The invention relates to a method for operating a fluidized bed boiler (6), comprising the steps of: a) providing fresh ilmenite particles having a shape factor of 0.8 or lower as bed material to the fluidized bed boiler (6); b) carrying out a fluidized bed combustion process; c) removing at least one ash stream comprising ilmenite particles from the fluidized bed boiler; d) separating ilmenite particles from the at least one ash stream, wherein the separation includes a step of using a magnetic separator (12) comprising a field strength of 2,000 Gauss or more; e) recirculating separated ilmenite particles into the bed of the fluidized bed boiler; wherein the average residence time of ilmenite particles in the fluidized bed is 100 h or more.

A system for providing wind-assisted air supply to coal-fired power plants through the use of a wind funnel communicating with an air handler system of a coal-fired boiler is disclosed. The shape, size and orientation of the wind funnel may be controlled in order to optimize the collection of wind and generation of increased air pressure for delivery to the coal-fired boiler system. Increased operating efficiency of coal-fired power plants may be achieved with the wind funnel system.

The invention relates to a method for operating a fluidized bed boiler (6), comprising the steps of: a) providing fresh ilmenite particles having a shape factor of 0.8 or lower as bed material to the fluidized bed boiler (6); b) carrying out a fluidized bed combustion process; c) removing at least one ash stream comprising ilmenite particles from the fluidized bed boiler; d) separating ilmenite particles from the at least one ash stream, wherein the separation includes a step of using a magnetic separator (12) comprising a field strength of 2,000 Gauss or more; e) recirculating separated ilmenite particles into the bed of the fluidized bed boiler; wherein the average residence time of ilmenite particles in the fluidized bed is 100 h or more.

A fluidized-bed boiler integrating a multifunctional inertia-gravity separator and a plurality of models of boilers. The fluidized-bed boiler is a steam boiler, a hot-water boiler or a phase-transformation boiler. The fluidized-bed boiler includes a hearth, a single horizontal drum, a vertical single drum, vertical and horizontal headers, vertical and horizontal membrane walls, a primary high-temperature inertia-gravity water-cooling separator, a secondary low-temperature inertia-gravity water-cooling separator, a single-stage high-temperature water-cooling inertia-gravity separator, an equalizing, separating and heat storing device, a membrane water-cooling wall shaft, a shell shaft and a dry-wall shaft. The present disclosure provides a circulating fluidized bend boiler with a plurality of models of boilers, which comprehensively improves the boiler performance, drastically realizes the energy conversation, consumption reduction and emission reduction and has advanced process.

A heat exchanger pipe in a flow duct for gases. The pipe first section has a second section with an inner pipe for transferring heat transfer medium; an outer pipe that radially encloses a part of the inner pipe; and a medium layer between the outer pipe and the part of the inner pipe. The second section of the heat exchanger pipe bends less than 90 degrees. Furthermore, the first section is insulated in its entirety, or non-insulated in the vicinity of other heat recovery surfaces only. In the device the temperature of the heat transfer medium flowing in the inner pipe is at least 500? C., the temperature of the outer surface of the outer pipe is higher than 600? C., or an auxiliary agent is fed to the thermal device.

A fluidized bed boiler with a support construction for a particle separator. The fluidized bed boiler includes a bottom-supported furnace in which at least one particle separator with a support construction is in gas flow connection with an upper portion of the furnace and includes a furnace side portion, an outer portion opposite to the furnace side portion, and a conical lower portion. At least two bottom-supported downcomer pipes are in fluid connection with a steam drum and adjacent to the outer portion of the particle separator. The support construction includes a frame-like supporting member surrounding at least a portion of the conical lower portion, and an outboard portion of the supporting member is attached to the at least two downcomer pipes to support the at last one particle separator.