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This research aimed to study the possibility of applying solar energy as a cheap source of energy for thermal disinfestation. Grain wheat, Magnus variety at 10% moisture content was chosen as a disinfesting material. The research examined, on a theoretical basis, the possibility of reaching grain thermal disinfestation temperature in a simple constructed heating apparatus. The apparatus heated grain in a continuous flow system. Grain was considered as a working fluid and its thermal properties were applied to a model to predict grain temperature. Apparatus was assumed to work under constant surface temperature (70 deg C, 80 deg C, 90 deg C and 100 deg C) and constant surface heat flux. A solar collector was constructed to heat grain in static state. In static state experiment, lethal temperature was reached and many batches per day could be disinfested according to the collector characteristics and radiation availability. In the continuous flow system, grain behaved as a fluid and heating progress was found to follow convective mode. With constant surface temperature and grain flow rate of 22 kg h-1, surface temperature should be at least 100 deg C to reach lethal temperature at the end of the heating tunnel, if the grain depth is 4 cm. With 2 cm grain depth surface temperature of 80 deg C was sufficient for lethal temperature at the end of the tunnel. Increasing the surface temperature to 100 deg C could reduce the required apparatus length to 190 cm. Under constant surface heat flux conditions, when solar energy was used, grain temperature and disinfestation rate were found to be dependent on collector efficiency and available radiation quantity. Comparison between simulated and measured grain temperature showed total agreement. Using thermodynamical approach, grain temperature could be predicted within an error of 1 K. Finite element method gave a good approximation for grain mean temperature. For grain temperature prediction in every point, more modifications are recommended in applied finite element method model. Under constant surface heat flux, grain temperature and disinfestation rates could be predicted accurately using the developed model. No adverse effect of heat treatment on grain quality was detected in the heated grain. With these results it is possible to construct a solar driven thermal disinfestation apparatus for grain flow in a continuous flow system.