Abstract: A boiler with a cyclonic combustor includes a first chamber which is substantially uncooled and refractory lined, a second chamber in fluid communication with the first chamber, ducts for supplying air and fuel directly into the first chamber and for forming a cyclonic flow pattern of hot gases for combustion within the first and second chambers, an exit throat at the end of the second chamber and a heat exchanger surrounding the second chamber for keeping low combustion temperature in both chambers.

Abstract: A process and apparatus for burning fuel includes supplying fuel and primary air to the upstream end portion of a longitudinally extending precombustion chamber having a longitudinally extending outer wall. Fuel and primary air are flowed in a longitudinal downstream direction through the precombustion chamber while self-sustained combustion is maintained in the precombustion chamber by partially precombusting, mixing and heating the mixture of fuel and primary air. The uncombusted fuel and combustion products are flowed through a primary nozzle at the downstream end of the precombustion chamber. Secondary air is flowed longitudinally in a downstream direction through a longitudinally extending secondary air chamber having a longitudinally extending outer wall surrounding the outer wall of the precombustion chamber. The longitudinally flowing secondary air is heated while it cools the outer wall of precombustion chamber.

Abstract: A method of operating a circulating fluidized bed combustion reactor includes providing a reactor with an upright combustion chamber and an upright and cylindrical cyclonic combustor, feeding in combustible matter, supplying first and second streams of pressurized air, permitting combustion product gases to exit while retaining and returning granular material and uncombusted matter to the lower region of the combustion chamber and controlling the various flows.