Method and apparatus for enhancing the fluidization of fuel particles in coal burning boilers and fluidized bed combustion

Abstract

Semi-permeable screens are installed in a pulverized coal burning boiler and rotatably driven by a high speed rotatable shaft. A first one of the screens is located above the main combustion zone of the boiler and a second one of the screens is located directly under the burnout zone of the boiler. The underside of the first rotating screen repels the larger and slower burning fuel particles that escape from the main combustion zone so that they are recycled for a complete burn-out. The smaller glowing particles suspended in the combustion gases pass through the first rotating screen and are micronized by the comminution effected by the spiral vortexes generated above this first screen. The second rotating screen positioned under the burnout zone provides for mixing and comminution of the gases and burning coal particles respectively. The vortexes generated by the screens homogenize the heat distribution in the upwardly moving stream of gas and solid particulates. The fuel may consist of micronized or pulverized particles or lumps of solids and may be combusted by itself or in admixture with sorbents for the flame scrubbing of SO.sub.x and NO.sub.x.

Dependencies are inferred from the claim text.