Swanky malls are attractive hangouts. How fire-proof are they? With malls allocating space for eateries, safety measures remain a concern as studies by international agencies have found that 98% of malfunction of sprinkler systems could be due to human error.
While stringent rules could save lives, often insurance companies find themselves settling huge claims when goods are damaged by water used to douse the fire. The flip-side of sprinkler systems are that they are designed to drench the room to prevent fire from spreading. As a result, water damages the stored property.
The United States-based insurance company FM Global’s search for an answer ended at the National Centre for Combustion Research and Development of the Indian Institue of Technology - Madras. The company has entered an agreement with the Institute to develop a sprinkler design that would reduce water use and thereby reduce damage to stored goods.
The design for sprinklers remains a trial-and-error method. When fire begins and the sensors are activated, the sprinkler system automatically starts spraying water. The fire may have started elsewhere but the sprinkler would douse the entire floor.
Chetankumar S. Vegad, a Ph.D student at the Institute’s Aerospace Engineering department, is working to improve on the existing design. “The final outcome is water droplets. Our primary objective is to find how the droplet forms. Several forces like pressure, surface tension, inertia and gravitation. We want to make the optimum use of water but create a large mist that will react with the flame plume to suppress fire,” says Chetan.
Studying with laser
He uses laser to study the spread of water into fine droplets and how they react at different conditions. Chetan’s ultimate aim is to design a sprinkler nozzle to spray fine droplets that will evaporate and cause a water vapour blanket that will not only suppress the fire but also diminish damage to stored goods.
“In the 1970s, the buildings were compartments but with large malls and fancy architecture, the sprinkler systems are losing ground, unable to do the best thing,” says Chetan’s guide and professor S.R. Chakravarthy, who is also the coordinator of the NCCRD. A good nozzle design would also help reduce the use of water, he adds.
