India’s response to the second wave of COVID-19 dictated an exponential demand for oxygen and oxygen cylinders. Since oxygen was transported in liquid form in cryogenic tanks, quick conversion of liquid oxygen to gas and ensuring availability at the patients’ bed was a critical challenge faced by all hospitals managing COVID-19 patients.
An Indian Army Engineers team under Major General Sanjay Rihani undertook the initiative to find a solution to this challenge. A specialised task force was put together for the execution of innovation to ensure that oxygen is made available without the use of gas cylinders, thus cutting off the need to refill them frequently.
Over seven days, the team of Army Engineers, in direct consultation and with material support from CSIR & DRDO, put together a working solution using vaporisers, PRVs and liquid oxygen cylinders. In order to ensure continuous conversion of liquid oxygen into oxygen gas at the necessary pressure and temperature at the COVID bed, the team used a self pressuring liquid oxygen cylinder (250 litres) and processed it through a specially designed vaporiser and directly usable outlet pressure (4 Bar) with requisite leakproof pipeline and pressure valves.
A prototype with two liquid cylinders, capable of supplying oxygen to 40 beds for a period of 2-3 days has been made functional at Base Hospital, Delhi Cantonment. The team has also tested a mobile version to cater for typical shifting requirements in hospitals. The system is economically viable and is safe to operate since it removes the high gas pressure in the pipeline or cylinders and does not require any power supply to operate.