Liquefied oxygen, nitrogen, argon and carbon dioxide are stored on your site at very low temperature. When gas is required, the liquid is vaporised for supply to your process. For cryogenic applications such as food freezing that require a low-temperature liquid supply, the liquid is delivered from the storage tank to your process by an insulated line.
A typical installation normally consists of a tank, a vaporiser and controls. Systems are selected based on your volume, desired pressure, purity level, flow rate and operating pattern.
A typical liquid storage system used for argon, nitrogen and oxygen.
The storage vessels generally used for liquefied argon, nitrogen and oxygen are 500-, 1,500-, 3,000-, 6,000-, 9,000- and 11,000-gallon tanks. Liquid hydrogen storage vessels are nominally 1,500-, 4,500-, 9,000- and 20,000-gallon tanks.
Cutaway of a typical tank.
Ambient Air Vaporiser
While steam and electric vaporisers are occasionally used, the most widely employed vaporisers obtain heat from the surrounding air. These "ambient air" vaporisers are provided in arrays of many-finned tubes to provide vaporisation rates up to 40,000 scfh per array. Additional units are added to provide higher vaporisation rates.
Control manifolds are designed to control the pressure to your houseline and to protect that line from excessively cold gas or possible liquid carryover. The manifold consists of a temperature control valve and a pressure control valve. Also included are necessary block-and-bypass valves, as well as a pressure indicator and check valve. There are two basic units—one for rates up to approximately 23,000 scfh and another for rates up to approximately 43,000 scfh.
A typical control manifold.
*Note that the liquid storage system used in your region may be different; please check with your local office.