Patent Publication Number: US-6911231-B2

Title: Method for producing a heat transfer medium and device

Description:
RELATED APPLICATIONS 
     This application is a continuation-in-part application of U.S. patent application Ser. No. 09/437,659, filed on Nov. 10, 1999, now abandoned, which is a divisional of U.S. patent application Ser. No. 08/957,148 filed on Oct. 24, 1997 and which issued as U.S. Pat. No. 6,132,823 on Oct. 17, 2000, which in turn is based and claims priority on U.S. provisional patent application No. 60/029,266 filed on Oct. 25, 1996 and U.S. provisional patent application No. 60/036,043 filed on Jan. 27, 1997. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention relates generally to the field of heat transfer. More particularly, the present invention relates to a method for producing a heat transfer medium that is disposed within a conduit to rapidly and efficiently transfer heat. 
     2. Background Art 
     Efficiently transporting heat from one location to another always has been a problem. Some applications, such as keeping a semiconductor chip cool, require rapid transfer and removal of heat, while other applications, such as disbursing heat from a furnace, require rapid transfer and retention of heat. Whether removing or retaining heat, the heat transfer conductivity of the material utilized limits the efficiency of the heat transfer. Further, when heat retention is desired, heat losses to the environment further reduce the efficiency of the heat transfer. 
     For example, it is well known to utilize a heat pipe for heat transfer. The heat pipe operates on the principle of transferring heat through mass transfer of a fluid carrier contained therein and phase change of the carrier from the liquid state to the vapor state within a closed circuit pipe. Heat is absorbed at one end of the pipe by vaporization of the carrier and released at the other end by condensation of the carrier vapor. Although the heat pipe improves thermal transfer efficiency as compared to solid metal rods, the heat pipe requires the circulatory flow of the liquid/vapor carrier and is limited by the association temperatures of vaporization and condensation of the carrier. As a result, the heat pipe&#39;s axial heat conductive speed is further limited by the amount of latent heat of liquid vaporization and on the speed of circular transformation between liquid and vapor states. Further, the heat pipe is conventional in nature and suffers from thermal losses, thereby reducing the thermal efficiency. 
     An improvement over the heat pipe, which is particularly useful with nuclear reactors, is described by Kurzweg in U.S. Pat. No. 4,590,993 for a Heat Transfer Device For The Transport Of Large Conduction Flux Without Net Mass Transfer. This device has a pair of fluid reservoirs for positioning at respective locations of differing temperatures between which it is desired to transfer heat. A plurality of ducts having walls of a material that conducts heat connects the fluid reservoirs. Heat transfer fluid, preferably a liquid metal such as mercury, liquid lithium or liquid sodium, fills the reservoirs and ducts. A piston or a diaphragm within one of the reservoirs creates oscillatory axial movement of the liquid metal so that the extent of fluid movement is less than the duct length. This movement functions to alternately displace fluid within the one reservoir such that the liquid metal is caused to move axially in one direction through the ducts, and then to in effect draw heat transfer fluid back into the one reservoir such that heat transfer fluid moves in the opposite direction within the ducts. Thus, within the ducts, fluid oscillates in alternate axial directions at a predetermined frequency and with a predetermined tidal displacement or amplitude. With this arrangement, large quantities of heat are transported axially along the ducts from the hotter reservoir and transferred into the walls of the ducts, provided the fluid is oscillated at sufficiently high frequency and with a sufficiently large tidal displacement. As the fluid oscillates in the return cycle to the hotter reservoir, cooler fluid from the opposite reservoir is pulled into the ducts and the heat is then transferred from the walls into the cooler fluid. Upon the subsequent oscillations, heat is transferred to the opposite reservoir from the hotter reservoir. However, as with the heat pipe, this device is limited in efficiency by the heat transfer conductivity of the materials comprising the reservoirs and ducts and by heat losses to the atmosphere. 
     It is known to utilize radiators and heat sinks to remove excess heat generated in mechanical or electrical operations. Typically, a heat transferring fluid being circulated through a heat-generating source absorbs some of the heat produced by the source. The fluid then is passed through tubes having heat exchange fins to absorb and radiate some of the heat carried by the fluid. Once cooled, the fluid is returned back to the heat-generating source. Commonly, a fan is positioned to blow air over the fins so that energy from the heat sink radiates into the large volume of air passing over the fins. With this type of device, the efficiency of the heat transfer is again limited by the heat transfer conductivity of the materials comprising the radiator or the heat sink. 
     Dickinson in U.S. Pat. No. 5,542,471 describes a Heat Transfer Element Having The Thermally Conductive Fibers that eliminates the need for heat transferring fluids. This device has longitudinally thermally conductive fibers extended between two substances that heat is to be transferred between in order to maximize heat transfer. The fibers are comprised of graphite fibers in an epoxy resin matrix, graphite fibers cured from an organic matrix composite having graphite fibers in an organic resin matrix, graphite fibers in an aluminum matrix, graphite fibers in a copper matrix, or a ceramic matrix composite. 
     In my People&#39;s Republic of China Patent Number 89108521.1, I disclosed an Inorganic Medium Thermal Conductive Device. This heat-conducting device greatly improved the heat conductive abilities of materials over their conventional state. Experimentation has shown this device capable of transferring heat along a sealed metal shell having a partial vacuum therein at a rate of 5 meters per second. On the internal wall of the shell is a coating applied in three steps having a total optimum thickness of 0.012 to 0.013 millimeters. Of the total weight of the coating, strontium comprises 1.25%, beryllium comprises 1.38% and sodium comprises 1.95%. This heat conducting device does not contain a heat generating powder and does not transfer heat nor prevent heat losses to the atmosphere in a superconductive manner as the present invention. 
     BRIEF SUMMARY OF THE INVENTION 
     It is generally accepted that when two substances having different temperatures are brought together, the temperature of the warmer substance decreases and the temperature of the cooler substance increases. As the heat travels along a heat-conducting conduit from a warm end to a cool end, available heat is lost due to the heat conducting capacity of the conduit material, the process of warming the cooler portions of the conduit and thermal losses to the atmosphere. In accordance with the present invention and these contemplated problems that have and continue to exist in this field, one objective of this invention is to provide a method for producing a heat transfer medium that is environmentally sound, rapidly conducts heat and preserves heat in a highly efficient manner. Further, the present invention does not require a tightly controlled process environment to produce a heat transfer medium. 
     Another object of this invention is to provide a method for producing a device that conducts heat with a heat preservation efficiency approaching 100 percent. 
     Also, another object of this invention is to provide a method for the denaturation of rhodium and radium carbonate. 
     Yet another objective of this invention is to provide a method for producing a heat transfer device that is capable of transferring heat from a heat source from one point to another. 
     Still yet another object of this invention is to provide a method for producing a heat sink utilizing the heat transfer medium that rapidly and efficiently disburses heat from a heat-generating object. 
     A further objective of this invention is to provide a method for producing a device that rapidly conducts cold temperatures from one end of the device to the other end. 
     This invention accomplishes the above and other objectives and overcomes the disadvantages of the prior art by providing a method for producing a heat transfer medium that results in a heat transfer device that is relatively inexpensive to prepare, simple in design and application, and easy to use. 
     In the present method, the heat transfer medium is applied to a substrate in three basic layers. The first two layers are prepared from mixtures that are exposed to a surface or wall of the substrate. Initially, the first layer, which primarily comprises various combinations of sodium, beryllium, a metal such as magnesium or aluminum, calcium, boron and dichromate radical, is at least partially absorbed into the surface of the substrate to a depth of 0.008 mm to 0.012 mm. Subsequently, the second layer, which primarily comprises various combinations of cobalt, manganese, beryllium, strontium, rhodium, copper, ,β-titanium, potassium, boron, calcium, a metal such as magnesium or aluminum and the dichromate radical, builds on top of the first layer and actually forms a film having a thickness of 0.008 mm to 0.012 mm over the surface of the substrate. Finally, the third layer is a powder comprising various combinations of rhodium oxide, potassium dichromate, radium oxide, sodium dichromate, silver dichromate, monocrystalline silicon, beryllium oxide, strontium chromate, boron oxide, β-titanium and a metal dichromate, such as magnesium dichromate or aluminum dichromate, that evenly distributes itself across the surface. In an illustrative example, the three layers can be applied to the inner wall of a conduit and then heat polarized to form a superconducting heat transfer device, or can be applied to a pair of plates having a small cavity relative to a large surface area to form a heat sink that can immediately disburse heat from a heat source. 
     It is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. For example, the term superconducting is used to denote a process that is faster and/or more efficient than the currently known art. As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods, and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention. 
     Other objects, advantages and capabilities of the invention will become more apparent to those of ordinary skill in the art from the following description of the preferred embodiments when taken in conjunction with the accompanying drawings showing the preferred embodiment of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a superconducting heat transfer device made in accordance with the present invention. 
         FIG. 2  is a cross-sectional view of the device of FIG.  1 . 
         FIG. 3  is a perspective view of a plug used with the device in FIG.  1 . 
         FIG. 4  is a perspective view of a heat sink made in accordance with the present invention. 
         FIG. 5  is a side elevation view of the heat sink of FIG.  4 . 
         FIG. 6  is a cross-sectional view of the heat sink of FIG.  4 . 
         FIG. 7  is an example testing apparatus for testing a heat transfer device made in accordance with the present invention. 
         FIG. 8  is the data from the results of Test No. 1 on a preferred embodiment of a heat transfer device made in accordance with the present invention. 
         FIG. 9  is the data from the results of Test No. 2 on a preferred embodiment of a heat transfer device made in accordance with the present invention. 
         FIG. 10  is the data from the results of Test No. 3 on a preferred embodiment of a heat transfer device made in accordance with the present invention. 
         FIG. 11  is the data from the results of Test No. 4 on a preferred embodiment of a heat transfer device made in accordance with the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     For a fuller understanding of the nature and desired objects of this invention, reference should be made to the following detailed description taken in connection with the accompanying drawings. Referring to the drawings wherein like reference numerals designate corresponding parts throughout the several figures, reference is made first to  FIGS. 1 and 2 . A heat transfer device  2  produced according to the method of the present invention is shown. Heat transfer device  2  comprises a carrier such as conduit  4  containing a heat transfer medium  6 , which can be placed within a cavity  8  of conduit  4  without regard to the material comprising conduit  4 . The resulting heat transfer capabilities of medium  6  bearing conduit  4  are greatly enhanced relative to the known art, and are termed superconducting or superconductive herein. Medium  6  is activated at a temperature of 38° C. and can operate to a maximum temperature of 1730° C. Because medium  6  is capable of quickly and efficiently transferring heat through conduit  4  from a heat source (not shown), conduit  4  can be exposed to and operate within an environment having a source temperature far in excess of the melting temperature of the untreated material comprising conduit  4 . 
     During the initial stages of medium  6  activation, the medium  6  can react endothermically. As a result, medium  6  can absorb available heat from the heat source and thereafter transfer the heat throughout conduit  4 . If the cubic area of cavity  8  is small in relation to external surface  10  area of conduit  4 , as shown in  FIGS. 4 through 6 , medium  6  absorbs heat to provide a heat sink  12  that removes heat from the heat-generating source. Heat radiation is directly related to the density of heat capacity and the rate of heat conduction and thermal conductivity. This, in other words, determines the speed (rate) at which the volume (quantity) of heat can be transferred in each unit volume. It has been found that the rate at which the heat can be transferred using a device produced from the disclosed method is greater than the known art. 
     If conduit  4 , or other carrier such as disclosed below, has a small cavity in relation to a large external surface  10  area, the carrier is more capable of distributing heat across the external surface  10 . In applications where the temperature of the heat-generating source does not exceed 38° C., which is the activation temperature of medium  6 , the heat is immediately absorbed and dispersed by medium  6 . In cases where the heat generating source exceeds 38° C., heat sink  12  is still highly effective because of the ability of medium  6  to rapidly transfer the heat to heat sink external surface  14  and be efficiently dispersed to the atmosphere by thermal radiation. 
     Using the method of the present invention, medium  6  is applied to a substrate in three basic layers. The first two layers are prepared from mixtures of components, and the mixtures are exposed to the substrate surface, such as an inner conduit surface  16  or an inner heat sink surface  18 . Initially, first layer mixture is at least partially absorbed into inner conduit surface  16  or heat sink surface  18 , forming first layer  20 . Subsequently, second layer mixture builds on top of first layer  20  and actually forms a film over inner conduit surface  16  or heat sink surface  18 , forming second layer  22 . Finally, third layer  24  is a powder that is evenly distributed across inner conduit surface  16  or heat sink surface  18 . Although reference is made to conduit  4  below in the discussion of medium  6 , the application of medium  6  within heat sink  12  is the same. 
     First layer  20 , called an anti-corrosion layer, prevents etching of inner conduit surface  16 . A further function of first layer  20  is to prevent inner conduit surface  16  from producing oxides. For example, ferrous metals can be easily oxidized when exposed to water molecules contained in the air. The oxidation of inner conduit surface  16  can cause corrosion and also can create a heat resistance. As a result, there is an increased heat load while heat energy is transferred within conduit  4 , thus causing an accumulation of heat energy inside conduit  4 . Should this occur, the life span of medium  6  is decreased. 
     Next, second layer  22 , called the active layer, prevents the production of elemental hydrogen and oxygen, thus restraining oxidation between oxygen atoms and the material of conduit  4  (or carrier). Second layer  22  conducts heat across inner conduit surface  16  analogously to that of electricity being conducted along a wire. Experimentation has found that heat can be conducted by medium  6  at a rate of 15,000 meters per second. Second layer  22  also assists in accelerating molecular oscillation and friction associated with third layer  24  to provide a heat transfer pathway for heat conduction. 
     Third layer  24  is referred to, due to its color and appearance, as the “black powder” layer. Upon activation of medium  6 , the atoms of third layer  24 , in concert with first layer  20  and second layer  22 , begin to oscillate. As the heat source temperature increases, frequency of oscillation also increases. When the activating temperature reaches 200° C., the frequency of oscillation has been calculated to be 230 million times per second, and when the activating temperature is higher than 350° C., the frequency of oscillation has been calculated to reach up to 280 million times per second. Based on known theory, the higher the activating temperature, the higher the frequency of oscillation. Therefore, based on this theory, the higher the load, the higher the performance efficiency of the conduit. During the heat transfer process, there is neither phase transition nor mass transfer of medium  6 . Experimentation has shown that a steel conduit  4  with medium  6  properly disposed therein has a thermal conductivity that is generally 20,000 times higher than the thermal conductivity of silver, and can reach under laboratory conditions a thermal conductivity that is 30,000 times higher that the thermal conductivity of silver. 
     Medium  6  has a long, but limited useful life. Tests have shown that after 110,000 hours of continuous use, both the amount of medium  6  and the molecule vibration frequency remain generally the same as from the initial activation. However, at 120,000 hours of continuous use, the ability of medium  6  to transfer heat starts to decline. After about 123,200 hours of continuous use, medium  6  became ineffective. As is expected, lower working temperatures slow the decline. 
     As disclosed generally herein, the term mixture as used herein is a portion or entire composition of matter consisting of two or more components in varying proportions. Further, the individual components of a mixture as used herein may or may not be soluble in the mixture. A mixture can include the components in solutions, suspensions, layers, or in any other arrangements or combinations thereof. 
     To prepare first layer  20 , a first layer mixture is manufactured and thereafter applied to inner conduit surface  16 . A representative first layer mixture is manufactured by the following steps, preferably conducted in the order of listing: 
     (a) placing 100 ml of distilled water into an inert container such as glass, preferably ceramic; 
     (b) mixing between 2.0 and 5.0 grams of sodium peroxide into the water; 
     (c) mixing between 0.0 and 0.5 grams of sodium oxide into the mixture of step (b); 
     (d) mixing between 0.0 and 0.5 grams of beryllium oxide into the mixture of step (c); 
     (e) mixing between 0.3 and 2.0 grams of a metal dichromate selected from the group consisting of aluminum dichromate and, preferably, magnesium dichromate into the mixture of step (d); 
     (f) mixing between 0.0 and 3.5 grams of calcium dichromate into the mixture of step (e); and 
     (g) mixing between 1.0 and 3.0 grams of boron oxide into the mixture of step (f) to form the first layer mixture. 
     It is preferred for the steps (a) through (g) to be conducted in the order listed and under conditions having a temperature between 0° C. and 30° C., preferably 5° C. to 8° C., and a relative humidity of no greater than 40%. The steps for addition of beryllium oxide and the metal dichromate can be reversed in order so that the metal dichromate is added to the first layer mixture prior to the addition of beryllium oxide without causing negative effects. When medium  6  contains manganese sesquioxide, rhodium oxide or radium oxide, either sodium peroxide of sodium oxide may be eliminated, but the resulting heat transfer efficiency of medium  6  will be lower and the life span of medium  6  will be reduced. As to the remaining components of the first layer mixture and subject to the above exceptions, each component should be added in the order presented. If the components of the first layer mixture are combined in an order not consistent with the listed sequence, the mixture can become unstable and may result in a catastrophic reaction. 
     The first layer mixture is termed an aqueous mixture as each of the components is mixed into the water. The components may be of differing solubility in water, with some of the components being soluble and other components having low or possibly no solubility in water. Therefore, while some of the components may dissolve completely in the water, others of the components may only partially dissolve in the water, and still others of the components may not dissolve at all in the water. Thus, it is preferable for the components to be fine powders to enhance dissolution, mixing or dispersion, as appropriate, and to enhance penetration into the surface of a heat transfer device, as disclosed below. It has been found that the solubility of the components in water is not of importance and not of interest. The combination of the components resulting in the first layer mixture produces the desired results when applied as the first layer, as disclosed below. 
     Prior to manufacturing a mixture for second layer  22  and compiling the compounds for third layer  24 , rhodium and radium carbonate undergo a denaturation process. To denature 100 grams of rhodium powder, blend 2 grams of pure lead powder with the rhodium powder within a container (not shown) and subsequently place the container with the rhodium and lead powders into an oven (not shown) at a temperature of 850° C. to 900° C. for at least 4 hours to form rhodium oxide. Then separate the rhodium oxide from the lead. To denature 100 grams of radium carbonate powder, blend 11 grams of pure lead powder with the radium carbonate within a container (not shown) and subsequently place the container with the radium carbonate and lead powders into an oven (not shown) at a temperature of 750° C. to 800° C. for at least eight hours to form radium oxide. During experimentation, a platinum container was utilized in the denaturation process. The material comprising the container should be inert with respect to rhodium, rhodium oxide, radium carbonate, radium oxide and lead. Lead utilized in the denaturation process preferably should be 99.9% pure and can be recycled for subsequent use in further like denaturation processes. Subsequent testing of medium  6  at a resting state and an active state with a PDM personal dosimeter (not shown) resulted in no radioactive emissions of any kind detectable over background radiation. 
     An isotope of titanium is utilized in medium  6 . In some countries the isotope is known as B-type titanium, and in the USA, the isotope is known as β-titanium. 
     Second layer  22  is derived from a mixture that is applied to inner conduit surface  16  over first layer  20 . Similar to the first layer mixture, a second layer mixture is manufactured by the following steps, conducted preferably in the order of listing: 
     (a) placing 100 ml of twice-distilled water into an inert container such as glass, preferably ceramic; 
     (b) mixing between 0.2 and 0.5 grams of cobaltous oxide into the twice-distilled water; 
     (c) mixing between 0.0 and 0.5 grams of manganese sesquioxide into the mixture of step (b); 
     (d) mixing between 0.0 and 0.01 grams of beryllium oxide into the mixture of step (c); 
     (e) mixing between 0.0 and 0.5 grams of strontium chromate into the mixture of step (d); 
     (f) mixing between 0.0 and 0.5 grams of strontium carbonate into the mixture of step (e); 
     (g) mixing between 0.0 and 0.2 grams of rhodium oxide into the mixture of step (f); 
     (h) mixing between 0.0 and 0.8 grams of cupric oxide into the mixture of step (g); 
     (i) mixing between 0.0 and 0.6 grams of β-titanium into the mixture of step (h); 
     (j) mixing between 1.0 and 1.2 grams of potassium dichromate into the mixture of step (i); 
     (k) mixing between 0.0 and 1.0 grams of boron oxide into the mixture of step (j); 
     (l) mixing between 0.0 and 1.0 grams of calcium dichromate into the mixture of step (k); and 
     (m) mixing between 0.0 and 2.0 grams of aluminum dichromate or, preferably, magnesium dichromate, into the mixture of step (l) to form the second layer mixture. 
     It is preferred for the twice-distilled water to have an electrical conductivity that approaches 0. The higher the electrical conductivity, the greater the problem of static electricity interfering with medium  6  and causing a reduction in the thermal conductive efficiency. The steps of (a) through (m) are preferably conducted under conditions having a temperature between 0° C. and 30° C. and a relative humidity of no greater than 40%. When medium  6  contains rhodium oxide or radium oxide, the amount of manganese sesquioxide may be reduced or eliminated; however, the life span of medium  6  will be reduced and the thermal conductive efficiency will be reduced. Generally, β-titanium may be added to the second layer mixture at any step listed above, except that it should not be added to the twice-distilled water at step (b) or as the last component of the mixture. Adding β-titanium at step (b) or as the last component of the mixture can cause instability of the second layer mixture and may result in a catastrophic reaction. The steps for adding manganese sesquioxide and beryllium oxide may be reversed in order so that beryllium oxide is added to the second layer mixture prior to the addition of manganese sesquioxide. Likewise, the steps for adding potassium dichromate and calcium dichromate may be reversed in order so that calcium dichromate is added to the second layer mixture prior to the addition of potassium dichromate. If the components of the second layer mixture are is combined in an order not consistent with the listed sequence and the exceptions noted above, the mixture can become unstable and may result in a catastrophic reaction. 
     The second layer mixture also is termed an aqueous mixture as each of the components is mixed into the water. The components also may be of differing solubility in water, with some of the components being soluble and other components having low or possibly no solubility in water. Therefore, while some of the components may dissolve completely in the water, others of the components may only partially dissolve in the water, and still others of the components may not dissolve at all in the water. Thus, it is preferable for the components to be fine powders to enhance dissolution, mixing or dispersion, as appropriate. It has been found that the solubility of the components in water is not of importance and not of interest. The combination of the components resulting in the second layer mixture produces the desired results when applied as the second layer, as disclosed below. 
     Prior to preparing third layer  24 , silicon is treated by magnetic penetration. Monocrystalline silicon powder having a preferred purity of 99.999% is placed within a non-magnetic container (not shown) and disposed within a magnetic resonator (not shown) for at least 37 minutes, preferably 40 minutes to 45 minutes. The magnetic resonator utilized during experimentation is a 0.5 kilowatt, 220 volt and 50 hertz magnetic resonator. If the silicon being used has a lower purity that 99.999%, the amount of silicon needed in third layer  24  increases. The magnetic resonator is used to increase the atomic electron layer of the silicon, which in turn, increases the speed that heat is conducted by medium  6 . 
     A representative powder of third layer  24  is manufactured by the following steps, preferably conducted in the order of listing: 
     (a) placing between 0.0 and 1.75 grams of denatured rhodium oxide into an inert container such as glass, preferably ceramic; 
     (b) blending between 0.3 and 2.6 grams of sodium dichromate with the rhodium oxide; 
     (c) blending between 0.0 and 0.8 grams of potassium dichromate with the mixture of step (b); 
     (d) blending between 0.0 and 3.1 grams of denatured radium oxide with the mixture of step (c); 
     (e) blending between 0.1 and 0.4 grams of silver dichromate with the mixture of step (d); 
     (f) blending between 0.2 and 0.9 grams of the monocrystalline silicon powder treated by magnetic penetration with the mixture of step (e); 
     (g) blending between 0.0 and 0.01 grams of beryllium oxide with the mixture of step (f); 
     (h) blending between 0.0 and 0.1 grams of strontium chromate with the mixture of step (g); 
     (i) blending between 0.0 and 0.1 grams of boron oxide with the mixture of step (h); 
     (j) blending between 0.0 and 0.1 grams of sodium peroxide with the mixture of step (i); 
     (k) blending between 0.0 and 1.25 grams of β-titanium with the mixture of step (i); and 
     (l) blending between 0.0 and 0.2 grams of aluminum dichromate or, preferably, magnesium dichromate, into the mixture of step (k) to form the third layer powder. 
     The powder for third layer  24  preferably should be blended at a temperature lower than about 25° C. By blending at lower temperatures, the heat conducting efficiency of medium  6  improves. Further, the relative humidity should be below 40%. It is preferred for the relative humidity to be between 30% and 35%. Generally, radium oxide and β-titanium may be added to the powder of third layer  24  at any step listed above, except that neither one should be added to the powder as the first or last component. Adding either radium oxide or β-titanium as the first or last component of the powder can cause instability of medium  6  and may result in a catastrophic reaction. The steps for adding potassium dichromate and silver dichromate may be reversed in order so that silver dichromate is added to the powder of third layer  24  prior to the addition of potassium dichromate. Likewise, the steps for adding strontium chromate and beryllium oxide may be reversed in order so that beryllium oxide is added to the powder of third layer  24  prior to the addition of strontium chromate. If the components of the powder of third layer  24  are combined in an order not consistent with the listed sequence and the exceptions noted above, medium  6  can become unstable and may result in a catastrophic reaction. 
     The powder of third layer  24  can be stored for prolonged periods of time. To prevent degradation by light and humidity, the powder of third layer  24  should be stored in a dark, hermetic storage container (not shown) made from an inert material, preferably glass. A moisture absorbing material also may be placed within the storage container so long as the moisture absorbing material is inert to and is not intermingled with the powder of third layer  24 . 
     Once the mixtures for first layer  20  and second layer  22  and the powder of third layer  24  are prepared, the heat transfer device  2  can be fabricated. Conduit  4  can be any one of a variety of metallic or non-metallic materials and should have very little oxidation, preferably no oxidation, on inner conduit surface  16 . It is recommended for conduit  4  to be clean, dry and free of any oxides or oxates, particularly if conduit  4  is manufactured of a metal. This can be accomplished by conventional treatment by, for example, sand blasting, weak acid washing, or weak base washing. Any materials used to clean and treat conduit  4  should be completely removed and inner conduit surface  16  also should be dry prior to adding medium  6  to conduit  4 . Additionally, the wall thickness of conduit  4  should be selected to take a wear rate of at least 0.1 mm per year into account. This wearing is caused by the oscillation of third layer&#39;s 24 molecules. For steel, the wall thickness should be at least 3 mm. Obviously, softer materials need to be thicker. The conduit  4  may be of considerable length. In fact, it has been found that the performance efficiency of the conduit  4  increases with length. 
     A representative heat transfer device  2  is manufactured utilizing the following steps: 
     (a) placing the first layer mixture into a first layer mixture container; 
     (b) submerging conduit  4  having cavity  8  within the first layer mixture such that the first layer mixture fills cavity  8 , conduit  4  preferably having a non-horizontal placement both within the first layer mixture and relative to the earth, conduit  4  also having a lower end  26 , at a temperature between 0° C. and 30° C. for at least 8 hours so that at least a portion of the first layer mixture can at least partially penetrate the wall of conduit  4  to a depth of between 0.008 mm and 0.012 mm, and then removing conduit  4  from first layer mixture; 
     (c) drying conduit  4  naturally at ambient conditions to form first layer  20  within cavity  8 ; 
     (d) placing the second layer mixture into a second layer mixture container: 
     (e) submerging conduit  4  with first layer  20  within the second layer mixture such that the second layer mixture fills cavity  8 , lower end  26  being oriented in a downward direction, at a temperature between 55° C. and 65° C., preferably 60° C., for at least 4 hours, and then removing conduit  4  from second layer mixture; 
     (f) drying conduit  4  naturally at ambient conditions to form a film of second layer  22  within cavity  8  having a thickness between 0.008 mm and 0.012 mm; 
     (g) welding an end cap  28  on the opposite end of conduit  8  from lower end  26  by a precision welding technique, preferably heli-arc welding done in the presence of helium or argon; 
     (h) welding an injection cap  30  having a bore  32  between 2.4 mm and 3.5 mm, preferably 3.0 mm, on lower end  26  preferably by the method utilized in step (g); 
     (i) heating lower end  26  to a temperature not to exceed 120° C., preferably 40° C.; 
     (j) injecting the powder of third layer  24  through bore  32  in an amount of at least 1 cubic meter per 400,000 cubic meters of cavity  8  volume; 
     (k) inserting plug  34 , preferably conical-shaped and solid plug  34 , as shown in  FIG. 3 , into bore  32 ; 
     (l) heating lower end  26  to a temperature between 80° C. and 125° C.; 
     (m) removing plug  34  from bore  32  for no more than 3 seconds, preferably 2 seconds, and reinserting plug  34  into bore  32 ; and 
     (n) sealing plug  34  within bore  32 , preferably by the method utilized in step (g), to form heat transfer device  2 . 
     If the temperature of lower end  26  in step (i) exceeds 60° C., lower end  26  should be allowed to cool to at least 60° C. prior to injecting the powder of third layer  24  into cavity  8 . By following the steps above, lower end  26  becomes heat polarized. In other words, lower end  26  is polarized to receive heat from the heat source and transfer the heat away from lower end  26 . 
     The purpose of removing plug  34  from bore  32  in step (m) above is to release air and water molecules from cavity  8  of conduit  4  to the outside environment. A blue gas has been observed exiting bore  32  once plug  34  is removed. However, if a blue light is observed emitting from bore  32  prior to plug  34  being reinserted into bore  32 , the powder of third layer  24  has escaped to the atmosphere and steps (j) through (m) need to be repeated. If step (j) can be accomplished in a humidity-free environment under a partial vacuum, steps (l) and (m) can be eliminated, but it is not recommended. 
     Manganese sesquioxide, rhodium oxide, and radium oxide are not needed in all applications of medium  6 . These three components are used in medium  6  when heat transfer device  2  is exposed to an environment of high-pressure steam is and conduit  4  is manufactured of high carbon steel. In this special case, high pressure is defined as being 0.92 million Pascal or higher. Manganese sesquioxide, rhodium oxide, and radium oxide are not needed and may be eliminated from medium  6  when the use of heat transfer device  2  is not in a high pressure steam environment, even if conduit  4  is made of high carbon steel. Additionally, when manganese sesquioxide, rhodium oxide, and radium oxide are eliminated from medium  6 , the powder of third layer  24  should be provided in an amount of 1 cubic meter of third layer powder per 200,000 cubic meters of cavity 8 volume. 
     As disclosed above, heat sink  12  utilizes heat transfer medium  6 . A representative heat sink  12  is manufactured utilizing the following steps: 
     (a) placing the first layer mixture into a first layer mixture container; 
     (b) submerging first plate  36  and second plate  38  within the first layer mixture such that the first layer mixture covers at least one side of each of first plate  36  and second plate  38  at a temperature between 0° C. and 30° C. for at least 8 hours so that at least a portion of the first layer mixture can at least partially penetrate the first layer mixture covered side  40  to a depth between 0.008 mm and 0.012 mm, first plate  36  and second plate  38  having mating edges  42  and forming a relatively small volume cavity  8  with respect to the surface area of first plate  36  and second plate  38  when first plate  36  and second plate  38  are placed together, and at least one of first plate  36  and second plate  38  has an opening  44  between 2.4 mm and 3.5 mm, preferably 3.0 mm, and then removing first plate  36  and second plate  38  from the first layer mixture; 
     (c) drying first plate  36  and second plate  38  naturally at ambient conditions to form first layer  20  on the first layer covered sides  40  of first plate  36  and second plate  38 ; 
     (d) placing the second layer mixture into a second layer mixture container; 
     (e) submerging first plate  36  and second plate  38  within the second layer mixture such that the second layer mixture contacts first layer  20  at a temperature between 55° C. and 65° C., preferably 60° C., for at least 4 hours, and then removing first plate  36  and second plate  38  from the second layer mixture; 
     (f) drying first plate  36  and second plate  38  naturally at ambient conditions to form the film of second layer  22  having a thickness between 0.008 mm and 0.012 mm on first layer  20 ; 
     (g) welding first plate  36  and second plate  38  together along mating edges  42  by a precision welding technique, preferably heli-arc welding done in the presence of helium or argon, so that the first layer covered sides  40  face one another; 
     (h) injecting the powder of third layer  24  into cavity  8  through opening  44  in an amount of at least 1 cubic meter per 400,000 cubic meters of cavity volume; and 
     (i) sealing opening  44  preferably by the method utilized in step (g) to form heat sink  12 . 
     Heat sink  12  can be manufactured in the same manner as heat transfer device  2 ; that is, heat sink  12  may be heat polarized, but it is not necessary. Also, the steps calling for welding in the manufacture of heat transfer device  2  and heat sink  12  can be accomplished by using glues, adhesives and/or epoxies, preferably heat tolerant glues, adhesives and epoxies. Additionally, all welding should be conducted to a depth of two-thirds of the thickness of conduit  4 , end cap  28 , injection cap  30 , first plate  36  or second plate  38 . After welding, a leakage test, such as the Helium Vacuum Leakage Test, should be performed. 
     All materials comprising conduit  4 , end cap  28 , injection cap  30  and plug  34  of heat transfer device  2  or first plate  36  and second plate  38  of heat sink  12  should be compatible with one another. This prevents problems, particularly material fractures, associated with the different expansion/contraction rates of different materials used in combination and corrosion associated with anodic reactions. The material selected also should be compatible with and able to withstand the external environment in which heat transfer device  2  or heat sink  12  operates. For example, if heat transfer device  2  is operating in an acidic environment, the material should be resistant to the acid present. 
     Heat transfer medium  6  also can conduct cold temperature transfer when a cold source is exposed to either end of conduit  4 . Cold temperatures have been successfully transferred across conduit  4  when one end thereof came in contact with liquid nitrogen having a temperature of −195° C. 
     The invention will be better understood by reference to the following illustrated examples. With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to on skilled in the art, and all equivalent relationships to those described in the specification are intended to be encompassed by the present invention. 
     The following examples describe various compositions of first layer  20 , second layer  22  and third layer  24  and are known to be useful in preparing a superconducting heat transfer device  2  or heat sink  12 . The components preferably are added to the respective layers  20 ,  22 ,  24  in the amounts listed, in the order of listing and in accordance with the respective steps described above. 
     EXAMPLE 1 
     For forming first layer  20 , into 100 ml of distilled water add 5.0 grams of sodium peroxide, 0.5 gram of sodium oxide, 2.0 grams of magnesium dichromate or aluminum dichromate, 2.5 grams of calcium dichromate and 3.0 grams of boron oxide. 
     For forming second layer  22 , into 100 ml of twice-distilled water add 0.5 gram of cobaltous oxide, 0.5 gram of manganese sesquioxide, 0.5 gram of strontium carbonate, 0.2 gram of rhodium oxide, 0.8 gram of cupric oxide, 0.6 gram of β-titanium and 1.2 grams of potassium dichromate. 
     For forming the powder of third layer  24 , combine 1.75 grams of rhodium oxide, 1.25 grams of β-titanium, 3.1 grams of radium oxide, 2.6 grams of sodium dichromate, 0.4 gram of silver dichromate and 0.9 gram of monocrystalline silicon powder. 
     EXAMPLE 2 
     For forming first layer  20 , into 100 ml of distilled water add 5.0 grams of sodium peroxide, 0.5 gram of beryllium oxide, 2.0 grams of magnesium dichromate, 2.0 grams of calcium dichromate and 3.0 grams of boron oxide. 
     For forming second layer  22 , into 100 ml of twice-distilled water add 0.5 gram of cobaltous oxide, 0.5 gram of strontium chromate, 0.8 gram of cupric oxide, 0.6 gram of β-titanium and 1.2 grams of potassium dichromate. 
     For forming the powder of third layer  24 , combine 1.6 grams of sodium dichromate, 0.8 gram of potassium dichromate, 0.4 gram of silver dichromate and 0.9 gram of monocrystalline silicon powder. 
     EXAMPLE 3 
     For forming first layer  20 , into 100 ml of distilled water add 5.0 grams of sodium peroxide, 0.5 gram of beryllium oxide, 2.0 grams of magnesium dichromate, 3.5 grams of calcium dichromate and 3.0 grams of boron oxide. 
     For forming second layer  22 , into 100 ml of twice-distilled water add 0.5 gram of cobaltous oxide, 0.5 gram of strontium chromate, 0.8 gram of cupric oxide, 0.6 gram of β-titanium and 1.2 grams of potassium dichromate. 
     For forming the powder of third layer  24 , combine 1.6 grams of sodium dichromate, 0.8 gram of potassium dichromate, 0.6 gram of silver dichromate and 0.9 gram of monocrystalline silicon powder. 
     EXAMPLE 4 
     For forming first layer  20 , into 100 ml of distilled water add 2.0 grams of sodium peroxide, 0.3 gram of beryllium oxide, 2.0 grams of magnesium dichromate, and 1.0 gram of boron oxide. 
     For forming second layer  22 , into 100 ml of twice-distilled water add 0.5 gram of cobaltous oxide, 0.5 gram of strontium chromate, 0.4 gram of β-titanium and 1.0 gram of potassium dichromate. 
     For forming the powder of third layer  24 , combine 0.5 gram of sodium dichromate, 0.8 gram of potassium dichromate, 0.1 gram of silver dichromate, 0.3 gram of monocrystalline silicon powder, 0.01 gram of beryllium oxide, 0.1 gram of strontium chromate, 0.1 gram of boron oxide and 0.1 gram of sodium peroxide. 
     EXAMPLE 5 
     For forming first layer  20 , into 100 ml of distilled water add 2.0 grams of sodium peroxide, 0.3 gram of beryllium oxide, 2.0 grams of magnesium dichromate and 1.0 gram of boron oxide. 
     For forming second layer  22 , into 100 ml of twice-distilled water add 0.3 gram of cobaltous oxide, 0.3 gram of strontium chromate, 1.0 gram of potassium dichromate and 1.0 gram of calcium dichromate. 
     For forming the powder of third layer  24 , combine 0.3 gram of sodium dichromate, 0.1 gram of silver dichromate, 0.8 gram of potassium dichromate, 0.2 gram of monocrystalline silicon powder, 0.01 gram of beryllium oxide, 0.1 gram of strontium chromate, 0.1 gram of boron oxide, 0.2 gram of β-titanium and 0.1 gram of sodium peroxide. 
     EXAMPLE 6 
     For forming first layer  20 , into 100 ml of distilled water add 2.0 grams of sodium peroxide, 0.3 gram of magnesium dichromate, 1.0 gram of boron oxide and 1.0 gram of calcium dichromate. 
     For forming second layer  22 , into 100 ml of twice-distilled water add 0.3 gram of cobaltous oxide, 0.01 gram of beryllium oxide, 1.0 gram of potassium dichromate, 1.0 gram of boron oxide and 2.0 grams of magnesium dichromate. 
     For forming the powder of third layer  24 , combine 0.3 gram of sodium dichromate, 0.1 gram of silver dichromate, 0.8 gram of potassium dichromate, 0.2 gram of monocrystalline silicon powder, 0.1 gram of strontium chromate, 0.01 gram of beryllium oxide, 0.1 gram of boron oxide, 0.1 gram of sodium peroxide, 0.2 gram of β-titanium and 0.2 gram of magnesium dichromate. 
     EXAMPLE 7 
     For forming first layer, into 100 ml of distilled water add 2.0 grams of sodium peroxide, 0.3 gram of magnesium dichromate and 1.0 gram of boron oxide. 
     For forming second layer  22 , into 100 ml of twice-distilled water add 0.2 gram of cobaltous oxide, 1.0 gram of calcium dichromate, 1.0 gram of potassium dichromate, 0.5 gram of boron oxide, 1.0 gram of magnesium dichromate and 0.01 gram of beryllium oxide. 
     For forming the powder of third layer  24 , combine 0.3 gram of sodium dichromate, 0.05 gram of silver dichromate, 0.8 gram of potassium dichromate, 0.2 gram of monocrystalline silicon powder, 0.1 gram of strontium chromate, 0.01 gram of beryllium oxide, 0.1 gram of boron oxide, 0.1 gram of sodium peroxide, 0.2 gram of β-titanium and 0.2 gram of magnesium dichromate. 
     EXPERIMENTAL 
     1. Introduction 
     Adding an appropriate quantity, on the order of several milligrams, of third layer  24  powder, which is an inorganic thermal superconductive medium to pipe, such as conduit  4 , or flat interlayed piece, such as plates  36 ,  38 , that already has been treated with the first layer mixture and the second layer mixture, creates a superconductive heat transfer device  2 . For example, the addition of the third layer  24  powder into the cavity  6  of the conduit  4  or between the plates  36 ,  38  and then sealing the cavity  6  after subsequently eliminating the residual water and air upon heating, will create a heat transfer device  2 . Subsequent test results illustrate that third layer  24  is a superconductive medium and that a heat-conducting device made of third layer  24  is a thermal superconductive heat pipe. 
     The fact that a conventional heat pipe shares a similar outside shape to a thermal superconductive heat pipe used to raise some misunderstandings. Therefore, it is necessary to give a brief description on the differences and similarities of the two. A conventional heat pipe makes use of the technique of liquids vaporizing upon absorbing great amounts of heat and vapors cooling upon emitting heat so as to bring the heat from the pipe&#39;s hot end to its cold end. The axial heat conducting velocity of the heat pipe depends on the value of the liquid&#39;s vaporization potent heat and the circulation speed between two forms of liquid and vapor. The axial heat conducting velocity of the heat pipe also is restrained by the type and quantity of the carrier material and the temperatures and pressures at which the heat pipe operates (it can not be too high). The present heat transfer device  2  is made of a heat transfer medium whose axial heat conduction is accomplished by the heat transfer mediums&#39; molecules high-speed movement upon being heated and activated. The present heat transfer device&#39;s  2  heat conducting velocity is much higher than that of any metal bars or any conventional heat pipes of similar size, thus the term superconducting or superconductive, while its internal pressure is much lower than that of any convectional heat pipe of the same temperature. The applicable upper temperature limit of the present heat transfer device  2  is beyond the allowed upper temperature limit of the conduit  4  material. 
     The heat transfer device  2  made from the method disclosed herein can influence most if not all categories of heat transfer, especially on the heat utilization ratio. The heat transfer device  2  made from the method disclosed herein also is applicable in the development and utilization of solar energy and geothermal energy, and for the recycling of lower energy level heat. 
     2. Testing Method and Principle 
     The heat conducting velocity of a metal bar depends on the bar&#39;s heat conductivity, temperature gradient and the cross-sectional area orthogonal to the temperature gradient. Metals have higher heat conductivities than nonmetal solids. Among metals, silver has the highest heat conductivity of about 415 W/mK. The heat transfer devices  2  produced from the present inventive method are an entirely new development. However, it does appear that using the measurements of their effective or apparent heat conductivities and axial and radial heat fluxes as an indication of their properties is scientific and logical. 
     The testing method used to test the properties of the present heat transfer devices  2  employed an upgrade Forbes Method, in which a thermal superconductive heat pipe was taken to be a semi-infinite rod. Given that the temperature of the rod&#39;s reference surface is T 0  K, the temperature of a cross-section×meters away from the reference surface is T K, the temperature of the fluid (water) which is adjacent to the rod surface and which undergoes heat convection between itself and the rod is T t  K, the heat conductivity of the rod is k W/mK, the convectional heat transfer coefficient of the surface is h W/m 2  K, the girth of the rod is P meters, and the cross-sectional area of the rod is f m 2 , the principal differential equation of heat transfer is
 
 d   2   T/dx   2 −( h·p )/( k·f )·( T−T   ∞ )=0  (1)
 
     This is a heterogeneous differential equation. Suppose ⊖=T−T ∞  and Equation (1) then transforms into a homogeneous equation, by assuming m 2 =hp/kf, we have
 
 d   2   ⊖/dx   2   −m   2 ⊖=0  (2)
 
     For cylindrical objects, m 2 =4h/(kd 0 ), where d 0  is the diameter of the cylindrical object. 
     Suppose
 
⊖=⊖ 0  at x=0  (3)
 
⊖=0 at x=∞  (4)
 
     The solution that satisfies the above boundary conditions is
 
⊖=⊖ 0   (−mx)   (5)
 
     Under the boundary condition defined by Equations (6) and (7)
 
⊖=⊖ 0  at x=0  (6)
 
 d⊖/dx =0 at  x=L   (7)
 
then another solution of Equation (2) is
 
⊖/⊖ 0   =Exp (− mx ){[1 +Exp (2 m ( L−x ))]/[1 +Exp (2 mL )]}  (8)
 
     Since some experimental conditions may appear similar to that specified by Equations (6) and (7), and the value of the expression inside the square brackets is close to 1, therefore we have
 
⊖/⊖ 0   =Exp (− mx )  (9)
 
which also is correct.
 
     The axial heat conducting velocity across the reference surface is
 
 Q   x   =−kf ( d⊖/dx ) x=0   (10)
 
     From Equation (5), we can deduce the following
 
( d⊖/dx ) x=0 =−⊖ 0   mExp (− mx )| x=0 =−⊖ 0   m   (11)
 
     By substitution with Equation (6), we have
 
 Q   0   =k·f·m·⊖   0   (12)
 
     The speed of heat flux from rod to water is
 
 Q   0   =V·ρ·C   p ·( T   0   −T   i ) watts  (13)
 
where
 
     V=volume flow rate of water (m 3 /s) 
     ρ=density of water (kg/m 3 ) 
     C p =specific heat of water (J/kgK) 
     T o =outlet temperature of water (K) 
     T i =inlet temperature of water (K) 
     and
 
 Q   i   =d   0   πLhΔt   ln   (14)
 
where
 
     L=length of the rod (meters) 
     d 0 =outer diameter of the rod (meters) 
     h=convectional heat transfer coefficient (W/m 2 K) 
     Δ t   ln =(⊖ 0 −⊖ L)ln(⊖   o /⊖ L ) 
     Upon having measured the above quantities, the effective heat conductivity of a thermal superconductive heat pipe can be calculated and the heat flux also can be calculated. 
     3. Testing apparatus 
     Based on the above mentioned testing principle and mathematical model, a testing apparatus, as shown in  FIG. 7 , comprising the thermal heat conductive pipe  102 , cooling water casing pipe  104 , thermocouples  106 , pressure gauge  108 , water vapor heating chamber  110 , condensed water collector  112 , and evacuation valve  114  was assembled. 
     4. Testing results 
     There are many advantages to using saturated water vapor as the heat source to activate the heat transfer medium  24  inside the heat transfer device  2 . Saturated water vapor has a higher condensing heat transfer coefficient and the saturated water vapor comes into direct contact with the heated surface of the heat transfer device  2  exclusive of contact heat resistance. Keeping the pressure of the saturated water vapor under control means keeping the heating temperature under control, and can provide the heat transfer device  2  with a stable heat flux. After the flow rate and the inlet temperature of the cooling water is specified, the testing system will come into a stable equilibrium. All of the physical quantities that are measured are stable and well repeatable. 
     The following chart illustrates four representative groups of measured results, and  FIGS. 8-11  show these results graphically. 
     
       
         
           
               
            
               
                   
               
               
                 Results of Measurement 
               
            
           
           
               
               
               
               
               
            
               
                   
                 Axial Heat 
                 Radial Heat 
                 Effective Heat 
                   
               
               
                 No. 
                 Flux (W/m 2 ) 
                 Flux (W/m 2 ) 
                 Conductivity (W/mK) 
                 k/k Ag   
               
               
                   
               
               
                 1 
                 8.618 × 10 6   
                 4.396 × 10 4   
                 1.969 × 10 6   
                 4.746 × 10 3   
               
               
                 2 
                 8.363 × 10 6   
                 4.267 × 10 4   
                 3.183 × 10 6   
                 7.672 × 10 3   
               
               
                 3 
                 8.260 × 10 6   
                 4.214 × 10 4   
                 2.624 × 10 5   
                 6.324 × 10 2   
               
               
                 4 
                 8.831 × 10 6   
                 4.505 × 10 4   
                 3.235 × 10 4   
                 7.795 × 10 2   
               
               
                   
               
            
           
         
       
     
     The temperature distribution curve, effective heat conductivity, convectional heat transfer coefficient of the pipe surface of the cooling segment, and heat conducting velocity were obtained under different cooling water flow rates. Although these values show certain differences, they indicate that the heat pipe is thermally superconductive. 
     Changes of cooling water flow rates causes changes in temperature distribution, but no changes in heat conducting velocity. This means that the heat conducting velocity in the heating segment has reached its upper limit. That the heat conducting area of the heating segment was designed not great enough was due to the underestimation of the heat conducting capability of the heat pipe. Changes in temperature distribution brought changes in the value and sign of slope m in the correlation equation. That the convectional heat transfer coefficient was changed means that the effective heat conductivity also was changed. The thermal superconductivity of the heat pipe is confirmed by these changes. When m has a plus sign, the outlet temperature of the cooling water approaches the temperature at the base of the heat pipe (at x=0). A conventional heat exchanger can attain such a high heat transfer efficiency only under the condition of counter flow. If the cooling water flow rate is increased, then the outlet temperature of the cooling water approaches that at the other end (x=L). A conventional heat exchanger can reach such a great heat transfer efficiency only when the heat conducting area is infinite. 
     Therefore, the foregoing, including the examples, is considered as illustrative only of the principles of the invention. Further, various modifications may be made of the invention without departing from the scope thereof and it is desired, therefore, that only such limitations shall be placed thereon as are imposed by the prior art and which are set forth in the appended claims.