METHOD OF AUTOMATIC CONTROL OF DISPERSE MATERIALS DRYING PROCESS IN SHAFT DRIER WITH APPLICATION OF MICROWAVE ENERGY Russian patent published in 2008 - IPC F26B25/22 

FIELD: technological processes; drying.

SUBSTANCE: invention is related to methods of automatic control of disperse materials drying processes in devices that use microwave energy and may be used in food, chemical and adjacent industries. In the method of automatic control, which stipulates measurement of flow rate, humidity and temperature of initial material, which is supplied to drier, flow rate and humidity of dried material, moisture content, temperature and flow rate of drying agent before and after the drying, the innovation is that drying is performed in shaft drier with application of microwave energy, information from sensors that measure flow rate, humidity and temperature of initial material, which is supplied to drier, flow rate and humidity of dried material, moisture content, temperature and flow rate of drying agent before and after drying, is sent to microprocessor, which generates the setting for temperature mode and mode of drying agent supply at the inlet to drier by means of actuators of heater, fan and magnetrons, additionally sensors are used that measure consumed power of fan, heater and magnetrons, information from which is sent to microprocessor, which continuously determines the mark of derivative of function of total cost of power and material expenses per unit of mass of dried material, and if the mark is positive, then it reduces the flow rate of initial material, if the mark is negative, then it increases it. Besides, correction of drying process control mode is performed at two levels, at that on the first level in case of deviation of current value of moisture flow that is evaporated in drier from the setting, temperature and supplied flow rate of drying agent are affected, and at the second level, if the change of temperature and flow rate of supplied drying agent does not provide the required humidity of dried material, the voltage in magnetrons power supply circuits is affected.

EFFECT: increase of drying and finished product quality with reduction of power inputs.

1 dwg