Abstract: Oil shale having a relatively wide range of heating value is combusted by supplying the oil shale and a further fuel having a heating value greater than the heating value of the oil shale to a combustor. The oil shale is fed to the combustor at a substantially fixed rate, independently of the heating value of the oil shale, and the further fuel is fed to the combustor at a rate such that the heating value of the fuel in the combustor remains substantially constant in the face of variations in the heating value of the oil shale. Preferably, the temperature of combustion of the products of combustion is the parameter used to control the rate at which the further fuel is fed to the combustor.

Abstract: A method of wood waste disposal which regulates factors such as the amount of wood residue being fed to an incinerator at any given time so that wood residue from a mill is processed promptly and efficiently without compromising the efficient operation of the incinerator. The wood residue is separated into at least two fractions, the first fraction being directed to a storage bin for later use as required, and the second fraction being directed to the incinerator. During periods of slack feed of the second fraction to the incinerator, portions of the first fraction, as required, are directed to the incinerator as make-up, in order to maintain an optimal range of incinerator conditions by manipulating the volume and flow of wood residue in cooperation with manipulating other factors.

Abstract: A natural draft, gravity feed pellet stove. The body of the stove is formed by a vertical section of large diameter pipe, with an air intake pipe extending from the back of the stove to below a combustion grate. Pellet fuel is discharged onto the grate through a slot at the bottom of a hopper, and the grate is sloped so that the pellets roll away from the slot and over the grate as they are combusted. The combustion gasses flow into two exhaust pipes, each having a diameter similar to that of the intake pipe so as to establish a 2:1 exhaust/intake flow ratio. Cross-drilled reburner tubes are installed across the intake ends of the exhaust pipes to provide additional air for complete combustion. The bottom plates of the storage hopper are free from attachment along their lower edges, so that these expand and contract on a continuous basis with changes in the temperature of the stove; this causes cyclical distortion of the plates which shifts the fuel downwardly towards the discharge opening.

Abstract: A power plant has two fluidized beds, one of the fluidized beds being used for generating main steam and the other being used for generating reheated steam. Further, the power plant includes a control apparatus for controlling the main steam by adjusting the fuel flow for the main steam generating fluidized bed and the fuel flow for the reheated steam generating fluidized bed so that each of the main steam temperature and the reheated temperature is maintained at a respective predetermined value.

Abstract: To detect a regulating quantity which is directly proportional to the combustion temperature, an infrared measuring device in the form of an infrared pyrometer is provided in the descending waste gas flue of an incineration plant and measures the temperature of the waste gases. The influence of radiation from the glowing fuel bed or the flame is excluded by arranging this measuring device in the descending waste gas flue. The temperature-dependent regulating quantity which is determined in this way can be used directly or indirectly to influence the combustion process. In a preferred application, the temperature-dependent regulating quantity serves to influence the supply of fuel and the speed of the combustion grate, while a regulating quantity derived from the mass flow of steam serves to influence the supply of primary air.

Abstract: A method and device in combustion plants for solid fuels with a movable grate means for feeding the fuel through the fireplace of the combustion plant, for the control of the fuel feed through the fireplace of the plant. To control that the fed fuel is completely combusted when discharged from the fireplace of the plant the degree of combusted fuel is sensed by a sensor means (9) in a zone (B) at the end of the movable grate means (1) in order to obtain a control signal to the drive means of the grate means.

Abstract: Wood-waste products, such as wood shavings, wood chips and sawdust, are burned in an apparatus having a waste burner comprising an elongated cylinder in which fuel and air are mixed and ignited before entering an enlarged combustion chamber. The waste burner is characterized by an elongated cylinder having a length substantially larger than its diameter so that the fuel can be heated to a temperature sufficient to pyrolyze volatiles and initiate combustion in the cylinder. A wood-waste burner apparatus is also provided and comprises the waste burner of the invention and a combustion chamber for receiving unburned fuel and combustion products emanating from the burner. A process for burning wood-waste products is also provided. The invention is especially well suited for retrofitting packaged boilers to accommodate wood-waste fuels.

Abstract: Process and apparatus for supplying combustible material to a fluidized bed in a vessel connected to a separating device for the solid particles entrained with the smoke and containing a certain proportion of unburnt matter, the particles recovered being recycled into the fluidized bed. During a normal operation of the fluidized bed supplied with combustible matter, the solid particles recovered in the separating device are accumulated in a silo and periodically, the supply of combustible matter is stopped and the particles accumulated in the silo are recycled into the fluidized bed with a regulated flow rate, so that the combustion of the unburnt matter contained in the recycled particles maintains the temperature of the fluidized bed at the desired level. The exothermic reaction is maintained alternately by the combustion of the combustible matter in the normal operating phase and by the combustion of the unburnt matter in the recycling phase.

Abstract: A gas turbine engine power plant having a coal burning fluidized bed utilized as the heating source for the power plant. The fluidized bed comprises inerts and coal in which is immersed a temperature sensitive device, the signal from which is used to control the supply of coal to the bed to thereby maintain the bed at a predetermined temperature and to limit the bed temperature to a predetermined maximum value. The bed can be fluidized by the flow of compressed air from the compressor of the gas turbine engine power plant and the whole of the compressor delivery air flows through the bed in direct chemical contact with the bed materials and is then cleaned prior to delivery to the turbines of the power plant from which it is discharged to atmosphere.