FORCE AND STATIC PRESSURE RESULTING FROM AIR-FLOW THROUGH SCREENS

Several clean agricultural screens were tested to determine force and static pressure drop across the screen created by airflow through the screen. Wind pressures on screens and static pressure drop across scre ens increased exponentially with increases in apparent air velocity. F abric density, configuration, and dimensional characteristics greatly affected wind pressures and static pressure drops, Forces against the screens were not merely a function of the net solid area of screening material. The coefficient of drag was calculated at various apparent a ir velocities for each screen; it was unstable at lower apparent air v elocities but tended to stabilize to one value for the higher velociti es through each screen.