Desorption isotherm and heat pump drying kinetics of peas

Moisture desorption isotherms and thin layer drying kinetices of peas in a laboratory pilot heat pump dryer were measured and modeled. A mesh bottom tray was used and air flow was parallel to the two faces of the thin layer. Air drying temperature, and relative humidity were varied from 25 to 65°C and 0.20 to 0.60, respectively. The air velocity was 1.5 m s^-1. A two component exponential model was used to represent the heat pump drying curves. The model parameters were correlated with the temperature and relative humidity. The two component model and correlations for the parameters developed can be used to predict the moisture content of peas during heat pump air drying.