Vessel open volume exchange

The capacity of the pumping system is usually measured in pounds (or kilograms) per minute of carbon dioxide measured at the pump inlet. The open vessel volume multiplied by the density of the carbon dioxide at the system operating conditions will determine the amount of carbon dioxide needed to fill the vessel and the time to make one vessel exchange. The dilution theory thus provides a first estimate of the necessary pump characteristics. However, because pump capacity has a major impact on system cost, it is very important to determine experimentally the actual required cycle to provide the cleanliness levels need. Most suppliers have facilities to assist in obtaining this information. 

---