• One product puts out fires of varying intensities
  • Another removes dyes used in textile industry from water
  • IT MAY not be common knowledge that while the Defence Research and Development Organisation (DRDO) develops weapons systems for India's armed forces, it produces a number of technologies, which have civilian and military applications. International attention has now turned on the DRDO with its developing technologies, which are alternatives to halon and chlorofluorocarbons (CFCs).

    Ozone layer depletion

    Although halon and CFCs have excellent fire-fighting capabilities, they have been banned worldwide because they deplete the ozone layer of the environment. Scientists at the Centre for Fire, Explosives and Environment Safety (CFEES), a DRDO laboratory located in New Delhi, have developed products, which can be effective alternatives to halon and CFCs. One of these products is monoammoniumphosphate (MAP)-based multi-purpose, dry chemical powder for extinguishing fires of different intensities. Another product is heptafluoropropane, which is the nearest replacement for halon and has a worldwide market. The CFEES has also developed an Intelligent Fire Sensor with software based on a fire signature database that allows its fire detection system to accurately identify true fire situations in a few seconds while rejecting false alarms. Three other technologies that the CFEES has developed are an advanced oxidation process for treatment of effluents contaminated with toxic and hazardous organics; cement-based solid matrix for disposing sludges contaminated with heavy metals; and activated carbon spheroids for protection against nuclear, biological and chemical warfare.The DRDO has transferred all the six technologies/products to industries for production. Dr. W. Selvamurthy, Chief Controller, Research and Development, DRDO, said fire hazard was a major problem during combat, and although halon and CFCs had excellent fire-fighting properties, they caused ozone depletion and damaged the environment. The Montreal Protocol, to which India is a signatory, has called upon the parties to phase out the CFCs, halons and other man-made ozone-depleting chemicals. Halons are one of the six categories of chemicals that are covered under the phase-out programme of the Montreal Protocol. The CFEES had played an active role in formulating the phase-out strategy for the halon and integrating it with the `Country's Programme for Phase-out of Ozone-depleting Substances.'

    International market

    The DRDO had helped in identifying specific alternative technologies to ozone-depleting substances and transferring the technologies to industries in the fire-fighting sector. "These products have not only national but international market," Dr. Selvamurthy said. A.K. Kapoor, Director, CFEES, said "We want to popularise these products. They have more applications in the civilian sector than in the defence sector. We would like them to be produced for civilian benefits," said Kapoor. The CFEES took up a project on the development of dry chemical powder as fire extinguisher to replace halon and successfully developed a MAP-based multi-purpose dry chemical powder for fighting different classes of fires. The powder, which is an alternative to halon, conforms to national and international standards. Another is the technology for production of heptafluoropropane, an internationally acceptable alternative to halon, which can suppress different classes of fire and it has applications in critical defence areas.The intelligent fire sensor is highly sensitive detection system coupled with powerful intelligent analysis allows fire detection even in dusty environment. Use of laser diode source and multiple reflection increases the sensitivity of smoke detection. The sensors to sense the temperature and smoke make the fire detector sensitive to both slow-smouldering and fast-flaming fires. This will result in significant reduction in loss of lives and property. The system can be installed on board the ships, offshore machinery rooms, aircraft cargo compartments, industries, chemical plants, warehouses and so on. The CFEES has developed pitch-based activated carbon spheroids, which are strategic absorbent material. They will be useful for the protection of armed forces in the event of a chemical war.

    Eco friendly

    The powder has good mechanical strength, low ash content and is eco friendly. Dr. Selvamurthy said, "We are self-sufficient in our defence against NBC warfare. All the equipment and devices are indigenously manufactured."Dyes used in textile and hosiery industries pollute water. The DRDO has developed a technology to remove these dyes from the water used in these industries. Mr. Kapoor said, "This will have applications in the hosiery industry in Tirupur, Tamil Nadu. The process can be used for treating other pollutants as well."