Abstract: A recirculating fiber filter (1) and method is provided for removing particulates from moving fluid streams. High aspect ratio fibers (2) are used which readily nest with each other to form the high voidage fiber filter bed. In the method, fibers are continuously removed from the bottom of the bed regenerated to remove particulates and recycled back to the top of the bed and distributed thereon. Dirty fluid is passed from the top to the bottom of the filter. Dendrites of the particulate impurity appear to buildup in a thin section (A) at the top of the filter and provide the primary mechanism for further particulate entrapment. Recirculation of fibers offers a continuously fresh volume of fibers at the top for capture of particulates.

Abstract: Nitrogen oxide pollutants are substantially reduced and sulfur dioxide minimized in multisolid fluidized beds by staged combustion of the fuel. The lower combustion region is operated at substoichiometric conditions such that NO.sub.x is reduced by carbon and carbon monoxide to nitrogen gas. The upper combustion region is operated at excess oxygen conditions to complete the combustion of char and carbon monoxide. Elevated temperature excursions in the upper region which deter sulfur capture are prevented by recycling cool entrained bed particles therethrough.

Abstract: Continuous chemical and biological reactions may be carried out in a liquid fluidized reactor (1). Improved mixing and mass transport between gas/liquid/solid phases is provided by fluidizing large particles (2) with a liquid in a dense bed in the bottom of the reactor (1) while recirculating small entrained particles (3) and the liquid through the reactor (1), particle separator (9), external regenerator (10) and conduits (7) and (8) back through the dense bed of large particles (2).

Abstract: A method of operating a fluidized bed system in a single vessel, typically as a combustor system for power or steam generation burning high-sulfur coal or as a gasifier for high-sulfur coal, which comprises forming an entrained fluidized bed in a first space region containing a first solid bed particle component, such as sand or hematite ore containing over 90% Fe.sub.2 O.sub.

Abstract: A method of operating a fluidized bed system, typically as a combustor system for power or steam generation by burning high-sulfur coal, which comprises forming an entrained fluidized bed in a first space region containg a first solid bed particle component, such as a hematite ore containing over 90% Fe.sub.2 O.sub.