EXTRUDER AUTOMATIC CONTROL METHOD Russian patent published in 2001 - IPC

FIELD: food-processing industry. SUBSTANCE: method involves measuring temperature and pressure of material in zone upstream of die; measuring flow rate and moisturecontent of basic material, flow rate of cooling agent, power of adjustable extruder drive; regulating extruder auger rotational speed, cooling agent and basic material flow rate; directing extrudate from die into vacuum chamber; measuring flow rate and moisture content of extrudate at vacuum chamber outlet end; setting required temperature value in extruder zone upstream of die by changing drive power of pump, which supplies cooling water to extruder casing; measuring pressure of medium in vacuum chamber and setting required pressure ratio in extruder zone upstream of die and in vacuum chamber by changing drive power of vacuum pump; measuring temperature and flow rate of evaporated moisture discharged from vacuum chamber for condensation in double-section evaporator of refrigerating machine, with sections of refrigerating machine operating alternatively in condensation and regeneration modes; measuring temperature of dried air discharged from evaporator, of cooling water directed from regeneration section of evaporator for cooling extruder casing. Cooling water circulates in "extruder casing-regeneration section-extruder casing" closed cycle. Method further involves measuring temperature of refrigerant at evaporator inlet end and flow rate of refrigerant discharged from evaporator section operating in condensation mode, and power of vacuum pump drive, cooling water pump power and compressor drive power; calculating amount of evaporated moisture in vacuum chamber on the base of measured values of flow rate and moisture content of basic material and extrudate; setting flow rate of refrigerant in sectioned evaporator by regulating power of machine compressor drive. EFFECT: increased efficiency by stabilized temperature mode at minimum permissible level in zone upstream of die. 1 dwg