METHOD OF AUTOMATIC CONTROL OF DRYING PROCESS Russian patent published in 2004 - IPC

FIELD: automatic control of drying dispersed lumping materials of high moisture content, such as sugar beet pulp.

SUBSTANCE: proposed method of control of drying process performed by means of superheated steam consists in dividing flow of waste drying agent into main flow directed to chamber, thus forming recirculation loop and additional flow; proposed method includes also measurement of flow rate and moisture content of initial product and measurement of flow rate and moisture content of dried product, flow rate and temperature of drying agent at drier inlet, temperature of product admitted to drier at correction of temperature of superheated steam at drier inlet; heat is delivered by combined method in two zones of drier; drying-off of initial product is performed by preheated air in zone of dense layer and drying with superheated steam is performed in vibrating fluidized layer of product; part of waste superheated steam is directed over additional flow for preheating air; flow rate of dried-off product, flow rate of air fed for drying-off and moisture content of air at dense layer inlet and outlet amplitude of oscillations of gas distributing grate in zone of vibrating fluidized layer are additionally measured. Flow of moisture is corrected by present magnitude of moisture flow of product and present magnitude of amount of moisture evaporated from product per unit of time; amplitude of oscillations of gas distributing grate is set by present magnitude of flow rate of dried-off product at correction of pressure differential in vibrating fluidized layer; excessive amount of waste superheated steam is determined by present magnitudes of flow rates of dried-off and dried product; this part of superheated steam is directed over additional flow and moisture content of dried product is stabilized by presence of product in zone of vibrating fluidized layer.

EFFECT: improved quality of product; reduced power requirements.

1 dwg