Reference to Copending Applications

This application claims the benefit of U.S. Provisional Patent Application

Serial No. 61/661,156 filed June 18, 2012, which is incorporated herein by reference in its entirety.

Technical Field

The present disclosure relates generally to a heat exchanger.

Background

Conventional heat exchangers are configured to transfer heat from a treatment fluid flowing on one side of a barrier to a working fluid flowing on another side of the barrier. For example, stacked plate heat exchangers include a shell for housing a plurality of corrugated heat transfer plates. The plates are arranged face-to-face in a stack along a longitudinal direction. Collectively, the adjacent plates in the stack define transversely extending passages for the treatment fluid that are interleaved with transversely extending passages for the working fluid.

Summary

In at least some implementations, a heat exchanger includes a core and a shell. The core may have a periphery and a plurality of plates with a plurality of passages interleaved therebetween, a portion of the passages extending and open to the periphery of the core. The shell includes a plurality of panels releasably connected together to define a pressure vessel in which the core is received in assembly, and the shell is adapted to be at least partially disassembled to provided access to the core and enable cleaning of the passages and the plates, or to enable repair or replacement of the core. The shell also is adapted to be reassembled into a pressure vessel with the core inside for further use of the heat exchanger.

In at least some implementations, a heat exchanger may include a core and a shell. The core may have a periphery and a plurality of plates with a plurality of passages interleaved therebetween, where some of the passages define at least part of a working fluid circuit and different passages define at least part of a treatment fluid circuit. The shell may include a plurality of panels releasably connected to another component to define a pressure vessel in which the core is received in assembly. The shell is adapted to be at least partially disassembled to provided access to the core and the shell being adapted to be reassembled into a pressure vessel with the core inside for further use of the heat exchanger.

Brief Description of the Drawings

The following detailed description of preferred embodiments and best mode will be set forth with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of one implementation of a heat exchanger;

FIG. 2 is a partially exploded view of the heat exchanger of FIG. 1;

FIG. 3 is a front view of a plurality of a plate pack that defines part of a core of the heat exchanger;

FIG. 4 is a bottom view of a plate;

FIG. 5 is an enlarged, fragmentary view of a portion of a couple of plates of the plate pack; FIG. 6 is a view of a portion of a plate pack including a seal before it is attached to the plates in assembly of the heat exchanger;

FIG. 7 is a side view of a plate pack including a seal welded to the plate pack; FIG. 8 diagrammatic and fragmentary view of a portion of a plate pack to illustrate fluid flow paths within the plate pack;

FIG. 9 is an top view of an end panel liner of the heat exchanger;

FIG. 10 is a perspective view of a circumferential liner for an end panel;

FIG. 11 is a perspective view of a post of the core;

FIG. 12 is a cross-sectional view of the post of FIG. 11 taken generally along line 12-12;

FIG. 13 is a perspective view of a post of the core including attachment posts; FIG. 14 is a front view of a liner for the plate pack;

FIG. 15 is an end view of a liner;

FIG. 16 is a top perspective view of a liner for a post of the core; and

FIG. 17 is an end view of the liner of FIG. 16.

Detailed Description of Preferred Embodiments

Referring in more detail to the drawings, FIG. 1 illustrates one implementation of a heat exchanger 10 for transferring heat between different fluids, referred to herein as a working fluid and a treatment fluid. The treatment fluid is fed to the heat exchanger at a different temperature than the working fluid, and heat transfer between the fluids and the heat exchanger components either raises or lowers the temperature of the working fluid to a desired level. In general, as shown in FIGS. 1 and 2, the heat exchanger 10 may include a shell 12 defining an interior volume 14, and a core 16 disposed within the interior volume 14. The shell 12 may have one or more sections or panels that are connected together and/or to the core 16 to define the interior volume. The core 16 may include a pack 19 of interconnected plates 20 defining separate fluid circuits 22, 24 (see e.g. FIG. 8) through which the treatment and working fluids flow, respectively, to exchange heat through the plates 20 and between the fluids. In the implementation shown, the core 16 has a longitudinal axis 26, a periphery 28 and at least a portion of the fluid circuits 22, 24 may extend and be open to the periphery 28 of the core.

As best shown in FIG. 1, the shell 12 may include a plurality of side panels, with four side panels 30, 31, 32, 33 shown. In the example of a cylindrical heat exchanger, as shown, the side panels 30-33 may comprise arcuate plates that define partial cylinders, each spanning approximately 90 degrees circumferentially so that the four side panels define a substantially complete 360 degree sidewall of the heat exchanger. The side panels 30-33 could be formed from sections of a pipe, rolled metal sheets or flat metal panels, by way of non-limiting examples. The shell 12 may also include end panels 34, 35 that span and close the gaps between the open ends defined by the side panels 30-33. The end panels 34, 35 may be generally circular plates adapted to be coupled to the side panels 30-33 to define at least part of the outer shell (note that in FIG. 2 the lower end panel 35 is shown attached to the core 16). Each panel 30-35 may include a plurality of holes 36 through which fasteners 38 may be received to releasably couple the side panels 30-33 to the core 16 and to the end panels 34, 35, as will be described in more detail herein.

Each of the side panels 30-33 of the shell 12 may carry or be communicated with inlet and outlet fittings adapted to convey treatment and working fluids into and out of the heat exchanger 10, and any suitable quantity and arrangement of fittings may be used. For example, the first side panel 30 in one form may carry a first fitting 39 acting as an inlet or outlet for the working fluid and a second fitting 40 acting as a drain for the working fluid circuit. The second side panel 31 includes a third fitting 42 acting as an inlet or outlet for the treatment fluid and a fourth fitting 44 through which gasses may be vented from the treatment fluid circuit. An appropriate check valve may be included in the fitting 44 or elsewhere in the vent path to allow only one way flow out of the heat exchanger through this fitting, and, if desired, that check valve may only open above a threshold pressure. The third side panel 32 includes a fifth fitting 46 acting as a working fluid outlet or inlet and a sixth fitting 48 acting as a working fluid circuit vent. The fourth side panel 33 includes a seventh fitting 50 acting as a treatment fluid outlet or inlet and an eighth fitting 52 acting as a treatment fluid circuit drain. In the orientation shown, the treatment fluid flows from either top- to- bottom or bottom-to-top and the working fluid flows from either bottom-to-top or top-to-bottom through the heat exchanger providing a cross flow of fluids to improve heat exchange.

The core 16 can be any suitable heat exchanger core but, as shown, is preferably a stacked plate type of heat exchanger core. Referring to FIGS. 2-8, the core 16 may have a plurality of corrugated plates 20 stacked along the longitudinal axis 26. Each plate 20 may be formed without any sharp corners or the like, if desired, and are shown as being circular. Rectangular (or triangular or other polygon shapes) plates with rounded corners may also be used. In particular, in one implementation the plates 20 are arranged in a pack or stack of cassettes 54 defining a cylinder of connected plates, as best shown in FIGS. 2 and 3. As best shown in FIG. 8, each cassette 54 may have an upper plate 56 and a lower plate 58 welded to the upper plate 56 along the plate peripheries. Further, each upper and lower plate 56, 58 may be corrugated, somewhat flexible and resilient. Each plate 56, 58 of a cassette 54 may be the same shape and have a peripheral edge with a transition region 62, as best shown in FIG. 5, connecting a lower edge portion 64 with a higher edge portion 66. When one plate of a cassette 54 is inverted relative to the other plate, the lower edge portions 64 lie flat against each other and the higher edge portions 66 diverge away from each other defining a passage 68 between the plates of a cassette. Each passage 68 is open to the periphery of the plate pack 19 at two diametrically opposed locations. Adjacent cassettes 54 may be welded together and, as best shown in FIG. 8, the cassettes 54 are alternated with the transition region 62 of each cassette 54 being disposed in the same area to provide alternating or interleaved fluid passages. The fluid passages 68 on one side of the transition area 62 define part of the working fluid circuit 22 and the fluid passages 68 on the other side of the transition region 62 define part of the treatment fluid circuit. Each fluid passage 68 may be open to the periphery of the plate pack at two diametrically opposed locations, each edge of such an opening defining a transition area 62 so that there are four transition areas 62 in this embodiment of the heat exchanger 10.

As shown in FIGS. 4 and 5, the plates 20 may include two or more location features which are shown as bumps 70 and corresponding recesses 72. When the bumps 70 are formed, such as by a punch or other forming tool or process, recesses 72 are formed on the opposite sides of the plates as the bumps. The bumps 70 from one plate 20 may be fitted into a recess 72 of another plate 20 to facilitate accurate alignment of the plates prior to and during the welding of the plates 20 and cassettes 54.

Referring to FIG. 2, in addition to the plate pack 19, the core 16 may include one or more flow diverters 73 arranged to prevent fluid from flowing only along the periphery of the plate pack 19 and between the plates 20 and shell 12. The flow diverters 73 may extend radially outwardly from the plates 20 and have an outer edge 75 adapted to engage (or nearly engage) an inside surface of an adjacent side panel 30-33 of the shell 12. The flow diverters 73 may be provided at any and various axial heights along the plate pack 19. In use, fluid flowing axially along the plate pack 19 will encounter the flow diverters 73 and be directed radially inwardly into the fluid passages 68 defined by the plates 20.

As best shown in FIGS. 6, 7, 14 and 15, the core 16 may also include transition liners 74 that may be disposed between the shell 12 and the plate pack and may extend axially along the periphery of the plate pack. The transition liners 74 may extend along the axial length of the plate pack 19 and be generally C-shaped in cross- section. In the implementation shown, four liners 74 are provided, each spaced from adjacent liners by about 90 degrees around the periphery of the plate pack 19. Each liner 74 is sealed to the plate pack 19 at a transition area 62 of the plates. The free ends 76 of the "C" of each liner 74 may extend away from the plate pack 19 and be of a length and orientation to engage a side panel of the shell 12 in assembly. The closed side 78 of the "C" may be received against the plate pack 19 and may be curved to be generally complementary to the round peripheral edge of the plates 20. A plurality of slots 80 formed in the liners 74 may be provided to enable an outer edge of the adjacent plates 20 to extend into the slots 80. Then, the liners 74 may be welded to the edges of the plates 20 to provide a seal between them and prevent cross flow of the working and treatment fluids at the transition areas 62 of the plate pack 19. While a particular liner 74 construction and arrangement is shown, the heat exchanger 10 may have any suitable liner, seal or obstruction or omit the same according to design requirements. FIGS. 11-13 illustrate a post 82 that may be received within the C-shaped liners 74 of the core 16, with one post 82 provided for each liner 74, as shown in FIG. 2. Each post 82 has a back surface 84 received against the liner 74 in assembly, side surfaces 86 received against the free ends 76 of the liner 74, a front surface 88 exposed in the open portion of the "C" of the liners 74 and upper and lower surfaces 90. A plurality of threaded blind bores 92 may be provided open to the front surface 88 of each post 82, in two axially extending but circumferentially spaced apart rows. Each bore 92 in one row aligns with the holes 36 formed through one side panel 30-33 of the shell 12 and each bore 92 in the other row of bores aligns with the holes 36 formed through a different side panel of the shell. In this way, two side panels of the shell are attached to each post 82 and each side panel 30-33 is attached to two posts 82 by a plurality of fasteners 38 as shown in FIGS. 1 and 2.

Blind bores 94 may also be provided in the upper and lower surfaces 90 of each post 82, with each of these bores 94 adapted to receive an attachment rod 96 that extends axially from the post 82 as shown in FIGS 1, 2 and 13. In assembly, each attachment rod 96 extends through an adjacent end panel 34, 35 of the shell 12, and each attachment rod 96 may be threaded to receive a nut 98 that clamps the end panels 34, 35 to the posts 82. In this way, the side panels 30-33 and end panels 34, 35 are connected to the posts 82. Similarly, blind bores 100 (FIG. 2) may be provided about the side surfaces of the end panels 34, 35, as shown in FIGS. 1 and 2. These bores 100 align with holes 36 formed through the side panels 34, 35 to facilitate connecting the side panels 30-33 to the end panels 34, 35 with suitable fasteners 38. In this way, a pressure tight vessel of interconnected components can be obtained.

The end panels 34, 35, side panels 30-33 and posts 82 may be formed of carbon steel which may provide suitable strength for the shell 12 at a reasonable cost. However, the carbon steel may corrode when exposed to the fluids routed through the heat exchanger 10. To prevent such corrosion, the carbon steel components may be enclosed or covered with suitable liners, gaskets or seals. These components could also be coated with an anti-corrosion substance, if desired. In the implementation shown, the liners 74 may be formed of a material resistant to corrosion from contact with the working and treatment fluids, such as, for example, stainless steel. As best shown in FIGS. 7, 9 and 10, end panel liners 102 may also be provided to prevent or reduce corrosion of the end panels 34, 35. FIGS. 7 and 9 illustrate a generally planar liner 102 adapted to overlie and be sealed to (such as by welding) an inner surface of each end panel (FIG. 7 shows only one plate liner 102 but a similar liner may be provided at the opposite end of the plate pack 19). These liners 102 may have cutouts 104 along their periphery into which the transition liners 74 and posts 82 extend. A circular and ring-shaped sidewall liner 105 (FIG. 10) may also be provided for the outer side surface of each end panel 34, 35. These liners 105 are received between the end panels 34, 35 and side panels 30-33 in assembly. Like the transition liners 74, these liners 102, 105 may be formed from stainless steel or some other material resistant to corrosion with the fluids in use of the heat exchanger 10. Of course, the heat exchanger components also could be formed from other materials including, by way of non-limiting examples, nickel alloys like stainless steel, with or without any liners.

Further, FIGS. 16 and 17 show a post liner 106 which, like the transition liner 74, may be generally C-shaped. One post liner 106 is provided for each post 82 and the post liners 106 may be oriented in opposing direction to the transition liners 74 to define boxes or enclosures in which the posts 82 are received. The post liners 106 have holes 108 aligned with the bores 92 formed in the front surface 88 of each post 82. Of course, suitable seals and/or gaskets may be provided between the liners 74, 106 and posts 82, and/or the liners 102, 105 and panels 30-35 of the shell 12, as desired.

Accordingly, the shell 12 consists of a plurality of side panels 30-33, posts 82 and end panels 34, 35 that are bolted together to form a pressure vessel. Within the pressure vessel, a core 16 of welded together plates 20 and appropriate fluid separators liners, seals, etc., are arranged to provide alternating and interleaved fluid flow circuits 22, 24 for the working and treatment fluids that maintain the fluids separate from each other but permit heat transfer between the fluids through the heat exchanger components. In the arrangement shown, with other arrangements being possible, the working fluid occupies opposite quadrants of the heat exchanger (that is, fluid enters an inlet fitting on one side panel and exits an outlet fitting in the opposite side panel), as does the treatment fluid, which, in addition to the top-to-bottom flow through the heat exchanger noted previously, contributes to the cross-flow of fluids to improve heat exchange. Of course, the fluids may enter and exit any desired panel, including the same panel (e.g. a fluid could enter and exit from the same panel) depending on the arrangement of the flow paths, any flow diverters and the like provided in the heat exchanger.

Further, the components of the shell 12 may be releasably connected together. In the illustrated implementation, the shell components are held together by threaded fasteners 38, the removal of which provides access to the core 16 generally as shown in FIG. 2, so that the plate pack/core may be cleaned, repaired or replaced as desired. The passages in the fluid circuits of both the treatment and working fluids may be cleaned mechanically (e.g. scraping, scrubbing, etc), chemically (e.g. use of various cleaners, solvents, etc), by flushing or spraying with fluid under pressure or in any other suitable manner. Thereafter, the shell 12 may be reassembled for further use of the heat exchanger 10, such as by reuse of the fasteners 38 or otherwise. Of course, the panels may be connected together by other releasable mechanism(s), such as one or more clamps, hinges or the like, in addition to or instead of the fasteners 38.

While the forms of the invention herein disclosed constitute presently preferred embodiments, many others are possible. It is not intended herein to mention all the possible equivalent forms or ramifications of the invention. It is understood that the terms used herein are merely descriptive, rather than limiting, and that various changes may be made without departing from the spirit or scope of the invention.