For normal operation condition the sand trap louvers
should be selected for a maximum free area velocity
of 600 feet per minute (FPM).
Example:
Given:
Airflow: 2658 CFM
Assumed free area velocity: 600 FPM
Calculate for free area, neck size and pressure
drop.
1. Free Area = 2658 CFM / 600 FPM = 4.43 ft².
2. From Free Area Chart the outer frame size is
48in X 48in ( W1 X H1 ).
3. From Table 1 neck size is 1100mm X 1100mm
( W X H ).
4. Pressure drop = 0.151 in. W.G. (38Pa).
Note:
For optional screens the pressure drop is
additive and to be calculated separately.