| 摘要 |
A fluid dosing device for introducing a reagent into an exhaust gas flow in a selective catalytic reduction system is described. The dosing device comprises an injection nozzle (26) having an outlet end (30) from which the reagent is injectable into the gas flow (38), and a heat shield (240) disposed around the outlet end (30) of the injection nozzle (26) and arranged to shield the outlet end (30) from the exhaust gas flow (26), in use. The heat shield (240) comprises an outlet aperture (244) through which the reagent can pass into the gas flow (38) during injection of the reagent. According to the invention, the heat shield (240) further comprises gas flow modifying means (250) arranged to guard against deposition of the reagent between the injection nozzle (26) and the heat shield (240), thereby reducing the likelihood of thermal bridging between the heat shield and the injection nozzle.
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