METHOD FOR AUTOMATIC CONTROL OF COMBINED BOILING-AND-DRYING PROCESS IN TREATMENT OF LOOSE PRODUCT Russian patent published in 1998 - IPC

FIELD: food production industry. SUBSTANCE: this relates to automation of technological processes and can be used for automation of processes in preliminary hydrothermal treatment, boiling and drying of loose primary products for example cereals, leguminous and other cereal products in food concentrates industry. Method is based on power-saving technological procedure with recirculated utilization of heat-carrying agent. Method for automatic control of combined process provides for changing delivery flow rate of heat-carrying agent and liquid, measuring of moisture content of primary product prior to boiling, of boiled and ready product after drying, flow rate of primary product, temperature of primary product prior to boiling, in process of boiling and drying, of heat-carrying agent at inlet and outlet from product bed during boiling and drying, liquid spraying pressure, heat-carrying agent pressure differential, flow rate of heat-carrying agent after boiling basing on measuring velocity of heat-carrying agent flow, pressure and flow rate of cooling liquid delivered to heat exchanger. Corrected are current values of moisture content of product in boiling and drying according to flow rate and temperature of heat-carrying agent before and after drying of primary product. Corrected is flow rate of spraying liquid according to amount of condensed steam, moisture content of boiled product and pressure differential of heat-carrying agent at inlet and outlet from product bed. Flow rate of ready product after drying is determined according to flow rate of primary product before boiling and according to moisture content of primary product and ready product before boiling and after drying. Additionally effected is feeding steam to heat-carrying agent supplied to drying. Measured are flow rate and temperature of steam. Fresh steam is added according to amount of condensed steam in boiling. This is determined according to flow rate of heat-carrying agent before and after boiling. Method is directed at improving quality of ready product, reduction of material and power expenses, improved accuracy and reliability of automatic control process. EFFECT: higher efficiency. 1 dwg