Reducing agent dosing system for injection of reducing agent into effluent stream of combustion engine for selective catalytic reduction, has reducing agents introduced into stream of engine, and flow sensor integrated in feed line

摘要

The system has a reducing agent tank containing reducing agents that are conveyed by a feed pump (1) i.e. gear pump, over a delivery line (3). The reducing agents are introduced over a nozzle (4) into the effluent stream of a combustion engine. A flow sensor (5) i.e. calorimetric flow sensor, is integrated in the feed line between the feed pump and the nozzle. The flow sensor comprises a heating element and two temperature sensors (11, 12), where heating power of the heating element is kept constant and difference in temperature between the two temperature sensors is detected.