Omer E. Mohamed Osman¹, Mohamed A. Ismail¹*, Ali M. Al-Amri¹ and Emad A. Almuhanna¹

Department of Agricultural Systems Engineering, College of Agricultural and Food Sciences, King Faisal University, P. O. Box 400, Al-Ahsa 31982, Kingdom of Saudi Arabia.

 

The objectives of the study were to test a mathematical model to predict moisture contents within wheat stored in a cylindrical metallic silo and to verify the tested model by comparing the experimental moisture values with the predicted ones. The tested finite difference model was used to simulate moisture diffusion in both the radial and vertical directions in the silo. The model predicted grain temperatures and moisture contents in the silo using input data of initial grain temperature, initial grain moisture content, ambient air temperature, storage time, number of spatial elements in both directions, finite difference spatial increment in both directions and thermo-physical properties of grain and silo wall material. The experimental data was collected during the period of 91 days. Results showed that under the storage conditions moisture diffusion took place within the stored wheat in the silo. The tested model predicted wheat moisture content accurately and within the bounds of the experimental error. The standard error of estimate between measured and predicted moisture contents was 0.29 to 0.59% (w.b.). It was also found that Chung’s sorption equation was satisfactory in simulating the moisture contents within wheat bulk stored in the metallic silo. Computer simulation of moisture contents and temperatures of stored bulk grain to monitor safe storage conditions could be opted as reliable, inexpensive and a fast technique.

Key words: Moisture diffusion, simulation, finite difference, wheat, silo.