Superficial gas velocity: calculation basis / definition 1

[plantprowler]

In Ludwig's Handbook I found a correlation for air agitation intensity using gas sparging that is based on "superficial gas velocity". See image below; Thumb Rule #5.

I am confused about the correct area basis to use when calculating a superficial gas velocity in a tank: Would this be based on the tank's entire cross section? i.e. I multiply velocity by C/S Area of tank to get gas flow rate?

 

[georgeverghese]

Yes, superficial velocity is to be based on total vessel cross sectional area.