SIMULATION OF A PLANT PILOT SPRAY DRYER AS A SERIES OF WELL STIRRED CONTINUOUS DRYERS CONSIDERING HEAT AND MASS TRANSFER AND EQUILIBRIUM LINE

摘要

In this work we propose a model of a spray dryer like a series of well stirredrndryers. That is, a series of dryers in which ones the output variables are equal to staternvariables, the typical assumption for modeling a well stirred continuous reactor. Thernstate equation were water mass balance and heat balances in the product, and air,rnadditionally a water mass and heat balance at the interface jointly with the waterrnequilibrium relation between the product and air. A plant pilot spray dryer was modeledrnassuming one and two well-stirred stages. Low-fat milk with 10-20% of solids wasrndried at different air inlet temperatures (120-160oC), an air flow of 0.19 kg dry air-s-1rnand the inlet product flows between (1.4 to 4.2) X 10-4 kg dry solids-s-1. The resultrnshows that the model predict the experimental behavior of outlet air temperature atrndifferent inlet conditions (air flow, and temperature). The model represent a method forrnthe estimation outlet product moisture content as function of outlet air temperature.rnThis has application for automatic control because the outlet product moisture contentrnis not easily measure on-line.