METHOD OF AUTOMATIC CONTROL OVER FOODSTUFFS DRYING IN BELT DRIER USING CONVECTIVE AND SHF HEAT Russian patent published in 2012 - IPC F26B25/22 

FIELD: process engineering.

SUBSTANCE: drying in performed in belt drier using convective and SHF heat. Note here that, in drying, measured are initial stock consumption, temperature and moisture content of fed material, as well as those after processing, drying agent consumption, drying agent temperature and moisture content before and after drying, power consumed by blower, ionic centrifuge and calorifer drier. Drying parameters are controlled in three zones. For this, data from transducers is loaded into microprocessor. The latter uses algorithm loaded therein to set, subject to initial stock consumption and temperature in first zone, temperature, moisture content and consumption of drying agent in second and third zones and conveyor belt speed, the drying agent temperature and feed speed by means of actuators of ionic centrifuge, calorifer heater and blower with their data being fed to microprocessor for correction of drying conditions in three zones, each being made up of there levels: first zone consists of two levels: in the first level, power of SHF-radiation is affected. If this does not ensure preset temperature, initial stock feed rate is affected. Second zone consists of three levels: in first level, SHF-radiation power is affected. In second level, in case outflowing drying agent moisture content does not meet specifications, supply voltage of calorifer hear elements is affected. Drying agent consumption is varied. Said third zone consists of two levels: In first level, SHF-radiation power is affected. In second level, in case outflowing drying agent moisture content does not meet specifications, belt conveyor speed is affected. Note here that drying conditions are varies in second and third zone in all levels with due allowance for drying agent temperature at drying chamber outlet.

EFFECT: higher quality of finished product due to optimised drying parameters.

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