Exhaust gas treatment device for selective catalytic reduction of nitrogen oxides contained in exhaust gases of engine, has shut-off valve arranged in pressure line between feed pump and metering unit

摘要

The device (3) has feed pump (7) that sucks the aqueous urea solution from a tank (1), and supplies the sucked aqueous urea solution to internal combustion engine through an exhaust tract. A shut-off valve (40) e.g. passive two-way valve with shut-off element is arranged in pressure line (25) between the feed pump and metering unit (13). The shut-off valve has bistable spring element that is provided to supply high clamping force and/or low holding force. An independent claim is included for method for selective catalytic reduction of nitrogen oxides contained in exhaust gases of internal combustion engine.