IMPROVEMENT OF INDUSTRIAL DRYING OF NATURAL-RUBBER THROUGH ANALYSIS OF HEAT AND MASS TRANSFERS

An analysis of convective drying of natural rubber in granule form. Ex ploitation of the mathematical model developed from analysis of intern al transfers requires determination of the 'drying rate' and the 'ener gy exchange coefficient' between the material and the drying air. This was performed using a portable laboratory drier at the production sit e, avoiding the problem of changes in the material during transport. A nalysis of the drying kinetics of material in thin layers led to model ling the drying rate at the temperatures, rates and relative humidity values encountered in industrial driers. The energy exchange coefficie nt was found by measurement of air and granule temperatures. Thick lay er trials showed the suitability of the model for simulation of change s in moisture content and temperature of air and granules in a granula r environment. The study as a whole led to the development of a comput er program for simulating a zone drier. This software can be used to o ptimise the management of an industrial natural rubber drying installa tion.