Boundary layer coal nozzle assembly for steam generation apparatus

摘要

A steam generating system includes a nozzle for pulverized coal and air which includes an elongated generally cylindrical body having a nozzle at one axial portion thereof. The apparatus also includes a nozzle tip that is generally sleeve shaped and dimensioned to overlap an axial extremity of the body. The tip is mounted for pivotal movement about the extremity of the body and the nozzle tip includes first and second surfaces dimensioned and configured for receiving therebetween all flow from the body. The apparatus also includes a seat plate that is also generally sleeve shaped and dimensioned and configured to provide sealing between the extremity and the nozzle tip. The seal plate is mounted for pivotal movement about the extremity of the body and is dimensioned and configured to have third and fourth surfaces disposed respectively in closely spaced relationship to the first and second surfaces throughout all possible pivotal positions of the seal plate and the nozzle tip. This closely spaced relationship defines an elongated slat for passage of air. The seal plate includes a stop to limit relative pivotal motion between the nozzle tip and the seal plate. The first and second planar surfaces are disposed with the plan thereof parallel to the direction of flow of gases and thus allow the gases to pass through the slot without impediment.