GB476272A - Improvements in or relating to the storage of fresh fruit - Google Patents

Abstract

476,272. Preserving fruit. PIQUE, J. J. Dec. 1, 1936, No. 32918. [Class 49] In storing fresh fruit, the content of carbon dioxide and oxygen in the atmosphere of the storage chamber is adjusted at the outset, as soon as the fruit has been placed in the storage chamber and the latter closed, to give the atmosphere most suitable for the fruit being stored, and the atmosphere in the chamber is thereafter controlled to maintain the most suitable condition thereof by introducing oxygen and employing a liquor which absorbs carbon dioxide to absorb this gas therefrom. In the example given, the fruit is contained in boxes or trays 1 which are stacked on a slatted platform 2 in the storage chamber 3 which is heat-insulated and has an inner surface of metal or other gas-impervious material. A tubular cooler 4 and a fan 5 are disposed centrally in the chamber for cooling and circulating the atmosphere therein. Nitrogen and carbon dioxide are first supplied to the chamber from cylinders 5a, 6, air leaving through valve 8 which is closed when the atmosphere has the desired composition, e.g. for Cox's Orange Pippin apples, about 5 per cent carbon dioxide, and about 2À5 per cent oxygen and for Bramley's Seedlings about 8-10 per cent of carbon dioxide and about 13-11 per cent of oxygen, the remainder in each case being nitrogen, the storage temperature being 40‹ F. As the oxygen is absorbed by the fruit more is supplied from a cylinder 9 or by delivering air to the chamber by a pump 10 or through a valve 11 to the cooler 4. To absorb the carbon dioxide the atmosphere is withdrawn from the chamber 3 through a pipe 16 by a pump 15 which supplies it through a pipe 17, the lower end of which has perforations 18, to a vessel 12 which is packed with Raschig's rings and filled to the level of valve 24 with milk of lime. The treated atmosphere returns through pipe 19 and cooling coil 20 to the chamber. Water lost from chamber 12 is replaced from the storage tank 23a. When the milk of lime is spent, it is drained off through valve 25 and water is added to wash the rings and drained off, and a fresh charge of milk of lime made in tank 27 is fed by pump 28 to the vessel 12. The pump 12 may be controlled by a carbon dioxide and oxygen measuring apparatus 30. A pressure gauge 34 is provided. When choked the perforations 18 are cleared by closing valves 35, 36 in pipes 17, 19 and blowing air in through a valve 37, the air being released through a valve 38. Specification 172,673, [Class 49], is referred to.