PURPOSE: To enhance not only granulation efficiency but also yield by automatically changing the temp. of the inflow air supplied to a fluidized bed so as to be blown up corresponding to the temp. and humidity of the open air while controlling the pressure in the fluidized bed to a constant level and making drying capacity always constant.
CONSTITUTION: A set amount of the raw material such as a single powder or a powder mixture weighed by a weighing machine 2 is sent to a fluidized bed type mixing and granulation dryer 3 and hot air is supplied to the dryer 3 from below so as to be blown up. A binder is supplied from a tank 7 to be sprayed to the raw material bed for a required time through a spray gun 9 in the amount corresponding to the delivery amount of the raw material to granulate the raw material and drying is performed in succession to granulation to obtain a granular product. At this time, the pressure in the above mentioned fluidized bed is controlled to a constant level and the temp. of inflow air supplied to the fluidized bed so as to be blown up is automatically changed corresponding to the temp. and humidity of the open air by a pump 18, a sensor 19, a comparing operation apparatus 20, a heat exchanger 21 and a sensor 22 to make drying capacity constant. As a result, granulation efficiency and yield are enhanced.
SATO TAKENORI
IZAWA HIROSUMI
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