BACKGROUND OF THE INVENTION

Previous heat exchangers in attempting to overcome the major problems associated in heat transfer utilized various means to improve thermal exchange efficiency, much as those listed below:

MEANS TECHNIQUE

Surface Contact Increase surface area

Surface structure (e.g., corrugations)

Surface Impact Flow patterns Turbulence

Surface Temperature Counterflow

Progressively staged heat transfer

Surface Contact Duration Cavity expansion

Flow restriction Multiple pass

Transfer Effectiveness Material selection

Cleaning Continuous transfer elements

Typically, each additional step used for improvement adds to the exchanger's cost due to manufacturing complexity and materials so tradeoffs had to be made between efficiency and economics.

Heretofore, prior inventors have tried maximizing the thermal transfer ability of an exchanger, by varying the means mentioned to meet specific applications. Whereas, in applications requiring low flow resistance to the moving medium, e.g., air, the efficiencies of prior heat exchangers were low, due to their construction. Some devices utilize heat conductive plates or fins projecting into a first medium which are attached to a partition separating the other, second medium. These devices have a large surface area contact with the first medium, yet not in both mediums. Other devices, attempting to overcome flow resistance, have the separating partition molded of one material, with fins on both sides thereof. These devices are expensive to manufacture and heavy in weight. Further devices improved efficiency by passing fins through the partition, thereby partially extending the fins into both mediums. This reduced contact resistance, since the fins were continuous. Most of the devices mentioned' tend to align and affix the fins parallel to the flow of the medium. This

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causes the least medium turbulence, while maintaining a large surface contact in the medium. However, to increase the efficiency of this type of exchanger, more fins must be added, thereby increasing flow resistance and expense of manufacture. Therefore, a primary object of this invention is to provide a configuration of fins extending both internally and externally through a partition which forms an inner chamber, whereby a low flow resist¬ ance of the medium contained in this chamber is achieved. Another object of this invention is to provide fins with large exposed surface areas, constructed of high thermally conductive materials placed so as to sequentially and directly impact the flowing medium while maintaining a low flow resistance. Yet another object of the invention is to provide a cumulative thermal storage and transfer capacity associated with the mass of the thermally conductive fins. Yet an- other object of the present invention is to provide a configuration of high thermally conductive fins projecting into a flowing medium whereby higher thermal exchange is achieved by maximizing the turbu¬ lence of this medium. Still another object of this invention is to provide a staged, progressive heat exhange so as to maximize the te - perature gradient between the two exchanging mediums. Still a further object of this invention is to provide a simple cleaning means for the fins, so as to maintain thermal transfer effectiveness. A further object of this invention is to expand the cavity.in which the medium is flowing. Still another object of this invention is to provide a construction which utilizes a minimum of costly high thermally conduc¬ tive materials only where the heat exchange is desired to be maximized. Still a further object of this invention is to provide a construction which is easily expandable by placing extra sections of the invention in series for additional thermal accumulation and exchange. Still a further object of this invention is to provide a convenient means for ease of installation for an intended usage. Another object of this invention is to provide a heat exchanger of novel construction which is simple and inexpensive to manufacture or reproduce. A further object of the present invention is to provide such a heat exchanger which is light in weight and suitable for use in a variety of appli¬ cations.

SUMMARY OF THE INVENTION

The present invention resides in a heat exchanger being of a simple and easily reproducable construction, with an associated low cost to manufacture, wherein a partition, which forms an enclosur and separates two mediuma, has an array of highly heat conductive fin which project and traverse through the full width of and generally to the center of the enclosure, thereby being perpendicular .to the flow of the inner medium and partially extending into both mediums whereby the fins become a thermal link between the two mediums. Another characteristic of this invention, is the use of dissimilar thermally conductive materials. The aforementioned enclosure is constructed of a lower thermally conductive material as compared to the fins which are made of a very high thermally conductive mater¬ ial. The use of dissimilar materials further directs the thermal exchange between the two mediums and conserves the usage of expensive highly conductive materials. In another embodiment of the present invention, an outer enclosure encases the aforementioned enclosure whereby the outer medium can be circulated past the fins extending from the inner enclosure which are in a direct thermal relationship between the two mediums.

This novel invention utilizing many techniques for increasing heat exchange has the following combined advantages:

1. A very low flow resistance to the moving medium.

2. The usage of dissimilar thermally conductive materials to direct the transfer of heat to desired regions so as to reduce the exchanger's external heat loss, as in units constructed of a single material, and to reduce the unit cost by using costly materials with high thermal conductivity only where heat exchange is desired to be maximized. 3. Cavity enlargement for the inner moving medium so that it may move freely while interacting with the fins to have an increased sur¬ face contact duration with the highly conductive fins for extended thermal exchange. 4. The extension of each fin being in one solid piece, into two separated mediums by projecting it through the partition separating the two mediums, thereby eliminating most losses associated with

contact resistance, as in exchangers with fins fastened or attached to the partition.

5. Each fin has large surface area exposure to the two mediums thereby causing a head-on impact and increased turbulence to augment heat exchange. 6. Each fin is mounted perpendicular to the flow of the moving medium thereby causing a head-on impact and increased turbulence to augment heat exchange.

7. The arrangement of multiple fins, placed in a laterally staggered fashion relative to one another causes the internal medium to flow in a serpentine pattern sequentially impacting each successive fin with¬ out diminishing the mass of the flow. The superiority of this arrange¬ ment particularly when combined with dissimilar thermally conductive materials is momentary compression and entrapment of the medium upon impacting each fin and a progressively staged heat exchange. In practice, the fins nearest the source medium inlet assume a high temperature, whereas progressively towards the outlet they are reduced in temperature. An increased thermal exchange results when a higher temperature gradient exists between the fin and the receiving medium, whereby this advantage is gained by the usage of the laterally staggered fin arrangement or countercurrent flow techniques. Another advantage with this arrangement is a vertically induced draft caused by the heated fins within the inner enclosure.

8. The length of the heat exchanger can be easily varied, which also alters the number of fins or thermal transfer stages. There- fore, depending on the amount of heat exchange desired, the length of the unit may be readily chosen and is easily accomplished just by adding further sections.

9. The fins extending into the outer medium can accomodate various mediums and flow directions of those mediums, e.g., crossflow, countercurrent, etc..

10. By increasing the mass of the fins, this exchanger begins to accumulate heat in the fins thereby providing a means for thermal storage and subsequent dispersal.

11. The entire heat exchanger is easily reproducable, low in cost, compact in size, light in weight, and has versatility in application. The embodiments of this invention later described have particular utility in applications wherein problems have previously plagued

industry. Present day flue waste heat recovery exchangers suffer from low performance and high cost which has brought them into low regard with the public in general. This is mainly due to their tube type construction which does not provide sufficient impact surface area and turbulence to the excaping heated gaseε. To overcome these problems, the employment of generally known techniques would be restricted by regulations demanding very low resistance to the flow of the exhaust gases. However, these problems have been overcome with the present invention and experiments have shown the present . invention, with its low cost, far surpasses the performance of even the most highly acclaimed and expensive units on the market today. Another particular application in which prior exchangers have low performance is in the field of earth tubes. These devices, mainly comprised of tile tubes, saturate the closely surrounding earth with heat due to their lack.of effective thermal exchange to the surrounding medium. With the present invention, the deploy¬ ment of highly heat conductive fins, with large exposed surface areas extending far into the surrounding medium, widely disperse the heat far away from the tube. Whereby, the exchange of much larger quantities of heat can be achieved, thereby cooling guildings inexpen¬ sively. A particular reduction in power consumption is obtained when this invention's earth tube is utilized in conduction with heat pumps. A further application in which the state of the art is commonly inefficient concerns combustion type domestic and commercial water heaters, in which a large portion of the thermal energy produced by burning of fuel is exhausted out the vent stack. The present invention is applied internally to the water heater, wherein the heated gases in the vent stack communicate with protruding thermally conductive fins located therein, and capture this normally wasted heat, channeling it directly into the water contained in the tank, thereby reducing fuel consumption of the unit. Another application of this invention is to passive solar walls, e.g., tro be walls. These walls have been enjoying an increased popularity due to rising energy costs. However, without a means for effectively conducting the solar energy into the wall, a long time is required for full thermal saturation of the wall, therefore, decreasing their effectiveness. With the present invention embedded internally into such mass walls, with high thermally conductive materials projecting

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through to the outer conductively plated face of the wall, solar abεorbtion is enhanced, as well as thermal transfer ability, due to the placement of the invention, which provides a conduit means internal to the wall, with ports for room air intake and heated air exhaust for heat dispersal.

In solar applications, such as flat plate collectors, there is a disadvantage in that the conductive plate is only attached to the outside of a conduit or tube. The tube and collector plate are constructed of a similar highly thermally conductive material, and welded or pressed togther so as to conduct the thermal solar energy to the liquid contained in the conduit. The present invention as applied to a solar flat plate collector has a multiple advantage, in that the high thermally conductive plate passes completely through the conduit or tube, separating this tube into halves, which are attached to the plate by flanges located on the edges of each tube half. This simple construction is easily mass-produced, and yields high thermal transfer efficiency, and further, reduces unit cost by not needing the highly thermally conductive materials to be used throughout. The thermal dissipator of the present invention, using the advantages of fins and dissimilar conductive materials, comprises: a first member or housing having a low thermal conductivity, into which high thermally conductive fins are embedded or pressed, in which these fins directly cool the first member by utilization of thermally conductive fins extending externally and substantially beyond the first member into an outer medium or ambient atmosphere. An application of this invention to an oil pan or container of a vehicle engine or transmission, or an electrical transformer housing, or hydraulic fluid reservior, yields an effective cooler for the oil contained therein. Previous units, in this application, have predominantly been constructed of the same material throughout, with either external fins attached, or internal tubes attached to the container, so as to provide an increased surface radiator for thermal dissapation. This works to an extent, although failure of members still occurs due to heat buildup. With the application of fins of a highthermal conductivity projecting through the container wall, communicating with the hot oil, and providing for an increased' internal Surface area thermal dissapation occurs at an intensified rate, due

to the natural thermal flow of heat present through the fins into the cooler, preferably moving ambient atmosphere. -As is also the case with bearings and housings containing bearings, the heat buildup associated with usage and loading often hastens bearing fatigue and failure. The present, invention embedded into such a housing, which contains a bearing or being a brake drum for instance, serves as an effective thermal radiator, which projects substantially into the ambient atmosphere. The highly heat conductive fins are embedded into the (housing so as to communicate with and touch the hottest area of the member desired to be cooled, and project through this lesser thermally conductive barrier or housing into the cooler ambient atmosphere, for effective heat dissapation.

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BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects, advantages, and applications of the invention will become apparent from the following detailed description of several preferred embodiments as illustrated in the accompanying drawings, forming a part hereof, and in which:

Figure 1, is an isometric view of the present invention as applied to flue waste heat recovery units.

Figure 2, is an isometric view of an alternative configuration of a flue waste heat recovery unit. Figure 3, is a cutaway top view along lines A-A of the unit depicted in figure 4.

Figure 4, is a frontal cutaway view of the flue waste heat recovery unit shown in figure 1. Figure 5, is a cutaway view of the flue waste heat recovery unit depicting a typical airflow pattern of the outer medium within the unit shown in figure 1.

Figure 6, is a cutaway view of the flue waste heat recovery unit depicting a typical airflow through the inner chamber of the invention, as in figure 1, describing a serpentine airflow pattern. Figure 7, illustrates a building or structure utilizing a submerged or buried application of this, invention less the outer casing as applied for cooling premises.

Figure 8, illustrates a water heater or steam boiler unit, cutaway view, utilizing the conductive fins with said fins dispersing heat directly into the liquid medium.

Figure 9, is an isometric cutaway view of an alternate flue waste heat recovery embodiment.

Figure 10. is a cutaway view of an embodiment of the invention as adapted to an engine exhaust waste heat recovery unit and muffler combination.

Figure 11. is an isometric view depicting an application in the heat exchanger mode, employing highly heat conductive fins or plate of generally thicker material than that of the barrier or vail through which the fins protrude, as would be applied to a transmission pan, Figure 12. illustrates a cutaway isometric view of a plate-type waste heat recovery embodiment of the invention. *

Figure 13, is an isometric cutaway view of a heat dissipating roller bearing, utilizing embedded fins.

Figure 14, is an elevational view of a vehicle brak drum utilizing attached heat dissipative fins.

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DETAILED DESCRIPTION

The construction of the invention as applied to flue waste heat recovery is in general best illustrated in the provided views in FIGS. 1-6 showing the relationship between the various parts. The term "fluepipe" is herein generally employed for clarity to include such apparatus and conducting means as chimney, smokestack, ducts, and the like. The term "furnace" herein is utilized for clarity and would include all combustion heating devices, e.g., furnaces, stoves, boilers, etc., utilizing discharge or exhaust flues. The term "room air" is herein generally employed for clarity to mean atmospheric mediums, whether liquid or gas, to be used for heating or cooling purposes.

In general, the waste heat recovery unit assembly shown in FIG. 1, is indicated by the letter "A", as being essentially a replacement for an existing section of fluepipe, and is composed of an enlarged inner enclosure (1) and outer enclosure (2) which are shown as being rectangular in form in this particular embodiment, though round, square, oval, or other symmetrical or asymmetrical construction may be employed. The inner enclosure (1) is connected to the outer enclosure (2) by means of a pair of end plates (5), thereby forming and sealing outer chamber (14). End caps (7) are generally comprised of covers with starting collars attached so as to fit directly onto existing fluepipes. ' The end caps (7) fasten to the inner enclosure (1) forming inner chamber (13). Heat conductive fins (3) are inserted, by pressure, into the inner enclosure (1) through slots which are slightly narrower than the thickness of fins (3), thereby sealing the joints. The fins (3) traverse and project sustantially into the outer chamber (14) and generally into the middle of the inner chamber (13). Approxi¬ mately half of the number of fins (3) are interposed with and evenly spaced from the other half of the number of fins (3) mounted on the opposite side of the inner enclosure (13). Thereby, the fins (3) form a 'laterally staggered array, as shown in FIG. 6. This configur¬ ation maximizes turbulence with minimal resistance to the flow of heated flue gases rising in the inner chamber (13) and causes the gases to stay essentially in one mass and sequentially head-on impact each fin (3) whereby the gases are momentary compressed, entrapped, and the deflected to the subsequent fin as the gases travel in a

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serpentine pattern through the inner chamber (13), thereby trans¬ ferring the heat from the gases through the fins (3) into the outer chamber (14).

It is important to note that in the embodiments which follow, the prior principles of operation, description, and the configuration of fins (3) attached to the inner enclosure (1) remain the same.

In FIG 5, room air is forced by a fan (6) through inlet (16) into an outer chamber (14), then circulated upwardly, communicating with the fins (3) which traverse the outer chamber (14), proceeding then over the airflow dividers (8), down the opposing side of the outer chamber (14), completing the U shaped airflow pattern, and there¬ upon exiting through the outlet (15) and register (10). A ductwork may be attached to outlet (15) alternatively, so as to disperse the heated air throughout the premises. The main body of unit "A" should preferrable be constructed of materials that are of a lesser thermal conductivity, e.g., tin, iron, steel, etc., as compared to the highly thermally conductive materials that comprise the fins (3), e.g., copper, aluminum, and alloys. These fins (3) may have improved surfaces, e.g., coated, corrugated, clad, or constructed in many physical configurations, e.g., mesh attachment, tapered, etc.

Shown in figures 3 and 4 is an attached fin cleaning apparatus, for overcoming surface fouling, and maintaining thermal transfer efficiency. Singularly comprised of a rod (4), which passes through lineally aligned precision fitted guide holes (17), positioned in both inner and outer enclosures (1 & 2) so that when the rods (4) are manually pulled outward, the attached scraper blade (9) presses against and cleans the full width and length of the fin's (3) upper portion. By manual operation of said scraper combination (9 & 4), sequentially starting at the top scraper, then on to the next lower one, the debris accrued and removed is finally deposited into the firebox of the attached stove. Scraper combination (9 & 4) when in a closed position, rests against and parallel to inner enclosure's (1) interior wall, during normal use of the waste heat recovery device "A". However, if both the upper and the lower surfaces of the fin (3) were desired to be cleaned, only a slight modification would be required.

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Furthermore, for convenient operation when the waste heat recovery unit "A" is installed, a bi-metallic thermostat (11) is provided which activates the fan (6) when a certain ambient outer chamber (14) temperature is present. This feature, combined with a fan speed control and line switch (12), provides convenient operation of the waste heat recovery unit.

Figure 7 describes a further application of this heat exchanger, wherein the inner enclosure (1) is shown embedded into a subterranian medium (20), e.g., earth, mud, or water. The room air present in building (18) is drawn by a fan (6) through the inner enclosure (1), and transfers the heat of the room air into the cooler subterranian medium by means of the array of thermally conductive fins (3) attached to the inner enclosure (1), and protruding therefrom. The inner enclosure (1) should preferrably be constructed of corrosion- resistant material, e.g., plastic, stainless steel, tile. The fins

(3) should preferrably be constructed of corrosion-resistant and highly thermally conductive materials, e.g., copper, aluminum, brass, alloys. The fin (3) extension length into the subterranian medium (20) is determined by this medium's thermal conductance and saturation capacity.

Figure 8 describes a further application of the present invention embodied as a water heater. Heat conductive fins (3) extend into the water (22) contained in the tank (21), and project through the walls of and into the interior of the inner enclosure (1). The heated products of combustion rise from, the combustion chamber (20), and sequentially impact upon each successive thermally conductive fin (3), thereby transferring the heat present in said gases through the fins (3) directly into the water (22) which surrounds the inner enclosure (1). The thermostat (11) regulates the temperature of the water (22) within the tank (21).

In another embodiment of the invention as a waste heat recovery unit shown in Figure 9, this unit makes advantage of counter-current flow of the two adjacent mediums for increased heat exchange. This unit may be attached to a furnace or stove by essentially replacing a section of the existing fluepipe with this unit. The medium e.g., room air, to be heated is forced by a fan (6) through an inlet at the top of the unit, and passes substantially the full length of the outer

chamber (14), and subsequentially emerges from the mesh covered outlet port (15) in a directed flow determined by the manual positioning of deflector (30).

Figure 10 depicts the usage of this invention as a vehicle heater and muffler combination, being similar in construction and operation as the device in Figure 1. The vehicle engine exhaust gases pass through the existing exhaust manifold (24) and continue through the inner enclosure (1), where the gases sequentially impact the heat conductive fins (3), thereby transferring the heat present in the gases to the fins (3), which conduct the heat to the outer chamber (14). The thermally conductive fins (3) are sealed, e.g., welded or glued to the inner enclosure (1) so as to prevent cross- contamination, therby providing for safe and convenient operation. The fan (6) forced air, either from passenger compartment or outside, enters at the inlet port (16) and is heated as it passes by the array of fins (3), located within the outer chamber (14). This heated air is then ducted through the exit port (15) to the cabin or passenger compartment. The vehicle engine exhaust gases, after being utilized, emanate from the tailpipe connector (25) and out the existing tailpipe. Shown in Figure 11 is an embodiment of the present invention as an oil cooler consisting of a pan or casing (23) constructed of dissimilar thermally conductive materials. The materials of construc¬ tion of this unit are similar to those described for unit "A" of Figure 1. The array of high thermally conductive fins (3) project through the wall of the pan (23) into an outer atmosphere. The hot oil contained in the pan (23) lies in direct contact with the array of thermally conductive fins (3), and is cooled through the use of the fins (3) by transferring the heat present in the oil to the outer, preferrably moving atmosphere or ambient air. The intersection of the pan (23) and the fins (3) are sealed by conventional techniques. Shown in figure 12 is an embodiment of the present invention as a waste heat recovery unit, which forms essentially a replacement section of an existing fluepipe, or the like, and utilizes a highly heat conductive fin (26) to which has attached upon opposite sides, two flanged tube halves forming an inner enclosure (1). Attached to each end of the inner enclosure (1) and fin (26) assembly, which is shown as running the entire length of the outer enclosure (2), are means for the attachment, to existing pipes, ducts, and the like. A

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fan (6) forces room air into a plenum integral with the top of this unit, where the air accumulates and is evenly distributed down into the outer chamber (14), wherein the room air picks up heat present in the fin (26), and inner enclosure (1), prior to discharge into the lower plenum and out the-register (10). Preferrably, the materials utilized in construction are similar to those described for Figure 1.

Figure 13 illustrates new applications utilizing dissimilar thermally conductive metals, as applied to bearings, motor housings, clutch housings, and the like, shown herein as being applied to a roller bearing (27), which has been installed into a housing (28). The housing (28) is constructed of a thermally lower conductive material as compared to the embedded, highly thermally conductive fins (26), which contact the bearing's outer race and project radially outward from the housing (28). The thermal energy generated within the bearing (27) is quickly conducted and dissipated through the fins (26) to the ambient atmosphere or medium.

In Figure 14, radially projecting high thermally conductive fins (26), e.g., copper, aluminum, brass, alloys, are embedded into a lower thermally conductive brake drum (29), e.g., cast iron, steel, whereby the heat produced by frictional braking forces within the brak drum (29) is conducted and dissipated to the outer atmosphere through the embedded fins (26).

While the preceding descficiptions contain many specifics, these should not be construed as limitations on the scope of the invention, but rather as an exemplification of preferred embodiments thereof. With rising fuel prices, conservation measures are enlarging the applications for heat exchangers. The particular applications listed below, and the embodiments shown in the drawings are examples of the versatility of this invention.

AIR-AIR HEAT EXCHANGERS:

Recyclic Dryers (fibers, clothes, grains, papers, etc.)

Cooling Towers

Flue Waste Heat Recovery

Fireplace Inserts Vehicle passenger compartment air heater

Integrated devices, e.g., Combustion chambers with exchangέrs: wood and coal stoves, fireplaces, furnaces, boilers, etc.

AIR-LIQUID HEAT EXCHANGERS:

Heaters (Preheaters, Boilers, Distillation Processes, Refining

Processes, etc.) Solar thermal storage transfer (focused concentrators, water reservoirs and tanks, etc.)

Flue Waste Heat Recovery as applies to Water Heaters

Coolers for Machinery (Transformer oil, Hydraulic oil. Transmissi and Motor oil, etc.) Conventional hot water space heating systems, with individual room controlled heat exchangers

Vessel engine compartment cooling

AIR-SOLID HEAT EXCHANGERS:

Passive and active Solar thermal storage (Tro be walls, water tanks, eutectic phase change materials, etc.)

Molding and Casting operations Earth Heat utilization (Geothermal Heating, Cooling tubes for buildings, etc.) Heating floors, sidewalks, driveways, swimming pool walls, etc.

HEAT DISSIPATION AND COOLING:

Housings; (Ball, pin and roller bearings; bushings; transmissions; transformers; electric motors, engines, hydraulic and pneumatic pumps, compressors, and reservoirs; etc) High intensity Lamps Guns and Cannons

Electrical Resistors Heat sinks (soldering welding, etc.)

Accordingly, the scope of the invention should be determined not by the embodiments illustrated, but by the appended claims, and their legal equivalents.