Hi, this is Wayne again with a topic “New system can sterilize medical tools using solar heat”.
Narrator Autoclaves are devices used to sterilize medical tools in hospitals, clinics and doctor’s offices.. To be effective, they require a steady supply of pressurized steam at a temperature of about 125 degrees Celsius for roughly 30 minutes.. This is usually provided by electrical or fuel powered boilers.. However, in many rural areas, especially the developing world, power can be unreliable or unavailable, and fuel is often quite expensive..
A team of researchers at MIT and the Indian Institute of Technology has designed and tested a device that can generate the needed steam using just the power of sunlight, meaning no need for fuel or electricity.. The key to their new system is the use of optically, transparent aerogel.. The material is essentially a lightweight foam made of silica and consists mostly of air. Light as it is. The material provides effective thermal insulation, reducing the rate of heat loss by tenfold..
The insulating material is bonded to their solar collector, which consists of a copper plate with a heat absorbing black coating bonded to a set of pipes on the underside.. As the sun heats, the plate water flowing through the pipes underneath picks up that heat. With the insulating layer on top plus polished, aluminum mirrors on each side of the plate to direct extra sunlight. The system can generate high temperature steam instead of just hot water., Using gravity to feed water from a tank into the plate.
The steam then rises to the top of the enclosure and is fed out through another pipe which carries the pressurized steam to the autoclave.. The team tested their prototype in Mumbai, India. And, even though the sky was hazy and cloudy during their testing providing only 70 % of insulation compared to a sunny day, the device still succeeded in producing a steady supply of steam needed for sterilization for the required half Hour period. The researchers say once the aerogel material becomes commercialized. The entire system could be built at a very low cost, since all the other components are already widely available throughout the developing world. .