Inventor's 'clean air' exhaust rejected

IT resembles a giant cocktail shaker, costs next to nothing to make, is easy to fit and could stop us getting some forms of cancer. Yet nobody, it seems, wants to know.

That, anyway, is the response so far from vehicle and engine manufacturers towards the cyclonic diesel exhaust, a new device that its inventor claims will remove potentially lethal emissions.

Although it is unleaded, diesel fuel produces nitrous oxides, hydrocarbons and sulphur dioxides. Doctors believe these dust 'particulates' can cause cancers and affect people who have breathing problems. Tests at the Robens Institute of Industrial and Environmental Health and Safety at Surrey University showed that rats which inhaled diesel fumes developed lung tumours.

James Dyson, the cyclonic exhaust's inventor, maintains it can trap 95 per cent of the harmful gases. Instead of getting into the atmosphere, they are deposited as a black soot in the end of the device, to be disposed of later. But he has received rejections from manufacturers GKN, T & N, Eminox, Volvo and Perkins.

'Anyone who has been stuck behind a lorry for any length of time will know what I am talking about,' he says. 'All it is emitting is black dust and grime. There are 20 million diesel engines in Europe alone. Every one produces six grammes of dirt for every hour it is used. That is a huge amount, which goes on to cause cancer and acid rain. I can stop it - I'm very disappointed, not for myself but also for society.'

Mr Dyson is an industrial designer whose inventions have made him wealthy. He introduced the 'ballbarrow' - the wheelbarrow with a football-type wheel - to the nation's gardens and his new, powerful vacuum cleaner, the Dyson Dual Cyclone, is selling well. It was the latter's development that led to the cyclone exhaust.

The 'cocktail shaker' would replace the silencer in the usual diesel exhaust system. Smoke from the engine enters the wide end at an angle, is spun round and round at high speed and broken down to a fine dust at the narrow end. Once that end is full - every routine service interval, claims Mr Dyson - it can be unscrewed, sealed and thrown away.

It can be made of aluminium or rolled tin, involves no fancy gadgetry, relies on its shape for the cyclone effect and would have the same sound-deadening qualities as a normal silencer. Previously, cyclones were only thought capable of breaking particles down to 20 microns - small, but not small enough. Mr Dyson maintains his cyclone breaks them down to 0.1 of a micron.

Manufacturers gave a variety of reasons for rejecting the idea. Some were working on their own anti-pollution systems, most of which involve 'burning up' the gases or cleaning the fuel and oil.

Andrew Bowen of Glacier, part of T & N, said his company had 'no problem with (Mr Dyson's) product. There is nothing wrong with it and it has high potential, but we decided to market a product we already had, which extracts contaminants from both diesel and petrol engines.'

Robert Searles of Johnson Matthey, the world's leading auto-catalyst maker, said: 'Nobody will certify a system that requires regular emptying because many vehicle users will not bother to do it.'

He claimed that unless the soot was disposed of properly, it could lead to 'hot spots' of toxic waste in the soil. Far better, he said, in the short term at least, that the dust is emitted into the atmosphere. Mr Dyson said without legislation he could see no way to get his exhaust off the ground. 'Until the Government shows more inclination to clean up the environment big business will not do anything.'

(Photograph omitted)