Mist opportunity

The American military is to evaluate a UK-developed system that deluges chemical or biological agents with six trillion droplets of decontaminant per second.


The American military is to evaluate a UK-developed system that deluges chemical or biological agents with six trillion droplets of decontaminant per second.


The system, called PDX Basilisk, is designed to fill areas affected by airborne hazardous particles with an ultra-fine mist of decontaminating chemicals.


Hertfordshire engineering group Pursuit Dynamics, which developed Basilisk, has signed a contract with Darpa, the US military’s top-secret technology research arm. Under the year-long deal, Darpa will look at uses for PDX Basilisk as part of its research into new technologies for dealing with chemical, biological and radiation attacks on cities and buildings.


Basilisk is the latest specialist application to be developed by Pursuit Dynamics for PDX, which uses steam-injection technology to create a supersonic vapour flow and ‘shockwave’ that atomises water and chemicals to a fine mist.


The company claimed it can continuously project a higher volume of decontaminant over a greater distance and at smaller droplet size than is possible with any alternative technology. According to Pursuit Dynamics, it can fill a 600m3 area within 15 seconds.


The PDX system also turns the decontaminant into 4.5-micron droplets. Kester Scrope, the firm’s commercial director, said this is crucial in helping the system to fight chemical and biological agents, as the mist plume will remain suspended in the air long enough for the decontaminant to do its work. It also allows the mist to spread over every surface, including complex cavities that would otherwise remain untreated.


‘When droplets are that small they assume gas-like behaviour,’ said Scrope. ‘As they get smaller there is a massive improvement in performance in terms of hanging in the air. We have also proved this does not damage the effectiveness of the decontaminant materials.’


The firm is billing its technology as superior to spray systems, which it said produce large droplets that only stay in the air for a short time, and ‘thermal foggers’ — gasgenerating devices that Pursuit claims produce less mist and can damage decontaminants.


Scrope was unable to comment on the specifics of Darpa’s research. However, he said the system could theoretically be deployed in a number of ways — for example, by being fitted into the fabric of buildings for instant response, or as a portable unit that could be taken to decontaminate a specific area.


Basilisk is an extension of PDX Fire Mist, a fire control system developed by Pursuit Dynamics that uses the same technology to create a water mist. The core PDX technology is also being applied to a variety of other applications, most notably in the food and beverage industry where the company believes it can increase the efficiency of production processes.