GB397848A - Improvements in and relating to the storage of fruit - Google Patents

Abstract

397,848. Storing and preserving crops ; hatching-appliances ; treating grain. KIDD, F., Low Temperature Research Station, Downing Street, Cambridge. Feb. 29, 1932, No. 6059. [Classes 5 (i), 5 (ii), and 58.] Animal and vegetable materials, including fertile eggs, potatoes and other roots, bulbs and seeds are preserved during storage and transport by controlling the composition of the atmosphere surrounding the materials by treating it with physical or chemical absorbents for carbon dioxide of a reversible character so that regeneration may be conveniently effected, and then returning the treated gas to the chamber with, if desired, a proportion of fresh air. The absorbents for carbon dioxide used include sea or river water, potassium or sodium carbonate solutions or other inorganic or organic solvents. Where a solid absorbent is employed, a plurality of absorption chambers may be used which are employed alternately in absorbing the gas and in treating the absorbent to expel the gas therefrom. The oxygen content of the gas may be reduced, e.g. by burning carbon or carbon-containing material therein. The regeneration of the absorbent may be effected by aeration, by reduction of pressure, by change in temperature, e.g. by heating with waste heat from the refrigerating plant, by increasing the surface of the absorbent liquid while being treated with heat, cold or vacuum or passage of air &c., or by finely subdividing the liquid and passing it in contact with a gas, or by employing catalysts. To promote absorption the absorbent may be cooled by means of the brine or other cooling medium used for keeping the storage chamber at the desired low temperature. Means may be provided to absorb volatile substances given off by the materials under storage, e.g. by placing absorbents in the storage chamber or by providing chambers containing absorbents in the path of the circulating gas. As shown, gas containing carbon dioxide is withdrawn from a fruit storage chamber 1 by a pump 3 through a trunk 2 and a pipe 4 and passes to a pipe 7, one branch of which is connected through a valve 8 to a spray eliminator 9 through which a regulated part of the gas is byepassed to the chamber 1. The remainder of the gas passes through the other branch of pipe 7 and a valve 10 to a chamber 11, where the carbon dioxide is absorbed by a descending solution of sodium or other alkali metal carbonate or other appropriate liquid. The treated gas passes through pipe 16 and valve 17 to the spray eliminator 9 and back through pipe 19 and a cooler 20 having a cooling coil 21 to the chamber 1. A controlled amount of air may be added to the returning gas through a valve 24. The used absorbent liquid is delivered from chamber 11 by a pump 28 through a pipe 30 to the top of a chamber 31, where it is revivified by a current of air supplied through a pipe 34 and distributor 35 and leaving the chamber by a pipe 36. The treated liquid returns to chamber 11 through a pipe 14.