Structure and working principle of oxygen generator

In the medical device field , an oxygen concentrator (Oxygen Concentrator - Different from Oxygen Generator) is a device with the function of enriching oxygen from the air (concentrating and increasing oxygen concentration) with an output oxygen concentration of about 90-95%.

This is a device used to provide oxygen to patients without using liquid oxygen or oxygen cylinders, which is very dangerous and inconvenient to use at home or small medical facilities. as well as economic efficiency.

The principle of operation of the traditional oxygen generator

In natural air, the oxygen content accounts for about 21%, the rest is nitrogen and other gases (79%). The principle of the oxygen generator is to naturally suck in the machine, then absorb and discharge nitrogen gas out, retaining the oxygen supplied to the patient through another route. To absorb nitrogen, people use zeolite particles.

Air is sucked through the filter, then put into an air compressor (the pressure here is about 2-3 at), after being cooled in the form of compressed air, it will pass through a 4-way valve system, This valve system in turn opens and closes to bring compressed air through to the tank, and at the same time pushes the nitrogen retained by the Zeolite particles in the two molecular sieve beds out, pushing new oxygen into the oxygen accumulator. The cycle, the opening and closing time of the valve is automatically controlled by an electronic circuit based on the calculation of the tank capacity, flow or gas pressure.

Air is pumped into the tank at a suitable pressure. The nitrogen gas will be absorbed by the chemical (zeolite particles), when the specified pressure is reached, the oxygen will be pushed into the container (oxygen accumulator) causing the pressure in the zeolite container to decrease. When reduced to a certain pressure, the valve will close the oxygen intake and discharge the absorbed N gas to regenerate the chemical.

Just like that, compressed air is passed through the valve and filter system, humidified to bring oxygen to the patient for use, a part is extracted through the oxygen sensor to monitor the oxygen content if it is lower than 60%, it will be sent to the machine. alarm for repair or filter replacement.

Due to the above principle of operation, when the machine is operating, it will hear "beep" and "beep" sound . The "beep" sound is when the pressure is compressed, the "x" sound is when the N gas is released to regenerate the chemical. The valve opening and closing time is very important for the output oxygen rate.

After a period of use (about 5-7,000 hours depending on the brand), the fabric bags containing chemicals will often be torn, crushed chemicals combined with moisture will clog the pipes. Normally, it is necessary to check, maintain the pipeline and replace the zeolite periodically to ensure the oxygen ratio is up to standard.

Structure of the oxygen generator

The figure below shows the general structure of an oxygen generator (usually without aerosol generator and SpO2 detector):

Advanced Technology Fractionators (ATF)

ATF technology oxygen generator.

In oxygen generators using ATF technology, the number of columns containing Zeolite is increased many times into an integrated cluster with a rotating valve system. The ATF system is already packaged so there is no need to use a 4-way solenoid valve, a cycle control circuit.

Cluster ATF-8.

Comparison of traditional oxygen concentrator and oxygen concentrator using ATF technology.