CHART Orca MicroBulk CO2 Series - Vaporization; Vapor Pressure; Condensation; Condensation and the Perma-Cyl Microbulk Storage System

10
Introduction Product Manual - Orca
™
CO
2
Series MicroBulk Delivery System
Vaporization
Changing liquid into vapor by warming the liquid for the
purpose of subcooling or for gas use. The Orca CO
2
Series
delivery system uses a pressure building coil inside of a
propylene glycol/water bath heat exchanger in the cabinet.
Vapor Pressure
Pressure of the vapor space within the tank. Measured by
reading the tank pressure gauge or the Flowcom
®
Flow
Meter System.
Condensation
The conversion of vapors into liquid by cooling the vapors.
The Orca CO
2
Series storage vessel pressure during normal
operation will rise above the saturation pressure of the
liquid. This warmer gas will condense to the colder liquid
pressure during transit. The liquid splashes into the gas space
during normal movement of the truck/trailer. The splashing
condenses the gas and drops the pressure. This is known as
"splash-down."
Condensation and the Perma-Cyl
®
MicroBulk Storage System
An example of condensation can be seen in the lling theory
of a Perma-Cyl tank. Top lling a Perma-Cyl tank without
venting is possible due to condensing warmer gas into liquid.
Depressurization Flash Losses
Dropping the vapor space pressure below the saturation
pressure of the liquid causing the liquid to boil. During
the venting of the tank below the saturation pressure of
the liquid, the liquid temperature will drop, the density
will increase, weight of the liquid will decrease, and the
saturation pressure will drop.
Entrainment
Liquid carried along with venting gas. This can occur during
violent depressurization of a tank and during the top lling
of a tank with the vent valve open. Large product losses will
occur during this event.
Liquid Growth
As liquid warms to higher saturation pressures, the volume
increases. Warm liquid is less dense. Less dense liquid takes
up more volume. Liquid growth is a safety concern if the
liquid is allowed to grow until it lls the storage vessel. This
condition is called liquid full or hydraulically full. During
this condition the pressure rises rapidly, the safeties will
relieve, and the tank will vent liquid.
Pressure Drop
Pressure lost due to the ow of liquid. The faster liquid ows
through the piping circuit, the higher the pressure drop.
Stratication
Warm liquid is less dense. In a tall vertical tank this less dense liquid will nd its way to the top of the tank. Colder more
dense liquid will remain at the bottom. The layering of temperature zones from top to bottom is called stratication.