Abstract: A process for desulfurizing fuel wherein a fuel is introduced and burned in a first fluidized bed and wherein a second fluidized bed is utilized to treat the products of combustion from the first fluidized bed.

Abstract: A fluidized combustor is provided with a burning zone having cooling passages in its upper portion and a lower portion beneath said passages yet deep enough so that material therein may be operated in a fluid bed combustor mode with cooling by fluidizing excess air, a separate zone being provided for selective storage therein of materials transferred from the burning zone.

Abstract: A chemical reactor with a first upstream fluid bed which primarily burns coal and a second downstream fluid bed which primarily desulfurizes.

Abstract: The leak detector disclosed herein is of the type which detects the presence of halogen gases, such as fluorides, by the effect such gases have on the color of a flame in the presence of reactive copper. The flame is generated by a gas-fueled burner of exceptionally small and rather critical proportions, constructed so that the entire air supply for the burner may be obtained through a flexible search tube. Further, the reactive copper is provided integrally with the burner rather than as a separate element heated by the burner. The burner employs a disk-like flameholder which is proportioned to provide a stable flame despite the small size of the burner and which is itself constructed of copper so as to provide the reactive material to obtain flame color sensitivity.