GB1200731A - Grain drier - Google Patents

Abstract

1,200,731. Treating grain. JOHN WILDER Ltd. 5 Oct., 1967 [5 July, 1966], No. 30072/66. Heading A2Q. [Also in Division F4] A continuous grain dryer has means to control the flow of grain automatically to one of two rates of discharge or flow in response to the temperature of the dried grain or the temperature of the drying air as it leaves the dried grain, the two rates being a low mean rate (including zero) and a high rate. Thus the temperature-sensing device 15 permits the grain to flow freely so long as the emerging grain is dry, but stops or reduces the flow to a low rate if the emerging grain is still wet. Wet grain flows by gravity between the perforated walls 10, 11 through a drying zone 12 in which hot air passes through the grain and is extracted from the centre, then through a cooling zone 13 in which cold air passes through to the centre. Discharge is controlled by a mechanism 14 controlled by temperature sensitive device 15. Fig. 2 shows a suitable control circuit. The temperature sensitive device moves contact 17 to 18 when the grain is dry and to 19 when a lower temperature indicates that it is still wet. For dry grain and switch in position 18 current flows through coil 6 which opens discharge mechanism 14 to give a full rate of flow. With still wet grain and switch in position 19, timer motor 20 is energized, which closes contacts 21 for a pre-determined time in each cycle of the timing gear, e.g. for 2 minutes in every 5 minute cycle. When the contacts are so closed, coil 16 is energized to open discharge mechanism 14 for the predetermined proportion of each cycle, which continues until the slow moving grain is dry and the temperature rises sufficiently to operate switch 17 to reinstate full rate of discharge.