Method of separating a low density fly ash fraction from an overall group of fly ash

摘要

A method of separating a low density fly ash fraction from an overall group of fly ash entrained in a gas stream including the steps of passing the gas through a duct having a first area; passing the gas stream from the duct through an expansion nozzle; passing the gas stream through the expansion nozzle and into a hollow body having a second area, whereby the second area is larger than the first area; decelerating the gas stream as it enters the expansion nozzle to separate out low density ash particles; and collecting the low density ash particles from a hopper positioned adjacent the expansion nozzle.