27 May 2003

Manchester, England-based Per-Tec Ltd has launched a diesel particulate trap utilizing the electrostatic principle, which won the Diesel Innovation Award at the annual GreenFleet conference held earlier this month in London.

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Test of the Per-Tec trap on in service London taxi’s have shown a 70% PM mass reduction. The system is very effective in removing the ultra fine fraction of diesel particulates, which grow in size due to agglomeration in the electrostatic device. A 99% reduction of ultra fine particle number was reported across the 7 - 300 nm size range, as measured by an SMPS instrument. The system is effective regardless of the exhaust gas temperature and features fully automatic operation.

Electrostatic precipitation dates back to 19th century and its theory is well understood. One of major problems with applying the process within a diesel exhaust gas stream has been the draining of electrical field due to coating of the ceramic insulator with conductive soot layer. A part of the Per-Tec system is an electrode cleaning method, which has been designed to maintain the electrical field.

The Per-Tec trap has been tested on a number of vehicles, from London taxi cabs to 300 hp fire trucks. The system is approved in the UK by the Energy Savings Trust and listed in the TransportEnergy CleanUp register, currently for vehicles up to 3.5 ton (HD currently under final testing). TransportEnergy CleanUp grants cover up to 75% of the system cost for eligible retrofit installations. For more information contact Peter Kukla, Per-Tec, Peter.Kukla@man.ac.uk.

TransportEnergy CleanUp register

Source: Per-Tec