Resistance of Potatoes to Airflow

Knowledge of airflow resistance is an important consideration in designing an appropriate ventilation system and for proper fan selection. An airflow resistance device was designed and fabricated to measure the airflow resistance of potatoes. The device the composed of an air compressor, a rotameter, a cylindrical bin to contain the potatoes and an inclined u-tube manometer. Airf low resistance of potatoes was measured as a relationship between the airf low rate and pressure drop per unit depth (Pa/m) at 12 airflow rates of 0.085 to 0.55 m3/s/m2. Two airflow resistance models, namely, Shedd’s and Hukill nd Ives’, were f itted to measured data by using PROC NLIN of SAS. The eff ect of potato size below 120 g (small), at or above 120 g (large) and unsorted (mixed size), and bed depths of 25, 50, 75 and 100 cm of potatoes on resistance to airflow was determined. Results showed that the airf low resistance of small size potatoes for a 100 cm bed depth was 1.6 times higher than that for large size potatoes, and as the bed depth of potatoes was increased, the airf low resistance was increased