Design variables Pressure drop, filter drag, air-to-cloth ratio, and collection efficiency are essential factors in the design of a bag filters. Pressure drop (ΔP) is the resistance to air flow across the bag filters. A high pressure drop corresponds with a higher resistance to airflow. Pressure drop is calculated by determining the difference in total pressure at two points, typically the inlet and outlet. Filter drag is the resistance across the fabric-dust layer. The air-to-cloth ratio (ft/min or cm/s) is defined as the amount of gas entering the bag house divided by the surface area of the filter cloth.
