MARINE CORPS AIR STATION YUMA, Ariz. -- When people hear the word cryogenics, they may think of science fiction movies with people frozen in time by liquid nitrogen. Although the station Liquid Oxygen Farm at Building 420 deals with cryogenics such as liquid nitrogen and oxygen, their mission has nothing to do with preserving humans.
The LOX Farm is a facility that stores and creates liquid nitrogen and oxygen for the station.
The farm holds approximately 1,000 gallons of liquid nitrogen and 1,000 gallons of liquid oxygen to supply station squadrons, visiting squadrons, Branch Medical Clinic Yuma and the station fire department. These units put the chemicals to work in aircraft equipment, medical labs and treatment centers, missile launching systems, night vision testing equipment and flight line fire extinguishers.
This is done using a process called fractional distillation that pressurizes and cools air into a crude liquid form, said Sgt. Alejandro Bazante, Aviation Life Support Systems cryogenics work supervisor and a Madera, Calif., native. Once in liquid form, the process separates the nitrogen and oxygen from each other with a purity of 99.5 percent.
"We deal with high-pressure gases. We separate them from the atmosphere and put it in liquid form for larger volume," added Cpl. Zachary Barnes, ALSS cryogenic technician and a Cincinnati, Ohio, native.
The distillation process creates sub-zero temperatures of -321 degrees Fahrenheit for liquid nitrogen and -297 degrees Fahrenheit for liquid oxygen so cylinders can hold a large amount of the two elements, said Lance Cpl. Jerry Safley, ALSS cryogenic technician and a Springfield, Mo., native.
The gases in liquid form are so cold that even one second of exposure to skin can result in frostbite, permanently destroying the exposed nerve endings, said Safley.
To ensure proper protection from sub-zero temperatures, cryogenics personnel wear protective face shields, gloves and heavily woven over-garments.
Another hazard is suffocation. If cryogenic personnel are not careful when handling liquid nitrogen in confined spaces, oxygen asphyxiation can occur rapidly. That is why it is only handled outdoors.
"It's extremely dangerous. In a confined space, with too much nitrogen, you could pass out and never wake up," said Bazante.
Of all the hazards in cryogenics, handling liquid oxygen is the most dangerous, said Bazante. Any friction that creates static electricity near liquid oxygen may cause an explosion. Materials not flammable in normal environments will instantly combust when exposed to liquid oxygen.
"You have an extreme danger of combustion,” Bazante explained. “A few ounces of liquid oxygen is enough to fill a whole room with oxygen gas. It makes something eight-hundred and sixty times more flammable."
Even though the gas may be dangerous, it is extremely helpful for pilots, said Bazante.
“The liquid oxygen is in a little green container that turns into gas so pilots can breathe it,” said Bazante. “That is basically what is keeping them alive (while flying). When they are pulling (increased) gravity in the aircraft, it is hard for the heart to pump blood to the head. The oxygen helps.
"If they didn't have cryogenics, the pilots would have to fly at low altitudes and low speeds,” added Barnes.
With out the LOX Farm, the station would not be able to operate, said Bazante.
"Aircraft are always going to need oxygen and nitrogen. If you don't have cryogenics in the aviation field, you pretty much don't have an aviation field," said Bazante.