GB356794A - Improvements in or relating to the treatment of cereals and other starch containing food substances - Google Patents

Abstract

356,794. Roller grinding or crushing mills. KELSEY, T. S., 5, Old Palace Lane, Richmond, Surrey. June 6, 1930, No. 17585. [Class 59.] A process for treating cereals and other starchcontaining food substances comprises subjecting the flour obtained therefrom to the action of steam to soften the starch cells and immediately thereafter subjecting it to an energetic grinding action for the purpose of bursting or disrupting said starch cells. Flour in the form of a thin sheet or film is subjected to the action of steam at a temperature of about 200‹ F. and at a pressure of about 60 to 80 1bs. per square inch, just prior to its entry between the nip of a pair of rollers one of which is rotated at about three times the speed of the other, after passing between which it is brought into contact with a stream of humidified air, sifted and fed to an expansion chamber where excess moisture is separated therefrom. Apparatus for carrying out this process comprises a feed channel 1 whence flour is fed by a platform 2 reciprocated by an eccentric 3 to a distributer 4 having ribs 9 on its upper surface and reciprocated by an eccentric 10 on a shaft 11. Flour in the form of a thin sheet falls from the distributer 4 through steam jets issuing from perforated steam pipes 12, 13 substantially parallel to the sheet of flour, on to grinding rollers 5, 6 after passing between which it passes into the hopper 14, and is forced through a screen 16 by a rotary spiral brush 17 into an expansion chamber 18 where excess moisture is removed by the fan 20, the moisture passing by a conduit 19 into a cyclone separator 21 where any flour sucked through the conduit 19 by the fan 20 is separated and collected for use. Dampers 22 operated by levers 23 control the effect of the suction fan 20 on the upper part of the apparatus. The grinding rollers are hollow with a smooth outer surface, their temperature being controlled by the water and steam circulating system shown in Fig. 3, cold water entering along the pipe 24 and steam along the pipe 25 cocks 28, 29 and control valves being provided as shown. A pressure reducing valve on the steam pipe line and means to prevent the supply of more than a predetermined quantity of steam may be provided. Rollers, eccentrics, and brush 17 are driven from the same prime mover. The steam supply is automatically cut off when the rollers cease to rotate by the device shown in Fig. 5, in which a pair of centrifugal elements 32 joined by a spring 35 are pivotally mounted on members 34 attached to the shaft 11, fingers 36 on the elements 32 co-operating with a collar 37 and a sleeve 39 slidably mounted on the shaft, which sleeve is attached to the spindle 40 of a valve 41 in the steam pipe, the valve 41 being spring controlled at 42. The reciprocating distributer 4 may be replaced by slides. Scrapers 45 are provided on the rollers.