MXPA00004594A - Heat exchanger - Google Patents

Abstract

A heat exchanger comprising a plurality of plates (10A) is described. The plurality of stackable plates (10A), when stacked one upon the other, from fluid channels between adjacent plates (10A) allowing heat exchange between fluid flowing on one side of a plate (10A) and fluid flowing on the other side of the same plate (10A), each plate (10A) comprising interengaging means (3A, 3B) on at least one pair of opposing edge regions (32, 34, 36, 38) for engaging with interengaging means (3A, 3B) on a corresponding pair of edge regions of a neighbouring plate (10A) to form seals between these edges (32, 34, 36, 38) when the plates (10A) are stacked together.

Description

TERMOINTERCA BIADOR Field of the Invention The present invention relates to a plate-shaped heat exchanger and a plurality of plates for a heat exchanger. This refers particularly, but not exclusively, to a heat exchanger to supply cold fluid such as air to an electrical equipment cabinet. BACKGROUND OF THE INVENTION Plate heat exchangers generally comprise a stack of thin plates that normally have four sides. The plates are stacked to form a three-dimensional structure in which the external cold air and the extracted hot air pass through the opposite sides of each plate to allow heat exchange. Normally the cold air flow on one side of a plate is globally at the right angles to the hot air flow through the other side of the plate. Traveling down one side of the stack, the edges of the plates are normally sealed together in pairs. On an adjacent side, the edges of the plates are also sealed together in pairs, but in an inverted placement, so that, where the plate is sealed to its upper adjacent along an edge on one side of the stack, this is sealed to its adjacent lower one along another edge on an adjacent side of the stack. This allows the transverse flow of hot air and cold air on opposite sides of each plate, the two flows usually remain unmixed. The plates of the heat exchanger are usually made of metal such as aluminum or copper, which are good conductors of heat. In any case, the manufacture of these metal plates is expensive and difficult to assemble in stacks for the heat exchangers, particularly due to the need for formation seals between the edges of the alternating pairs of the edges of the plate. This results in an elongated assembly process and complicated use. In addition, the plates are also vulnerable to corrosion and can be heavy. The plastic plates have been developed to eliminate the problem of corrosion. These plastic plates can also be difficult to assemble and make you lose time in this. Plates, plastic or metal, are usually welded or glued to seal the edges together in the required shape, for example, to allow transverse flow. Sometimes separate staples and even sealing mechanisms are used, such as a seal. However, these placements are not satisfactory, particularly due to the time it takes to mount the plates in the stack with the necessary seals in place. Therefore, it is an object of the present invention to eliminate the problems mentioned above. United Kingdom patent application GB 2 063 450 A discloses a heat exchanger having a number of rectangular plates superimposed on each other, each plate having ridges on opposite sides. The patent of E.U.A. US 4,858,685 discloses an exchanger having a number of rectangular plates superposed one on top of the other, each plate having lips bent upward from exposed outer edges. SUMMARY OF THE INVENTION According to a first aspect of the present invention, a plurality of stackable plates for a heat exchanger are provided, which, when stacked one on top of the other, form fluid channels between the adjacent plates allowing thermal exchange between the fluid that runs on one side of a plate and the fluid that runs on the other side of the same plate, each plate comprises mechanisms that mesh internally in at least a couple of regions of the opposite edge to mesh with mechanisms that mesh internally in a corresponding pair of edge regions of a contiguous plate, to form seals between these edges when the plates are stacked together. Preferably, one or both fluids are gaseous like air. Preferably, the internal gear members are positioned so that the plates are stacked together with directions of fluid flow on opposite sides of any plate crossing. Preferably, the internally engaging mechanisms comprise an elongate member that extends along a region of the edge. Preferably, at least a pair of regions of the opposite edge are displaced at a higher level relative to a central region of at least one plate. Preferably, at least a pair of regions of the opposite edge are displaced at a lower level relative to a central region of at least one plate. Preferably, each second plate has edge regions that are substantially at the same level as a central region of the plate. Preferably, each plate is identical. In another embodiment, the alternating plates can be identical, there being two kinds of plates. Preferably, the internal meshing mechanisms comprise a projection along the edge regions projecting from one surface to form a recess on the other surface to accommodate a corresponding projection on a contiguous plate so that a seal is formed between the plates along the edge region when the plates are piled together. Preferably, each edge region of each plate comprises at least one projection along it. Preferably, one or more regions of the edge comprise two or more of the projections, separated one from the other. Preferably, the projections form a structure of the projection substantially continuous relative to the periphery of the plate. Preferably, each projection is of the same cross section. Preferably, the cross section is constant along the projection. Preferably, the cross section of the projections is generally rectangular or generally square. Preferably the width of the highest surface of the projection is greater than the base of the projection. For example, the sides of the projection may be angled relative to the plate in opposite directions, so that the highest surface of the projection is wider than the base of the projection. These sides can be straight. In one embodiment, there may be a lip formed at the junction between the highest surface and the sides of the projection, the lip extending laterally from the sides of the projection. Preferably, the elasticity of the projections of the adjacent plates allows a projection to be placed rapidly within the projection of the adjacent plate. Preferably, at least a pair of regions of the opposite edge of each plate comprises an extension of a surface of the edge region to prevent the internal meshing mechanisms of that plate surface from engaging with the corresponding internal meshing mechanisms. in a continuous plate contiguous to that surface of the edge region. Preferably, the internal engagement mechanisms are provided on one or more regions of the edge in the form of two projections and in which the extensions are placed between the projections. Preferably, one or more corners of each plate has an internal gear corner structure to mesh internally with a corresponding corner structure on a contiguous plate. Preferably, a corner structure comprises an extension member on one surface of the plate and a recess on the other surface of the plate. Normally, corner structures provide mechanisms to secure the plates together, by means of internal or external components such as staples and others. Preferably, a central region of the plate contains a plurality of stopped sections. Preferably the standing sections protrude from one side of the plate, but stand-up sections protruding from the other side of the plate can also be provided. Preferably, at least some of the stopped sections are lower than the separation of the central regions of the plates in the stack when the plates are stacked together. Preferably, one or more stop sections comprise elongated recesses through one of the higher surfaces placed to allow air flow through the recess. Preferably, the elongated recess is as deep as the height of some of the stopped sections. The stopped sections can be part of the plate, for example, they can be formed by pressing the plate. 0, the stopped sections can be added to the plate by gluing, welding or otherwise. Preferably, the regions of the opposite edge are substantially parallel to one another. In another aspect there is provided a heat exchanger comprising a plurality of plates according to the invention. Preferably, the heat exchanger comprises a plurality of identical plates. According to a second aspect of the invention, a plurality of stackable plates for a heat exchanger are provided, which, when stacked one on top of the other, form fluid channels between the adjacent plates allowing thermal exchange between the fluid running in one side of a plate and the fluid running on the other side of the same plate, each plate is welded in at least a pair of edge regions opposite a corresponding pair of edge regions of a contiguous plate to form seals between those edges. Preferably, the weld is formed by sonic welding. Preferably, the plates are made of a polymeric material. The plates of the heat exchanger may comprise plastics or industrial polymers. These plates have the advantage of being very cheap, so that they can be easily discarded and replaced with new plates at regular intervals. The plates can be made of an alloy of polymers and metal, either ferrous or non-ferrous, or alloys of plastics, or metals, or a combination of both. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will now be described by way of example with reference to the accompanying drawings. Figure 1 is a schematic pview of a basic version of a plate of the heat exchanger according to the invention. Figure 2 is a sectional, cross-sectional, exploded and schematic view of the side of a stack formed of a number of plates as seen in figure 1. Figure 3 is a cross-sectional, schematic view taken together, halved and along one edge of a stack of the improved first and second plates according to a preferred embodiment of the invention. The dotted line shows an improved alternative version of one of the plates. Figures 5A and 5C are cross-sectional, cross-sectional, sectional and schematic views through improved protrusions in the edge region of the adjacent plates according to the invention, the protrusions adapted to be quickly placed one inside the other are shown in the figures 5B and 5D. The Figure is a perspective view, schematic from above, of a first plate of the improved heat exchanger. The inserts show contiguous edges of this first plate in cross section. Figure 7 is a perspective view, schematic from above, of a second plate of the heat exchanger.

Figure 8 is a side view of the corner region of the plate 10A of figure 5 in the upper part of the plate 10B of figure 7, seen from the direction of the arrow 110. Figure 9 is a side view of the corner of the plate 10A of figure 6 in the upper part of the plate 10B of figure 7, seen from the direction of the arrow 120. Figure 10 is an overall perspective view of the stopped sections 45 and 50 , which show the air flow channel 60. Detailed Description of the Drawings Figure 1 shows a basic plate of the heat exchanger according to the principles of the invention. A central region 2 is bounded by, in this embodiment, a continuous projection of the generally square cross section 3. The plate 1 is normally formed by injection molding and the projection 3 is formed when a recess is pressed inside the part rear of the plate 1. Two opposite sides 3A of the projection 3 are at an approximately constant height along their length. The two remaining sides 3B have columns or extensions 4 which are also pressed outwards during injection molding. Columns 4 are spaced at intervals up to a point along sides 3B. The columns 4 that are higher than the projection in which they are formed, serve to separate that projection from a plate, from a corresponding projection of a contiguous plate when the plates are stacked together to form a heat exchanger. This can be seen more clearly in Figure 2 in which a series of identical plates, 201 to 206, are seen in a sectional, crossed and exploded view, where each two plates have been rotated 90 relative to their adjacent ones. As can be seen from Figure 2, the lower plate 201 has upright columns 4 on its raised columns with protruding edges that are higher than the projection 3B, in this way preventing the lower face of the projection 3A from the corresponding edge of plate 202, just above it, is positioned on ledge 3B. Up to a point between the outer edges of the lower plate 201, there is the projection 3A which has no column 4. Therefore, there is nothing to prevent the recess, in the rear part of the projection 3B of the plate 202 just above it, pass over the projection 3A to form a seal on the side of the plate when the plates are piled together. Similarly, for the next pair of plates 202, 203, at the outer edges, the projection 3A is inserted into the recess behind the projection 3B on the plate just above it, when the plates are stacked. Either way, two columns 4 to a point through the projection 3B at the trailing edge of the plate 202, prevent the projection 3A of the plate 203 from passing over the projection 3B of the plate 202. In this way, each edge of each plate forms a seal with the region of the corresponding edge of one, but not of another of its adjacent plates in the stack. This can be seen more clearly in Figure 3, in which there is a side view, sectional and transverse, through the middle portion of the stack of four plates 101, 102, 103 and 104. The most prominent edge of the plate 101 forms a projection 3A. The projection 3A is inserted into the recess formed in the rear part of the projection 3B of the plate 102. In any case, the projection 3B also includes separate erect projections 4 which prevent the recess to the rear part of the projection 3A from the plate 103, pass over projection 3B of plate 102. Therefore, fluid such as air, can flow between plates 102 and 103 from left to right, or vice versa, as seen in the drawing. Either way, no fluid such as air can run between the plates 101 and 102 from left to right or vice versa due to the effective seal formed by the circuit path provided between the plates 101 and 102, where the projection 3A enters the recess behind outgoing 3B. Either way, fluid such as air can run between the plates 101 and 102 in a transverse direction, for example, inside or outside of the paper, due to the upright columns 4 on the transverse edges of the plate 101 (not shown) and the stopped sections 60 which are periodically placed in the central region 2 of the plate 101. It will be evident that while the following description refers to the air, other fluids, including liquids, can be used. As will be appreciated by those skilled in the art, while the four extensions are positioned so as to extend from the grooves 3B on one surface of the heat exchanger plate, an alternative, or even additional embodiment, is that wherein the extensions are placed on the back of the surface of the plate, called projections from below 3A. Where front and rear extensions are provided, these could be on the contiguous edges of the same plate, although it depends on the opposite surfaces of that plate. The embodiment in which the identical plates are used is not ideal, since there are some induced spots on the plate 102 in the fold 6 where it is bent to pass over the stopped section 60 of the plate 101. Therefore, while this embodiment provides many of the advantages of the invention, and also reduces the production of expenses because it uses identical plates throughout the stack, it has some disadvantages. The presence of the fold 6 in the plate 102, particularly if the plate 102 is formed of a flexible material such as plastic, will tend to cause the protrusion 3B of the plate 102 to rise outward and separate from the protrusion 3A of the plate. 101. This is clearly not desirable since the air could then flow in both transverse directions between the plates 101 and 102. One solution is to provide a quick positioning mechanism between the projections 3A and 3B to prevent their separation. In fact, a quick placement can be used with any of the embodiments of the invention and will be described later. Either way, another option is to provide two kinds of plates in the stack. For example, one or both of the classes can be provided with an additional fold just inside the outer projections 3A and 3B, formed in opposite directions, to allow the plates to rest more naturally on each other. This can be seen in Figure 4, in which the plate 10B has a central section 26 which is lower than a region of the edge containing the projection 3A. The region of the border containing the projection 3A and the central region 26 are separated by an intermediate region 27B. Similarly, the plate 10A has a central region 26 which is generally higher than the region of the edge containing the projection 3B and the stopped sections 4. The projection 3B and the central region 26 of the plate 10A are separated by a region 27A, which is preferably of the same dimensions as region 27B. If the regions 27A and 27B were not present in the plates 10A and 10B, the circuit path forming the seal between the projections 3A and 3B and preventing the air flow between the plates 10B and 10A, could be less wavy and therefore, less effective. This could be particularly marked on the inner edge of the projections 3A and 3B. Due to the presence of the bends 28A and 28B in the plates 10A and 10B, the central region 26 of the plates 10A and 10B is generally at a constant spacing on the central region 26. In addition, the projections 3A and 3B are not subject to an elastic force, causing them to move apart, opening a flow of air between them. An alternative embodiment is one in which the plate 10B is generally leveled over the edge and the central regions, as indicated by the dotted line in Figure 4. In this case, the intermediate region 27B is at the same level as the the remainder of plate 10B. Other alternatives can be conceived, for example, the inner edge of the projection 3A of the plate 10B could extend below the level of the edge region. This could have the advantage of lengthening the wavy route between the plates 10B and 10A, improving the degree of sealing. Additional projections and recesses or other ways to lengthen and improve the route can also be provided, all that is needed is that with any shape that is selected, the structure is able to enter the structure of the adjacent plate to provide a seal. It is an advantage of simplicity to choose the structure so that it enters into or over an adjoining structure. In addition, the projections and recesses are especially easy to manufacture by injection molding. Other improvements seen in Figure 4 include the introduction of two different kinds of standing or protruding sections 60. The plates 10B have a higher stop section 45, in size and shape, to enter a recess formed at the rear of a section lower stop 50. The interaction of the stopped sections 45 and 50 separate and support the central regions 26 of the plates 10A and 10B. The stopped sections are usually recessed on their back side, both the stopped sections and the recesses interrupt the flow of air through the plate. Either way, the stopped sections could simply be glued or welded to one or both surfaces of a plate. Normally, the stopped sections cover around 3% (actually 3.11%) of the surface area of one side of the plate, to provide the correct degree of turbulence without excessive flow restriction. The coverage percentage of the area of the stopped sections can vary between 1 or approximately 2% and 12%. For example, where the sections stopped on the other side of the plate are hollowed, the effective area of the stopped sections is double, approximately 6% of the surface area of the plate. Referring now to FIGS. 5A and 5B, a possible quick positioning mechanism is shown. Here, a protrusion of the square cross section is initially pressed outward by means of injection molding. For example, in cooling, the projection deforms very slightly under its own weight, or by means of an additional deformation force to produce a slight elongation in the rear part of the recess 6. When two projections 3 with recesses 6 are pressed together, the swelling on the elongated outer surface of a projection 3 presses and is quickly placed within the interior portion of the recess 6 of a contiguous projection 3. It will be understood that pressure or closure structures, such as those used to seal plastic folders, are particularly convenient. This method of forming projections 3, in which the natural deformation in cooling produces a rapid positioning mechanism, is particularly advantageous since no additional steps are needed to produce the plates. In fact, a major advantage of the preferred embodiment of the invention is that, all the features necessary to provide the necessary air flow through the stack, are formed in the plate, in the injection molding, without the need of more steps of the procedure. Of course, other steps of the procedure may be introduced if desired, for example, if alternative rapid placement mechanisms are needed. These alternative quick-release mechanisms include separate pressure pegs relative to the outer and inner surfaces of the adjacent projections or the edge regions of the plates. Another advantage is that when stacking the plates together, sealing the edge of the plate in the necessary places occurs automatically, while the protrusions are inserted inside the recesses above and below the stack. This dramatically reduces the construction time for a plate-shaped heat exchanger. Another class of projection incorporating a quick-release mechanism is shown in Figures 5C and 5D. Here, the sides and the highest surface of the projection are flat, the sides are turned outward from each other relative to the surface of the main plate. In the embodiment it is shown that the sides are at an angle of approximately 80 to the plate and the highest surface of the projection. Even the pressure embodiments of the invention have only been shown using a projection, either 3A or 3B, around the outer edges of the heat exchanger plate. A more wavy route is provided and therefore a better seal if two or more projections are used. An example of a plate 10A including two substantially parallel projections 3A, 3B in the edge regions 32, 34, 36 and 38 of the plate 10A are seen in Figure 6. Here, the projections 30 are not continuous around the plate , but are bent by the corner recesses 20 and the extensions 22. The corner recesses 10 and the extensions 22 in conjunction with similar recesses in the plate 10B, as will be described later, are used to locate the plates 10A in the 10B. and 10B in 10A.

In Figure 6, the first plate of heat exchanger 10A includes a recess 20 in each of its corners. While a square plate is shown, and is preferred, a rectangular plate can be used. The walls of each corner recess 20 form the extension 22, which depends on the underside of the plate 10A. Between each pair of corner recesses 20, in this embodiment, there are two substantially parallel projections indicated at 3A and 3B. The parallel projections 3A, 3B are formed along the edges 32, 34 and 36.38 respectively of the plate. The stopped sections 40 are provided on the opposite edges 36, 38 to separate a plate from its adjacent one along the edges. The stopped sections 40 are spaced apart along the edges 36, 38 and are positioned in the slot between the substantially parallel projections 30. Two sets of centrally located stopped sections 45, 50 are also formed in the central region 26 of the plate 10A. The stopped sections 45, which extend beyond the stopped sections 50, are provided for structural strength and separation of plates. They also promote turbulence as do the lower stopped sections 50. The stopped sections 45 and 50 have semi-cylindrical channels or ducts 60 formed through their upper surface to reduce entrainment or stagnation, for example the accumulation of material as dust, particles, insects, etc., in the still air that forms behind any body when air or fluid flows around it. The semi-cylindrical shape of the channels 60 is seen in Figure 10. In the stopped sections 50, the channels 60 are of almost the same depth as the height of the stopped sections. However, the channels 60 may vary in shape, size and orientation. Normally, the channels or recesses 60 are elongated, although this is not necessary. The stopped sections 45 and 50 are formed in alternate rows. In the plate 10A, the shorter stop sections 50 form the row of most outside on all four edges. The rows are aligned in this embodiment, so that each stop section 45 is located practically halfway between two of the highest stop sections 50. The cross sections AA 'and BB' shown in the inserts in Figure 6 , are through, respectively, the region of the edge 32 and the parallel projections 30A and the edge section 38 and the parallel projections 3B. as can be seen from the insertion, the two projections, in this particular embodiment, are approximately the same height and width one from the other. The main section of the plate 26 is slightly lower than the level of the section of the edge 32. The region 27B just inward of the parallel protrusions 3A, 3B, is at the same level as the region between the protrusions 3A, 3B and the outer portion of the edge section 32. This is also accurate for the section of the edge 34. Either way, the edge sections 36 and 38 are slightly lower than the center region 26. In fact, the section 27A that is just inwards of the projections 3A, 3B in the edge sections 36 and 38, and the edge sections 36 and 38 are positioned just below the level of the central section 26. For both kinds of the edge section, the height of the projections 30 is approximately at a distance above the base level of section 27A and 27B, being suitable. These mechanisms that are related to the central section 26 of the plate 10A of the opposite edges 36, 38 are lower, while the opposite edges 32, 32 are higher. When a plate 10A is placed extending on a plate 10B, the lower edge sections 36, 38 engage the plate 10B. When a plate 10A is placed below a plate 10B, the higher edge sections 32, 34 mesh the plate 10B.

Figure 7 shows a second plate of the heat exchanger 10B according to the invention. The plate 10B includes a recess 24 in each of its corners. Each recess 24 forms an extension 26, which depends on the lower face of the plate 10B. On one side of each recess 24 is a rectangular relief wall 28. Each recess 24 is separated from its adjacent corner recesses 24 by two substantially parallel projections 3 (only schematic shown in Figure 7). The projections 3 are formed on the edge regions 40, 42, 44 and 46 and cover the length between the relief walls 28, where these are present, or the corner recesses 24. The stop sections 4 are provided in regions of the edge 40, 42 of plate 10B for the separation of plates. The stopped sections 4 are evenly spaced along the ends 40, 42 and are placed in the slot between the projections 3. A plurality of centrally positioned stopped sections 45, 50 are also formed on the central region 26 of the plate 10B . As with plate 10A, the stopped sections 45 and 50 are provided for structural strength, for plate separation and for the promotion of turbulence. The stopped sections 45 and 50 include channels 60 to reduce drag as shown in Figure 10. Stopping sections typically cover approximately 3% on one side of each plate in this case (or 3% on each side where the sections stops have recesses). The stopped sections promote the variation of the fluid velocity, induce differential pressures through the plates, thus providing turbulence in the flow.

The stopped sections 45 and 50 are also formed in alternate rows on the plate 60, the stopped sections 45 forming the extra rows. Each extension 50 is positioned at a point almost parallel to the midpoint between the two extensions 45. In other words, the pattern of the sections stopped on the plate 10B is the opposite of the plate 10A. In the preferred heat exchanger according to the present invention, both kinds of plates are used and stored in alternative forms one on the other. Each pair of plates comprises a plate 10A and a plate 10B. Figures 8 and 9 show how the plates 10A and 10B are aligned in each pair, in this case with 10A above. The extensions 22 of the plate 10A are located in the corner recesses 24 of the plate 10B. The projection 3A of the region of the edge 46 of the plate 10 enters the corner, and preferably, snaps into the recess behind the projection 3B of the edge region 38 of the plate 10A. The alignment of the plates 10A and 10B thus creates a sandwich in which the edges of the pairs of plates are sealed lightly together along the opposite edges, allowing the flow of air between the intervening edges. In this way, if the plates are stacked in this manner, air is allowed to flow between a first and second plate in one direction and the second and third plate in another direction, preferably transverse. Of course, the plates could be placed and / or formed so that the air flow between a first and second plate is at an acute angle or even in a parallel direction relative to the air flow between the second and third plates, as could understood by someone specialized in the technique. The plates of the heat exchanger, according to the present invention, are preferably made of plastic material such as industrial polymers. The plates subjected to industrial polymers are durable and very cheap to manufacture. The low cost of the plates means that they can simply be discarded and replaced with new ones when they become old or the heat transfer characteristics deteriorate them due to the construction of particles. This is simpler than the cleaning methods required by conventional embodiments. Advantageously, the plates can be recycled to form new plates. In this way, with a very simple design, the present invention provides a heat exchanger that is quick and easy to assemble. An airtight seal is provided between the plates of the heat exchanger when the plates are inserted one inside the other at selected edges when stacked, so that sealing, gumming or welding joints are not required. The plates are positioned to provide a cross-flow or counter-flow heat exchanger with unmixed flow. Structural simplicity reduces manufacturing and production costs and also improves productivity. This contrasts with conventional heat exchangers that are difficult to assemble and take a long time to do, and do not provide a tight seal between the plates. It will be appreciated that the internal gear members while forming preferably from internal lock structures such as a boss / recess structure, could be formed from a series of discrete adjacent structures, although this is less preferred. These structures could be a series of shorter protrusions interspersed with pressure adjusting mechanisms, or a series of adjacent, discrete press fit mechanisms, such as pressure pins. In fact, the internal meshing members could be provided simply by nearly flat but displaced edges of each or each alternating plate, thus they will provide a degree of sealing at the edges, for example, in Figure 4 where the regions 27A and 27B are find Alternatively, or in addition, for the arrangement of the internal engagement mechanisms as in the first aspect of the invention, the opposite edges of the adjacent pairs of plates can be welded together by sonic welding using sonitrodes. The sonitrodes are usually made of steel that has slightly wrinkled ends that grip a material to be welded. The sonitrodes send a high frequency vibration within the material mentioned in 95-105dB, which agitates the material enough to form a weld. The frequency of the vibration is adjusted to the material to be welded, as well as the form of length and strength of the weld to be formed. In the same aspect of the invention, a minimum slot of 3mm between the adjacent plates is preferred, although it is not essential. In preferred embodiments of practice, it has been found that the plates resist pressure of 10 psi (pounds per square inch) before the seals are exposed between the edges.

Claims (30)

1. CLAIMS 1. A plurality of stackable plates for a heat exchanger, which, when stacked one on top of the other, form fluid channels between adjacent plates, allowing thermal exchange between the fluid running on one side of a plate and the fluid that runs on the other side of the same plate, each plate comprises internal meshing mechanisms in at least a couple of regions of the opposite edge to mesh with the internal meshing mechanisms in a corresponding pair of edge regions of a contiguous plate to form seals between these edges when the plates are stacked together, wherein a central region of the plate contains a plurality of stopped regions, in which at least some of the stopped regions are lower than the separation of the central regions of the plates in the stack, when the plates are stacked together.
2. 2. A plurality of plates according to claim 1, wherein the stopped regions are practically cylindrical.
3. 3. A plurality of plates according to any preceding claim, wherein one or more of the stopped regions comprises a recess through higher surfaces placed to allow the fluid flowing through the recess.
4. 4. A plurality of plates according to claim 3, wherein the recess is elongated.
5. 5. A plurality of plates according to claim 3 or claim 4, wherein the recess is substantially semi-cylindrical in cross section.
6. 6. A plurality of plates according to claim 4 or 5, wherein the elongated recesses are as deep as the height of some or all of the stopped regions.
7. A plurality of plates according to any preceding claim, wherein the internal engagement members are positioned such that when the plates are stacked together, the directions of the fluid flow on opposite sides of any plate crossing.
8. 8. A plurality of stackable plates according to any preceding claim, wherein the internal meshing mechanisms comprise an elongate member extending along a region of the edge.
9. 9. A plurality of plates according to any preceding claim, wherein at least one pair of regions of the opposite edge is displaced at a higher level relative to the central region of at least one plate.
10. A plurality of plates according to any preceding claim, wherein at least one pair of regions of the opposite edge is displaced at a lower level relative to the central region of at least one plate.
11. 11. A plurality of plates according to any preceding claim, wherein each alternating plate has regions of the edge that are almost at the same level as a central region of the plate.
12. 12. A plurality of plates according to any preceding claim wherein each plate is identical.
13. A plurality of stackable plates according to any preceding claim, wherein the internal meshing mechanisms comprise a projection along the edge regions extending from one surface to form a recess on the other surface to accommodate a corresponding projection in a contiguous plate so that a seal is formed between the plates along that region of the edge when the plates are stacked together.
14. 14. A plurality of plates according to claim 13, wherein each edge region of each plate comprises at least one projection therethrough.
15. 15. A plurality of plates according to claim 14, wherein one or more edge regions comprise two or more of the projections spaced apart from one another.
16. 16. A plurality of plates according to claim 14 or 15, wherein the projections form a substantially continuous projection structure around the periphery of the plate.
17. 17. A plurality of plates according to any of claims 13 to 16, in which the projection is of the same cross section.
18. 18. A plurality of plates according to any of claims 13 to 17, wherein the cross section of the projections is generally rectangular or generally square.
19. A plurality of plates according to any preceding claim wherein at least a pair of regions of the opposite edge of each plate comprises an extension from a surface of the edge region to prevent the internal engagement mechanisms on that surface of the plate are engaged with the corresponding internal meshing mechanisms in a contiguous plate adjacent to that surface of the edge region.
20. 20. A plurality of plates according to claim 19, wherein one or more regions of the edge in the form of two protrusions and in which the extensions are positioned between the protrusions are provided in the internal meshing mechanisms.
21. 21. A plurality of plates according to any preceding claim, wherein one or more corners of each plate has an internal engaging corner structure for engaging internally with a corresponding corner structure in a contiguous plate.
22. 22. A plurality of plates according to claim 21, wherein a corner structure comprises an extension member on one surface of the plate and a recess on the other surface of the plate.
23. 23. A heat exchanger comprising a plurality of plates according to any preceding claim.
24. 24. A heat exchanger, according to claim 23, wherein the plurality of stackable plates are stacked one on top of the other, to form fluid channels between the adjacent plates allowing thermal exchange between the fluid running on one side of a plate and the fluid running on the other side of the same plate, each plate comprises internal meshing mechanisms in the regions of the edge of the plate.
25. 25. A heat exchanger according to claim 23, wherein the plurality of stackable plates are stacked one on top of the other, to form fluid channels between adjacent plates that allow thermal exchange between the fluid running on one side of a plate and the fluid running on the other side of the same plate, each plate is welded in at least a pair of regions of the edge opposite a corresponding pair of edge regions of a contiguous plate to form seals between those edges.
26. 26. A heat exchanger according to claim 25, wherein the weld is formed by sonic welding.
27. 27. A heat exchanger practically as described with reference to the attached figures.
28. 28. A plurality of plates for a heat exchanger practically as described herein, with reference to the appended figures.
29. 29. A plurality of stackable plates, or a heat exchanger, according to any preceding claim, wherein, in each plate, the internal meshing mechanisms in a pair of opposite edge regions mesh with internal meshing mechanisms in a first adjacent plate. adjacent, and internal meshing mechanisms in a second pair of regions of the opposite edge mesh with the internal meshing mechanisms in a second adjacent adjacent plate.
30. 30. A stackable plate that can be multiplied to form a plurality of stackable plates according to any of claims 1 to 23 or 28 to 29.