Oxygen concentrator

This type of adsorption system is therefore functionally a nitrogen scrubber, allowing the other atmospheric gases to pass through, leaving oxygen as the primary gas remaining.

[2] Gas separation across a membrane is a pressure-driven process, where the driving force is the difference in pressure between inlet of raw material and outlet of product.

[3] Home medical oxygen concentrators were invented in the early 1970s, with the manufacturing output of these devices increasing in the late 1970s.

Both of these delivery systems required frequent home visits by suppliers to replenish oxygen supplies.

In the United States, Medicare switched from fee-for-service payment to a flat monthly rate for home oxygen therapy in the mid-1980s, causing the durable medical equipment (DME) industry to rapidly embrace concentrators as a way to control costs.

This reimbursement change dramatically decreased the number of primary high pressure and liquid oxygen delivery systems in use in homes in the United States at that time.

The number of manufacturers entering the oxygen concentrator market increased greatly as a result of this change.

This type of adsorption system is therefore functionally a nitrogen scrubber, allowing the other atmospheric gases to pass through, leaving oxygen as the primary gas remaining.

An oxygen concentrator has an air compressor, two cylinders filled with zeolite pellets, a pressure-equalizing reservoir, and some valves and tubes.

As the first cylinder reaches near pure oxygen (there are small amounts of argon, CO2, water vapour, radon, and other minor atmospheric components) in the first half-cycle, a valve opens and the oxygen-enriched gas flows to the pressure-equalizing reservoir, which connects to the patient's oxygen hose.

At the end of the first half of the cycle, there is another valve position change so that the air from the compressor is directed to the second cylinder.

The pressure in the first cylinder drops as the enriched oxygen moves into the reservoir, allowing the nitrogen to be desorbed back into gas.

Partway through the second half of the cycle, there is another valve position change to vent the gas in the first cylinder back into the ambient atmosphere, keeping the concentration of oxygen in the pressure-equalizing reservoir from falling below about 90%.

The advantage of the multi-bed technology is the increased availability and redundancy, as the 10 L/min molecular sieves are staggered and multiplied on several platforms.

Gas mixtures can be effectively separated by synthetic membranes made from polymers such as polyamide or cellulose acetate, or from ceramic materials.

[6] While polymeric membranes are economical and technologically useful, they are bound by their performance, known as the Robeson limit (permeability must be sacrificed for selectivity and vice versa).

Membrane materials have expanded into the realm of silica, zeolites, metal-organic frameworks, and perovskites, due to their strong thermal and chemical resistance as well as high tunability (ability to be modified and functionalized), leading to increased permeability and selectivity.

Gas separation across a membrane is a pressure-driven process, where the driving force is the difference in pressure between inlet of raw material and outlet of product.

[17] Unlike in commercial airlines, users of aircraft without cabin pressurization need oxygen concentrators that are able to deliver enough flowrate even at high altitudes.

Oxygen flares up the furnace's fire to burn at a higher temperature needed for the production of glass.

Oxygen concentrators are considered sufficiently foolproof to be supplied to individual patients as a prescription item for use in their homes.

People who depend upon oxygen concentrators for home care may have life-threatening emergencies if the electricity fails during a natural disaster.

To meet that need, another process, called vacuum swing adsorption (VSA), has been developed by Air Products.