GB504173A - Improvements in or relating to methods of and apparatus for moistening products - Google Patents

Abstract

504,173. Moistening porous products; conditioning tobacco. GUARDITE CORPORATION. July 19, 1937, No. 11134. Convention date, Feb. 19. [Class 58] [Also in Group VI] Porous products such as grains, tobacco, and other organic products are moistened by applying to the outside water, subjecting a chamber containing the moistened product to a vacuum sufficient to evaporate water within the grain to free the interstices thereof from all air and other non-condensable gas, leaving a substantial portion of the water remaining with the product to be available as eventual final moisture, and then introducing steam to transfer this remaining water to the interior of the product to supplement the steam condensed therein and to establish the desired total final moisture. Grain after washing and wetting is fed from a hopper 10 through a control valve 11 to a conveyer 12 that discharges it through inlets 14, 14a, 14b into treating tanks 13, 13a, 13b. After the tank 13 has been tilled the inlet 14 is closed and the tank put into communication through the opening 15 with a vacuum pump 38, the vacuum later being assisted by steam jets 60 drawing air through the apertures 15 and 16. The vacuum is maintained until the temperature of the grain falls a few degrees when the vacuum valves 15a, 16a, are closed and steam is admitted through a valve 17: evacuation is maintained during the steaming through a holding line 63 provided with a valve 61. The tank is provided with a conical perforated false bottom 18 and a similar top 19 ; a steam inlet 20 may be used alternatively to or in combination with the inlet 17. With three tanks used in conjunction as shown the valves are automatically actuated from a panel board 31 on which predetermined settings of the controls are made. In treating wheat evacuation by the pump proceeds until a pressure of two inches absolute of mercury is reached when the valve 15a is closed and the steam jets 60 started and continued till the temperature falls, the vacuum valves then being closed and steam admitted through the pipe 70, strainer 71, reducing valve 73 and desuperheaters 74, steam separator 75 and pipe 76 from which it enters the tank preferably at a temperature of about 30-50‹ F. above the maximum temperature to which the wheat is to be raised, such maximum temperature desirably not exceeding 120‹ F. The wheat is maintained at this temperature for a period of thirty minutes : a time cycle controller then opens the valve 33 to discharge the tank. Specification 488,638 is referred to.