Fumes Flow

Hello,

I'm working on the optimization of a curing oven. We have 2 exhaust chimneys (inlet/outlet) for the fumes generated by the process. Unfortunately, I can't make any accurate measurements in the ducts because the straight portion is very very short.

Here is the data I have:

- dry and wet temp. in the ducts, from which I can obtain the density d2.
- extraction fan speed, from the charts I can obtain the air flow for a density d1= 1.2kg/m3.

I'd like to know how I can estimate the fumes flow for the density d2.

Isn't it Q1/Q2 = SQRT (d2/d1) ? I got it using the formula Q=V1(m/s)*surface(m2)meaning Q1/Q2=V1/V2 with V1 function of SQRT(...../d1).

Thanks for your help.

William