Given the dreadful surge of COVID cases in India, with people dying for lack of oxygen, I was wondering if the smart folks here could put our heads together to brainstorm a way to develop a how-to manual on how to cobble up a DIY oxygen concentrator to help them.
If I understand it correctly, the principle is simple enough - we need a zeolite-filled pressure vessel that can take around 20psi, pressurise it with air and then relieve the pressure. The gas that comes out first should be oxygen-enriched, with the gas at the end nitrogen-rich. Over time the oxygen enrichment in the gas coming out falls, and the nitrogen concentration rises.
The question is, how to cobble this together with everyday items with little to no engineering workshop capabilities, perhaps even in a home. The goal is to let the manual describe several DIY oxygen concentrators at varying degrees of complexity, based on the user's expertise and access to engineering support. So start with a basic human-operated one, and then add complexity such as automatic pressure swings perhaps controlled by an Arduino or Raspberry Pi, and an electric pump.
A bicycle inner tube is a possible starting point; it is common, can take pressures up to 120psi and already comes with a valve to pressurise and de-pressurise it. Couple this with a bicycle hand pump as the initial model. Alternatively a soft drink bottle can be pressurised from 30 - 50 psi, but a way to add a valve to it will be needed.
What about sourcing the zeolite? Do we need to worry about contamination of the zeolite by humidity, dust, etc? What about inhalation of the zeolite dust by the user? Which means we would need a filter and trap too, at the valve.
P.S. I don't know what the law is in India regarding the DIY development of medical devices in an emergency/pandemic, but one may hope that saving lives takes precedence over licensing in times like these.
