Product-air capacity with purge calculator

When purge is specified relative to delivered product air, inlet air equals product air plus purge. The specified denominator must be retained.

Units

Q_{\text{product}} = \frac{Q_{\text{supply}} - Q_{\text{leak}}}{1 + r_{\text{purge}}}

Calculator

Enter the values you know and leave one box empty. Calculate finds the empty one, the result or any input.

Given

Q_{\text{product}} = \frac{720 - 70}{1 + 0.25} = 520

Symbol	Meaning	Unit
$Q_{\text{product}}$	net product-air delivery	cfm
$Q_{\text{supply}}$	free-air supply before leakage	cfm
$Q_{\text{leak}}$	leakage before the dryer	cfm
$r_{\text{purge}}$	purge air divided by product air	fraction

Symbol	Meaning	Unit
$Q_{\text{product}}$	net product-air delivery	L/s
$Q_{\text{supply}}$	free-air supply before leakage	L/s
$Q_{\text{leak}}$	leakage before the dryer	L/s
$r_{\text{purge}}$	purge air divided by product air	fraction

Results are estimates for study and screening. Check the inputs, units and assumptions before you use them for design, billing or contract decisions.