Abstract:
A single ended filly encapsulated water cooling cartridge for thermoelectrically cooling fluids has a vertically mounted cylindrical water flow pipe with a plurality of flat sides and acting as a cold plate communicating with an inlet of the water cooling cartridge, a like plurality of heat sinks circumferentiary positioned around the water flow pipe with longitudinal fins extending radially outwardly from each heat sink, a cylindrical shell enveloping the heat sinks and the water flow pipe and forming an annulus air passageway therein, an axial forced air fan mounted on the top of the water cooling cartridge to induce air flow along the heat sinks, thermoelectric elements acting as heat pumps positioned between the heat sink and the water flow pipe, and a temperature control thermostat.

Description:
BACKGROUND OF THE INVENTION 
     1. The Field of the Invention 
     The present invention relates to an apparatus for cooling fluids. More particularly, the present invention relates to an in-line thermoelectrically operated water-cooling device formed as a single-ended cylindrical cartridge vertically mounted on a flowboard. 
     2. The Prior Art 
     The present invention pertains to methods and systems for water conditioning, treatment and purification and, in particular, to domestic units which are readily adaptable to treat local water in accordance with any existing long term or varying temporary condition to produce water of high purity and to a flowboard for controlling fluid distribution in the system. 
     Impurities in natural raw waters (surface or well water) occur in four basic different forms, namely non-ionic and undissolved impurities; ionic and dissolved impurities; gaseous impurities; and biological impurities. Each of these impurities requires separate treatment techniques and equipment for their removal. 
     Non-ionic and undissolved impurities include, but are not Limited to, turbidity, silt, mud, suspended solids, organic matter, bacteria, oil colloidal matter and colloidal silica. 
     Ionic and dissolved impurities include: a wide variety of salts dissolved in water and dissociated to form positive ions, called cations, and negative ions, called anions. The major cations in natural raw water are calcium, magnesium sodium, potassium, ammonium, iron and manganese. The major anions are carbonate, bicarbonate, hydroxide, chloride, sulfate, nitrate, phosphate, and silica. 
     Gaseous impurities include a number of gases that are soluble in water. Some are found naturally in well water, such as carbon dioxide, hydrogen sulfide, and methane. Others are the result of water purification or industrial application and include such gases as ammonia, oxygen and chlorine. 
     Biological impurities include all types of microorganisms, bacteria, viruses, and pyrogen. 
     In most cases, all of these four forms of impurities coexist simultaneously and in differing amounts and their relative proportions can vary, even seasonally. No single treatment or technique is adequate for or capable of removing all impurities in one step. Multiple related or interdependent processes are normally required to rid water from such impurities. Generally these processes must be constantly monitored to assure each form of impurity is being properly treated and removed. 
     The inventor of the subject invention is also the inventor of U.S. Pat. Nos. 6,080,313 and 6,099,735, the disclosures of which are incorporated herein by way of reference. These patents describe counter-top modular water purification and disinfection systems to remove water impurities and produce water of high quality and purity as presented in the forgoing introduction. All water treatment and control modules are single ended, bottle-like cartridges of different functions mounted on a uniquely designed flow circuit forming a base, which was named “flowboard.” The subject invention discloses the use of a water cooler in the form of a bottle-like cartridge to be mounted on a flowboard of a stand-alone water-cooling apparatus or as a cooling module in a water purification system of the type described in the aforementioned patents. The flowboard is a flat box-like assembly concealing a fluid conduit extending between an inlet and an outlet and a plurality of mounting receptacles connected to the conduit, each receptacle receiving a single ended cartridge or a module vertically therein, whereby water is purified and cooled while passing from the inlet to be dispensed at the outlet. Prior art in thermoelectric fluid cooling, for example, U.S. Pat. Nos. 4,384,512 to Keith; 4,752,389 to Burrows; 4,913,318 to Forrester; 5,209,069 to Newman; 5,501,077 to Davis et al; and 5,544,489 to Moren describe the use of conventional thermoelectric cooling devices as affixed to the surface of a water container for the purpose of cooling water by natural convection within the container. U.S. Pat. No. 4,281,516 to Berthet et al describes a thermoelectric cooling device comprising a liquid flow circuit in the form of a bendable metal tube imbedded within the cold plate of a multi-plate thermoelectric cooler system. U.S. Pat. No. 5,494,195 to Knuettel et al describes a thermoelectrically cooled beverage dispenser comprising a liquid flow circuit in the form of a channel having affixed conventional thermoelectric devices. 
     None of the prior art devices depicts an in-line, fully integrated, single element fluid cooling system in the form of a detachable bottle-like coaxial cylindrical cartridge, having only one port for fluid inlet and outlet, and is easily mounted on or removed from a flowboard or a manifold without tools and without disturbing the piping, wiring or other parts of the apparatus. 
     It is therefore an object of the present invention to provide a fully functional single-element thermoelectric water cooling device in the form of a vertically mounted cylindrical cartridge, which is similar to those used for water filtration and purification. 
     It is another object of the present invention to provide a cooling cartridge that provides immediate, on-demand cold water without requiring a reservoir for storing cold water. 
     It is another object of the present invention to provide a water-cooling cartridge, which is easy to install or to replace without the need for any tools or equipment. 
     It is another object of the present invention to provide a water-cooling cartridge, which has a single end with a water inlet and a water outlet forming a single concentric port. 
     It is a further object of the present invention to provide a water-cooling cartridge that can be mounted on a flowboard so as to be included with various other elements for water treatment. 
     It is a further object of the present invention to provide one or more water-cooling cartridges that can be mounted on a flowboard for a stand-alone counter top water cooler. 
     It is still a further object of the present invention to provide one or more water-cooling cartridges that can be mounted on a linear flowboard in the form of a manifold. 
     It is another object of the present invention to provide a water-cooling cartridge whereby the water flows upwardly through an annulus of a chamber and leaves axially through the water outlet tube. 
     It is another object of the present invention to provide a water-cooling cartridge whereby the water flows upwardly through a single entry circumferential helix disposed on an internal compartment, forming a narrow annulus with the water pipe, for the purpose of enhancing flow velocity and subsequently heat transfer rate. 
     It is a further object of the present invention to provide a water-cooling cartridge whereby the water flow pipe has external flat surfaces preferably of equal size so as to form a square wall pipe having a square internal channel. 
     It is a further object of the present invention to provide a water-cooling cartridge whereby the water flow pipe is a rectangular block with external flat surfaces of equal sides so as to form a square wall pipe having drilled or cast therein a circular internal passageway. 
     It is a further object of the present invention to provide a water-cooling cartridge whereby the water flow pipe is a conventional cylindrical pipe having affixed blocks of external flat surfaces and internal contoured surfaces for mating the pipes. 
     It is another object of the present invention to provide a water-cooling cartridge that can include a multi-section finned heat sink affixed circumferentially around the water flow pipe in which the heat sink is separated from the external surface of the water flow pipe by an insulating material. 
     It is another object of the present invention to provide a water-cooling cartridge having a multi-section finned heat sink which is formed of an economical highly heat conductive material such as aluminum. 
     It is another object of the present invention to provide a water-cooling cartridge in which the finned member of the heat sink has extruded, machined or molded longitudinal fins of different lengths which extend along the length of the heat sink with each heat sink affixed to one side of the water flow pipe external wall so as to form a continuous circular heat exchanging surface. 
     It is still another object of the present invention to provide a water-cooling cartridge which employs one or more thermoelectric elements positioned between the surface of the water flow pipe and the heat sink so as to circumferentiary surround the water flow pipe. 
     It is another object of the present invention to provide a water-cooling cartridge which has the heat sink positioned within an external shell and provided with an integrated forced convection means, such as an electrically operated fan. 
     It is another object of the present invention to provide a water cooling cartridge whereby the fan is placed at the top of the cartridge so as to induce atmospheric air through an opening of the bottom of the shell in a coaxial flow pattern parallel to the hot sink finned members so as to cool the hot sink and to enhance heat transfer across the cartridge. 
     It is another object of the present invention to provide a water-cooling cartridge which has no exposed piping, piping connections or electrical wiring. 
     It is another object of the present invention to provide a water-cooling cartridge, which is temperature controlled with an integrated thermostat. 
     It is still a further object of the present invention to provide a water-cooling cartridge that can meet the infrequent or continuous variable demand of cold water by the use of a single cartridge having adequate diameter, height, internal heat transfer enhancing means such as a helix, and number of thermoelectric devices, or by a series of standard size water-cooling cartridges of the type described herein. 
     These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims. 
     SUMMARY OF THE INVENTION 
     The present invention is an apparatus for cooling and dispensing fluids having a flowboard with a fluid passageway extending between an inlet and an outlet, and a water-cooling cartridge removably fixed to a mounting block or receptacle within the flowboard connected to the passageway. The water-cooling cartridge has a coaxial inlet and outlet for communicating with the fluid passageway of the flowboard. The water-cooling cartridge has: a square water flow pipe acting as a cold junction or cold plate and communicating with the inlet of the water-cooling cartridge; a finned heat sink positioned around the water flow pipe and separated therefrom with insulating material; a thermoelectric device acting as a heat pump securely positioned between the heat sink and the water flow pipe; a shell enclosing the heat sink defining a coaxial passageway for induced cooling air flow and forming an external housing for the water-cooling cartridge; a fin mounted at the top of the water-cooling cartridge so as to draw or induce air flow along the heat sink; and a thermostatic device for controlling water temperature above its freezing point. 
     The water outlet tube is axially placed in the water flow pipe and communicates with the outlet of the water-cooling cartridge. The interior wall of the water flow pipe for low capacity cooling defines an annulus with an exterior surface of the outlet axial tube and communicates with the inlet of the water-cooling cartridge. For high capacity water cooling, the interior of the water flow pipe is slightly tapered and houses a relatively large diameter cylindrical compartment, forming a narrow annulus with the water flow pipe. The compartment has a single inlet circumferential helical channel disposed on its external surface in close proximity to the water flow pipe so as to form a continuous single passageway for water flow. 
     The water flow pipe preferably has flat external surfaces defining a square internal channel or forming a cylindrical channel within a rectangular metal block. The water flow pipe acts as a cold junction or cold plate (cold side), where heat is absorbed from the fluid mostly by convection. It is preferable to maintain the cold plate temperature at about 35° F. (as determined by the design of the thermoelectric devices and process requirements). Lower temperatures should be avoided to prevent water freezing and subsequent blocking of water flow. Heat transfer between solids and liquids is relatively higher than between solids and air. Therefore, the heat sink (hot side), where heat is rejected, is normally large with multiple protrusions or fins to increase the exposed surface. However, in another embodiment of the water flow pipe, internal longitudinal fins or means to induce turbulence could be provided to enhance heat transfer through the liquid. A unique design of such heat transfer enhancement means is described hereafter. The thermoelectric devices are affixed to at least one of these external flat surfaces. The water flow pipe, with its flat external surfaces, is preferably made of high conductive metal hygienically acceptable for potable water service (such as copper or aluminum with an inert surface coating). The heat sink preferably has four sections, which are affixed circumferentiary to the fill length of the external wall of the water flow pipe. The cross section of each heat sink forms a segment of a circle having a flat base plate and equally spaced variable-length fins extending outwardly therefrom. Each plate mates with one side of the water pipe external wall and is secured thereto, preferably with non-heat conductive screws. The outer perimeter of the four mounted finned sections of the heat sink form a circular cross section that can be easily inserted in the cooling cartridge cylindrical shell to form a coaxial annulus for airflow. Means to position the cooling cartridge in its shell and prevent air by-pass are also provided. 
     An insulating material is affixed between the external flat surfaces of the water flow pipe and a base plate of the heat sink. The insulating material extends around the perimeter of the thermoelectric devices. 
     The airflow is enhanced by a fan which is mounted at the top of the water flow pipe and within the shell The shell and the water flow pipe define an air passing annulus. The fan is placed so as to draw or induce air upwardly through the air passing annulus. 
     In the present invention, a housing is detachably mounted onto the flowboard and over the water-cooling cartridge. A spigot is in fluid communication with the outlet of the flowboard and extends outwardly of the housing. Preferably a water filter is in fluid communication with the fluid passageway of the flowboard by a receptacle of the same type used for the subject water cooling cartridge. An electrically operated single ended solenoid valve means is also mounted on the flowboard for controlling fluid flow through the fluid passageway. The valve means is controlled by a fluid dispensing push button (switch) accessibly exposed on an exterior surface of the housing. 
     A non-intrusive surface thermostat is securely placed directly on the flat conductive top of the water flow pipe to provide an indicative measure of the water temperature within the water flow pipe. The location of the thermostat at the top of the water flow pipe is selected because upwardly flowing cooled water reaches it minimum temperature at this point. The thermostat disconnects power to the thermoelectric devices if surface temperature of the water flow pipe drops below a set point, preferably 35° F., to avoid water freezing in the pipe. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will now be described, by way of example, with reference to the accompanying drawings, in which: 
     FIG. 1 is a perspective view of the present invention with the housing in place; 
     FIG. 2 is a perspective view, similar to FIG. 1, showing the present invention with the housing removed; 
     FIG. 3 is a vertical section through the present invention; 
     FIG. 4 is a horizontal section taken along line  4 — 4  of FIG. 3; 
     FIG. 5 is a vertical section, similar to FIG. 3, showing the water-cooling cartridge of the present invention in greater detail; 
     FIG. 6 is a top plan view taken along line  6 — 6  of FIG. 5; 
     FIG. 7 is a horizontal section taken along line  7 — 7  of FIG. 5; 
     FIG. 8 is a horizontal section taken along line  8 — 8  of FIG. 5; 
     FIG. 9 is a perspective view of the thermostat compartment and terminal block below the fan associated with the present invention; 
     FIG. 10 is an exploded perspective view of the water-cooling cartridge of the present invention with the shell removed; 
     FIG. 11 is a side elevation of the heat transfer enhancer means for a high capacity water cooling cartridge in accordance with the present invention; 
     FIG. 12 is a vertical section taken along line  12 — 12  of FIG. 11 as placed in the water flow pipe of the present invention; and 
     FIG. 13 is an electrical schematic, on block level, of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A water cooling and dispensing apparatus  10  in accordance with the teachings of the present invention is shown in FIG.  1 . The apparatus  10  includes a detachable housing  12  affixed onto and over a flowboard  14 . The flowboard  14  is of a type described previously mentioned U.S. Pat. Nos. 6,080,313 and 6,099,735 to the present inventor, the disclosures of which are incorporated herein by reference. The flowboard provides a circuitous pathway for water to travel from an inlet  16  to an outlet  46  (see FIGS.  2  and  3 ). A water supply tube  18  is connected to the inlet  16  so as to allow potable water to enter the flowboard  14 . The tube  18  can be connected to any water supply suitable for delivering potable water. The outlet  46  of the flowboard  14  is connected to a spigot  20  extending outwardly from one end of the housing  12 . The spigot  20  is illustrated as in a suitable position for dispensing filtered and cooled water into a glass  22 . 
     The housing  12  includes a cool air intake vent  24  and a hot air outlet vent  26 . The cooling air intake vent  24  is positioned near the bottom of the housing  12  adjacent the top of the flowboard  14 . The hot air outlet vent  26  is positioned adjacent the rear end of the top surface  28  of the housing  12 . A housing locking mechanism  30  is mounted on the top  28  of the housing  12 . A handle  32  is pivotally received by the mechanism  30  so as to be movable between an upright position and a position lying against the top surface  28  of the housing  12 . A water dispensing push button (electrical switch)  34  is mounted on the top surface  28  near the front end of the housing  12 . Depressing button  34  activates the system solenoid valve  42  (to be described hereinafter) allowing water to enter the flowboard  14  and be released from the spigot  20 . A power supply cord  36  extends from the housing  12  so as to be connected to the electrical apparatus within the housing  12  to a source of electrical power. 
     FIG. 2 shows present invention with the housing  12  removed revealing the flowboard  14 , a water cooling cartridge  38 , a water filter  40  and a solenoid valve  42 . The water cooling cartridge  38 , the water filter  40  and the solenoid valve  42  are single-ended and are mounted onto the flowboard  14  without any exposed piping or wiring. The housing  12  can be fitted onto the flowboard  14  by abutting with the shoulder  44  extending around the perimeter of the flowboard  14 . 
     The flowboard  14  has water inlet port  16  at one end and water outlet port  46  at the opposite end. The water outlet port  46  can be connected to the spigot  20  so as to allow the cooled water to pass therefrom. 
     The water-cooling cartridge  38  has a cylindrical configuration and is received in a receptacle  54  on the flowboard  14 . Similarly, the water filter  40  has a cylindrical configuration and is received in a receptacle  48  on the flowboard  14  and the solenoid valve  42  is received in a receptacle  50 . The water-cooling cartridge  38  is spaced from the top surface  52  of the flowboard  14  forming an open area  86  (see FIG. 3) allowing cooling air to enter the air passing annulus  56  on the interior of the water-cooling cartridge  38 . The receptacles  48 ,  50 , and  54  are of a similar design to that described in previously mentioned U.S. Pat. Nos. 6,080,313 and 6,099,735. 
     FIG. 3 shows that the flowboard  14  has an inlet  16  connected to a water supply (not shown) by a liquid tube  18  and the outlet  46  connected to spigot  20 . A fluid passageway  58  extends through the flowboard  14  between the inlet  16  and the outlet  46 . A spigot support member  60  is affixed onto an interior wall of the housing  12  so as to support the spigot  20  in its desired orientation. 
     As described in previously mentioned U.S. Pat. Nos. 6,080,313 and 6,099,735, the solenoid valve  42  is mounted in the receptacle  50  and has a plunger  62  that engages a valve seat disposed within the valve mounting block  50 . The plunger  62  shuttles between a normally closed position preventing fluid flow through the passageway  58  and an opened position allowing fluid flow through the fluid passageway  58 . The valve  42  is actuated by the dispensing push button  34 , which is accessibly mounted on the top surface  28  of the housing  12 , via an AC/DC transformer  64 . The transformer  64  is electrically connected to terminal blocks  66  mounted on the support surface  68  within the housing  12 . The power supply line  36  supplies AC power to the transformer  64 . A housing closure switch  70  is positioned adjacent to the bottom of the housing  12  and is electrically connected to the transformer  64  and to the terminal block  66  so as to prevent the application of power to the various components until such time as the housing  12  is securely placed onto the flowboard  14 . It should be noted that, in the present invention, virtually all of the electrical connections are located above the flowboard  14 . Thus, if any flooding should occur due to leakage within the flowboard  14 , the electrical system and components will be isolated from any water. 
     The water filter  40  is received in the receptacle  48  so as to communicate with the flow of fluid through passageway  58  in the flowboard  14 . As seen in FIG. 3, the liquid from the fluid passageway  58  will enter the opening  74  at the bottom of the water filter  40 , flow through the outer annulus of the filter  40 , radially inwardly through the filter media  76  and into the inner annulus  78 . Filtered water exits downwardly through axial pipe  80  to passageway  58  via the filter mounting receptacle  48 . The operation of this filter  40  is similar to that described in previously mentioned U.S. Pat. No. 6,080,313. 
     In order to secure the housing  12  onto the flowboard  14 , a locking mechanism  30  is mounted on the top surface  28  of the housing  12 . A handle  32  is pivotally connected to the mechanism on the upper end of the housing locking rod  82  extends from the top surface  28  downwardly so as to be threadedly received by a support member  84  located in the flowboard  14 . Rotation of the handle  32  will cause the rod  82  to rotate to engage with (or disengage from) the flowboard  14 . The support member  84  is provided in the center of the flowboard  14  between the filter cartridge  40  and the water cooling cartridge  38  and provides the necessary strength to support the weight of the apparatus. 
     The primary feature of the present invention is the water-cooling cartridge  38 , best seen in FIG.  5 . The water-cooling cartridge  38  is received in a mounting block  54  fixed in the flowboard  14 . The water-cooling cartridge includes a water flow pipe  88 , a multi-section heat sink  90 , a shell  92 , an airflow inducing fan  94 , thermoelectric devices  96 , and temperature control thermostat  132 . As can be seen, the water flow pipe  88  communicates with the inlet  98  of the water-cooling cartridge. The heat sink  90  is positioned around the water flow pipe  88 . The shell  92  encloses the heat sink  90  and the water flow pipe  88 . The airflow fan  94  is mounted at the top of the water-cooling cartridge  38  so as to draw air across the heat sink  90 . The thermoelectric devices  96  are positioned between the heat sink  90  and the water flow pipe  88 . 
     The water flow pipe  88  has an axial outlet water tube  102  which communicates with the outlet  100  of the water-cooling cartridge and is sealed with an O ring  109 . The outlet tube  102  is removable and replaceable and retained in place at both ends by perforated chambers  126  and  127  to allow for water flow between the cartridge inlet and outlet. The interior wall  104  of the water flow pipe  88  defines an annulus  106  with an exterior surface of the tube  102 . This annulus  106  communicates with the inlet  98  of the water-cooling cartridge  38 . Both the inlet  98  and outlet  100  of the water-cooling cartridge  38  form a single ended concentric port. 
     The heat sink  90  is affixed circumferentially around the water flow pipe  88  for its full external surface. The blades of the fan  94  extend over the top of the air passing annulus  130  formed between the shell  92  and the heat sink  90 . Air flow is induced by the fan  94  and enters the water-cooling cartridge  38  at the air inlet aperture  108  at the bottom of the shell  92 , flows upwardly along the fins  162  of the heat sink  90 , and exits through the air outlet port  110  at the top of the water-cooling cartridge. Hot air from port  110  exits the housing  12  at the hot air vent  26 . 
     Power is provided to the water-cooling cartridge  38  via a circular terminal block  112  (see FIG.  6 ). The circular terminal block forms a disk with radially extended fins  146  for positioning the block on top of fan  94  and within the shell  92  of the water-cooling cartridge, as well as for allowing air movement within the annulus  106 . The contact strips of the terminal block  112  engage corresponding power supply terminals  113  securely mounted to the inner surface of housing  12 . Both the fan  94  and the thermoelectric devices  96  are preferably operated with a DC power supply as illustrated in FIG. 11. A flexable diaphragm  114  (FIG. 3) is positioned within the housing  12  so as to isolate intake air from venting air and to keep airflow in the desired direction. 
     FIG. 4 illustrates the interior configuration of flowboard  14 . For safety concerns, only fluids (water) will flow through the flowboard  14 . All of the electrical components and power lines within the housing  12  are isolated from the flowboard  14 . 
     Water will enter the flowboard  14  through the inlet  16  and will flow through the valve receptacle  50  to enter the axial chamber  120  responsive to the solenoid valve  42 . Water will then flow through flow passageway  58  to the receptacle  48  for the filter cartridge  40 . The fluid passageway  58  also extends from the filter cartridge  40  to the water-cooling cartridge  38  before exiting at the outlet  46 . 
     Returning to the detailed view of the water-cooling cartridge  38  in FIG. 5, the water will be cooled as it contacts the cold sink formed by the inner wall  104  of the water flow pipe  88 . The water will then flow axially downwardly through the interior of the outlet tube  102  (as illustrated by the arrows) through the outlet  104 . Thereafter, water enters the fluid passageway  58  within the flowboard  14 . 
     The inner wall  104  of the water flow pipe  88  should be of a highly heat conductive material, such as copper or aluminum This wall could be plated with a noble metal or coated with a thin layer of a suitable coating for handling potable water. In another embodiment (not shown), the wall  104  could have extended fins to increase the area of contact and enhance heat transfer. As such, the cooling effect caused by the thermoelectric element  96  can be rapidly imparted to the water as its flows through the annulus  106 . An insulating material  97  is placed around the exterior surfaces of the water flow pipe  88 , except for the area occupied by the thermoelectric devices  96 , to completely isolate the cold plate from the heat sink. 
     The heat sink  90  is positioned adjacent to the wall  104  of the water flow pipe  88  such that the thermoelectric devices  96  are sandwiched between the heat sink  90  and the inner wall  104 . The insulating material  97  will reside in those spaces between the heat sink  90  and the inner wall  104  of the water flow pipe  88  which were not occupied by the thermoelectric devices  96 . The fins of the heat sink  90  will extend into the annulus  130 . The design and configuration of the heat sink is determined by process requirements and ability to remove heat generated by the thermoelectric devices. The annulus  130  passes the air from the air inlet  108  through the outlet  110 . The flow of air through the annulus  130  is created by the inducing action of the fan  94  located at the top of the water flow pipe  88 . A surface sensing thermostat  132  is positioned at the top of the water flow pipe  88 , where water temperature reaches its minimum, so as to sense the temperature of a copper block  138  in direct contact with the water inside the water flow pipe  88 . Conventionally, the thermostat should be set at between 35° to 40° F. The thermostat  132  includes electrical connections extending outwardly from the cavity  134 . The wiring bundle  136  extends outwardly of the water cooling cartridge  38  through a slot located at the top of the cartridge  38 . Terminal block  112  is provided at the top of the cartridge  38 . 
     FIG. 6 is a top plan view taken along line  6 — 6  of FIG. 5. A cartridge locking threaded flange  139  engages the top of the cartridge  38  so as to securely retain the fan  94  and the other elements in place within the interior of the cartridge  38 . The circular terminal block  112  forms a disk with radially extended fins  146  for positioning the block on top of fan  94  within the shell  92  of the water cooling cartridge, as well as for allowing air movement through the cartridge annulus. The circular terminal block  112  comprises a positive contact strip  142  located at the center of the terminal block, while a negative contact strip  144  will extend around the terminal block  112 . 
     FIG. 7 is a transverse section taken along line  7 — 7  of FIG. 5 showing the thermostat compartment  150 . The thermostat  132  is affixed onto a panel  152 , preferably of thermally neutral material, such as plastic, residing above the water flow pipe  88 . Wires  154  extend through holes  176  formed in the panel  152  and are connected to the thermoelectric devices mounted on the wall of the water flow pipe  88 . A system wiring harness  154  is positioned adjacent to the wall of the shell  92  so as to allow the bundle of wires to be extended through the interior of the housing  12 . The thermostat  132  is, in the preferred embodiment of the present invention, an AIRPAX (TM) series 5005 thermostat. This is a thermostat specifically designed for switching DC power. A construction of the thermoelectric assembly offers excellent mechanical shock and vibration resistance. The thermal response is rapid due to its low mass. 
     FIG. 8 is a transverse section taken along line  8 — 8  of FIG.  5 . It can be seen that a tubular shell  92  extends around the various components of the water-cooling cartridge  38 . The heat sink  90  includes a flat base  160  from which fins  162  extend outwardly. The fins  162  extend from the flat base  160  associated with each of the heat sinks  90  so as to have an outer end, which resides in very close proximity to the inner wall  164  of the shell  92 . The shell has four equally spaced radial members  93  to position the assembly of the water pipe  88  and its surrounding heat sinks  90  in a non-rotating axial alignment. Meanwhile, the members engage the space between the adjacent heat sinks and restrict air by-pass through those vacant areas. Each of the fins  162  has a length which is different than the length of each adjacent fin. The heat sinks  90  are preferably formed by molding or extrusion from an economical heat conductive material, such as aluminum. The fins  162  will extend through the air-passing annulus  130  to provide greater convection and heat transfer between the air passing therethrough and the surfaces of the heat conductive material of the heat sinks  90 . Each of the heat sinks  90  has its flat base  160  secured by non-conductive screws  166  to the wall  104  of the water flow pipe  88 . The wall  104  is shown as having flat exterior surfaces suitable to accommodate conventional flat surface thermoelectric devices  96 . Insulating material  97  is positioned between the flat surfaces  160  of the heat sinks  90  and the exterior surface of the wall  104  of the water flow pipe  88 . FIG. 8 also shows the water flow annulus  106  and the outlet tube  102 . 
     FIG. 9 is a perspective view of the panel  152  for supporting the thermostat  132 . Height control flanges  170  extend upwardly from the flat top surface of panel  152 . A central aperture  172  is cut in the panel  152  to match the end block  138  of the water chamber associated with the water flow pipe  88 . This end block of the water chamber is preferably designed as a hexagonal nut to be used for securing the top of the water flow pipe and also to provide an elevated base for the surface-sensing thermostat  132 . Various holes  176  are formed in the plate  152  so as to allow the various wires to extend to the thermoelectric elements. A wiring bundle hole  178  is formed in one height control flange  170  to allow the wiring bundle to extend outwardly therethrough. 
     FIG. 10 is an exploded view of the water-cooling cartridge  38  of the present invention with the shell  92  removed. The water flow pipe  88  is shown, for convenience, with a square external cross section with flat surfaces and acts as a cold junction or cold plate. It will be appreciated that any number of flat surfaces can be used for the water flow pipe. A like number of finned heat sinks  90  are positioned around the water flow pipe and are separated therefrom by insulating material  97 . One or more thermoelectric devices  96 , acting as a heat pump, are also positioned between the heat sink and the water flow pipe and secured thereto. The outlet and inlet of the water flow pipe form a single ended concentric port  182  which is externally threaded  180  for engaging the threaded mounting block  54 . When the heat sinks  90  are secured to the water flow pipe  88 , the heat sinks  90  will act as “hot plate” while the walls  104  of the water flow pipe  88  will act as “cold plate.” The size, number, and design criterion of the thermoelectric devices  96  will depend upon the desired capacity of the water-cooling apparatus  10 . 
     The thermoelectric devices  96  preferably include an array of bismuth telluride semiconductor pellets that have been doped positive or negative. The pairs of positive/negative pellets are connected electrically in series and thermally in parallel. A metalized ceramic substrate material provides the platform for the pellets and the small conductive tabs that connect them. When DC voltage is applied to the module, via wiring connection  184 , the semiconductor material absorbs heat energy on one substrate surface and releases it on the opposite surface. The surface where heat energy is absorbed becomes cold. The opposite surface, where heat energy is released, becomes hot. The thermoelectric devices  96 , as employed in the preferred embodiment of the present invention, are manufactured by Melcor Thermoelectrics of Trenton, N.J. 
     FIGS. 11 and 12 are external and vertical section views, respectively, of the heat transfer enhancer means for a high capacity water-cooling cartridge in accordance with the present invention. The simple design of the annulus flow of the subject cooler, as described earlier and shown in FIG. 5, has a heat load of about 600-750 BTU per hour and is capable of producing 40° F. cold water at a rate of about three gallons per hour. For a conventional water pipe of 1.5 inches in diameter, as depicted in FIG. 5, the upward flow has a Reynolds number of less than 100 and it is stipulated that the flow is laminar and that the heat transfer across the water pipe takes place by forced convection in an annulus. 
     Increasing the flow rate through the annulus tends to increase the heat transfer rate as a result of enhancing the heat transfer film coefficient at the boundary layer of the water pipe wall. However, the enhancement in heat transfer is not necessarily proportional to the increase in flow rate. As a result, the exchanger performance tends to worsen as the flow increases and eventually the cooler fails to meet its outlet design temperature. Any significant increase in the thermal performance of the cooler, for example, by increasing its performance 2-4 fold, cannot be simply achieved by just increasing flow through the unit. In such case, other means to enhance heat transfer across the surface of the water pipe is required, providing heat can be also transmitted from the wall of the water flow pipe to its surroundings. 
     Therefore, it is an important object of the subject invention to provide a heat transfer enhancing means that increases heat transfer rate by about three fold and subsequently the capacity of the water cooler using essentially the same water pipe design as shown in FIG.  5 . 
     In the enhanced capacity water cooler, the axial water flow outlet tube  102  is designated  102   a  (FIGS. 11 and 12) to allow for an enlarged sleeve of plastic material  140 , forming a coaxial compartment around the axial water outlet tube  102   a  and acts as a small reservoir  142  for cooled water. A helical channel  144  of small rectangular of hemispherical cross section is formed by molding, extruding or pinning the external surface of the coaxial compartment. The channel engages the annulus space between the coaxial compartment  140  and the internal wall of the water pipe  104  and forms a single closed helical passageway duct  146  against the internal water pipe wall, having only one inlet water port  148  and one outlet water port  150 . In such embodiment, water travels in a duct that is much smaller than the original annular passageway, maintaining direct contact with the water pipe wall, for a relatively long path, at a velocity off 10-20 fold the annulus flow of the original embodiment. A slight tapering of the water pipe makes placement of the helical coil  144  easier and sealing of the helix-protruded edges  152  against the internal wall of the water pipe more effective. It is also possible that the helical channel can be formed as a self-supported, spring-like member, acting as a stint within the water pipe, without the support of the coaxial compartment (not shown). 
     FIG. 13 is an electrical schematic for the present invention. The wiring is extended to housing closure switch  70 , solenoid valve  42  , its actuator push button  34 , fan  94 , thermostat  132  and multiple parallel runs to thermoelectric elements  96 . A primary objective of the electrical system is that the system will not be energized unless the system housing  12  is safely secured and locked in place on the flowboard  14 , the fan and the thermoelectric elements are switched off when the thermostat reaches the set point temperature. Water can be withdrawn when the solenoid valve is actuated, regardless of water temperature. Other features for monitoring and alarm systems are not shown for the sake of simplification of the present drawings. 
     It is believed that the present invention is the first thermoelectric cooling apparatus in the form of a coaxial cylinder that can be used for the cooling of fluids. It is also believed that the present invention is the first thermoelectric cooling apparatus in the form of a single-ended fully encapsulated fluid-cooling cartridge. 
     The foregoing disclosure and description of the invention are illustrative and explanatory thereof. Various changes in the details of the illustrated construction may be made without departing from the true spirit of the invention as defined by the appended claims. 
     Technical References 
     1. C. Y. Chen, G. A. Hawkins, and H. L. Solberg, Tran. ASME 69,99 (1940) 
     2. M. Jakob, Heat Transfer, Vol I, Page 551, Wilet, N.Y. (1949) 
     3. W. H. McAdams, Heat Transmission, 3 rd  Edition, McGraw Hill, N.Y. (1954) 
     4. Perry&#39;s Chemical Engineering Handbook, 6 th  Edition, Pages 10-17