Portable coolers or ice chests for keeping foods beverages cold, are usually of a weight and size for be conveniently carried and transported by a user. Such cool are thermally insulated to retain the cooling effect of ice other pre-frozen cooling materials placed in the coo chamber along with the foods or beverages. Inexpens coolers are commonly made from materials such as expanded foamed cellular polystyrene while more expensive contain incorporate rigid plastic container walls. Although ice often readily available, replenishment of the ice or cooling material may be quite inconvenient at a campi picnic or recreational site. For larger coolers, suffici quantities of ice may not be available for initially pack the cooling chamber. The presence of water in the coo chamber from the melting ice is also often undesirable unl food containers and wrappers are waterproof and adequat sealed. Other portable coolers incorporate conventio refrigeration systems using freon or CFC's and sm electrically powered compressors requiring 12-volt DC 120 volt AC power sources, or Peltier effect systems. O unplugged from the power source, these coolers no lon operate. In addition to portable coolers intended recreational use, there exists a need for portable cool capable of storing specir ^" * goods, for example, medi products or other valuable or highly perishable materi within specific and critical temperature ranges for relativ long time periods advantageous when such goods are to stored or shipped and where conventional refrigerati equipment is not available or is impractical.

The portable cooler of the present invention offers alternative to using ice or other pre-frozen cooli materials, thereby obviating the disadvantages a inconvenience of using and replenishing ice common with above-described coolers. Moreover, coolers of the inventi do not require a source of electrical power for cooli

operation. In another embodiment, a two reactor assemb apparatus is provided in which the evaporator is replaced a reactor assembly. A different complex compound is used each of the two reactor assemblies. Although such a pow source is used to charge the system, once charged, the cool will typically operate for hours without need of electric power. In yet another embodiment, the evaporator and reacto or two reactors, may be reversed to provide a heat stora container. Summary of the Invention

The apparatus of the present invention comprises portable cooler assembly including a container having cooling cavity or chamber, an evaporator in therm communication with the cooling chamber, a reactor assemb comprising one or more reactors containing a complex compou of ammonia or other suitable polar refrigerant and one or mo metal salts, means for heating the complex compound within t reactor, and a valved conduit for directing the refrigera between the reactor assembly and the evaporator. Th evaporator and reactor components may be permanently installe in the portable cooler, or may be removable. In operating th cooler, prior to cooling use, the reactors are heated t desorb the refrigerant which is directed to the evaporator A valve or other closure member in the refrigerant condui between the evaporator and the reactors is opened to commenc the cooling operation. In another embodiment, or two reacto assembly apparatus is provided in which the evaporator i replaced by a reactor assembly. A different complex compoun is used in each of the reactor assemblies. The advantages o the apparatus and components and the operation will be mor fully explained in the following detailed description.

Brief Description of the Drawings

Figure 1 is a schematic side-view of the interior of th portable cooler illustrating the components?

Figure 2 is a perspective view of a portable cooler the invention, partially cut-away to expose the interior the container;

Figure 3 is a detailed illustration of one embodiment a reactor design; and

Figure 4 is a perspective view of the reactor a evaporator components, illustrating another embodiment of t invention.

Detailed Description of the Invention

Shown in Figure 1, the basic apparatus comprises container 10 having sidewalls, a bottom and a lid 11 f accessing the interior cavity or chamber 13 in which foo beverages or other goods to be cooled or maintained at relatively cool temperature are placed. An evaporator 20 located and positioned within the chamber so that it thermally exposed to the chamber interior whereby cooling fr the evaporator surface is efficiently transferred to the goo within the chamber. A reactor assembly 12 is secured on t exterior of the container so that it is exposed to ambient a temperature conditions. A conduit 14, cooperating with valve 16, directs ammonia between the reactor assembly a evaporator. In the schematic apparatus illustrated Figure 1, the reactor shown includes a heater 15 whi provides heat for the complex compound present in the reacto the purpose of which will be explained more fully hereinafte

Referring also to Figures 2 and 4, reactor assembly includes one or more reactors 31 containing the compl compounds of a polar refrigerant and a solid metal sal These complex compounds comprise chlorides, bromide sulphates and chlorates of metals selected from the gro consisting of an alkali and alkaline earth metal, chromiu manganese, iron, cobalt, nickel, cadmium, tantalum a rhenium, or a double metal chloride salt, complexed with polar refrigerant, capable of forming coordinative bonds wi the salt. Another salt of special interest is Na BF Example of polar refrigerants suitable for forming su

complexes comprise ammonia, water, lower alkanols, especial methanol, amines, especially methylamine, sulfur dioxide, a phosphine. It is to be understood that by referen hereinafter to the preferred refrigerant, ammonia, oth suitable polar refrigerants are also intended. The sal generally suitable for the invention are disclosed in U.S Patent No. 4,848,994, the description of which is incorporate herein by reference. The preferred ammoniated comple compounds used in the apparatus of the invention are selecte from the group consisting of LiCl-0-3 (NH ₃ ) , BaCl ₂ -0-8(NH ₃ ) CaCl ₂ -4-8(NH ₃ ) , CaCl ₂ -2-4(NH ₃ ) , CoCl ₂ • 2-6 (NH ₃ ) , SrCl.,-1 8(NH ₃ ), SrBr ₂ -0-8(NH ₃ ) , CaBr ₂ -2-6(NH ₃ ) , NiCl ₂ • 2-6(NH ₃ ) , FeC • 2-6 (NH ₃ ) , Na BF ₄ • 0.5-2.5 (NH ₃ ) , and the ammoniated doubl metal chloride salts disclosed in the aforesaid incorporate patent. The LiCl complexes include a number of coordinatio steps between 0 and 3. The most preferred complexes are thos of SrCl ₂ and CaCl ₂ . The compound in the reactor may be complex compound of a single metal salt, or, a mixture o salts may be used. For example, where rate of adsorptio and/or desorption is important for quick cool down, loa control, etc. , one or more additional salts may be used t take advantage of complex compounds having such properties.

In operating the apparatus of the invention, the comple compounds alternately adsorb and desorb ammonia which i alternately directed to and from the evaporator. Whe charging or re-charging the system, prior to the coolin operation, the complex compound in the reactors is heated b internal or external heating means causing ammonia desorptio in an endothermic reaction. The reactors are preferabl completely charged by desorbing substantially all of th ammonia that can be desorbed at the temperature to which th reactors are heated. The desorbed ammonia is discharged t the evaporator, where it is now acting as a condenser, i cooled by exposure to ambient temperature conditions. Coolin of the evaporator during the charging cycle is preferabl accomplished by exposure of the exterior of the evaporato

coil, plate or tubes to air. If desired, evaporator cool with forced air or other cooling means may also be used.

In a preferred embodiment, the reactor assembly inclu internal heating means, preferably electrical resista heating elements in the form of wires or the like within e reactor. One design of such a reactor is illustrated Figure 3 with electrical resistance wires 34 and 35 extendi within a heater core 30 which becomes heated as electri current is supplied to the wires. Heat exchange fins 32 thermal contact with heater core 30 assist in directing he to the layers of complex compounds 36 located between t fins. As the complex compound is heated, ammonia is desorb and passes through gas-permeable liner 38, comprising material such as woven fiberglass, wire mesh, gas permeab foam, fire brick, etc. into the open space within the housi or tube 37. The ammonia is then directed via manifold 25 a conduit 14, to the evaporator assembly 20. Valve 16, wh opened, allows ammonia to flow between the evaporator a reactor assembly components. The reactor design illustrat in Figure 3 is only one example of such a reactor, and oth reactor systems and shapes may be used, such as described co-pending U.S. Patent Application, Serial No. 07/320,65 filed March 8, 1989, the description of which is incorporat herein by reference. In the preferred design shown, the reactor assembly m include an electrical socket 21, or an electrical outlet, f supplying electrical current to the reactor heaters. Howeve the reactor assembly may also be provided with a permane power cord for plugging it into a suitable electric outle although a removable cord is preferable since the apparatus to be portable and the presence of a cord may disadvantageous, both from a standpoint of physic inconvenience as well as the wear or damage likely caused a permanent cord. The reactor assembly may also be provid witl in internal transformer and switching means for t alte aate use of AC or DC power. For this purpose, t reactor assembly may also be provided with a suitab

electrical outlet for attaching a DC extension cord so th the appliance could be recharged with a battery power sourc for example, a lighter outlet commonly found in a vehicl Also illustrated in the reactor assembly and exposed on t distribution manifold 25 is a pinch-off tube 26 through whi ammonia may be charged. Any suitable location and design a gas charge means may be used.

In one embodiment, the portable cooler assembly may assembled with the reactor and evaporator componen permanently installed. The location and positioning of t evaporator within the cooling chamber is for convenience a well as efficiency, and it may be positioned on the bottom top, and/or along one or more of the sides of the interio chamber of the container. The exterior of the evaporato assembly conduits or coils may be covered with a film o material that provides for efficient heat exchange, but whic will protect the coils from damage, or the coils may b directly exposed within the cooling chamber as illustrated i Figure 2. Also shown is a built-in conduit 24 for directin ammonia between the reactor and evaporator component. In th embodiment illustrated, support legs 17 and 18 extend at th bottom of the cooler for support and also to protect th reactor tubes 31, which are also preferably exposed to ambien conditions for convective cooling by the surrounding air or b using a fan or other cooling means. As an alternative to conventional evaporator shape illustrated in the drawings, th evaporator may be designed to more efficiently cool goods o containers of goods or products to be stored or transported i the cooler. For example, where tubes, vial or modules o medicines or the like are to be cooled, the evaporator may b a block with one or more cavities, or comprise a coil or othe means shaped to hold single or multiple containers. Thus, depending on the size or capacity of the cooler an evaporator, the latter may be designed and shaped t accommodate, hold, nest, surround, and/or cover any desire goods and/or containers for such goods.

To initiate the cooling cycle, valve 16 is opened and t condensed ammonia in evaporator 20 evaporates, thereby cooli the evaporator coils or tubes 27. The evaporating ammon from the tubes 27 flows through condenser manifold 22, condu 14 and is directed into reactor manifold 25 and distribut into reactors 31 where it is adsorbed into the compl compound mass within the reactors in a exothermic reactio Thus, it is important to keep the reactor assembly tub exposed to ambient conditions whereby they are cooled convective air.

In another embodiment, the reactor and evaporat assembly components may be removable from the container whe such a design is desired or advantageous. For example, whe extended or continuous use of the cooler is desired, with removable evaporator and reactor design, these componen could be exchanged for recharged components, with cooling th continued without substantial interruption for rechargin With such a design once an evaporator has been complete discharged with substantially all of the ammonia evaporat and adsorbed in the reactors, these components can be remov from the container, and other reactor and evaporat components which have been recharged as previously describe installed. Of course, such an embodiment would requi suitable valves on the reactor and evaporator components f connecting and disconnecting them to the conduit syst installed in the container.

Another embodiment of the invention includes a system which the entire functioning assembly of the assembly removable and replaceable. An example of the apparatus illustrated in Figure 4 with the evaporator, reactor a conduit and valve components being removable from a cooler a unit or as individual components, but which may be install in any cooling container which can accept the components or which they can be secured. The conduit may also be in t form of a relatively flexible hose, whereby it may be mo easily installed. Valve 16 is used for selectively directi the ammonia to and from the reactor and evaporator component

and which may be installed in different coolers, and desired, removed for recharging. Such an assembly may al include suitable brackets (not shown) for attaching t reactor assembly to the exterior of the cooler on which it to be installed. Brackets or means for securing t evaporator within the cooling chamber may be used, or the l may be shaped or notched for mounting the evaporator on t lid. This embodiment may be especially useful on relativel inexpensive foamed styrene coolers with only the necessity o forming a hole or notch in the container for installing th conduit between the evaporator and reactor components. Clips straps or the like could be provided for securing the reacto assembly and using a flexible conduit 14, the evaporator coul be placed where desired in the cooling chamber. The apparatus of the invention may include a plurality o evaporators using a single reactor assembly, by providin multiple conduits from the reactor assembly. It may also b beneficial or preferred to incorporate a receiver or ammoni reservoir cooperating with the evaporator. Multiple reacto assemblies may be used for single or multiple evaporator where desired or otherwise advantageous.

In another embodiment, the apparatus of the inventio incorporates two reactor systems comprising first and secon reactor assemblies, each comprising one or more reactors. Th first reactors are provided with a different ammonia-sal complex, from the complex (or other suitable pola refrigerant-salt complex) present in the second reactors whereby ammonia flows between the reactors containing the tw different salts as they alternately adsorb or desorb ammoni in exothermic and endothermic reactions, respectively. I such an apparatus, ammonia does not go through a liquid/ga phase change, and the evaporator is replaced by a reacto assembly that cools the cooling chamber as the comple compound therein desorbs ammonia. In this embodiment, it i important that the different complex compounds in the tw reactor assemblies have equilibrium temperatures differential

of between about 20°C and 150°C. The term "equilibr temperature differential" is intended to mean the differe between any two different complex compound equilibr temperatures at the same or substantially the same operat pressure, typically between about 0.1 and about 30 bars in apparatus of the invention. Such an equilibrium teιr.:,erat differential will provide sufficient practical temperat lift and yet be within practical and safe ranges for h rejection during exothermic ammonia adsorption. In cooling or inside reactor assembly, i.e., the reactors loca in the cooling chamber for providing cooling during ammo desorption, the preferred complex compounds are the ammonia BaCl ₂ , CaCl2, NaBf ₄ and SrCl ₂ complex compounds previou disclosed. The preferred ammonia complex compounds used the outside, second reactors in this embodiment LiCl•0-3(NH ₃ ) , SrBr ₂ -0-8(NH ₃ ) , CaBr ₂ -2-6(NH ₃ ) , CaCl ₂ -2-4(NH SrCl ₂ -l-8(NH ₃ ) , CoCl ₂ • 2-6 (NH ₃ ) , NiCl ₂ -2-6(NH ₃ ) , FeCl ₂ • 2 (NH ₃ ) SnCl ₂ -0-2.5(NH ₃ ) , NaBF ₄ • 0.5 - 2.5 (NH ₃ ) .

This reactor construction of the two reactor system is previously described for the single reactor apparatus. O the outside reactors need incorporate a heating means heating the complex compound therein since the inside reacto will adsorb and desorb ammonia at ambient temperat conditions. To charge the apparatus, the outside reactors a heated to desorb ammonia which is directed to the cooli reactors where it is adsorbed in the salt in an exother reaction. When the apparatus is to be used for cooling, t valve between the first and second reactors is opened, a because of the equilibrium pressure difference between the t complexes, ammonia is desorbed from the cooling reactors in endothermic reaction which cools the chamber. The du reactor system coolers are preferably used where cooli chamber temperatures between about 5°C and about 20°C a suitable. In a reactor incorporating ammonia SrBr ₂ complexe it is desirable to heat the composition to temperatures bel about 110°C due to melting of the complexes under certa

operating conditions. It is also to be understood that t complex compound in the first or inside reactors must have higher equilibrium pressure than the complex compound in t second, outside reactors, at any given operating pressure. In a specific example of portable cooler according to t invention, a 30 liter cooling chamber incorporates a react assembly comprising nine complex compound reactors, each 1.625" diameter with the reactor tubes 24" long containing total of 2.6 kg of SrCl ₂ solid adsorbent salt, and using t reactor configuration illustrated in Figure 3. The evaporat design comprises ten evaporator tubes, each 24" long with a OD to provide a total evaporator volume of about 2,700 c Such a configuration results in a cooling equivalent of abo 10 pounds of ice. Of course, such a specific cooler is onl by way of example and the reactor and evaporator componen may be of any suitable size and configuration.

Cooling chamber temperatures in a portable cooler of th present invention are between about -20 ^β C and 25°C dependin on the salt and complex used and the rate of ammoni evaporation. However, the invention is not to be so limite and, if desired, may be designed to achieve coole temperatures, for example, down to -70 ^β C, where using suitable. Normal practical operating pressures in the syste are between about 0.1 and about 30 bars. A thermostat o other means of regulating the ammonia evaporation rate may b used, for example, a temperature control incorporating throttling valve in the ammonia vapor conduit line fo controlling the refrigerant bleed control rate. In anothe embodiment, the reactor assembly may be designed as a pull-ou type that may be heated by other heating means. Moreover, th size and shape of the cooler and the components describe herein are not to be limited to those shown in the drawings Thus, a cooler of the invention may be relatively small, fo example, less than a quart volume capacity, up to a 100 250 gallon size or larger, which may be mounted to o transported in a truck bed, or the like. For usua

recreational portability, containers up to about 40 gallo are suitable. Where the container is to be used for stori or transporting specific containers or goods, it may designed, shaped, and insulated to accommodate such container, or containers. For example, where vials, tubes other containers for medicines, biological samples, specimen organs or the like are to be stored or transported, t container may be constructed and designed to meet the cooli capacity requirements including adequate reactor capacit insulation, and temperature control means, for maintaini necessary cooling chamber temperatures for up to at lea about 100 - 150 hours or more. The apparatus of the inventi may also be combined with a conventional refrigeration syste For example, it may be constructed to include convention electrically operated refrigeration components, a preferably, manual and/or automatic switching means f operating the reactor assembly of the invention wh electrical power to the conventional refrigeration componen is interrupted. Although the invention has been described in terms of cooler, it may also be modified to function as a heating heat storage container. In such an embodiment, the evaporat and the reactor assembly may simply be reversed, so that t reactor components are located in the chamber of t container, and the evaporator assembly located outside. Su an alternative use of the equipment may be readi accomplished where the evaporator and reactor components a removable as previously described. Where each of the components are of a size to be installed in the containe they may be interchanged for transforming the container f use as either, or both, a cooler and/or a heat storage cas as desired. This same interchangeability may be tak advantage of using the two reactor embodiment previous described. In either alternative, temperatures within t container using the described heat producing react components will provide interior temperatures from about 50

to about 600°F, where ammonia is the refrigerant, and ev higher for certain other refrigerants. Of course, t practical limits for such heating will also depend on t materials used for container construction, insulation, safe requirements, etc. Such modifications and embodiments withi the scope of the invention described herein will be evident t those skilled in the art as well as the advantages and use hereof.