Public sector power equipment major BHEL has shown interest in manufacturing oxygen concentrators with design and technical support from the Indian Institute of Science, Bengaluru.

Oxygen concentrators are machines that produce oxygen-rich air by sucking air into the machine and chemically removing nitrogen in it. The principle is roughly the same as catalytic converters, that clean exhaust fumes in cars.

In a concentrator, compressed air is passed through sieve beds containing Zeolite powder or pellets. Zeolite loves nitrogen, it adsorbs the gas.

Since atmospheric air is 78.09 per cent nitrogen and 20.95 per cent oxygen, when you remove nitrogen, you are left with oxygen-rich air. The nitrogen then gets naturally released from the Zeolite.

Typically, there are two canisters of Zeolite beds, so that when one is adsorbing Nitrogen, the other is rejuvenating itself by releasing the gas.

Increased need

The technology is not new or too complicated, but all the machines have all along been imported from China — perhaps because it was believed that the market is not very big.

The machines cost about 1 lakh apiece, and needs electricity to work — as such oxygen cylinders have been a cheaper option.

The market for concentrators has been only remote places, or when patients require continuous supply of oxygen in which case the machine is a cheaper option than cylinders.

But now, due to the Covid-19 crisis, the need for the concentrators has increased sharply. The machines can work either in tandem with ventilators or, when the patient is not severely affected, used independent of the ventilator.

Prof. Praveen C Ramamurthy of the Centre for Nano Science and Engineering of IISc, has now designed a concentrator that is cheaper, simpler and more effective. The total cost of bills of material is estimated at ₹15,000, so the product that hits the market will be far cheaper than those imported.

Prof Ramamurthy told BusinessLine on Thursday that BHEL has come forward to take up manufacture of the concentrators. While no formal agreement has been signed, it is expected that the PSU could start producing the machines in sufficient numbers in a month’s time.

Tweaking the design

Right now, the output from the concentrator machine of IISc design contains over 70 per cent oxygen, but scientists are exercising themselves over getting the number to over 90 per cent, which Prof Ramamurthy believes is doable.

Further, the compressor capacity is also being tweaked, so that it requires less power. When that is achieved, the machine does not have to rely on grid-supplied electricity, it can work well either with batteries or solar power.

In a situation when the number of Covid-19 infections shoot up, calling for more ventilators, the oxygen concentrators would come in pretty handy, Prof Ramamurthy said. He also sees big export opportunities for the product — being very low cost, it can compete with the Chinese products.

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