Arrangement for an after treatment of exhaust gases from an internal combustion engine

摘要

To reduce NOx components in the exhaust gas from a compression-ignition internal combustion engine with the aid of a reducing catalytic converter, a metering device for the supply of reducing agent to be additionally introduced into the exhaust gas, in the form of fuel, is provided to improve the performance of the catalytic converter. For this purpose, use is made of a positive displacement pump designed to meter very small quantities with a helix in the form of a helical groove arranged on a cylindrical body of revolution, the delivery rate being varied by driving the body of revolution at a variable rotational speed.