Is stack velocity “directly” proportional to the absolute temperature, since PV=nRT?

Stack velocity is NOT directly proportional to absolute temperature.  The Ideal Gas Equation is PV=nRT, where “V” is volume of a gas in relationship to the temperature, “T” of the gas.

Velocity of a gas stream is determined by the following equation:

v =  KpCp [(Ts)(delta p)/(Ps)(Ms)]1/2


Now, Qs = (As)(vs) where As is the area of the stack and vs is the velocity of the stack gas.

The pmr (pollutant mass rate) = (cs)(Qs) where cs is the concentration of the pollutant (mass per unit volume) and Qs is the volumetric flow rate of the stack gas [(As)(vs)].