Gasification of Liquid Oxygen

Liquid oxygen is converted back to gas by gasification, usually installed on the sites where oxygen comes liquefied. High-pressure (up to 165 atm gauge) or hot gasificators are intended to convert to gas all the liquid oxygen charged and to fill oxygen cylinders to high pressure.

A charge of liquid oxygen in a hot gasificator of 35 liters capacity will be enough to fill three oxygen cylinders of 40 liters capacity each to a pressure of 150 to 165 atm (gauge). This type of gasificator can fill six cylinders an hour (36 cu m of gaseous oxygen per hour). Losses of liquid oxygen to evaporation range from 5 to 10 percent of the charge.

Medium-pressure (up to 15 atm gauge) or cold gasificators store liquid oxygen under the specified pressure and convert part of the charge to gas under the same pressure in pace with its consumption. Gaseous oxygen is delivered to torches over pipelines.

A cold gasificator consists of a steel sphere inside which is placed a thin-walled brass gasometer to receive liquid oxygen. The liquid oxygen from the gasometer is passed through a heater which consists of coils immersed in a bath filled with hot water.

The water is heated by steam or electric heaters. The operation of a gasificator is controlled by means of suitable valves on a distribution board.

Instead of gasificators, liquid oxygen can be converted to gas by plunger pumps intended for pressures up to 20 atm (gauge) (the medium-pressure class) and 200 atm (gauge) (the high-pressure class). A plunger pump can discharge oxygen either into a pipeline or into oxygen cylinders.

Plunger-pump gasificators have an output of 65 to 85 liters of – liquid oxygen per hour. This type of plant can fill ten oxygen cylinders of 40 liters capacity each to a pressure of up to 165 atm (gauge) every hour. Losses to evaporation do not exceed percent of the oxygen held in the storage tank of the plant.