US20130292089A1

US20130292089A1 - Dual passage concentric tube heat exchanger for cooling/heating of fluid in a low pressure system

Info

Publication number: US20130292089A1
Application number: US13/849,128
Authority: US
Inventors: Robert A. Norcross, Jr.
Original assignee: NORCROSS CORP
Current assignee: SAINT CLAIR SYSTEMS Inc
Priority date: 2012-05-01
Filing date: 2013-03-22
Publication date: 2013-11-07
Also published as: WO2013165877A1

Abstract

Disclosed is a heat exchanger that includes a first, second, and third tube. The first tube may have a first cooling/heating medium inlet at a first end and a first cooling/heating medium outlet at a second end and the second tube is disposed about and concentric with the first tube. The second tube may have a fluid inlet on the same first end as the first tube and a fluid outlet on the same second end as the first tube. The third tube is disposed about and concentric with the second tube, and may have a second cooling/heating medium inlet on the same first end as the first tube and a second cooling/heating medium outlet on the same second end as the first tube. A clamping mechanism may be utilized to secure the tubes in their respective positions and allow the tubes to receive fluid and cooling/heating medium respectively.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/640,747, filed May 1, 2012. The entire contents of each application are hereby incorporated by reference herein.

FIELD OF THE INVENTION

The present invention is directed to a dual passage concentric tube heat exchanger for cooling/heating a fluid, such as ink, in a lower pressure system. Such invention is applicable, for example, to industrial processes such as printing.

BACKGROUND

Viscosity control is essential in many of today's manufacturing and printing processes. Viscosity is the measure of the resistance of a fluid to deformation by either shear stress or extensional stress, but is commonly perceived as the “thickness” or resistance to flow of a fluid. Viscosity can be an important quality of a finished product (e.g., a lubricant, paint, or ink) or can affect a finished product (e.g., printed material). Perhaps more importantly, an inappropriate viscosity can adversely affect modern industrial equipment. For example, if the viscosity of printing ink falls outside of an acceptable viscosity range on the high side of the range, not only is print quality affected, but the printing press can also become fouled. In addition, excess fluid, especially in the case of ink, is applied is the viscosity is not correct, thus wasting natural resources required to make the ink.
Along the lines of viscosity, temperature also plays an important role in the quality of the finished products of these printed materials. In warmer climates or in climates at higher elevations, such as for example, Mexico City (which can experience large differences in temperature between the nighttime and daytime temperatures, temperature conditioning of the ink plays a very important role in ensuring the proper viscosity and print quality. For example, a hot fluid typically has a lower viscosity than that same fluid at a cooler temperature. Thus, in the printing systems temperature of the ink effects the actual physical viscosity and thus affects material transfer and lay down, which may cause a printing process failure.
One solution to the problem above would be to implement a heat exchanger or a cooler into the system to compensate for the temperature increase. However, currently there are no heat exchangers that are cost effective enough to install in these systems to maintain the temperature of the ink at a an acceptable temperature, especially in areas of the world that are typically faced with this “hot ink” issue (e.g., India, Columbia, Brazil, Malaysia, etc). Furthermore, conventional heat exchangers are typical designed for high pressure systems and thus they require a more complex assembly structure which is often machined as one single piece or welded together. Thus, it is difficult for the consumer to maintain these types of exchangers without cutting apart the apparatus. Therefore, the conventional heat exchangers are not cost effective in small scale devices.
Furthermore, the disassembly process can be cumbersome, time consuming and often costly due to the amount of skill and time required to execute the dismantling. Additionally, most heat exchangers not scalable into a size that could be seamlessly installed into most of these types of low pressure systems, especially those that are installed inline in the fluid flow path. Thus, these low pressure systems require a heat exchanger that is small, lightweight, cost effective and that can be easily dismantled for maintenance and repair.

SUMMARY OF THE INVENTION

The present invention relates to a dual passage concentric tube heat exchanger (hereinafter “heat exchanger”) for cooling/heating fluid in a low pressure system that is low cost and that can be easily assembled and disassembled for cleaning purposes. More specifically, the heat exchanger of the present invention may include a first tube, a second tube, a third tube and a clamping mechanism to clamp the first tube, second tube and third tube together therebetween. The first tube may have a first cooling/heating medium inlet at a first end and a first cooling/heating medium outlet at a second end and the second tube may be disposed about and concentric with the first tube. The second tube may have a fluid inlet on the same first end as the first tube and a fluid outlet on the same second end as the first tube. The fluid inlet is not connected to the cooling/heating medium inlets or outlets and is thus a separate flow. The third tube may be disposed about and concentric with the second tube, and may have at least one second cooling/heating medium inlet on the same first end as the first tube and at least one second cooling/heating medium outlet on the same second end as the first tube. The at least one second cooling/heating medium inlets and outlets of the third tube may or may not be connected with the first cooling/heating medium inlets and outlets of the first tube. That is, one channel may be formed for providing a first medium (e.g., a cooling medium) and a second channel may be formed to provide a second medium to the heat exchanger assembly. To secure the first tube, second tube and third tube about each other concentrically, a clamping mechanism may be utilized to secure the tubes in their respective proper locations and allow them receive fluid and cooling/heating medium respectively as well.
More specifically, the clamping mechanism may include a first receiving piece, a second receiving piece and a plurality of removable connecting pieces. The first receiving piece may be formed to receive on one side thereof the first end of the first tube, second tube and third tube respectively and the second receiving piece may be formed to receive the on one side thereof the second end of the first tube, the second tube and the third tube, respectively. The plurality of connecting pieces may be configured to connect the first receiving piece to the second receiving piece and provide pressure to the first receiving piece and the second receiving piece respectively to clamp the first tube, the second tube and third tube together concentrically therebetween via a securing mechanism.
In some exemplary embodiments, the first receiving piece and the second receiving piece may include first, second and third circular recessed portions each having a sealing mechanism disposed therein. Accordingly, each of the first circular recessed portions may be configured to receive the first and second ends of the first tube respectively, the second circular recessed portions may be configured to receive the first and second ends of the second tube respectively, and the third circular recessed portions may be configured to receive the first and second ends of the third tube respectively.
The sealing mechanisms in each of the receiving portions may be removable (such as O-rings) or formed integrated therein. Furthermore, the first circular recessed portions preferably have about the same circumference as the first tube, the second circular recessed portions have about the same circumference as the second tube, and the third circular recessed portions have about the same circumference as the third tube so that the first tube, second tube and third tube fit respectively therein.
In some exemplary embodiments of the present invention, at least one least one medium inlet aperture may be formed between the second recessed portion and the third recessed portion of the first receiving piece, and at least one medium inlet aperture may be formed in the center of the first receiving piece within a perimeter of the first circular recessed portion of the first receiving piece. Additionally, at least one least one medium outlet aperture may be formed between the second recessed portion and the third recessed portion of the second receiving piece, and at least one medium outlet aperture may be formed in the center of the second receiving piece within a perimeter of the first circular recessed portion of the second receiving piece.
Furthermore, at least one least one fluid inlet may be concentrically formed between the second recessed portion and the first recessed portion of the first receiving piece, and at least one fluid outlet may be formed concentrically between the second recessed portion and the first recessed portion of the second receiving piece. In some instances, two fluid inlets may be concentrically formed in a semicircular shape between the second recessed portion and the first recessed portion of the first receiving piece, and two fluid outlets are formed concentrically in the semicircular shape between the second recessed portion and the first recessed portion of the second receiving piece.
In some exemplary embodiments of the present invention, each of the plurality of connection pieces may be configured to receive a bolt on each end thereof to clamp the first tube, second tube and third tube concentrically between the first receiving piece and the second receiving piece.
Furthermore, in an effort to provide turbulence or a spiral flow within the fluid flow channel or the cooling/heating medium flow channel, one or more spiral structures may be disposed within any one of the first, second or third tubes to instigate a turbulent or spiral like flow within the tube's passageway. Preferably at least one spiral structure is formed around the outer perimeter along a longitudinal axis of the first tube to create turbulence within fluid passing through the second tube from the fluid inlet to the fluid outlet of the second tube.
The fluid received within the second tube may be a low pressure ink, adhesive, coating, lacquer, U.V. ink. The illustrative embodiment of the present invention is configured to cool the fluid as it pass through the second tube and transfers heat to the cooling/heating medium passing through the first and third tubes respectively. The cooling/heating medium may be water, refrigerant or any other medium that is capable of acting as a cooling/heating medium in a heat exchanger. Thus, the temperature of the fluid at the first end of the second tube is preferably a warmer than the temperature of the ink at the second end of the second tube due to heat transference between the inner surface of the second tube and the outer surface of the first tube.
Furthermore, in an effort to provide for efficient heat transfer between the cooling/heating medium and the fluid, the first tube, the second tube and the first tube may preferably made of stainless steel or any other material with a high degree of thermal conductivity and resistance to corrosion. Additionally, to reduce costs and the weight of the assembled heat exchanger, the first receiving piece and the second receiving piece may be formed out of a hard resin material or any other durable, lightweight material that may be formed or machined according the illustrative embodiment of the present invention.
Advantageously, the illustrative embodiment of the present invention provides a low cost, lightweight, heat exchange that can be used in low pressure systems to maintain the temperature of a fluid. Furthermore, since the illustrative embodiment of the present invention is easily assembled and disassembled, maintenance and cleaning can be efficiently carried out with little to no down time or special equipment.

BRIEF DESCRIPTION OF THE DRAWINGS

For a fuller understanding of the nature and desired objects of the present invention, reference is made to the following detailed description taken in conjunction with the accompanying drawing figures wherein like reference characters denote corresponding parts throughout the several views and wherein:

FIG. 1 is a perspective view of a dual passage concentric tube heat exchanger for cooling/heating a fluid in a lower pressure system according to an exemplary embodiment of the present invention;

FIG. 2 is an exploded perspective view of the dual passage concentric tube heat exchanger for cooling/heating a fluid in a lower pressure system according to the exemplary embodiment of the present invention;

FIG. 3 is a cross sectional view of the dual passage concentric tube heat exchanger for cooling/heating a fluid in a lower pressure system according to FIG. 1 in which a spiral structure is installed therein;

FIGS. 4A-C is a perspective views and prospective cross-sectional views of an exemplary receiving piece according to the exemplary embodiment of the present invention; and

FIG. 5 is a cross sectional view of the dual passage concentric tube heat exchanger for cooling/heating a fluid in a lower pressure system according to FIG. 1 in which a spiral structure is not installed therein; and

FIGS. 6A-B illustrate a perspective view of a collapsible arm assembly configured to secure and suspend the heat exchanger of the illustrative embodiment of the present invention in a vertical direction according to an exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, reference will now be made in detail to various embodiments of the present invention, examples of which are illustrated in the accompanying drawings and described below. While the invention will be described in conjunction with exemplary embodiments, it will be understood that the present description is not intended to limit the invention to those exemplary embodiments. On the contrary, the invention is intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims.
Unless specifically stated or obvious from context, as used herein, the term “about” is understood as within a range of normal tolerance in the art, for example within 2 standard deviations of the mean. About can be understood as within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of the stated value. Unless otherwise clear from context, all numerical values provided herein are modified by the term about.
Herein the term fluid refers to any liquid, gas, plasma or any other substance that is capable of continually deforming. Additionally, throughout the specification the term cooling/heating medium refers to any medium, such as water, refrigerant, gas, or any other fluid that is capable of being temperature controlled.
The present invention relates to a dual passage concentric tube heat exchanger (hereinafter “heat exchanger”) for cooling/heating fluid in a low pressure system that is low cost and that can be easily assembled and disassembled for cleaning purposes. More specifically, the heat exchanger of the present invention may include a first tube, a second tube, a third tube and a clamping mechanism to clamp the first tube, second tube and third tube together therebetween. The first tube may have a first cooling/heating medium inlet at a first end and a first cooling/heating medium outlet at a second end and the second tube may be disposed about and concentric with the first tube. The second tube may have a fluid inlet on the same first end as the first tube and a fluid outlet on the same second end as the first tube. The third tube may be disposed about and concentric with the second tube, and may have at least one second cooling/heating medium inlet on the same first end as the first tube and at least one second cooling/heating medium outlet on the same second end as the first tube. To secure the first tube, second tube and third tube about each other concentrically, a clamping mechanism may be utilized to secure the tubes in their respective proper locations and allow them receive fluid and cooling/heating medium respectively as well.
More specifically, FIGS. 1-2 are perspective views of an exemplary embodiment of an assembled heat exchanger 100 that is in accordance with illustrative embodiment of the present invention. Furthermore, FIG. 2 provides an exploded perspective view illustrating other elements of the heat exchanger 100 which are hidden in FIG. 1. FIG. 2 also illustrates the simplistic assembly structure of the exemplary embodiment of the present invention. As can been seen from FIGS. 1 and 2, the heat exchanger 100 includes a first tube 120, a second tube 130, a third tube 140 and a clamping mechanism 110 to clamp the first tube 120, second tube 130 and third tube 140 together therebetween.
The first tube 120 as shown in FIGS. 2 FIG. 3 receives cooling/heating medium through a first cooling/heating medium inlet at a first end and removes fluid through a first cooling/heating medium outlet 112 at a second end. The second tube 130 may be disposed about and concentric with the first tube 120 to form a fluid passageway 137 between the inner surface of the second tube 130 and the outer surface of the first tube 120. The second tube 130 may be configured to receive fluid through a fluid inlet 106(107) (shown in FIGS. 4A-C) through the same first end as the first tube and a fluid outlet 106 on the same second end as the first tube. The third tube 140 may be disposed about and concentric with the second tube to form a second cooling/heating medium passage way 147 between the outer surface of the second tube 130 and the inner surface of the third tube 140.
The third tube 140 may receive the cooling/heating medium through at least one second cooling/heating medium inlet through the same first end as the first tube and discharge the cooling/heating medium through a second cooling/heating medium outlet through the same second end as the first tube. Thus, when assembled cooling/heating medium is configured to pass through the first tube 120 in a first cooling/heating medium passageway 127 and through a second cooling/heating medium passageway 147 between the outer surface of the second tube 130 and the inner surface of the third tube 140, thereby creating dual surfaces that are configured to transfer heat therebetween.
The clamping mechanism 110 is utilized to secure the tubes in their respective proper locations and allow each of the tubes to receive fluid and cooling/heating medium respectively. The clamping mechanism 110 is advantageously, a mechanical clamping mechanism that is easily tightened and loosened to allow the entire heat exchanger system to be easily dismantled for cleaning and maintenance. Since the illustrative embodiment of the present invention is being utilized in a low pressure system, there is no need for high pressure or torsion sealing mechanisms that often require the heat exchanger components to be welded together.
More specifically, the clamping mechanism 110 may include a first receiving piece 102, a second receiving piece 103 and a plurality of connecting pieces 115. Both the first receiving piece 102 and the second receiving piece 103 may be formed identically to receive the first tube 120, second tube 130 and third tube 140 respectively in circular recessed portions (125, 135, and 145) formed therein that are configured to receive each of the tubes respectively. Within each of these circular recessed portions may be a sealing mechanism (126, 136, and 146 respectively) which is capable of providing a seal to prevent fluid from escaping through the ends of the tubes. These sealing mechanisms may, for example, be O rings that fit into the circular recessed portions of the first and second receiving pieces 102(103). Alternatively, the sealing mechanism may also be a seal that is integrally formed within the circular recessed portions of the first and second pieces at the time of manufacture, such as a silicon adhesive affixed to the walls of the circular recessed portions. Furthermore, a first circular recessed portion 125 preferably has about the same circumference as the first tube 120, a second circular recessed portion 135 has about the same circumference as the second tube 130, and a third circular recessed portion 145 have about the same circumference as the third tube 140.
The plurality of connecting pieces 115 connect the first receiving piece 102 to the second receiving piece 103 and provide pressure to the first receiving piece 102 and the second receiving piece 103 respectively to clamp the first tube 120, the second tube 130, and third tube 140 together concentrically therebetween when for example bolts 116 are screwed into each of the ends of the connecting pieces 115. The bolts 116 may be fed through corresponding apertures 117 in the first and second receiving pieces 102(103) respectively. These bolts 116 may be tightened to clamp the heat exchanger assembly 100 together and then loosened to take the heat exchanger assembly 100 apart and provide easy access for cleaning and maintenance.
FIGS. 4A-C depict various views of the receiving piece 102(103). More specifically, FIG. 4B is cut along line B-B of perspective view FIG. 4A and FIG. 4C is a perspective cross sectional view cut along lines A-A of FIG. 4A. An additional depiction of receiving piece 103 is omitted for brevity as it is nearly identical to first receiving piece 102 since the flow direction of the fluids and mediums may be reversed at any time in the illustrative embodiment of the present invention.
Thus, the structural make up of these sections will be described in combination with reference to FIGS. 4A-C. More specifically, FIG. 4A is a forward facing perspective view illustrating the structural make up of the receiving pieces 102(103). In particular, at least one least one medium inlet/outlet aperture 111 may be formed in the receiving pieces between the second recessed portions 135 and the third recessed portions 145 of the receiving pieces 102(103). The medium inlets/outlets are in connection with a cooling/heating medium flow channel 118 within the receiving pieces, and provide a flow path for the cooling/heating medium into and out of the third tube 140.
Alternatively, although FIG. 4C represents inlets and outlets 111 and 112 as being fed from the same channel 118, inlets and outlets 111 and 112 may also be fed from separate channels so that inlet and outlet 111 and passage way 147 may receive a heating medium and inlet and outlet 112 and passageway 127 may receive a cooling medium from separate sources (or vice versa) so that the fluid in passageway 137 may be either heated or cooled via the same heat exchanger. In this example, since heat transfer is only occurring through one surface to the fluid in passageway 137, the heat transfer rate can be increased by expanding the temperature differentiation between the heating or cooling medium and the fluid to more effectively cool or heat the fluid via the same device.
In this alternative embodiment, the cooling medium may be controlled by a first valve and the heating medium may be controlled by a second valve to allow the heat exchanger to both heat and cool the fluid depending upon the environment in which the fluid is being used.
Furthermore, at least one medium inlet/outlet 112 aperture may be formed in the center of the receiving pieces within the perimeter of the first circular recessed portion 125 of the receiving pieces 102(103). Like the inlets/outlets 111, this additionally medium inlet 112 may also be connected to the flow channel 118 and configured to provide a flow path for the cooling/heating medium into and out of the first tube 120.
As a means for providing a flow path for the fluid to and from the heat exchanger assembly 100, least one fluid inlet/outlet 106 may be concentrically formed between the second recessed portions 135 and the first recessed portions 125 of the receiving pieces 102(103). In some instances, two fluid inlet/outlet openings 107 may be concentrically formed in a semicircular shape between the second recessed portion 135 and the first recessed portion 125 of the receiving pieces 102(103).
In some instances it may be beneficial to create a turbulent flow in the fluid as it passes through the second tube of the heat exchanger assembly of the illustrative embodiment of the present invention. For example, one or more spiral structures 150 may be implemented within the flow path of the fluid channel between the outer surface of the first tube 120 and the inner surface of the second tube 130. The spiral structure 150 may be configured to wrap around the outer surface of the first tube to form a spiral structure 150 as is shown in the FIGS. 2 and 3 accordingly. However, as shown in FIG. 5, there may be some instances where turbulent flow is not need and thus, the spiral structure can be removed to provide a clear passageway for the fluid. These spiral structures 150 spin the fluid, being cooled/heated, around the inside and outside cooling/heating surfaces to increase the thermal exchange between the two surfaces within a short flow distance, e.g., about 6 inches.
It should be noted, however, that although the illustrative embodiment of the present invention illustrates the above spiral structure 150 as being disposed in the fluid passageway between the inner surface of the second tube 130 and the outer surface of the first tube 120, one or more spiral structures may be disposed within any one of the first, second or third tubes to instigate a turbulent or spiral like flow within the tube's passageway. Preferably, however, at least one spiral structure is formed around the outer perimeter along a longitudinal axis of the first tube to create turbulence within fluid passing through the second tube from the fluid inlet to the fluid outlet of the second tube.
As mentioned above, the receiving pieces 102(103) are held together/connected by a plurality of connection pieces 115. As a means for applying pressure to the first, second and third receiving tubes by the receiving pieces to effectively create a mechanical seal, each of the plurality of connection pieces may be configured to receive a bolt 116 on each end thereof to clamp the first tube 120, second tube 130 and third tube 140 concentrically between the first receiving piece 102 and the second receiving piece 103. As these bolts 116 may be tightened to applied more pressure to the clamping mechanism and loosened to apply less pressure or to dismantle the assembly altogether, the simplistic design is effective for low pressure systems while still allowing of easy assembly and disassembly.
In most applications, the fluid received by the second tube through the inlet 106 is ink that is flowing through a low pressure system. Alternatively, however, adhesive, coating, lacquer, U.V. ink or the like may also be utilized in the illustrative embodiment of the present invention. Thus, the illustrative embodiment of the present invention is configured to temper or condition fluids as they pass through the second tube and transfer heat to or absorb heat from the cooling/heating medium passing through the first and third tubes respectively through the inner surface of the second tube 130 and the outer surface of the first tube 120. Thus, the illustrative embodiment effectively provides a dual passage concentric tube heat exchanger which transfers heat through two different surfaces and two different flow paths. Thus, the temperature of the fluid at the inlet 106 is preferably different than the temperature of the fluid at an outlet 109 on the other end of the second the heat exchanger assembly 100.
Preferably, in order to ensure that the appropriate heat transfer occurs between cooling/heating medium and the fluid between the inlet 106 and the outlet 109, the diameter of the first tube 120 in one exemplary embodiment is about 0.75 inches, has a wall thickness of about 0.065 inches and a length of about 6 inches. Also preferably, the diameter of the second tube 130 in the exemplary embodiment is about 0.5 inches, has a wall thickness of about 0.065 inches and a length of about 6 inches. And finally, the diameter of the third tube 140 in the exemplary embodiment is about 2.5 inches, has a wall thickness of about 0.065 inches and a length of about 6 inches.
Alternatively, in some embodiments of the present invention, to aid in assembly and disassembly of the tubular heat exchanger, the first tube 120 may be configured to be longer than the second tube 130 and the second tube 130 may be configured to be longer than the third to 140 to aide the user in inserting each of the tubes consecutively into the circular recessed portions 125, 135 and 145 respectively.
Furthermore, the first tube 120, the second tube 130, and the third tube 140 may preferably be made of unpolished stainless steel or any other material with a high degree of thermal conductivity and resistance to corrosion. Additionally, to reduce costs and the weight of the assembled heat exchanger, the first receiving piece and the second receiving piece may be formed out of a hard resin material or any other durably, light weight material that may be formed according the illustrative embodiment of the present invention.
FIGS. 6A-B illustrate a perspective view of a collapsible arm assembly configured to secure and suspend the heat exchanger of the illustrative embodiment of the present invention in a vertical direction according to an exemplary embodiment of the present invention. Referring to FIGS. 6A-B, the heat exchanger assembly 100 of the illustrative embodiment of the present invention may be mounted vertically between a collapsible arm assembly 600. This collapsible arm assembly 600 includes a mounting plate 605, and two rotatable arms 610 hingedly mounted to the mounting plate 605 and extending outward in a perpendicular direction from the mounting plate 605. As shown in FIG. 6B the two rotatable arms 610 are configured to be rotated toward each other to be connected at an end distal from the mounting plate via a securing mechanism 615 to hold the heat exchanger assembly in vertically in place. The securing mechanism may be for example a removable pin, or any or latching mechanism.
Furthermore, although the above description describes the heat exchanger 100 of the illustrative embodiment of the present invention as being installed vertically, the heat exchanger of the illustrative embodiment of the present invention may be installed in an orientation which suits the overall system in which it is installed. Additionally, the cooling/heating medium may either flow in parallel with the fluid or counter parallel with the fluid depending upon the architectural or temporal requirements of the system in which it is installed.
In some embodiments of the present invention, the overall length of the heat exchanger of the illustrative embodiment of the present invention is about 10 inches or less from the first end of the first 120, second 130, or third 140 tubes to the second end of the first, second, or third tubes. Thus, the present invention is able to achieve optimal heat transfer between the fluid and the cooling/heating medium within a relative short distance thereby allowing the overall assembly to be compact and lightweight.
The heat exchanger described above in the illustrative embodiment of the present invention may be installed inline within a low pressure system requiring the use of fluid within a particular temperature range in order to insure the proper viscosity of the fluid is achieved. Also integrated into this low pressure system may be system for controlling the cooling/heating medium, i.e., the flow rate, temperature, etc. This control system may be any of the known external control systems known in the art and thus, the description of which will be omitted for brevity. Additionally, the temperature of the fluid and the cooling/heating medium may be measured by any of the conventional technology known in the art in order to ensure a proper temperature gradient through the heat exchanger of the illustrative embodiment of the present invention.
Although the illustrative embodiment of the present invention depicts the fluid channel 118 running horizontally through the middle of the first and second receiving pieces 102(103), the passage way may also run vertically though the first and second receiving pieces 102(103), as opposed to coming out/going into the side of the first and second receiving pieces respectively. Furthermore, although the above heat exchanger is configured to cool the fluid passing through the second tube, that same configuration may also be configured to heat the fluid passing through the second tube as well by providing a medium in the first and third tubes that is warmer than the fluid in the second tube.
Advantageously, as stated above, the illustrative embodiment of the present invention provides for a lightweight, compact heat exchanger that is capable of thermally conditioning fluid in low cost, low pressure system (e.g., less than about 40 psi). Furthermore, the present invention allows for easy dismantling and maintenance of the above described heat exchanger so that it may be used in remote locations as a means for efficiently cooling/heating medium in low pressure systems, such as printing systems. Also, since the above described invention may be easily installed through the use of a collapsible arm mechanism the fluid being cooled/heated in the heat exchanger may be easily configured to be self flushing due to gravity. Even further, due to its simplistic design it may be easily mounted inline in any low pressure system for a relatively low cost compared to other conventional heat exchangers. Finally, since heat transfer is occurring through two different surfaces and on two different kinds of fluids in the present invention, the fluid can be more efficiently and quickly be cooled over a relatively short distance.
The foregoing specification and the drawings forming part hereof are illustrative in nature and demonstrate certain preferred embodiments of the invention. It should be recognized and understood, however, that the description is not to be construed as limiting of the invention because many changes, modifications and variations may be made therein by those of skill in the art without departing from the essential scope, spirit or intention of the invention.

Claims

1. A heat exchanger for cooling/heating fluid at a low pressure, the heat exchanger comprising:

a first tube receiving a cooling/heating medium through a first cooling/heating medium inlet at a first end and discharging the cooling/heating medium through a first cooling/heating medium outlet at a second end;

a second tube disposed about and concentric with the first tube, the second tube receiving fluid from a fluid inlet on the same first end as the first tube and a fluid outlet on the same second end as the first tube;

a third tube disposed about and concentric with the second tube, the third tube receiving the cooling/heating medium through at least one second cooling/heating medium inlet on the same first end as the first tube and discharging the cooling/heating medium through at least one second cooling/heating medium outlet on the same second end as the first tube; and

a clamping mechanism including a first receiving piece, a second receiving piece and a plurality of connecting pieces, wherein the first receiving piece is formed to receive on one side thereof the first end of the first tube, second tube and third tube respectively and the second receiving piece is formed to receive the on one side thereof the second end of the first tube, the second tube and the third tube, respectively,

wherein the plurality of connecting pieces are configured to removeably connect the first receiving piece to the second receiving piece and provide and release pressure to the first receiving piece and the second receiving piece to clamp the first tube, the second tube and third tube together concentrically therebetween.

2. The heat exchanger of claim 1, wherein the first receiving piece and the second receiving piece include:

first circular recessed portions having first O-rings disposed therein and each configured to receive the first and second ends of the first tube respectively;

second circular recessed portions having second O-rings disposed therein and configured to receive the first and second ends of the second tube respectively; and

third circular recessed portions having third O-rings disposed therein and each configured to receive the first and second ends of the third tube respectively.

3. The heat exchanger of claim 2, wherein the first circular recessed portions have the same circumference as the first tube, the second circular recessed portions have the same circumference as the second tube, and the third circular recessed portions have the same circumference as the third tube.

4. The heat exchanger of claim 2, wherein the at least one second cooling/heating medium inlet is formed between the second recessed portion and the third recessed portion of the first receiving piece, the first cooling/heating medium inlet is formed in the center of the first receiving piece within a perimeter of the first circular recessed portion of the first receiving piece.

5. The heat exchanger of claim 2, wherein the at least one second cooling/heating medium outlet is formed between the second recessed portion and the third recessed portion of the second receiving piece, and the first cooling/heating medium outlet is formed in the center of the second receiving piece within a perimeter of the first circular recessed portion of the second receiving piece.

6. The heat exchanger of claim 2, wherein the fluid inlet is concentrically formed between the second recessed portion and the first recessed portion of the first receiving piece, and the fluid outlet is formed concentrically between the second recessed portion and the first recessed portion of the second receiving piece.

7. The heat exchanger of claim 6, wherein the fluid inlet is concentrically formed into two divided semicircular shapes between the second recessed portion and the first recessed portion of the first receiving piece, and the fluid outlet are formed concentrically into two divided semicircular shapes between the second recessed portion and the first recessed portion of the second receiving piece.

8. The heat exchanger of claim 1, wherein each of the plurality of connection pieces are configured to receive a bolt on each end thereof to clamp the first tube, second tube and third tube concentrically between the first receiving piece and the second receiving piece when each bolt is tightened.

9. The heat exchanger of claim 1, wherein one or more spiral structures are disposed around the outer perimeter along a longitudinal axis of the first tube to create turbulence within fluid passing between the outer surface of the first tube and the inner surface of the second tube.

10. The heat exchanger of claim 1, wherein the fluid is a low pressure ink and wherein a first temperature of the ink at the first end of the second tube is different than a second temperature of the ink at the second end of the second tube.

11. The heat exchanger of claim 1, wherein the first tube, the second tube and the third tube are made of stainless steel.

12. The heat exchanger of claim 1, wherein the first receiving piece and the second receiving piece are formed out of a hard resin material.

13. The heat exchanger of claim 1, wherein the cooling/heating medium is water.

14. The heat exchanger of the claim 1, wherein the heat exchanger is mounted vertically or otherwise between a collapsible arm assembly wherein the collapsible arm assembly includes:

a mounting plate; and

two rotatable arms hingedly mounted to the mounting plate and extending outward in a perpendicular direction from the mounting plate,

wherein the two rotatable arms are configured to be rotated toward each other to be connected at an end distal from the mounting plate via a securing mechanism.

15. The heat exchanger of claim 1, wherein the first tube receives a cooling medium and the third tube receives a heating medium, the cooling medium controlled by a first valve and the heating medium controlled by a second valve.