Patent ID: 12235057

DETAILED DESCRIPTION OF THE INVENTION

The invention herein includes deflector and grid support assemblies which may be used in shell and tube heat exchangers and heat exchanges having such assemblies therein, which can be used to provide variations in alternating flow patterns through the deflector and grid support assemblies to allow the heat exchanger design to be modified or tailored to provide a desired level of axial flow while improving tube contact, reducing tube vibration and minimizing sudden or extreme pressure drops from turbulent flow or too much transverse cross-current flow within the shell of the heat exchanger. The assemblies herein are improvements over various prior art structure attempts to achieve a balance in thermal properties, pressure consistency and tube stability and may be varied to provide modifications for different exchanger designs and flow patterns. The integration of grids and deflector plates as an assembly facilitates the separation of the tube support function of the grid plates from the heat transfer augmentation function of the deflector plates. The deflector plates in using sequential assemblies according to the disclosure herein do not require an overlap to develop a support structure to carry the installed tube weight and resist flow induced forces. The invention by using assemblies as described herein provides for a large number of variations and combinations of deflector shapes and sizes that can be integrated within the core grid structure as guided by use of Computational Fluid Dynamics (CFD) to optimize heat transfer against pressure loss.

As used herein, words such as “interior” and “exterior,” “inner” and outer,” “upwardly” and “downwardly,” “inwardly” and “outwardly,” “radially” and “circumferentially,” “upstream” and “downstream,” “higher” and “lower,” “top” and “bottom,” “left” and “right,” “horizontally” and “vertically” and “distal” and “proximal” and words of similar import refer to directions in the drawings in accordance to their ordinary meaning and are for assisting in clarifying the features of the invention unless otherwise specified. As used herein “fluid communication” means that a fluid, whether a liquid, a gas or vapor, flows from one component to another component, either directly, or indirectly through one or more intervening components, wherein the intervening components may be, for example, conduits, pipes, valves, gates, doors, dividers, or an open space such as a manifold, a plenum, an opening defined in a component such as a tube sheet, a grid or other tube support and the like.

Reference herein to a “heat exchanger” is intended to mean an apparatus used for transferring heat between two or more fluids either for either a cooling or heating process. Reference herein to “shell and tube heat exchangers” or “tubular heat exchanger” are intended to refer to a classes of heat exchangers commonly use in thermal heating and cooling of, e.g., liquids and gasses, boiling of liquids and condensing of vapors. Shell and tube heat exchangers typically include a vessel, such as a larger pressure-vessel, known as a “shell” or housing through which fluid flows from an inlet to an outlet. Within the shell are one or more tubes, which may be individual tubes or one or more tube bundles flowing typically lengthwise (longitudinally) through the shell. The shells may be oriented vertically or horizontally with respect to a support surface on which a shell is mounted. In referring to flow through the shell, with respect to the ground or other shell support surface, flow may be horizontal or vertical and still extend longitudinally through the shell.

In the present application, reference to flow extending longitudinally through the shell means flow passing through the shell in a direction that is lengthwise or over the longest dimension of the shell from one end to another. As shown in the drawings, flow extends in a direction generally parallel to a horizontally extending configuration for convenience only and such orientation should not be interpreted to be limiting. Flow in the shell herein may be single pass flow (meaning going once across the shell lengthwise) or double or multiple pass flow (meaning the flow may traverse the shell more than once lengthwise before exiting the shell). While the drawings show a single pass flow for easily explaining the benefits of the invention, one skilled in the art, based on the disclosure, will readily comprehend the applicability of the deflector and grid support assemblies herein for a wide variety of single pass, multiple pass and stacked configuration flow arrangements as well as in a variety of shell configurations including the single or multiple use of end support standard tube sheets in addition to the assemblies herein.

The deflector and grid support assemblies herein may be further used alone or in combination with other known grid supports, rod supports or prior art designs either as an improvement to such designs, intermingled with such designs or as a replacement of prior art designs. The deflector and grid support assemblies may also be used in one heat exchanger shell, in a group of heat exchanger shells in series, or in all heat exchangers in series.

Flow within the shell extending in a direction contrary to longitudinal flow will be referred to herein as non-axial flow, transverse flow, or cross-current flow. Transverse flow may be flow moving in a direction that is across or generally orthogonal to the general direction of lengthwise flow. However, non-axial flow or cross-current flow may also be flow having elements of axial and non-axial flow that is not fully axial flow. It is understood further herein that reference to “axial” flow is a reference to lengthwise flow along, or generally parallel to, the longitudinal axis of the shell of the heat exchanger. It will be understood to those of skill in the art based on this disclosure that fluid flow, by its nature, if not ideally laminar, may have variations in flow and that reference to flow that is generally axial is meant to convey that the general direction of flow extends lengthwise and in the axial direction of the shell, and that substantially axial flow is meant to convey that the flow is primarily in the lengthwise, axial direction of the shell. Such axial flow may also occur flow within and around and over longitudinally extending tubes, with preferably a controllable or lower level of turbulence or cross-current flow.

It should also be understood, based on this disclosure, by one skilled in the art that the invention as described herein is not limited to use in cylindrical shells or to exchangers with primarily axial flow streams, and instead may be employed in varying outer shells or vessels, such as rectangular vessels or in containment structures of other shapes and with varying internal tube arrangements. For example, in addition to straight tube, the deflector and grid support assemblies can be used to support U-tubes, hairpin tubes and J-tubes that are installed in single shells, twin parallel shell connected with an integral manifold or two perpendicular shells connected by a mitered weld or elbows of selected radius, respectively. Examples of such configurations may be found in the prior art. See, e.g., K. P. Singh et al,Mechanical Design of Heat Exchangers and Pressure Vessel Components, Springer-Verlag Berlin Heidelberg (1984), pp. 6, 10 with respect to U-tubes and hairpin tubes (available to review: https://books.google.com/books?id=lt95BgAAQBAJ&printsec=frontcover#v=onepage&q&f=f alse; and see also, http://www.josephoat.com/products/shell-and-tube-heat-exchangers/#jp-carousel-10532 with respect to J-tubes.

“Fluid” herein is intended to refer to liquids, gasses, including air, water vapor, mixtures of liquids and gasses, steam, superheated steam, coolants, heating agents and a wide variety of related materials that are used for heating or cooling using shell and tube heat exchangers through thermal exchange therein.

The deflector and grid support assemblies herein may be used alone or with baffles or other structures known for use in heat exchangers, but preferably only if such other prior art structures contribute to enhancing the heat exchange properties or otherwise improving overall function.

Use of the term “shell-side” flow refers to flow within a shell originating in a shell-side inlet for introducing a fluid to the interior of the shell that will leave through a “shell side outlet”. The shell side flow, as noted above, may be single pass or multiple pass flow within the shell, and while such inlets typically introduce shell side fluid on an end of the shell opposite the introduction of tube-side flow, this is not necessarily the case and would not be required in practicing the invention herein.

Use of the term “tube-side” flow is flow within a heat exchanger that is introduced into the tubes from a tube-side inlet into the shell in fluid communication with an inlet to one or more generally longitudinally extending tubes, and that exits the heat exchanger through a tube-side outlet in the shell in communication with one or more outlets of the generally longitudinally extending tubes. In many heat exchanger designs, such fluid communication is provided to the individual tube inlets or outlets through an open structural area (a plenum) defined between one end of the shell, a tube sheet (support sheet) welded or connected in some manner to at least one end of the longitudinally extending tubes and, in some instances, may include a further divider, e.g., extending in a longitudinal plane between the tube sheet and the shell to separate tube inlet and tube outlet flow. Such structures, inlet and outlet designs and flow division is well known in the art, and can be modified in a variety of ways. A simple design is used for illustrating the function and design of the deflector and grid support assemblies herein, but such design as presented should not be considered to be limiting.

Heat exchangers may be of a variety of designs and end uses and benefit from the deflector and grid support assemblies herein. For example, industrial shell and tube heat exchangers are known and employed for use in electrical and steam generating power plants, nuclear power plants for heating, condensing (such as for condensing exhaust steam from a steam turbine), cooling and the like.

Tubes herein may be formed of a variety of materials but for most industrial applications, use of materials with good heat transfer are preferred. Generally metals and metal alloys are used, such as brass, a variety of stainless steel alloys, copper alloys, titanium, nickel alloys, austenitic nickel-chromium-based superalloys (Inconel®), nickel molybdenum (Hastalloy®), and the like depending on the end application, structural and thermal requirements. Selection of tubing material is application and environmentally driven and driven by industry specifications and requirements as well as cost and thermal properties (such as mechanical strength, corrosion resistance and the coefficient of thermal expansion).

Various equipment typically used with shell and tube heat exchangers in various end applications may be employed herein without departing from the spirit and scope of the invention which is the use and integration of deflector and grid support assemblies as described further herein. As such equipment and shell and tube heat exchangers are well known in the art, the details of their operational and installation specifics, and structural optional or extraneous fixtures are omitted herein for brevity except, when necessary, to explain operation of the deflector and grid support assemblies of the present invention.

The invention will now be illustrated with respect to various preferred embodiments of the deflector and grid support assemblies and with reference toFIGS.1-11.

With respect to embodiments inFIGS.1-FIG.8,FIG.8shows an interior tube assembly in partial view for use within a heat exchanger. The deflector and tube assembly will be illustrated with respect to two variations having different placement of deflectors each of which can be used individually in different heat exchanger and tube arrangements or can be used together in the same heat exchanger and internal tube bundle. To illustrate a preferred embodiment of the assembly, two assemblies will be illustrated within a single heat exchanger having such assemblies installed therein, in heat exchanger embodiment100shown in a representative manner inFIG.8, wherein the heat exchanger is generally referred to as heat exchanger102having tube bundle104as best seen in partial view with the deflector and grid support assemblies exposed inFIG.1. For clarity, the tube bundle is not shown in detail inFIG.8to illustrate the deflector and grid support assemblies as well as a flow pattern without the view of the tubes obstructing such items. As seen inFIG.1, tubes extend longitudinally along and/or parallel to a central, longitudinal axis L-L′ through the tube bundle104and shell108. On either end of the tube bundle104is an end plate (tube sheet)106. The tubes104extend over much of the length of the heat exchanger102and are located within the shell108of the heat exchanger102(seeFIGS.1and8).

The shells and tubes, as noted above may be of a typical type found in standard industry shell and tube heat exchangers, but can be varied and still find benefit when used in combination with the deflector and grid support assemblies herein. Such assemblies are shown herein generally as deflector and grid support assembly110. Two variations of such assemblies110are shown and are referred to herein as first and second deflector and grid support assemblies110a,110b, wherein110ais illustrated in further detail inFIGS.2-4and110bis illustrated in further detail inFIGS.5-7. Use of alternating assemblies starting on an upstream shell-side flow with110ainFIG.8or with110binFIG.1are illustrated in a representative manner herein. It should be understood that the order, type and number of such assemblies110may be varied for different flow directional effects, levels of tube support, heat exchange efficiency or tube support, depending on the shell and tube heat exchanger design into which they are introduced. Further, other designs having open flow through grid structures and obstructed shell flow in view of deflectors in terms of the shape and positioning of deflectors or the other shape of the assemblies may also be used within the scope of the invention.

Grid supports are known in the art and are typically formed of a rigid support material, preferably one that will not interfere and/or may help in thermal transfer efficiency. Grids in the art are typically formed of metals or metal alloys, much like the tubes, but for strength are primarily formed of enhanced strength alloys, such as stainless steel in sheet form to make interconnected strips. Other metals as noted above for the tubes may also be used. For the assemblies herein, interconnecting strips formed of the same or similar materials used for forming interconnected strips are joined or otherwise connected, for example, by welding, slots, fasteners and any other means of interconnecting metal sheets or sheet in strip form.

Such strips as used in the present invention are preferably of a desired support strip thickness t as measured across the narrowest dimension of the strips taken along a first surface111a,111bof assemblies110a,110b, respectively at an edge of a strip as shown, for example inFIG.2. The thickness may be varied for different deflector and grid support assemblies in accordance with the level of structural support desired, ranging for example, in preferred embodiments from about 0.028 in. to about 0.083 in., although this can be varied in different end applications.

The interconnections areas where the strips may be interlocking or otherwise connected are spaced by a designed pitch p of the support tubes measured from the center of one passageway118within the grid to the center of the next, adjacent passageway. The passageways pass through the grid strips119in the grid support structures112herein. The grid support structures112used in the assemblies110herein may be formed using the same design principles for the grid portion's structural make-up. It will be understood by one skilled in the art, based on this disclosure, that the design of the grid support structures in terms of size, pitch and materials as well as shape and design may be altered for different arrangements based on the overall installation and operational conditions.

In addition to standard materials such as the metals and alloys noted above, and depending on the desired end use, high-temperature and wear-resistant aromatic polymers and/or composites may be used for forming the grid support structures, enabling heat molding formation in certain grid support structures. For example, polyarylenes such as PEEK, polyethersulfones, polyethersulfides, polyimides, polytetrafluoroethylene or composites thereof may be used in certain thermal and design environments.

The grid support structures112for the assembly design shown inFIGS.1-8herein in the first grid support structure112a, and second grid support structure112bare provided so as to preferably extend across substantially all of the shell108, as shown in the cross-sectional views ofFIG.8, as provided inFIG.3showing assembly110a, and as shown inFIG.6showing assembly110b. The grid support structures112preferably extend transversely across the shell. As shown, the shell108surrounds the assembly110which sits within the interior space116of the shell defined by the interior surface114of the shell108. Each grid structure112has interconnected strips119defining passageways118. The passageways118extend through the grid support structure in open grid areas from a first grid support surface to a second grid support surface as described below in a manner that is configured to support the longitudinally extending tubes104of the shell and tube heat exchanger102passing substantially perpendicularly (preferably fully perpendicularly) to the grid support surfaces from the first grid support surface to the second grid support surface without substantially obstructing shell-side flow in the heat exchanger in the open areas of the grid. The passageways as shown are of a diamond configuration, however, other configurations such as triangles, parallelograms, including squares and rectangles, ellipses and circles may be used in different grid support structure designs for different fluid flow and thermal transfer impact without departing from the spirt and scope of the invention. Further cross-support strips may also be incorporated as desired and varying grid support designs may be used including those designed and provided, e.g., as various AXI-Grid™ designs of Lindain Engineering, Marlton, NJ which have been employed in use in a variety of heat exchanger end applications.

In embodiments herein the grid support structures112a,112b, each have a respective first surface111a,111band a respective opposite second surface113a,113bwhich opposite second surface is spaced from the first surface longitudinally when viewing the grid support structures in installation view within the heat exchanger, i.e., measured in the general axial flow direction through the shell such that fluid may pass through the open grid passageways118from the first surface111to the second surface113in areas where the grid is open and not obstructed by a deflector plate as described below. The longitudinal spacing between the first surface111and the second surface113of each grid support structure provides the thickness in the area of the grid support structure in which it is measured.

The grid support structures may be of one common thickness throughout the grid support structure from the first surface to the second surface and the first surface configured to receive one or more deflector plate(s) in a first area for obstructing flow while allowing tubes to pass therethrough.

In a preferred embodiment shown inFIGS.1-8, the grid support structures are configured to not only receive deflector plates, but also to seat them in designated areas. As shown, the grid support structures shown have an area(s) where the thickness of the grid support structure is varied. As shown, each grid support has one or more first area(s) A1having a reduced thickness t1and a second area(s) A2having a larger thickness t2otherwise known as the full grid thickness herein. The reduced thickness areas A1provide an area to receive and also seat one or more deflector plates120, wherein each deflector plate has a first deflector plate surface121and an opposite second deflector plate surface123. In respective assemblies herein inFIGS.1-8, these plates are shown as first deflector plate(s)120awith first and second surface(s)121a,123a, and a second deflector plate(s)120b, with first and second surface121b,123b. The deflector plates120a,120bare each seated in a low thickness area A1of thickness t1. The thickness t1, t2of each grid support structure in each area A1, A2is measured from the first surface121to the second surface123in the longitudinal direction of the grid in its installation configuration as shown inFIGS.2-7. If a change in thickness is employed to create a seat for the deflector plate, instead of just installing the plate on a grid of common thickness throughout the support structure, the thickness may vary from 0.028 in. to 0.083 in. in thickness and to offset the overall thickness, if desired, by the thickness of the deflector plate used, which could typically be expected to vary from about 0.03 in. to about 0.25 in.

The first surface of the deflector plate(s)121and the first surfaces of the grid support structure(s)112herein are preferably aligned to be facing in the same direction longitudinally along the tube bundle within the shell108of the heat exchanger102. Further, the second surface123of a deflector plate preferably contacts the first surface111of a grid support structure112in an area A1, which in the embodiment shown is also an area of reduced thickness in preferably direct engagement. If the thickness were constant, area A1would designate the area in which the grid support structure112receives the deflector plate(s)121.

Such deflector plates120are preferably formed of materials similar to the those used to form the grid structure, but need not be. They should have sufficient strength and properties to resist corrosion and provide structural support, and sufficient thickness in the area in which they are received, or in the embodiment shown, seated and received, of the support grid structure to provide adequate life and wear.

The first surfaces111,121of the grid support structures and deflector plates are also preferably aligned to face oncoming upstream shell-side flow from the shell inlet, to thereby readily align substantially axial flow through the open grid passageways118around the tubes104passing through them, and to obstruct flow using the deflector plates in other areas of the assembly, which helps to support the tubes while contributing to cross-current flow for enhanced thermal transfer efficiency.

The deflector plates may have varied thicknesses which are dictated by the ability, if desired, to act as further support in the manner of a tube sheet when the tubes pass through receiving holes in the deflector plates120. Each deflector plate defines a plurality of tube receiving openings122that extend through the deflector plate from the first deflector plate surface121to the second deflector plate surface123, with the openings122preferably aligned with openings through the attached grid support structure so that the tubes may pass through the deflector plate and further through the support grid structure for additional support.

The openings122may be designed to allow for thermal expansion of the tubes based on appropriate expansion tolerances, may be much wider and still allow for axial flow around the tube and substantial deflection by the deflector plate, or may be welded or otherwise made to block area around the tube even accounting for expansion using flanges and the like for complete flow obstruction around the tubes extending through the openings. Thus, the openings122may be used to modify flow patterns, flow obstruction or tube support depending on the desired resistance to vibration, thermal exchange demands and desired flow, if any, around the tubes as they extend through the deflector plate.

The deflector plates may be configured in a variety of shapes. InFIGS.1-8they are shown as having either a centrally extending region (as inFIGS.5-7) with arcuate end features as the reach the edge of what is shown as a circular-designed grid support structure, or they may form arcuate end plate(s) conforming to the grid support structure shape (as inFIGS.2-4). It should be understood however, that deflector plates may be provided as strips, circles, “donuts” or other configurations depending on desired flow patterns within the shell. A further example of an alternative deflector plate design is described further below.

The peripheral exterior124around the deflector and grid support assemblies110is preferably configured to substantially conform to the interior surface114of the shell and extend across a transverse cross-section of the interior space116defined by the shell's interior surface114for impacting flow patterns while allowing substantially axial flow through the open grid areas A2in the assemblies, while substantially obstructing flow in the areas of the deflector plates. Such assemblies are preferably mounted to the shell in a structurally stable manner as through fasteners, flanges, welding, riveting and the like. In one embodiment the peripheral exterior124may include a containment structure126, for example, an outer rim or similar device support, for securing the deflector and grid support structure assembly within the rim, which may then be used for mounting to the assembly to the shell108.

The deflector plates may be received, or received and seated, within the grid support structures and the deflector plates may be connected to grid support structures using any attachment method known to those in the art, including by welding, bolting, and other mechanical devices or means, such as through brackets or fasteners, such as bolts, rivets and the like. However, it is also possible to use other attachment means, including adhesives, molded structures and the like depending on the thermal conditions in the shell and tube heat exchanger into which they will be employed. The invention may also include, for some materials, the molding the grid support structure and deflector plate constructions as assemblies or fabricating them as a unit by other manufacturing techniques.

As shown, alternating embodiments of assemblies110aand110bmay be used wherein the deflector plates in each assembly are not axially aligned to create a flow pattern as shown by arrow F inFIG.8, wherein flow passes through open grid areas A2in the grid support structures of the assemblies and is deflected and substantially or completely obstructed in the areas A1of the assemblies where the deflector plates are positioned. The assemblies are thus situated to direct shell side fluid flow to pass substantially axially through the second, open grid, areas A2of the grid support structures112a,112bin the assemblies110a,110band to substantially obstruct, or completely obstruct, flow through the first areas A1of the grid support structures112a,112bthat receive, or seat and receive, the deflector plate(s)120a,120b. The flow while moving generally axially from an upstream shell-side flow through the shell108(meaning it is moving generally along the longitudinal axis or parallel to it in an overall flow path), is allowed to vary in and out of the open grid areas to provide some degree of directional curving in and around the deflectors to allow controlled cross-current flow and provide better circulation of the shell side flow around the tubes and increase residence time of the fluid to enhance thermal exchange within the shell for improved heat exchange efficiency. The variations and placement of the assemblies maintains generally axial flow and helps to alleviate sudden pressure drops or variations that can be problematic. The deflector and grid support assemblies' function to provide strength and reduced vibration using the combination of the support of the deflectors, the grid support structures and the end tube sheets to better prolong the life and operation of the tubes and avoid issues with structural damage.

Also provided herein is a method of heating or cooling a fluid in a shell and tube heat exchanger using the assemblies herein. The assemblies may be designed for varying end uses and thermal property by modifying the grid support structure in thickness or material, as well as interconnecting designs and patterns as well as by modifying the shapes, thickness or elevational features (if any) and locations on the grid structure of the deflector plates. The same assembly may be used throughout but installed, for example, in a rotated manner to provide variations of deflection at different degrees with respect to the axial alignment of the deflector plates in the assemblies. Alternating designs such as110a,110balternating with just two or a plurality of such plates in an alternating arrangement along the length of the tube bundle with deflector plates not axially aligned can provide a different flow configuration.

Circular deflector plates dispersed around the periphery may also be used to achieve similar, varied, flow path effect. In a further embodiment generally referred to as200, is shown with respect to various deflector and grid assemblies210a,210band210cinFIGS.9-11, respectively, wherein analogous numbers refer to analogous components in each of the embodiments herein.

Each of the assemblies210may be used alone to enhance flow and efficiency in a heat exchanger, or two, three or more of them may be used in a repeating manner, a random pattern or in an alternating embodiment similar to that described above with respect toFIG.1andFIG.8and embodiment110. Further, different assemblies may be used together or in tandem with other embodiments described elsewhere herein and/or with or instead of prior art grid structures or baffle designs.

InFIG.9, a first deflector and grid support structure assembly210ais shown as leaving an open grid support structure212awith an open area A2in a central region. The deflector plate220ahas an exterior edge229aand an interior edge227aof a first ring-shaped deflector plate220athat defines an opening230a. The open grid area A2in the central region when the deflector plate220ais received on the grid support structure212is thus defined within the opening of the deflector plate. The deflector plate220ais positioned so as to obstruct flow in a first area A1, which is defined along an outer periphery232aof the grid support structure212a. As shown, the deflector plate220ais received by and positioned on the first surface211aof the grid support structure212abut is not seated in a recessed area with a different longitudinal thickness as in the embodiment100. As noted above, using a different thickness and seating the deflector is preferred but not necessary within the invention. Embodiment200shown inFIGS.9-11does not show a “seated” deflector, but could be readily modified in the manner of embodiment100to provide such seated area by using varying thickness in the grid support structure212of embodiment200.

FIG.10shows a second deflector and grid support structure assembly210b, in which a deflector220bis received on a first surface211bof a grid support structure212b. The deflector plate220bis also a ring-shaped deflector similar to that of220a, and has an exterior edge229band an interior edge227bthat defines an opening230b, but the ring is not sized to extend to the outer periphery232bof the grid support structure212b. Instead, the ring-shaped deflector plate220bis sized to leave an outer open grid area212balong the outer periphery232bof the assembly210band to further leave a central region of open grid support structure212bpositioned within the opening230bdefined by the interior edge227bof the deflector plate220b. In this assembly, there are two open grid support structure areas A2and one obstructed grid support structure area A1which lies beneath the ring-shaped deflector plate120binFIG.10.

In a third deflector and grid support structure210cshown inFIG.11, a grid support structure212chas a more enlarged outer peripheral area A2of open grid support structure than that of the assembly210b, however, there is no open grid region in the center of the assembly. Instead, a round plate deflector plate220cis positioned in a central area A1of the assembly where obstructed grid support structure flow is located. The central, round deflector plate220cis positioned so as to allow peripheral flow around the deflector, but obstruct central grid flow.

In each of assemblies210a,210band210c, the deflector plates include tube receiving openings222a,222band222c, respectively to allow tubes to pass therethrough after passing through the grid support structure, however, the deflector plates210a,210band210ceach substantially or completely obstructs flow in areas A1of the grid support structure212a,212b,212cwhere the first surface211a,211b,211cof the grid support structure is in respective contact with the second surface223a,223band223cof the respective deflector plates220a,220band220c. The areas A2of the grid support structure not in contact with the deflector plates allow for substantially axial flow through the grid support structure.

In viewing each of the assemblies, it is apparent that the deflectors may be sized and spaced to create coordinated, alternating flow patterns wherein210a,210band210cassemblies may be alternating to allow a narrow central flow, a further narrowed central flow with an additional peripheral flow and a blocked central flow and enlarged peripheral flow as shell side flow passes through each alternating assembly. Further, the arrangement of the assemblies could be varied and the size of the deflectors changed to modify the effects to encourage a desired heat exchange efficiency by cross-current flow and turbulence created by the deflector plate configurations to enhance heat exchange and residence time in the shell while allowing otherwise for substantially axial flow through the shell.

It will be understood by one skilled in the art, based on this disclosure that a variety of configurations may be designed for varying thermal and flow patterns within the scope and spirt of the invention herein. Further, tube bundle density can be modified, i.e., the pitch to tube diameter ratio may be varied as much as desired or necessary to reduce velocity and pressure drop. The pitch to tube ratio could be expected to vary from about 1.25 to 2.0 in a given design. The number and extent of deflector plates may also be varied to create multiple shell streams to establish the number of tubes that are crossed by each fluid stream as determined using computational fluid dynamics (CFD) programs and other flow modeling methods to further optimize the thermal and hydraulic performance of the above-referenced modular deflector and grid support assemblies for use in varying heat exchanger designs using the principles and beneficial design aspects as noted above.

It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.