Heat exchanger with jointed frame

A plate and frame style heat exchanger is disclosed herein the heat exchanger is formed by a plurality of heat exchange plates and frame members that are alternatingly stacked together to form fluid channel members. The frame members are formed by lengths of material that are formed or bent into the desired configuration for providing a first fluid tight seal around the periphery of the plates and a second fluid tight seal around respective fluid openings formed in the heat exchanger plates in order to achieve the desired flow configuration through the heat exchanger. In some embodiments the frame members are made up of two mating frame portions that join together in a self-aligning and self-fixturing relationship to facilitate assembly.

TECHNICAL FIELD

The invention relates generally to heat exchangers, in particular heat exchangers comprising a stack of spaced apart flat plates.

BACKGROUND

Bar and plate or plate and frame heat exchangers are most commonly used in industry for prototype applications or for low volume production and high model mix applications. For these types of applications it is desirable to keep production and manufacturing costs to a minimum, especially while allowing for flexibility in design without corresponding re-investment in expensive tooling. Traditional bar and plate or plate and frame style heat exchangers allow design flexibility and typically require minimal tooling costs, which is desirable given their application. However, bar and plate or plate and frame style heat exchangers are often labour intensive to build/manufacture, and may require numerous bar or frame components that are relatively expensive in material cost, and that may be relatively complex to assemble.

There is a continual need to reduce costs associated with the design and manufacture of this type of plate-type heat exchangers as well as to reduce the labour intensity and assembly complexity often required for their manufacture.

Accordingly, there is an on-going need to maintain or increase flexibility in plate type heat exchanger designs, while reducing or avoiding tooling costs, reduce the overall number of components and associated material costs, and to provide simpler and more robust assembly methods.

SUMMARY OF THE PRESENT DISCLOSURE

In accordance with a first example embodiment of the present disclosure there is provided a heat exchanger comprising a plurality of stacked heat exchanger plates; a plurality of frame members interposed between each of said heat exchanger plates, the frame members spacing apart each of said plates, the frame members and plurality of stacked heat exchanger plates together defining fluid channels therebetween; corresponding pairs of openings formed in each of said heat exchanger plates, the corresponding pairs of openings in adjacent plates aligning so as to define respective inlet and outlet manifolds for the flow of a first and a second fluid through corresponding ones of said fluid channels in said heat exchanger; wherein each of the frame members comprises a first sealing member adapted to correspond to the periphery of at least a portion of the heat exchanger plates; a second sealing member adapted to form fluid boundaries around the corresponding pair of openings formed in the heat exchanger plates; at least two free ends forming at least one joint such that said frame member provides a first fluid tight seal around the entire periphery of the plates, and a second fluid tight seal around one of said corresponding pairs of openings formed in the plates.

In accordance with another example embodiment of the present disclosure there is provided a method of making a heat exchanger, comprising the steps of providing a plurality of heat exchange plates having fluid openings formed therein; providing a plurality of frame members, the frame members being formed from at least one length of material having two free ends; bending said at least one length of material into a configuration to provide a first sealing member following the periphery of the heat exchange plates, and a second sealing member forming a boundary around at least one of said fluid openings in said plates, each of said free ends forming at least part of a joint to form a sealing frame member; forming an alternating stack of said heat exchanger plates and said sealing frame members to form first and second sets of fluid channel members.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Referring now toFIG. 1there is shown a portion of a heat exchanger100according to an example embodiment of the present disclosure. Heat exchanger100is comprised of fluid channel members10which serve as building blocks such that a plurality of fluid channel members10are stacked one on top of the other in order to form a heat exchanger for heating/cooling two different fluids flowing therethrough. It will be understood that suitable end plates (not shown) enclosing the stack of fluid channel members10and appropriate fluid inlet and outlet connections (not shown) for the various fluids flowing through the heat exchanger100would also be provided in accordance with principles known in the art. While the example embodiment shown inFIG. 1shows the fluid channel member10with inlet/outlet openings arranged at respective ends of the generally rectangular plates12,14for forming a parallel flow heat exchanger, it will be understood that various other forms of heat exchangers are also contemplated within the scope of the present disclosure as will be described in further detail below in connection with other example embodiments.

As shown, fluid channel member10comprises a pair of first and second plates12,14that are spaced apart from one another and connected together by a frame member16so as to form a fluid passageway18therebetween. A turbulizer or other heat transfer augmenting device (not shown) may be positioned within fluid passageway18between plates12,14depending upon the particular design and application of heat exchanger100. Plates12,14are essentially identical to each other and it will be understood that as fluid channel members10are stacked one on top of the other to form the heat exchanger100, the first (or upper) plate12of one fluid channel member10becomes the second (or lower) plate14of the adjacent fluid channel member10.

First and second plates12,14are generally rectangular in shape and made from any suitable material, such as aluminum or stainless steel. Aluminum plates are preferably made from pre-clad aluminum brazing sheet. Stainless steel plates may be made from stainless steel sheet clad with a filler metal such as copper; or the plates may be pre-coated with another suitable filer metal; or a filler metal may be provided as a shim in contact with each plate surface. Plates12,14are also generally flat and are each provided with four openings20,22,24,26with one opening being positioned at each of the respective corners of the plates12,14. The openings20,22,24,26serve as respective inlet/outlet ports for the inletting and discharging of a fluid into their corresponding fluid passageway18. When a plurality of fluid channel members10are arranged one on top of the other, the openings20,22,24,26align with the corresponding openings20,22,24,26in the adjacent fluid channel member10to form respective pairs of inlet/outlet manifolds (not shown) for two separate fluids to flow through the heat exchanger100as is known in the art.

Frame member16comprises a first or outer peripheral sealing member32and a second or manifold sealing member34. The first sealing member32generally follows the periphery or perimeter of the plates12,14around the longitudinal and end edges35,37of the plates12,14, the first sealing member32joining the first and second plates12,14together at their peripheries in a spaced apart relationship thereby forming a leak-tight, fluid passageway18therebetween. The first sealing member32, therefore, provides a fluid tight seal around the entire periphery of the fluid channel member10, the plates12,14and frame member16being joined together by brazing or any other suitable method to form a sealed, fluid passageway between plates12,14and frame member16.

The second sealing member34forms a fluid barrier or fluid boundary around two of the corresponding openings20,22,24,26formed in the plates12,14. In the example embodiment shown inFIG. 1, one frame member16(i.e. the uppermost frame member16shown inFIG. 1) has the second sealing member34formed around diagonally opposed openings20,24with the other frame member16(i.e. the lowermost frame member16shown inFIG. 1) having the second sealing member34formed around the opposite pair of diagonally opposed openings22,26. Accordingly, in the example embodiment shown, fluid can enter and exit the fluid passageway18formed between plates12,14via openings20,22while a second fluid flowing through the heat exchanger is prevented from entering fluid passageway18due to the positioning of the manifold sealing member34, the second fluid instead being permitted to enter/exit the adjacent fluid passageway18via openings24,26. Accordingly, it will be understood that heat exchanger100is comprised of a series of alternating fluid flow passageways18(1),18(2) for the flow of a first heat exchanger fluid through a first set of fluid flow passageways18(1) and a second heat exchange fluid through the second set of fluid flow passageways18(2) which fluids are brought into heat transfer relationship by means of the alternating arrangement of the fluid flow passageways18(1),18(2) through the heat exchanger100. It will be understood that while the second or manifold sealing members34are shown as being located so as to correspond to fluid openings at the diagonally opposed corners of the plates12,14for a parallel-flow, single pass heat exchanger, other configurations are also possible depending upon the desired fluid flow path through the fluid channel members10and heat exchanger100.

Frame member16is generally comprised of mating first and second frame portions16(1),16(2). In the subject example embodiment, the first and second frame portions16(1),16(2) are generally identical to each other, with the second frame portion16(2) being rotated 180 degrees with respect to the first portion16(1), or vice versa, as shown more clearly inFIGS. 2 and 3. Each of the first and second fame portions16(1),16(2) has one end40in the form of second sealing member34while the remainder of the frame portion16(1),16(2) follows the periphery of plates12,14, i.e. along the remainder of longitudinal edge35, end edge37and around the corner of the plate12,14and along a portion of the opposite longitudinal edge35before terminating at a second end42. As shown, the first sealing member32of each of first and second frame portions16(1),16(2) follows approximately half of the periphery of the plates12,14so that when frame portions16(1),16(2) are positioned in their mating relationship, a closed frame member16that follows the perimeter of plates12,14is provided.

In order to ensure that the first and second frame portions16(1),16(2) are appropriately aligned with each other in order to form a robust, first seal32around the entire periphery of the plates12,14and a robust second seal34around the manifold regions within fluid channel member10when the components are brazed or otherwise joined together, the first and second frame portions16(1),16(2) are provided with corresponding interlocking features to ensure the frame portions16(1),16(2) are securely positioned in their mating relationship. As shown inFIGS. 2 and 3, the first and second frame portions16(1),16(2) are provided with a mechanical connection. More specifically, the first and second frame portions16(1),16(2) each have a first end40that forms the second or manifold sealing members34, the first end40terminating at a free end that serves as a male interlocking member46in the form of a dovetail projection. A corresponding inside edge of the first sealing member32of the corresponding first or second frame portion16(1),16(2) is provided with a female interlocking member48in the form of a recess that corresponds to the dovetail projection found at the end of the first end40of the other frame portion16(1),16(2). Accordingly, when the two frame portions16(1),16(2) are positioned together to form frame member16, the male interlocking member46fits within the female interlocking member48thereby aligning and securely positioning the two frame portions16(1),16(2) in their mating relationship forming a joint. Accordingly, frame portions16(1),16(2) are self-aligning and self-fixturing.

The second end42of frame portions16(1),16(2) is generally provided with a blunt end edge, or free end, which simply abuts up against a corresponding end edge50of the first sealing member32where of the first sealing member32ends and transitions into the second or manifold sealing member34forming a butt joint. Although, it will be understood that the second end42could also be provided with similar interlocking features, if desired. However, provided that one of the free first or second ends40,42of the frame portions16(1),16(2) is provided with interlocking features to form a mechanical connection between the two, the first and second frame portions16(1),16(2) should be self-aligning and self-fixturing in order to facilitate assembly/manufacture of the heat exchanger100.

It will be appreciated by one skilled in the art, that in any of the interlocking, intersecting, or overlapping frame joints described above or in the following sections, the geometry and clearances in these joints is selected to be sufficient to encourage capillary flow of molten brazing filler metal, so that during brazing assembly the mechanical joints are securely and hermetically bonded. That is, the frame ends or frame portions are bonded to each other, and also the entire frame is bonded to the mating heat exchanger plates12,14to create strong and leak-tight fluid passages18.

Referring now toFIG. 4there is shown another example embodiment of a frame member116according to the present disclosure wherein corresponding or similar features will be referred to with similar reference numerals increased by a factor of100. In this embodiment, frame member116comprises first and second frame portions116(1),116(2) that are similar to frame portions16(1),16(2) except for the location and style of mechanical connection or joint provided for interlocking the two frame members116(1),116(2) together in their mating relationship. More specifically, the first end140of each of frame portions116(1),116(2) terminates with a free, blunt end edge141for forming a butt joint against a corresponding interior surface of the corresponding frame portion116(1).116(2), while the second end142terminates at a free end formed with a male interlocking member146in the form of a rounded jigsaw or “puzzle-piece” projection.

A corresponding female interlocking member148in the form of a recess that corresponds to the rounded jigsaw or “puzzle-piece” male interlocking member146is formed in the corresponding end edge150of the mating frame portion116(1),116(2) where the first sealing member132transitions into the second sealing member134at the first end140of the frame portion116(1),116(2). When the first and second frame portions116(1),116(2) are positioned together to form frame member116, the male interlocking member146fits within the female interlocking member148thereby forming a mechanical connection or joint within the first sealing member132formed by the two frame portions116(1),116(2), the mechanical connection thereby aligning and securely positioning the two frame portions116(1),116(2) in their mating relationship. Accordingly, frame portions116(1),116(2) are self-aligning and self-fixturing.

As shown in the embodiments ofFIGS. 1-4, the self-aligning or self-fixturing means or features can be provided within, or in-line with, the first sealing member132, as shown primarily inFIG. 4in respect of frame member116, or the self-aligning or self-fixturing means can be provided at a perpendicular junction between the two mating frame portions is as shown primarily in the embodiment ofFIGS. 2 and 3in respect of frame member16. Detailed views of the jigsaw and dovetail interlocking members are shown inFIGS. 5 and 6.

A further embodiment of a frame member216is shown inFIG. 7where once again similar reference numerals increased by a factor of200have been used to identify similar features of the frame member.

As shown, frame member216is comprised of two generally identical frame portions216(1),216(2), with one frame portion216(1),216(2) being rotated 180 degrees with respect to the other frame portion216(1),216(2). Frame portions216(1),216(2) each comprise a first sealing member232that extends around a portion of the periphery of the corresponding plates12,14and has one end240in the form of the second or manifold sealing member234. The second or manifold sealing member234extends or transitions from the first sealing member232towards the interior region of the frame member216in order to form the boundary or fluid barrier that will be positioned around one of the fluid openings formed in corresponding plates12,14. The first sealing member232extends along one of the longitudinal edges35, an end edge37and a portion of the opposite longitudinal edge35of the plates12,14so as to provide a complete seal or boundary around the perimeter of the plates12,14when the two frame portions216(1),216(2) are positioned in their mating relationship and positioned between plates12,14to form fluid channel member10.

In the subject example embodiment, rather than having a mechanical connection with interlocking features in the form of a jigsaw or dovetail connection as described above in connection withFIGS. 2-6, the embodiment shown inFIG. 7incorporates a stepped mating connection or overlapping joint256(see area encircled with dotted lines inFIG. 7) where the first and second frame portions216(1),216(2) meet at the transition area between a portion of the first sealing member232and a the second sealing member234. As shown, frame portions216(1),216(2) each have a first end240that forms the second or manifold sealing members234, the first end240terminating at a blunt end edge or free end241which abuts against the interior edge or surface of a portion of the first sealing member232of the corresponding frame portion216(1),216(2) when the frame portions216(1),216(2) are positioned together forming a perpendicular butt joint. The first and second frame portions216(1),216(2) are also each provided with a recessed or indented region258formed along the exterior surface or edge of the longitudinal edge portion of the first sealing member232proximal to where the first sealing portion232transitions into the second sealing member234. The recessed or indented region258is adapted for receiving the corresponding free end or end section242of the other frame portion216(1),216(2) when the two frame portions216(1),216(2) are positioned together in their mating relationship forming an overlapping joint so that the two frame portions216(1),216(2) form a generally flush or uniform edge around the periphery of the fluid channel members10. While the absolute end edge of free end242may not fully abut with the corresponding end portion of recessed area258, the overall overlap between the free end242and the recessed area258has been found to provide a sufficient joint between the two frame members216(1),216(2). Accordingly, once again frame portions216(1),216(2) are self-aligning and self-fixturing as they are positioned in their mating arrangement.

Another example embodiment of a frame member316is shown inFIG. 8wherein the frame portions316(1),316(2) are arranged in their mating relationship with the free end342of one of frame portions316(1),316(2) wrapping around a corner of the other mating frame portion316(1),316(2) forming an overlapping joint. While this particular arrangement does not provide for a flush or uniform edge around the outer periphery of the frame member316, an overlapping joint with a non-uniform edge may be suitable for certain applications. As shown in the drawings, the first and second frame portions316(1),316(2) each comprise a first sealing member332that follows a longitudinal edge35and end edge37of the plates12,14, the first and second frame portions316(1),316(2) having a first end340that forms the second sealing member334, the first end340terminating in a free end or blunt, end edge341that abuts against the interior edge or surface of the corresponding end edge portion37of the first sealing member332of the same frame portion316(1),316(2). The second end342of frame portions316(1),316(2) is generally provided with a free or blunt end edge which, as described above, simply wraps around the corner of the mating frame portion316(1),316(2).

FIG. 8Aillustrates a variation of the embodiment shown inFIG. 8wherein rather than having an overlapping joint with a non-uniform outer edge (as shown in the encircled area356inFIG. 8), a stepped connection similar to that shown inFIG. 7is incorporated into the overlapping joint in order to create a generally flush or uniform outer peripheral edge for frame member316. In the subject embodiment, the stepped connection is incorporated into the end edge37region of the frame member316as opposed to being incorporated into the longitudinal edge35portion of the first sealing member as in the case of the embodiment shown inFIG. 7. In this embodiment, the end edge37portion of the first sealing member332is provided with a recessed or indented region358, the recessed or indented region358adapted for receiving the corresponding free end or end section342of the corresponding frame portion316(1),316(2) when the two frame portions316(1),316(2) are positioned together in their mating relationship. Accordingly, the embodiment shown inFIG. 8Aoffers a variation wherein the two frame portions316(1),316(2) form a flush or uniform edge around the periphery of the plates12,14.

Various other forms of interlocking or self-aligning connections are contemplated within the scope of the present disclosure as shown, for example, inFIGS. 9, 9A and 10. For ease of reference, reference will be made to frame member16and frame portions16(1),16(2) although it will be understood that various other forms of interlocking or self-aligning connections could be incorporated into any of the frame members16,116,216,316or frame portions16(1),16(2),116(1),116(2),216(1),216(2),316(1),316(2) described above.

InFIG. 9, an overlapping connection or joint between mating frame portions16(1),16(2) is shown wherein an inside or interior edge of one frame portion16(1) is provided with a male projection46while the outer edge of the corresponding frame portion16(2) is provided with a corresponding female mating component or recess48for receiving the male projection when the frame portions16(1) are arranged in their mating relationship. It will be understood that this type of connection could be incorporated into the stepped connection256shown inFIG. 7orFIG. 8Aor into the overlapping connection356shown inFIG. 8.FIG. 9Aillustrates a variation to the overlapping connection shown inFIG. 9wherein the overlapping connection with male and female mating components46,48is incorporated into a stepped connection256in order to achieve a flush or uniform edge around the exterior of the frame member16when the first and second frame portions16(1),16(2) are positioned in their mating relationship.

FIG. 10illustrates another form of interlocking or self-aligning connection wherein one frame portion16(2) is bent or pinched so as form a pocket47within the outer edge of the frame portion16(2) for receiving a corresponding bent or hooked-end49of the corresponding frame portion16(1). In order to maintain a flush or uniform edge around the perimeter of the frame member16, the portion of the frame that continues after the formation of the pocket47is recessed or set-back with respect to the portion of the frame prior to the formation of the pocket47by a distance corresponding to the width of the material that forms the frame16. This ensures that the overlapping of the frame portions16(1),16(2) at the interlocking or mechanical connection forms a flush or generally edge around the exterior of the frame member16. Once again, this interlocking or self-aligning connection could be incorporated into the stepped connection256or into the overlapping connection356shown inFIGS. 7 and 8, for example.

While the frame members16,116,216,316have all been shown as being formed by lengths of material having a generally square cross-sectional area, it will be understood that the frame members16,116,216,316may also be formed with lengths of material having a rectangular, circular or oval cross-sectional shape. The lengths of material may be any suitable form of material, such as lengths of wire or rods or bars that is capable of being bent or formed into the desired configurations. Although not essential, in instances where circular or oval lengths of material are used, such as circular or oval wire or rods, to form frame members16,116,216,316, the frame members may be preferably flattened on their upper and lower surfaces, either before or after assembly. Provided that sufficient contact is provided between the frame member16,116,216,316and the corresponding surfaces of the plates12,14to achieve the desired seal, the specific cross-sectional shape of the wire or rod-like material used to form frame member16,116,216,316may vary depending upon the particular design and/or application of the heat exchanger100. For instance, certain diameter wire and/or rod material, or wire and/or rod material with certain aspect ratios, may have manufacturing limitations associated with the ability of the material to be bent to the desired radius to achieve a particular configuration of frame member16,116,216,316. In instances where the fluid channel members10must be appropriately sized to accommodate a turbulizer or other heat transfer augmentation device, a wire or rod of material having the required height to achieve the desired spacing apart of the plates12,14may result in the cross-sectional area of the wire or rod for forming the frame member being such that accurate bending of the wire or rod to achieve the desired configuration is difficult to achieve. Therefore, in certain instances where a sharp bend radius may be required to form the frame members, a tall, thin rectangular bar or a thick ribbon of material positioned on its edge may be preferable, as shown for instance inFIG. 16. Accordingly, it will be understood that the square cross-sectional shape has been shown for illustration purposes only and that rectangular, circular or oval shaped wire or rod material, or a thick ribbon or bar of material arranged on its edge or any other suitable shape of material may be used to form frame members16,116,216,316.

Referring now toFIG. 13there is shown another example embodiment of a frame member416according to the present disclosure. In this embodiment, frame member416is comprised of a first frame portion416(1) that forms the entire first sealing member432corresponding, generally, to the outer perimeter or periphery of the heat exchange plates12,14. The first frame portion416(1) is formed by a length of frame material that is bent into the desired configuration, the first frame portion416(1) having first and second free ends441,442in the form of hooked ends that come together to form a butt joint.

Second frame portions416(2) form the second sealing member434in the form of a fluid barrier or boundary that will encircle or surround one of the fluid openings20,22,24,26in plates12,14. The second frame portions416(2) are positioned in the interior region defined by the first frame portion416(1) at diagonally opposed corners thereof, the respective ends451of the second frame portions416(2) being received within corresponding pockets447formed in the interior surface or edge of the first frame portion416(1), similar to the interconnection described in relation to the embodiment shown inFIG. 10. While the subject example embodiment of frame member416has been shown as being adapted for a single pass, parallel flow heat exchanger with the corresponding inlet and outlet openings/manifolds being located in diagonally opposed corners of the plates, it will be understood that frame members comprising one-piece first sealing members and separate second frame portions forming the second sealing member can be modified for different configurations of heat exchangers.

Referring now toFIG. 14, there is shown another example embodiment of a frame member516according to the present disclosure. Frame member516is similar to the frame members16,116,216,316in that it too is comprised of first and second frame portions516(1),516(2) that are generally identical to each other, with the second frame portion516(2) being rotated 180 degrees with respect to the first portion516(1), or vice versa. Each of the first and second fame portions516(1),516(2) has one end540in the form of second sealing member534while the remainder of the frame portion516(1),516(2) generally follows the periphery of plates12,14, i.e. along the remainder of longitudinal edge35, end edge37and around the corner of the plate12,14and along a portion of the opposite longitudinal edge35before terminating at a second end542. Rather than providing a more complex dovetail or jigsaw mechanical connection between the first and second frame portions516(1),516(2) at the junction between the end edge541of the first end540of the frame portions516(1),516(2), the corresponding interior surface or mating edge of the end edge37portion of the first sealing member532of the corresponding frame portion516(1),51692) is provided with a recess or pocket547for receiving the blunt end edge541of the corresponding frame portion516(1),516(2) when the two frame portions are brought into their mating relationship. By having the end edges541of the first end540of the frame portions516(1),516(2) received within the corresponding recesses or pockets547formed in the corresponding portion of the first sealing member532, the first and second frame portions516(1),516(2) are brought into their self-aligning and self-fixturing mating relationship. This particular embodiment is suitable for applications where a flush or uniform exterior edge around the frame members516is not required.

Referring no w toFIG. 15there is shown a variation of the frame member516shown inFIG. 14. In this embodiment, rather than having pockets547formed in the exterior edge of the frame portions516(1),516(2) resulting in a non-uniform exterior edge of frame member516, the recess or pocket547for receiving the end edge541of the first end540of the corresponding frame portion516(1),516(2) is formed on the interior edge or surface of the corresponding portion of the first sealing member532along the end edge37of the plates12,14. More specifically, two slightly spaced apart protrusions549are formed by pinching or bending the material forming the frame portions516(1),516(2) with a rather small or tight bend radius so as to create the recess or pocket547between the two protrusions. This variation allows for a flush or uniform exterior edge around the perimeter or periphery of the resulting frame member516when the first and second frame portions516(1),516(2) are brought into their mating relationship.

While all of the above-described embodiments relate primarily to frame members suitable for forming fluid channel members10for a single pass heat exchanger wherein the fluid enters the fluid flow passageway18through an inlet opening positioned at one corner of the plate12,14and exits the fluid flow passageway18at a diagonally opposed corner, variations to the fluid channel members10so as to accommodate U-flow or two-pass heat exchanger applications are also contemplated within the scope of the present disclosure.

Referring now toFIG. 17there is shown a frame member616according to another example embodiment of the present disclosure that is adapted to create stackable fluid channel members10with corresponding heat exchanger plates12,14to form a U-flow or two-pass heat exchanger. In this embodiment, frame member616is a unitary structure comprised of a length of frame material having two fee ends641that is bent or formed into the desired configuration. Accordingly, frame member616has first and second ends640(1),640(2) in the form of the second or manifold sealing member634. The first and second ends640(1),640(2) form fluid boundaries or barriers around two adjacent openings (i.e. openings20,22or24,26) formed in the corresponding plates12,14and terminate at end edges or free ends641which form an overlapping or lap joint with the interior edge or surface of a corresponding portion of the first sealing member632. The remaining portion of the frame member616generally follows or corresponds to the periphery of the plates12,14in order to form first sealing member632around the edge of the plates12,14.

A flow separating region656is formed integrally within frame member616in order to accommodate for the U-shaped or two-pass fluid path through the fluid channel members10forming the heat exchanger. Flow separating region656is formed by bending the frame material along the end edge35opposite to the second or manifold sealing members640to form a narrow, elongated fluid barrier that projects into the interior region of the frame member616. The flow separating region656causes the fluid entering the fluid channel member10to flow from the inlet opening (for example opening20) along the length of the fluid passageway18formed by fluid channel member10in a first direction before turning or reversing directions around the end657of the flow separating region656and flowing along the length of the fluid channel member10in a second direction over the second half of the plates12,14to the outlet opening. The second fluid flowing through the heat exchanger is prevented from entering the fluid flow passageway18by the second or manifold sealing members634and instead enters the fluid flow passageway formed by the adjacent fluid channel member10. It will be understood that the frame members616in adjacent fluid channel members are rotated 180 degrees with respect to each other in order to create the alternating fluid flow passageways18(1),18(2) for the flow of two different fluids through the heat exchanger100.

Referring now toFIG. 18there is shown a frame member716according to another example embodiment of the present disclosure that is adapted to create multi-pass fluid channel members10when combined with corresponding heat exchanger plates12,14in a stacked, alternating relationship to form heat exchanger100. In this embodiment, frame member716is comprised of first and second frame portions716(1),716(2) that are each formed by a length of material having two free ends that is bent into the desired configuration. The first and second frame portions716(1),716(2) are generally identical to each other, with the second frame portion716(2) being rotated 180 degrees with respect to the first portion716(1), or vice versa. Each of the first and second fame portions716(1),716(2) has a first end740in the form of second sealing member734while the remainder of the frame portion716(1),716(2) generally follows the periphery of the corresponding heat exchange plates12,14, i.e. along a portion of one of the end edges37of the plate, along one of the longitudinal edges35, and a portion of the other of the end edges35before terminating at a second end742in the form of a free end.

The first end740or second sealing member734of each frame portion716(1),716(2) forms a fluid boundary or barrier around one of the fluid openings (i.e. one of openings20,22or24,26) of a corresponding pair of openings formed in the corresponding plates12,14, the first end740of the frame portions716(1),716(2) terminating at an end edge741in the form of a free end that forms an overlapping or lap joint with the interior edge or surface of a corresponding portion of the first sealing member732.

At least one flow separating region756is formed integrally within each frame portion716(1),716(2) in order to create a multi-pass fluid flow passageway through the fluid channel members10formed by heat exchange plates12,14and frame member716. Flow separating region756is formed by creating a narrow, elongated, tight-radius bend in the material forming frame portions716(1),716(2) along the longitudinal edge of the first sealing member732intermediate the first end740and second end742, although more proximal to the second end742, as shown in the example embodiment ofFIG. 18. The flow separating region756, therefore, extends into the interior region of the fluid channel member10bounded by frame member716in a direction generally perpendicular to the main, overall flow direction through the fluid channel member10, for example from inlet opening22through to diagonally opposed outlet opening24.

When the first and second frame portions716(1),716(2) are brought together into their mating relationship in order to form frame member716, the free end at the second end742of one frame portion716(1),716(2) abuts against a corresponding portion of the first end740or second sealing member734of the other of the frame portions716(1),716(2) thereby forming the first sealing member734around the entire periphery of the corresponding plates12,14. The flow separating regions756from each frame portion716(1),716(2) extend into the area bounded by the first sealing member734from opposite longitudinal sides of the frame member716in spaced apart relation to each other. Accordingly, the flow separating regions756effectively forming baffles within the fluid flow passageway18formed within fluid channel member10causing the fluid to make a series of switch-back or hair-pin turns around the respective ends757of the flow separating regions756through the fluid flow passageway18from the inlet opening (for example inlet opening22) before exiting the fluid channel member10through the corresponding outlet opening (for example outlet opening24). The second fluid flowing through the heat exchanger is prevented from entering the fluid flow passageway18by the second or manifold sealing members734and instead enters the fluid flow passageway18formed by the adjacent fluid channel member10and, in the subject example embodiment, flows in a direction generally opposite to the first fluid flowing through the heat exchanger100. In the subject embodiment, it will be understood that the combined frame members716(i.e. frame portions716(1),716(2) arranged in their mating relationship) in adjacent fluid channel members10are rotated 180 degrees with respect to each other in order to create the alternating fluid flow passageways18(1),18(2) for the flow of two different fluids through the heat exchanger100.

While the embodiment shown inFIG. 18shows frame portions716(1),716(2) each being formed with one flow separating region756it will be understood that each frame portion716(1),716(2) can be formed with as many flow separating regions756as is required in order to achieve the desired flow path through the fluid channel members10. Accordingly, the embodiment shown inFIG. 18is intended to be illustrative and not limited thereto.

Referring now toFIG. 19there is shown a frame member816according to another example embodiment of the present disclosure that is adapted to create stackable fluid channel members10with corresponding heat exchanger plates12,14to form a U-flow or two-pass cross-flow heat exchanger where the corresponding pairs of inlet and outlet manifolds are arranged at 90 degrees with respect to each other as shown in the drawing. In this embodiment, frame member816is a unitary structure comprised of a length of frame material, having two free ends841that is bent or formed into the desired configuration. Accordingly, frame member816has a pair of first ends840(1),840(2) in the form of the second or manifold sealing member834. The pair of first ends840(1),840(2) each forming a fluid boundary or barrier around adjacent openings (i.e. openings20,22or24,26) formed in the corresponding heat exchange plates12,14. Each of the first ends840(1),840(2) terminate at end edges or free ends841and form an overlapping or lap joint with the interior edge or surface of a corresponding portion of the first sealing member832to provide a complete seal around the corresponding fluid opening. The remaining portion of the frame member816generally follows or corresponds to the periphery of the plates12,14in order to form the first sealing member832around the edge of the plates12,14when the frame member816is sandwiched between corresponding heat exchange plates12,14.

In order to create the desired two-pass or U-flow fluid passageway through the fluid channel members10, frame member816also comprises a flow separating region856that is formed integrally within frame member816in order to accommodate for the U-shaped or two-pass fluid path through the fluid channel members10forming the heat exchanger. Flow separating region856is formed by bending the frame material to form a narrow, elongated fluid barrier between two adjacent fluid openings, the fluid barrier projecting into the interior region of the frame member816. The flow separating region856causes the fluid entering the fluid channel member10to flow from the inlet opening (for example opening20) along the length of the fluid passageway18formed by fluid channel member10in a first direction before turning or reversing directions around the end857of the flow separating region856and flowing along the length of the fluid channel member10in a second, opposite direction over the second half of the plates12,14to the outlet opening22. The second fluid flowing through the heat exchanger is prevented from entering the fluid flow passageway18by the second or manifold sealing members834and instead enters the fluid flow passageway formed by the adjacent fluid channel member10.

It will be understood that in order to create a cross-flow pattern through the heat exchanger where the first fluid flowing through the heat exchanger flows in a direction generally perpendicular to the direction of the second fluid flowing through the heat exchanger, the frame members816in adjacent fluid channel members10are inverted or flipped and rotated 90 degrees with respect to each other in order to create the alternating cross-flow fluid flow passageways for the flow of two different fluids through the heat exchanger100. It will also be understood that the heat exchange plates12,14forming the fluid channel members10with frame members816will not be generally rectangular in shape since one of the pairs of manifolds (i.e. fluid openings24,26shown inFIG. 19) are located outboard of the general fluid flow passageway.

Referring now toFIGS. 20 and 21, there is shown another example embodiment of frame members916A,916B used in conjunction with corresponding heat exchange plates12,14for forming a stacked plate heat exchanger100with an outboard fluid port.

In the subject embodiment, the heat exchanger100is comprised of a stack of fluid channel members10comprising a pair of first and second plates12,14that are spaced apart from one another and connected together by one of two different frame members916A,916B so as to form an alternating stack of fluid passageways18(1),18(2) therebetween. As in the previously described embodiments, a turbulizer or other heat transfer augmenting device (not shown) may be positioned within fluid passageways18(1),18(2) in the interior region defined by either of frame members916A,916B between plates12,14depending upon the particular design and application of heat exchanger100.

The plates12,14that would form fluid channel members10with frame members916A,916B are generally flat plates with a modified rectangular shape having an outboard area for accommodating a fluid inlet/outlet opening for the flow of one of the fluid through the heat exchanger. The plates12,14therefore are each provided with four openings20,22,24,26with three of the openings22,24,26being positioned at three respective corners of the plates12,14with the fourth fluid opening20being located in the outboard area of the plate. As in the previously described embodiments, the openings20,22,24,26serve as respective inlet/outlet ports for the inletting and discharging of a fluid into their corresponding fluid passageway18. When a plurality of fluid channel members10are arranged one on top of the other, the openings20,22,24,26align with the corresponding openings20,22,24,26in the adjacent fluid channel member10to form respective pairs of inlet/outlet manifolds (not shown) for two separate fluids to flow through the heat exchanger100as is known in the art with one of the manifolds from one of the pairs of manifolds being located in the outboard area of the heat exchanger.

In order to create the alternating fluid flow passageways18(1),18(2) through the heat exchanger for the two different fluids, two different frame members916A,916B are required. Frame member916A is comprised of mating first and second frame portions916A(1),916A(2) that are different to each other. Each of the first and second fame portions916A(1),916A(2) has a first end940in the form of a portion of the second sealing member934while the remainder of the frame portion916A(1),916A(2) follows the periphery of the corresponding heat exchanger plates12,14along the remainder of a longitudinal edge portion35and at least a portion of each of the end edge portions37of the plates forming a portion of the first sealing member932before each frame portion916A(1),916A(2) terminates at a second, free end942.

Each of the first ends940of frame portions916A(1),916A(2) forms a fluid boundary around a corresponding fluid opening before terminating at an end edge or free end941and forming an overlapping or lap joint with the interior edge or surface of a corresponding portion of the first sealing member932of the same frame portion916A(1),916A(2) to provide a complete seal around the corresponding fluid opening. Each of the second ends942of each of frame portions916A(1),916A(2) abuts a corresponding portion of the first end940of the corresponding frame portion916A(1),916A(2) forming corresponding butt joints when the frame portions916A(1),916A(2) are brought into their mating relationship forming frame member916and completing the first sealing member932. Accordingly, a first series of fluid channel members10A for forming the heat exchanger are formed by arranging frame member916A between a pair of corresponding plates, the first series of fluid channel members10A permitting a first fluid to enter the fluid passageway bounded by frame member916A through one of openings22,26and exit through the other of the openings22,26while the second fluid flowing through the heat exchanger is prevented from entering the fluid passageway bounded by frame member916A by means of the second sealing member934formed around the remaining two fluid openings formed in the plates.

Frame member916B (seeFIG. 21) is also comprised of mating first and second frame portions916B(1),916B(2) that are different to each other and different to frame portions916A(1),916A(2). Frame portions916B(1),916B(2) each have a first end940in the form of a portion of the second sealing member934while the remainder of the frame portion916B(1),916B(2) follows a portion of the periphery of the corresponding heat exchanger plates12,14before terminating at a second, free end942. Each of the first ends940of frame portions916B(1),916B(2) forms a fluid boundary around the opposite pair of corresponding fluid openings (i.e. openings22,26), the first ends940terminating at an end edge or free end941that forms an overlapping or lap joint with an interior edge or surface of a corresponding portion of the first sealing member932of the same frame portion916B(1),916B(2) to provide a complete seal around the corresponding fluid opening (i.e. openings22,26). Each of the second ends942of each of frame portions916B(1),916B(2) abuts a corresponding portion of the first end940of the corresponding frame portion916B(1),916B(2), forming corresponding butt or overlap joints, when the frame portions916A(1),916A(2) are brought into their mating relationship forming frame member916B and completing the first sealing member932. Accordingly, a second series of fluid channel members10B for forming the heat exchanger are formed by arranging frame member916B between a pair of corresponding heat exchange plates, the second series of fluid channel members10B permitting the second heat exchange fluid to enter the fluid passageway bounded by frame member916B through one of openings20,24and exit through the other of the openings20,24while the first fluid flowing through the heat exchanger is prevented from entering the fluid passageway bounded by frame member916B by means of the second sealing member934formed around the remaining two fluid openings (i.e. fluid openings22,26) formed in the plates.

Accordingly, it will be understood that the heat exchanger formed with frame members916A,916B is comprised of an alternating stack of the first series fluid channel members10A and the second series fluid channel members10B, i.e. an alternating stack of heat exchange plate, frame member916A, heat exchange plate, frame member916B, etc.

As in the previously described embodiments, frame members916A,916B are also formed from lengths of material that are bent or formed into the desired configuration, the frame portions for each of frame members916A,916B being brought into a mating relationship to complete the first sealing member934and thereby provide a complete, fluid-tight seal around the periphery of the heat exchange plates when all of the components are brazed, or otherwise joined together.

While heat exchanger100has been described as being formed by an alternating stack of generally flat plates12,14interposed with frame members16, variations to the plates12,14are also contemplated within the scope of the present disclosure.

Referring now toFIG. 11, an alternate embodiment of the plates12,14used to form fluid channel members10is shown. As shown, the plates12,14may be formed with a slight lip or edge13around the perimeter of the plate12,14, the plate12,14thereby adopting a slight dished-plate formation. By forming a slight lip13around the perimeter of the plate12,14, the frame member16can sit within the dished-edge to ensure that the frame member16is appropriately positioned around the perimeter of the plate12,14.

Referring now toFIG. 12there is shown another example embodiment of a plate12,14that can be used to form heat exchanger100. In this embodiment, rather than forming plates12,14as “dished-plates” with a lip or edge13around the entire perimeter of the plates12,14, the plates12,14can instead be formed with locating or fixturing tabs15positioned at specific locations around the perimeter of the plates12,14. Fixturing tabs15provide an interior edge against which the frame members16can abut when stacked on top of the plate12,14. In some embodiments, the fixturing tabs15can also be folded over the upper edge of the frame member16once it is positioned on top of the plate12,14to ensure that the frame member16is securely positioned thereon when forming fluid channel members10. For example with reference to the example embodiment shown inFIG. 7, a plate12,14with as few as two fixturing tabs15corresponding to the frame overlap locations256could be sufficient to hold and lock the overlapping frame member216(1),216(2) to its corresponding faying frame member216(1),216(2) in association with one of the plates12,14to form a “locked” subassembly comprising a plate12,14with frame member216positioned thereon. Such “locked” subassemblies may then be stacked together for joining in a brazing furnace to form heat exchanger100. An example of a heat exchange plate12,14with two fixturing tabs15formed only at the corners of the plate corresponding to the frame overlap locations (i.e. the stepped connection256) is shown inFIG. 12A.

The method of making a heat exchanger100comprising plates12,14and frame members16,116,216,316,416,516,616is to begin with a plurality of flat heat transfer plates12,14that have been stamped or cut to the desired shape and size with appropriate fluid openings20,22,24,26formed therein. Fluid openings20,22,24,26can also be stamped or cut into the plates12,14. The next step is to provide a plurality of frame members16by forming lengths of material such as lengths of wire, rods or bars that are bent into the desired frame shape depending upon the particular application or design of the heat exchanger100. Where lengths of wire material are used, a wire feed machine or CNC formed wire can be used to fabricate repeating patterns of the individual, mating frame portions16(1),16(2) with the wire material being bent into the desired form and in some instances interlocking members are formed in the wire material to provide for a mechanical connection between the individual frame portions16(1),16(2). In other instances, instead of using a wire feed machine, the frame members can be formed by bending the wire material free-form around a mandrel or jig. Whether a wire feed or CNC machine is used to fabricate the frame portions16(1),16(2) may depend of the type of interlocking connection that is incorporated into the frame portions16(1),16(2). For instance, the overlapping or stepped connections356,256are more conducive to be free formed as opposed to the dovetail or jigsaw connections.

In instances where wire material having a square cross-sectional shape is used, the formed wire frame portions may then be subjected to a post-bending flattening operation such as coining or spanking in order to flatten out any deformations in the material that result from the bending of the square-shaped wire material since the square-shaped wire material tends to deform in the vertical direction at the corner areas formed in the frame16. The flattening operation may also serve to ensure locking or securing together of the frame members at their respective joints. When round or oval wire frame material is used to form the frame members16, post-bending flattening operations may not be required since the round or oval wire frame material does not tend to deform as much in the vertical direction when bent to form corners as in the case of the square-shaped wire frame material. However, round or oval shaped wire material, rods or bars may be subjected to post-bending flattening operations, if desired, especially if additional locking or securing together of the frame members is required.

In embodiments where the frame members16are formed by two mating frame portions16(1),16(2), once the plurality of individual frame portions16(1),16(2) are formed, the frame portions16(1),16(2) are positioned together in their mating relationship by interconnection of the dovetail or jigsaw connections, or by means of the overlapping or stepped connections, to form frame members16. Fluid channel members10are then formed by arranging the plates12,14and frame members16in their alternating, stacked relationship with the frame members16in the first set of fluid flow passages18(1) being rotated 180 degress with respect to the frame members16in the second set of fluid flow passages18(2). Preferably, each fluid channel10will contain within the boundaries of the frame members16a suitable heat transfer augmentation device such as a turbulizer or fin (not shown) as is known in the art. Once the stack of fluid channel members10is formed, end plates to seal the outermost fluid channel members10in the stack are added, the entire assembly being joined together by brazing to form heat exchanger100.

It will be appreciated that although the frame members16,116,216,316,416,516may be joined together entirely by mechanical means such as interlocking members as described, additional assembly aids such as tack welding may be used if needed, to secure butt joints, for example. Tack welding may also be used to secure butt joints found in one piece frame members616.

In instances where dished plates or tabbed plates, such as those shown inFIGS. 11 and 12are used, various subassemblies comprising one plate12,14and one frame member16,116,216,316,416,516(i.e. as shown inFIG. 11) are formed, the various subassemblies then being stacked one on top of the other and joined together by brazing to form heat exchanger100, with appropriate end plates (not shown) and fluid inlet/outlet connections as is know in the art.

While various exemplary embodiments of the heat exchanger with a jointed wire frame have been described and shown in the drawings, it will be understood that certain adaptations and modifications of the described exemplary embodiments can be made as construed within the scope of the present disclosure. Therefore, the above discussed embodiments are considered to be illustrative and not restrictive.