Chopping Harmful Diesel Emissions
An award-winning desing reduces diesel exhasut emissions by 85%.
By Dean Jobb
THE MAGAZINE DEVOTED TO NICKEL AND ITS APPLICATIONS
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THIS COMPACT FILTER, made of S30403 and S30200 stainless steel, eliminates 95% of black smoke and 85% of
the soot particles from diesel engine exhaust gases.
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Nickel Magazine, July 2004 -- When a citizens' group in Amagasaki, western Japan, successfully sued it's local council, the impact was felt in the nation's capital, Tokyo. The lawsuit claimed the city had failed to protect Amagasaki residents from the diesel fumes spewing from trucks using a highway that ran by their homes, prompting leaders of the eight cities and prefectures that make up the sprawling Tokyo metropolitan area to introduce strict controls on diesel exhaust emissions.
For A'PEX ADS Company, a Japanese manufacturer of high-performance parts for racing cars and other vehicles, the challenge was to design a lightweight component that could filter out the smoke and soot from diesel-powered trucks, buses and cars. The result is the A'PEX DPF (diesel particulate filter) system, a compact unit not much larger than a conventional muffler, consisting of a stainless steel frame and casing and silicon-carbide fibre filters that collect and burn uncombusted materials. The design won A'PEX a Japan Stainless Steel Association prize in the best product category in April 2004.
The system, which can be incorporated into the design of a new vehicle or fitted on those already in operation, is capable of eliminating 95% of the black smoke and 85% of the soot particles a diesel engine produces. The results hold for stop-and-go city driving, as well as high-speed highway travel, thanks to an on-board computer that monitors temperature, pressure and engine speed to ensure optimal combustion.
The unit collects sooty emissions in one of its filter chambers, and once it is full, the chamber is closed off and exhaust gases are directed into a parallel chamber. An electrical charge is used to burn off the collected soot; the cleaned chamber is refilled with exhaust while the next chamber is cleaned; and the cycle is repeated.
The tube-shaped DPF and the trio of cylindrical filter housings inside account for about 90% of each unit and are made of stainless steel. S30403 is used for the outer casing, and S30200 is used for internal components. The stainless steel is supplied by Nisshin Steel, one of the leading producers of stainless steel in Japan.
The DPF is produced in four sizes ranging in weight from 23 to 43 kilograms, with the largest built for 10-ton trucks and buses and the smaller ones designed to be fitted on four- and two-ton trucks. The 38-kilogram unit, designed for use on a large city bus, sells for about US$7,000.
A'PEX says each unit will have an operational life of eight to 10 years, with a filter replacement after
five years or 250,000 kilometres of use. The unit was field tested on the bus fleet operated by the city of
Yokohama, and as of the end of 2003, about 8,000 units were in use.
Dean Jobb is a Wolfville, Nova Scotia-based freelance writer.
PHOTO: A'DPEX ADS Company
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A'PEX ADS Company |
