Sizing Vent for High Pressure Steam Feed
Sizing Vent for High Pressure Steam Feed
(OP)
Hi
We're trying to size a vent for a tank that may potentially experience 70 psig steam @ 150 lb/h. Typical feed will be a grain slurry with some vapour. Before the tank there is a back pressure regulator supposed to decrease the P down to atmosphere.
The inlet to tank is 2" size, and we're thinking a 4" outlet vent would be sufficient. We want to size the vent so that the vessel is not considered a pressure vessel (so that the pressure in the tank never exceeds 103kPa or 14psi) even if the HP steam enters if the BP regulator fails.
Unfortunately we don't really have any good fluids books for resources or the API info either. Would you use the Bernoulli equation with losses
P1/rho + V1^2/2g + Z1 = P2/rho + V2^2/2g + Z2 +fLV^2/2Dg
where 1=in vessel; 2=at end of vent (14psi); setting the P1-P2=14psi and iterating to find the line size until this condition is met? Do you assume V1=V2 thus P1-P2=losses from entrance, constriction and vent length?
Also do you assume constant density (and is it the density of the steam entering)?
Thanks.
We're trying to size a vent for a tank that may potentially experience 70 psig steam @ 150 lb/h. Typical feed will be a grain slurry with some vapour. Before the tank there is a back pressure regulator supposed to decrease the P down to atmosphere.
The inlet to tank is 2" size, and we're thinking a 4" outlet vent would be sufficient. We want to size the vent so that the vessel is not considered a pressure vessel (so that the pressure in the tank never exceeds 103kPa or 14psi) even if the HP steam enters if the BP regulator fails.
Unfortunately we don't really have any good fluids books for resources or the API info either. Would you use the Bernoulli equation with losses
P1/rho + V1^2/2g + Z1 = P2/rho + V2^2/2g + Z2 +fLV^2/2Dg
where 1=in vessel; 2=at end of vent (14psi); setting the P1-P2=14psi and iterating to find the line size until this condition is met? Do you assume V1=V2 thus P1-P2=losses from entrance, constriction and vent length?
Also do you assume constant density (and is it the density of the steam entering)?
Thanks.





RE: Sizing Vent for High Pressure Steam Feed
RE: Sizing Vent for High Pressure Steam Feed
Good luck,
Latexman