EXHAUST GAS CLARIFICATION APPARATUS FOR ENGINE

摘要

An exhaust gas clarification apparatus for an engine for reducing NOx in an exhaust gas by using a liquid reducing agent to clarify the exhaust gas, which is equipped with a temperature retaining device for retaining the temperature of at least a part of a system for supplying the liquid reducing agent including a spray nozzle and a piping therefor to a temperature lower than the boiling point of the solvent of the liquid reducing agent or to a melting point of the solute thereof or higher. The apparatus allows the liquid reducing agent being present in the system to conduct heat exchange with the system, which results in that the liquid reducing agent has a temperature lower than the boiling temperature of the solvent or of a melting point of the solute or higher. Accordingly, the solute is free from the precipitation caused by the evaporation of the solvent alone in the system, or the solute becomes dissolved or molten even in case it is precipitated, which leads to the prevention of clogging of spray holes of the spray nozzle.