Designing a baghouse system requires careful calculation and optimization of multiple design variables to ensure reliable performance, regulatory compliance, and long-term durability.

What Is Air Velocity?

When the velocity drops below the minimum conveying velocity, dust will begin to settle or drop out of the airstream, which then accumulates into large piles that eventually choke off the duct.Air velocity is the speed of air moving through the ductwork. It affects the amount of dust that can be conveyed through the system. The size of the ductwork, the type of collected dust, and the airflow rate determine the ideal velocity. This velocity within the system is measured in feet per minute, or ft/m.

Air Velocity Calculator

AIR VELOCITY CALCULATOR

Formula:
Velocity = CFM ÷ Duct Cross-Sectional Area
Velocity = fpm

Importance of Air Velocity In Baghouse Design

Proper air velocity ensures that dust stays suspended and doesn’t settle in the ducts.

In order to transport the dust through the system, the conveying air must reach a value called the minimum air conveying velocity. If the air velocity is below this value, the dust will ultimately settle at the bottom of the duct.

The capture velocity is the conveying air velocity at the point of introduction of the solids in the duct, usually a hood or a direct duct connection to a piece of equipment. In order to be able to transport the dust, the velocity must be greater than the minimum conveying velocity of the dust. Air velocity within the system is measured in feet per minute, or ft/min.

Note: This calculation is a good starting point, but duct material, layout, and type of dust must be considered. Consult with a dust collection expert to get a safe and efficient design.