Injection lance for uniformly injecting anhydrous ammonia and air into a boiler cavity

摘要

An injection lance for injecting a mixture of air and anhydrous ammonia into a boiler having a flue gas stream moving therethrough to reduce nitrogen oxides therein. The lance includes outer, intermediate and inner tubes. The outer end of the inner tube is in communication with a source of anhydrous ammonia while the outer end of the outer tube is in communication with a source of mixing air. The outer end of the intermediate tube sealably embraces the exterior surface of the inner tube so that air being introduced into the outer tube passes towards the inner end of the lance between the outer and intermediate tubes. The mixing air and the anhydrous ammonia are passed into the space between the inner tube and the intermediate tube and then are discharged from the lance through discharge nozzles or ports which extend from the interior of the intermediate tube to the exterior of the outer tube.