Pressure Build Up Vaporizer
Pressure Build Up Vaporizer
(OP)
Can someone please explain to me the basics of how a cryogenic vaporizer is designed? I.e., those used for oxygen or nitrogen supply. How do they increase the pressure from the liquid in the tank to the outlet? Isn't there a pressure drop within the piping of the exchanger?





RE: Pressure Build Up Vaporizer
RE: Pressure Build Up Vaporizer
http://en.wikipedia.org/wiki/File:Vacuum_Insulated_Evaporator_diagram.svg
RE: Pressure Build Up Vaporizer
Good luck,
Latexman
RE: Pressure Build Up Vaporizer
However, if heat is added to the closed vessel then the pressure increases as the ideal gas law would have it. Can the exchanger be operated in batch mode, in a sense having standing liquid on side gaining heat from flowing liquid on the other side, thereby increasing the pressure?
RE: Pressure Build Up Vaporizer
Another way to say it is, if heat is added to the closed vessel then the vapor pressure increases as the temperature would have it.
Good luck,
Latexman
RE: Pressure Build Up Vaporizer
In the diagram vapor will be drawn off the top of the tank. If this continues the pressure in the tank will fall and the liquid will get colder as it boils. When the valve above the vaporizer opens it allows vapor to come out of the vaporizer which then results in liquid flowing into the vaporizer by gravity. This boils rapidly and generates lots of vapor. If no vapor were removed from the tank it would eventually explode. When the desired pressure is reached the valve above vaporizer closes and the vapors being generated push the liquid out the bottom of the vaporizer, back into the insulated tank. The exact same effect could be accomplished with an electric heater in the tank.
The ideal gas law is not really relevant here. The change in vapor pressure of the liquid with temperature is. The liquid in the tank is almost always at its boiling point.