Abstract: A foreign object removal system is disclosed including a removal chamber projecting laterally from the combustion chamber of a fluid bed reactor and connected via a downwardly directed pipe to a material flow control plenum chamber, which includes means for fluidizing the mixture of inert bed particles and foreign objects at the bottom of the pipe for lateral movement into an air classifier, wherein the foreign objects are dropped to a collection tank and the fluid bed particles are carried upwardly by a stream of classifying air to a deentrainment chamber where their velocity is reduced and they are returned to the combustion chamber.

Abstract: A fluidized bed combustor for burning solid fuel or dirty liquid fuels comprised of a bubbling fluid bed with tubes in the bed, an isothermal, non-heat extractive freeboard/recycle cyclone flow path, a hot recycle cyclone, a connective heat exchanger and a particle filter. The bubbling fluid bed is operated at low superficial velocities of 0.5 to 7 ft/sec and is composed of fine particulates 45 to 2000 microns in diameter with up to 40% less than 200 microns. Fines elutriated from the bed are isothermally recycled back to the bed resulting in high combustion efficiency and good sulfur oxide suppression from sorbents contained in the bed. The material recycled in one hour is equivalent to twice the weight of the bed. Ammonia injected upstream of the recycle cyclone suppresses nitrogen oxides with high efficiency because of the excellent mixing in the cyclone. The heat transfer coefficient on the tubes in the bed is increased at least 2 to 4 times because of the fine particulate in the bed.

Abstract: A foreign object removal system is disclosed including a removal chamber projecting laterally from the combustion chamber of a fluid bed reactor and connected via a downwardly directed pipe to a material flow control plenum chamber which includes means for fluidizing the mixture of inert fluid bed particles and foreign objects at the bottom of the pipe for lateral movement into an air classifier wherein the foreign objects are dropped to a collection tank and the fluid bed particles are carried upwardly by a stream of classifying air to a deentrainment chamber where their velocity is reduced and they are returned to the combustion chamber.

Abstract: A fluid bed combustion method and apparatus are disclosed utilizing an induced draft fan downstream of the exhaust port of the combustion chamber. Fluidizing air is given a velocity vector toward one side of the chamber for moving foreign objects to that side where the objects are removed and separated by air classification from bed particles which are returned to the fluid bed. Air classification is accomplished using a blower which is valved off during preheat operation to draw hot air from above the fluid bed down through the particle bed.