Mobile Service Cart with Closed Circulation System

Abstract

An improved refrigeration and heating system comprising a thermochemical device, and a mobile service cart. The thermochemical device is capable of refrigerating or cooling the ambient air due to an internal chemical process. This same chemical process also produces a significant amount of heat as a by-product which, if left alone, would normally be vented or released in to the atmosphere and become lost. However because the theremochemical device is disposed at the center of the cart, the heat which is generated by the cooling process is retained and utilized to provide a separate heating area within the cart. This allows the current system to operate as a closed loop, meaning that the cart and thermochemical device work in conjunction to form a self-sustaining hot and cold storage area with very little maintenance or input from a user.

We claim: 
     
         1 . A mobile system for storing and maintaining food stuffs at a first temperature and a second temperature comprising:
 a cart comprising a front hemisphere and a rear hemisphere; and   a thermochemical device disposed within the cart,   wherein the thermochemical device is evenly distributed between the front and rear hemispheres, and   wherein heat produced by thermochemical device is retained within the cart.   
     
     
         2 . The system of  claim 1  where the front hemisphere and the rear hemisphere of the cart each comprise two thermally insulated halves separated by a tray rack. 
     
     
         3 . The system of  claim 2  where the tray rack comprises:
 a tray arm; 
 a plurality of tray partitions coupled to the tray arm in a vertical configuration; and 
 a gasket disposed between each of the vertically configured tray partitions. 
 
     
     
         4 . The system of  claim 3  where each gasket is comprised of at least two seals coupled to a first of the plurality of tray partitions and at least two seals coupled to a second of the plurality of tray partitions, the second tray partition being disposed directly beneath the first tray partition. 
     
     
         5 . The system of  claim 2  where the thermochemical device comprises a hot module and a cold module, wherein the hot module is in thermal contact with at least one thermally insulated half of each hemisphere, and wherein the cold module is in thermal contact with at least one other thermally insulated half in each hemisphere. 
     
     
         6 . The system of  claim 5  wherein the thermally insulated halves of the hemispheres in thermal contact with the hot module are diametrically opposed to one another. 
     
     
         7 . The system of  claim 5  wherein the thermally insulated halves of the hemispheres in thermal contact with the cold module are diametrically opposed to one another. 
     
     
         8 . The system of  claim 6  further comprising means for forming a closed loop flow of air through the hot module and the insulated halves of the hemispheres in thermal contact with the hot module. 
     
     
         9 . The system of  claim 7  further comprising means for forming a closed loop flow of air through the cold module and the insulated halves of the hemispheres in thermal contact with the cold module. 
     
     
         10 . The system of  claim 1  further comprising means for recharging the thermochemical device disposed in the cart. 
     
     
         11 . The system of  claim 1  where the thermochemical device comprises a working fluid and a reactor material,
 wherein the working fluid comprises: liquid ammonia, water, alcohol, hydrogen, carbon dioxide, or any combination thereof, and 
 wherein the reactor material comprises: salts, hydroxides, metal hydrides, carbonates, alcoholates, or any combination thereof. 
 
     
     
         12 . A method for storing and maintaining food stuffs at a first temperature and a second temperature comprising:
 cooling a first longitudinal half of a cart with a first closed loop of air flow;   heating a second longitudinal half of the cart with a second closed loop of air flow;   thermally insulating the first and second longitudinal halves of the cart from each other;   disposing a plurality of trays into the cart; and   thermally insulating a first portion of each of the plurality of trays from a second portion of each of the plurality of trays.   
     
     
         13 . The method of  claim 12  where cooling a first longitudinal half of a cart with a first closed loop of air flow comprises passing the air flow over a means for performing an endothermic reaction disposed in the first longitudinal half of the cart. 
     
     
         14 . The method of  claim 13  where heating a second longitudinal half of the cart with a second closed loop of air flow comprises passing the air flow over a means for containing an exothermic reaction produced by the waste product produced by the means for performing the endothermic reaction disposed in the first longitudinal half of the cart. 
     
     
         15 . The method of  claim 12  where disposing a plurality of trays into the cart comprises disposing the plurality of trays into in a tray rack, wherein the tray rack is disposed between the first and second longitudinal halves of the cart. 
     
     
         16 . The method of  claim 15  where thermally insulating a first portion of each of the plurality of trays from a second portion of each of the plurality of trays comprises dividing each tray into first and second portions by inserting each tray into a gasket defined in the tray rack. 
     
     
         17 . The method of  claim 12  further comprising recharging a thermochemical device disposed in the cart. 
     
     
         18 . A method for operating a system for storing and maintaining food stuffs at a first temperature and a second temperature comprising:
 activating a thermochemical device disposed within a cart;   operating the thermochemical device according to a predetermined set of programmable instructions;   deactivating the thermochemical device; and   recharging the thermochemical device.   
     
     
         19 . The method of  claim 18  where operating the thermochemical device according to a predetermined set of programmable instructions comprises:
 operating the thermochemical device for a predetermined amount of time; or 
 operating the thermochemical device until a chemical supply contained within the thermochemical device has been depleted. 
 
     
     
         20 . The method of  claim 18  further comprising detecting when one or more doors disposed on the cart are in the open position. 
     
     
         21 . The method of  claim 20  further comprising activating an alarm when a defect has been detected in the thermochemical device or for when the doors disposed on the cart have been detected in the open position. 
     
     
         22 . A mobile cart for maintaining food stuffs at a first temperature within a first portion and at a second temperature within a second portion comprising:
 a tank, a condenser, and at least one evaporator within the first portion;   at least one reactor and a fan within the second portion;   thermal insulation between the first portion and the second portion; and   a rack for accommodating a plurality of serving trays, wherein the rack is configured to maintain each of the plurality of serving trays simultaneously within the first and second portions.