylene ether, polybutylene terephtalate and polyether imides. The basic elements thus formed may then be coupled together rapidly and in any desired number, while using the connection members for building up a heat exchanger of suitable dimensions.

[0006] If the distance between a cross edge of the end wall and the tubular member situated nearest to said cross edge at one end of the basic element is larger than at the other end, a staggered arrangement of the tubular members in the heat exchanger can simply be obtained by rotating the basic elements alternately through 180° with respect to each other.

[0007] The invention will now be described in greater detail with reference to a few embodiments of the construction according to the invention shown in the accompanying Figures.

Figure 1 is a plan view of two juxtaposed and intercoupled basic elements of a heat exchanger according to the invention.

Figure 2 is a cross-sectional view of the upper parts of the two basic elements taken on the line II-II in Figure 1.

Figure 3 is a sectional view taken on the line III-III in Figure 1.

Figure 4 shows diagrammatically a sealing construction provided between a longitudinal edge of an end wall and a wall of a casing surrounding the heat exchanger.

Figure 5 shows diagrammatically a further embodiment of the connection members between adjacent basic elements.

Figures 6-9 show various possible arrangements of heat exchangers manufactured with the use of the basic elements according to the invention.

[0008] Each basic element 1 comprises a number of tubular members 2 extending between at least substantially rectangular end walls 3.

[0009] In the embodiment shown the tubular members are circular in cross-section over the greater part of their length. Near each end of the tubular member 2, however, the size of the cross-section of the tubular member gradually increases in the direction of the adjacent end wall 3 and that in such manner that four crescent-like widening parts 4 which, viewed in the longitudinal direction of the tube are staggered over 90 or more with respect to each other, are formed, each crescent-like widening extending from a radially extending boundary wall 5 in the direction of and tapering towards the radially extending boundary wall 5 of the subsequent crescent-like widening. Said crescent-like widenings preferably extend from the centre of the tubular member towards the end, although they are shown to be shorter in the Figures.

[0010] As will furthermore be apparent from Figure 1 the tubular members 2 are accommodated in a basic element 1 in such a manner that the tubular members are situated closer to one short cross edge of an end wall than near the other short transverse wall.

[0011] On one side of the basic element, near the longitudinal edges of the end walls 3, lugs 6 and 7 forming connection members and extending in the longitudinal direction of the end walls are provided which bound a groove 8 which is situated therebetween and is open on one side.

[0012] On the other side of the basic element a lug 9 forming a complementarily formed connection member is provided which fits in the groove 8.

[0013] As will be apparent in particular, for combining basic elements for the construction of a heat exchanger, the lugs 9 may be inserted into the grooves 8, the complementarily formed ends of the basic elements thus rigidly engaging each other and engaging with each other to produce a firm connection between the basic elements as well as a seal at the area of these connections. Optionally, prior to inserting the components one into the other, they may provided with a suitable adhesive.

[0014] Since, as explained above, the tubular members 2 are arranged so as to be staggered with respect to the centres of a basic element, the tubular members 2, viewed in a direction at right angles to the longitudinal direction of the tubular members 2, may be arranged so as to be staggered with respect to each other in a heat exchanger, as is shown in Figure 1, by rotating the basic elements alternately through 180° with respect to each other.

[0015] It will be obvious that by combining such basic elements a heat exchanger of any desired size can be formed.

[0016] Such basic elements may be placed in a casing in which for the sealing of the basic elements with respect to the wall of the casing, profiled members formed in an adapted manner can be connected to the longitudinal edges and cross edges of the outer basic elements. For example, Figure 4 shows an embodiment for the sealing at the level of the cross edges of the basic elements. In this embodiment, in contrast with the embodiments shown in Figures 1-3, the cross edge of an end wall is provided with a flange 10 which is thicker than the remaining part of the end wall 3 and in which a groove is provided which is open towards the outside.

[0017] This flange 10 is incorporated in a correspondingly formed recess provided in a sealing frame 11. The sealing frame 11 on its side remote from the basic element, comprises a flat wall which engages a wall 12 of the casing surrounding the heat exchanger.

[0018] Grooves for receiving gaskets 13 are also present in the frame 11.

[0019] It will be obvious that such sealing frames comprising suitably formed recesses for receiving the cross edges of the end walls 3 and of the connection members 6-9, respectively, can efficaciously be used to obtain a sealed connection between the basic elements combined to form a heat exchanger unit and the walls of the casing surrounding the heat exchanger unit thus formed.

[0020] Figure 5 shows a slightly modified embodiment of the connection members situated near the end walls to interconnect adjacent basic elements. In this case also, projecting lugs 14 and 15 and grooves accommodating said lugs are used, but a recess has also been provided to accommodate a gasket 16.

[0021] When such a heat exchanger is used, a first fluid will flow through the tubular members 2 and a second fluid will flow around the tubular members transversely to the longitudinal direction of said tubular members 2. Due to the above-described design of the gradually increasing cross-sections of the ends of the tubular members 2 as a result of the formation of the crescent-like widenings, a strong turbulence of the medium flowing through the tubular members 2 will be generated, which will promote the heat transfer.

[0022] The heat exchangers composed as described hereinbefore can be incorporated in several manners, alone or in combination with similar heat exchangers.

[0023] For example, Figure 6 shows an arrangement in which two heat exchangers 17 are used which are composed in the above-described manner and which are incorporated in two ducts 18 and 18' for the fluids between which heat exchange is to take place. For example, the tubular members 2 of one heat exchanger communicate at one end of said heat exchanger with a branch of the duct 18 and at the other end communicate with a chamber which also communicates with the ends of the tubular members 2 of the other heat exchanger. The tubular members 2 of the other heat exchanger open int) a further branch of the duct 18. Fluid passed through the duct 18 can flow through the two heat exchangers and the chamber 19 as indicated by the solid-line arro\ A. On the other hand, the fluid passed through the duct 18' will flow around the pipes 2 of the two heat exchangers and through a chamber 20 provided between the said heat exchangers, as indicated by the broken- line arrow B.

[0024] Parallel flow of both fluids has been effected herewith.

[0025] However, as appears from Figure 7, a countercurrent heat exchanger can also be produced while using the same arrangement.

[0026] Figure 8 shows an arrangement in which a single heat exchanger is used which is accommodated between two branches of a first duct 21 for the passage of a first fluid in the direction of the arrow C and two branches of a second duct 22 for the passage of a fluid in the direction of the arrow D.

[0027] Figure 9 is a diagrammatic perspective view of the arrangement of the two heat exchangers 17 corresponding to the arrangement shown in Figure 6 or 7. As shown in this Figure, as a result of the special construction of the heat exchanger according to the invention, not only a passage of the fluids in the directions of the arrows A and B may be used, but it will also be possible to pass the fluid passed around the tubular members 2 in the direction of the arrow G through one or more of the heat exchangers used instead of in the direction of the arrow B.

[0028] It will be obvious that in this manner the heat exchanger according to the present invention can be used in many different manners, whether or not in combination with another similar heat exchanger, for producing an exchange of heat between various fluids passed through the heat exchanger.

Claims

1. A heat exchanger comprising a number of spaced-apart tubular member for the passage of fluid, characterized in that the heat exchanger is constructed by means of a number of basic elements which are each formed integral and each comprise a number of tubular members extending between substantially rectangular end walls, in which connection members are provided near the two longitudinal edges of the end walls which, viewed in the longitudinal direction of the tubular members, are situated one behind the other and connection members which are formed complementarily with respect to said connection members are provided near the other longitudinal edges.

2. A heat exchanger as claimed in Claim l, characterized in that the spacing between a cross edge of an end wall and the tubular member situated nearest to said cross edge is shorter at one end of the basic element than at the other end,

3. A heat exchanger as claimed in Claim 1 or 2, characterized in that the connection members are formed by projecting lugs and grooves fitting one in the other to form a connection and seal between adjacent basic elements.

4. A heat exchanger as claimed in any of the preceding Claims, characterized in that a groove for receiving a gasket is provided at the level of the lugs and recesses.

5. A heat exchanger as claimed in any preceding Claim, characterized in that frames to form a connection against the walls of a casing or the like surrounding the heat exchanger unit are provided on the cross edges and the outer longitudinal edges of the basic elements combined to form a heat exchanger unit.

6. A heat exchanger as claimed in any of the preceding Claims, characterized in that the cross-section of the ends of the tubular members increases by providing one or more widenings which are crescent-like in cross-section.

7. A heat exchanger as claimed in Claim 9, characterized in that four widenings which are crescent-like in cross-section and extend each over an angle of approximately 90° are provided near one end of a tubular member.

8. A heat exchanger as claimed in Claim 6 or 7, characterized in that a crescent-like widening extends from the centre of a tubular member up to the end of the tubular member in question.

Drawing