Backpressure regulator
Backpressure regulator
(OP)
Hi All:
I'm operating a thermic oil system in my plant with an operating temperature of 380 Deg C with Therminol 72. I'm changing the expansion tank vent line forward pressure regulator with a backpressure regulator to hold constant static pressure inside the tank and also to minimize the N2 consumption and thermic fluid wastage
I'm wondering if someone can provide some insight as how to size this backpressure regulator. The tank has a 1/4" port for the vent line
My idea is to size the backpressure regulator based on the flow, when the forward pressure regulator ( on inlet N2 line) fails open
Thanks for all your in advance
Araza
I'm operating a thermic oil system in my plant with an operating temperature of 380 Deg C with Therminol 72. I'm changing the expansion tank vent line forward pressure regulator with a backpressure regulator to hold constant static pressure inside the tank and also to minimize the N2 consumption and thermic fluid wastage
I'm wondering if someone can provide some insight as how to size this backpressure regulator. The tank has a 1/4" port for the vent line
My idea is to size the backpressure regulator based on the flow, when the forward pressure regulator ( on inlet N2 line) fails open
Thanks for all your in advance
Araza
Asif Raza





RE: Backpressure regulator
You probably have a heater somewhere in the system. You could take the duty of that heater, calculate the change in density of the system at max duty, and convert that liquid volume into an equivalent nitrogen volume that needs to be vented. That would give you something more reasonable. That's what I usually do for outbreathing requirements...
RE: Backpressure regulator
Good luck,
Latexman
To a ChE, the glass is always full - 1/2 air and 1/2 water.
RE: Backpressure regulator
if you're replacing the "forward pressure" regulator for a back pressure regulator, how are you going to keep the pressure constant if the gas volume keeps changing??
How does the gas escape from the tank now??
To maintain a "constant" static gas pressure you need a regulator supplying gas to a certain pressure, say 5psi. your back pressure regulator then is set at say 6 psi so your pressure fluctuates between 5 to 6 psi.
So in this instance, yes, you could size you BP regulator to that or install some pressure relief valves to prevent the pressure going over your vessel design pressure if the incoming supply can over pressure the vessel. This is standard pressure vessel / pressurised vessel design.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Backpressure regulator
Dejan IVANOVIC
Process Engineer, MSChE
RE: Backpressure regulator
Good luck,
Latexman
To a ChE, the glass is always full - 1/2 air and 1/2 water.
RE: Backpressure regulator
Met11, excellent post..
yes I have a forward pressure regulator set 75 psig to maintain a static pressure to prevent thermic fluid from boiling. 75 psig is 5 psig more than the vapor pressure of the thermic fluid at its highest temperature
I would set the backpressure regulator to 80 psig; in the event the pressure increases inside the expansion tank the BPCV would open and release the pressure
Thanks all for your help
Araza
Asif Raza
RE: Backpressure regulator
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Backpressure regulator
Thank all is advance
Araza
Asif Raza
RE: Backpressure regulator