GB631037A - Removable cooling unit for compartments of transport vehicles - Google Patents

Abstract

631,037. Refrigerators. U. S. THERMO CONTROL CO. July 14, 1947, No. 18731. Convention date, July 30, 1941. [Class 29] [Also in Group XXIX] A self-contained removable unit for cooling the food storage &c. compartments of transport vehicles is driven by an internal combustion engine 75 in a casing 32 separated by an insulated wall 36 from a casing 46 containing the evaporator 123 and a fan 92, the whole being fitted in an aperture 53 in the front wall 54 of the truck. &c. so that the engine, the compressor 77 and the condenser 90 are outside the truck and the evaporator and fan inside. The speed of the engine 75 is governed by a thermostat 158 adjacent the evaporator. The gas engine fed from a fuel tank 93 drives by a belt 85 the refrigerant compressor, a fan 89 for cooling the condenser 90, and the fan 92 within the truck which draws in air from the central part of the truck, through an opening 49 in the casing 46, over the tubes of the evaporator 123' and supplies the cooled air to a longitudinal duct 101 arranged centrally beneath the roof 108 of the truck. Openings 115. 120 with baffles 116. 122 direct the cooled air over the side and end walls of the truck as shown in Fig. 2. To defrost the evaporator, or to warm the goods in the truck when necessary, a two-way valve 142 is turned by a handle 148 to supply hot gas from the compressor direct to the evaporator by a pipe 149. The expansion valve 135 is controlled by a thermostat 145 in the suction line 126 and supplies the evaporator through three capillary tubes 131, 132, 133. The thermostat 158 controlling the engine is in the path of the warm air returning to the evaporator and is connected by a pipe 159 with a bellows chamber 160, Fig. 14, to operate by a bellows 163 a lever 177 connected through a spring 179 and lever 180 to the throttle control 186 on the carburettor 76. A screw 197 regulates the pressure of a spring 192 acting against the bellows to set the thermostat. An arm 171 on the lever 177 carries an armature 172 positioned adjacent a magnet 173, and when the food compartment is warm the bellows 163 is constricted to bring the armature within the operative force of the magnet, which puts the throttle into position for full compression; this continues until the temperature falls sufficiently to enable the spring 192 to overcome the pull of the magnet 173 on the armature 172. The throttle is then gradually closed until, when the desired temperature is reached, the engine 75 is idling. The casing 32 is ventilated at 22, 34, 35. The water from defrosting falls into a pan 151 and overflows to' the outside through a pipe 154. The pan 151 is filled with mineral wool to hold the water which evaporates and passes through holes 155 to the warm air entering the evaporator thus maintaining the air in the truck humid.