Patent GB-1076584-A (GB)
Title: Improved apparatus for the storage of perishable animal and plant materials
IPC: F25D17/06
Filed: 1965-02-05
Abstract: 1,076,584. Preserving animal and plant materials. WHIRLPOOL CORPORATION. Feb. 5, 1965 [March 9, 1964], No. 5146/65. Heading A2D. [Also in Division F4] An apparatus for storing perishable animal and plant materials subject to respiratory deterioration changes on storage in air containing normal quantities of oxygen and carbon dioxide wherein oxygen is consumed and carbon dioxide is produced according to the following approximate respiratory change equation: nO 2  + (CH 2 O) n #nCO 2  + nH 2 O wherein CH 2 O represents a carbohydrate module from said materials, comprises a storage container for the materials; atmosphere control means for maintaining in the storage container a storage atmosphere of a predetermined composition to retard but not to prevent the progress of the equation; temperature control means for maintaining a predetermined temperature in the storage container; humidity control means 'for maintaining a predetermined relative humidity in the storage container; and air translation means for circulating the storage atmosphere in the storage container. A storage container 10 has circulating atmosphere passages 12, 14, 16 formed by a false top 11, a false side wall 13 and a false bottom 15. The bottom 15 comprises parallel spaced co-planer supports and parallel spaced cross supports through which circulating air is returned to a storage space 21 within the container 10. A blower 19 sucks air out of the storage space 21 and circulates it over a coil 44, a refrigerant evaporator 24, reheaters 99, 100 and various sensors including a temperature sensor 86 in the atmosphere passages 12, 14, 16. When cooling is required, as detected by the temperature sensor 86, refrigerant gas is compressed by a compressor 25 and passed by a line 36 through a blower (33) cooled condenser 27, a valve 37, an expansion valve 30 controlled by a thermostat 46 in a returned line 39, to the refrigerant evaporator 24. The refrigerant gas returns by the line 39 through a pressure regulating valve 32 to the compressor 25. When no cooling is required, a valve 31 in a line 43 opens to allow the refrigerant gas to by-pass the condenser 27 and return via the coil 44 in which this gas is cooled by the blower 19. When rapid cooling is required, such as immediately after loading the container with apples for example, sensors 74, 75 planted inside and on the surface of an apple respectively, are used to control the operation of a valve 41 which by by-passing the valve 32 and allowing an increased flow of refrigerant gas, produces increased cooling. Should the temperature fall below a preset limit as sensed by the sensor 86, reheaters 99, 100, are brought into circuit. The refrigerant compressor 26 is switched off when the ambient temperature, as detected by a sensor 104 of an external temperature control 103, falls below that required in the container 10. Defrosting is controlled either by a differential pressure switch 146 with sensors 147, 148, which operates when the ice built up on the evaporator 24 has created a sufficient atmosphere pressure difference on either side of it, or by a timer. The switch 146 stops the blower 19 and energizes a defrosting heater 183. After defrosting the blower is not re-started until a pre-determined low temperature is again reached. Humidity control is effected by a control 120 with its sensor 119, reduction of humidity being obtained by the control 120 causing valves 37, 41 to open allowing refrigerant to flow to the evaporator 24 and allowing the free flow of returning refrigerant to the compressor 25 respectively, reheaters 99, 100 also being placed in circuit. Humidity is increased by sucking air out of the container 10 along lines 126, 126A, via valve 127a, by means of a compressor 122 and feeding this air via a valve 125 to a water atomizer 132 fed from water 135 in the bottom of the container 10. A carbon dioxide control 231 with its sensor 230A either cause carbon dioxide to be fed into the container 10 from a cylinder 244 or may effect its removal by diverting the air sucked by the compressor 122 through a carbon dioxide absorber 127 and feeding the air back into the container 10 via the valve 130. The oxygen content of the storage atmosphere as sensed by a sensor 203, can be decreased by the control 204 opening a valve 206 to feed in a low oxygen atmosphere from a high pressure container 207, or increased by the control 204 starting up a compressor 220 to feed in outside air. The composition of the atmosphere maintained within the storage container 10 is varied according to the nature of. the materials stored therein. Materials that may be stored for long periods in the apparatus include cut flowers, flower bulbs, tobacco, apples, berries, peaches, pears, milk, butter, cheese, onions, celery, tomatoes, carrots, oranges, meat and meat products, eggs, potatoes, bananas, grapes, asparagus, beans, grains, nuts and peas.