Natural Draft Flue Sizing

[CardsFan1]

I am looking for information to design an exhaust stack for a chemical digester.
We have a chemical reaction that will exhaust 5700 cu ft. / min of gases. We are trying to determine the required diameter
of the stack to provide enough natural draft so that a ID or FD fan is not required.

I have a copy of STS 1 which has a small amount of information: "Gas passage diameter is usually established by the volume of process gas flowing and available draft..."
There is an equation to calculate available draft in inches of H2O. I am not sure how all of this relates and how to use it to calculate the diameter.

I would appreciate any suggestions for references of how to calculate this.

Even better, I would appreciate contact information a someone who is qualified to perform these calculations for me.

 

[nRGee]

You need to have following inputs to calculate stack height.

1) Max. Volume of flue gas flow
2) Pressure at the inlet of stack
3) allowable pressure drop across stack as per recommended practices or your site guidelines.


Considering the above inputs, you can calculate stack diameter by varying stack height height (draft or pressure at the tip of the stack will be varied with stack height).

P.S: Based on nature of flue gasses, if minimum temperature to be maintained across the stack consider temperature drop across the stack for calculated stack height and dia.