GB768359A - Improved process and apparatus for the treatment of hard-shelled nuts for the separation of the kernels from the shells thereof - Google Patents

Abstract

768,359. Shelling nuts and seeds. INVESTIGACAO E EXPLORACAO INDUSTRIAL SOC. AR.L. Jan. 29, 1954 [Sept. 25, 1953], No. 2760/54. Class 58. In shelling hard-shelled nuts and seeds, e.g. cashew nuts and Telfairia pedata seeds, the nuts or seeds are soaked in water to soften their shells and then introduced into a pressuretight chamber 1 in which the temperature and gaseous pressure are increased to desired values with or without introducing steam, the temperature attained being insufficient to cause bleeding of the shells or affect detrimentally the composition and value of the natural phenolic and resinous substances contained in them, e.g. not in excess of 124‹C., the temperature and pressure are maintained long enough to bring the pressure within the shells substantially to the chamber pressure, e.g. between 37 and 60 lb. per sq. in., and the pressure is then released explosively, e.g. in less than 0À005 of a second, to split the shells along their natural cleavages and eject the kernels undamaged. The nuts or seeds may be treated in the chamber for 2-5 to 4 minutes. The pressure and temperature may be raised by admitting compressed air and steam separately or simultaneously into the chamber through valves 8 and 9, respectively. Cashew nuts may be soaked for 20 to 55 minutes in water at 90‹C. and in water at room temperature for 15 to 20 minutes. The soaking times should be doubled if kernels are to be ejected without skins. The temperature of the chamber when the nuts are admitted may be 110‹C., steam may be admitted for 2 minutes to bring the pressure to 45 lb. per sq. in. and the temperature to about 120‹C., air may be introduced for 0À5 of a minute to bring the pressure to 60 lb. per sq. in., which may be sustained for 2 minutes and then released in 0À002 of a second. Telfairia pedata seeds may be soaked for about 40 minutes in water at 95‹C. and for 15 to 20 minutes: in water at 20‹ to 30‹C. to facilitate ejection of kernels without skins. The temperature of the chamber when the seeds are admitted may be 110‹C., air may be admitted for 0À5 of a minute to bring the pressure to 30 lb. per sq. in. and steam may be admitted to bring the temperature to 120‹C. and the pressure to 75 lb. sq. in., which may be released in 0À002 of a second. The seeds may be scorched or cut along their cleavages before being soaked. The chamber may be cylindrical and may have at least one closable charging opening 27 and at least two pressure release openings forming seatings for pistons 10 sliding in cylindrical parts 11 provided with exhaust ports 13. The pistons may be locked in their closing positions by latches 17 which engage the ends 18 of the piston rods 12. The latches may be withdrawn, and pressure within the cylinder thus released explosively, by actuation of a trigger 21 connected to the latches through links 19 and levers 20. The nuts or seeds may be contained in wire-mesh trays 29, provided with perforated lids, resting on supports 28 within the cylinder. Reference has been directed by the Comptroller to Specification 727,798.