An external bed type double-fluidized bed system for preventing boiler contamination includes a fluidized bed combustion furnace, a cyclone separator, a coal ash distributor and a fluidized bed pyrolysis furnace. The fluidized bed combustion furnace is connected with the coal ash distributor, the coal ash distributor is connected with the coal ash inlet on a side wall of the fluidized bed combustion furnace through a return feeder with which the coal ash outlet of the fluidized bed pyrolysis furnace is also connected through an external bed, and the return feeder is connected with the fluidized bed combustion furnace. A fuel coal is pyrolyzed in the fluidized bed pyrolysis furnace at a temperature to volatize alkali chlorides into a pyrolysis gas, thereby reducing the content of the alkali chlorides contained in the coal in the fluidized bed combustion furnace and relieving the contamination to a convective heat-absorbing surface.

An external bed type double-fluidized bed system for preventing boiler contamination includes a fluidized bed combustion furnace, a cyclone separator, a coal ash distributor and a fluidized bed pyrolysis furnace. The fluidized bed combustion furnace is connected with the coal ash distributor, the coal ash distributor is connected with the coal ash inlet on a side wall of the fluidized bed combustion furnace through a return feeder with which the coal ash outlet of the fluidized bed pyrolysis furnace is also connected through an external bed, and the return feeder is connected with the fluidized bed combustion furnace. A fuel coal is pyrolyzed in the fluidized bed pyrolysis furnace at a temperature to volatize alkali chlorides into a pyrolysis gas, thereby reducing the content of the alkali chlorides contained in the coal in the fluidized bed combustion furnace and relieving the contamination to a convective heat-absorbing surface.

A system includes a standpipe for receiving a flow of solids therethrough, the standpipe having at least one inlet configured to receive a gas for decreasing a solids-to-gas ratio of the flow, a sealpot having an inlet fluidly coupled to the standpipe and an outlet fluidly coupled to a riser, the sealpot being configured to fluidize the solids received from the standpipe and to transport the solids to the riser, and a drain device fluidly coupled to an outlet in the standpipe, the outlet being located upstream from the inlet of the sealpot. The drain device is configured to remove the excess gas from the flow of solids within the standpipe to increase the solids-to-gas ratio of the flow prior to the solids entering the sealpot.

A system includes a standpipe for receiving a flow of solids therethrough, the standpipe having at least one inlet configured to receive a gas for decreasing a solids-to-gas ratio of the flow, a sealpot having an inlet fluidly coupled to the standpipe and an outlet fluidly coupled to a riser, the sealpot being configured to fluidize the solids received from the standpipe and to transport the solids to the riser, and a drain device fluidly coupled to an outlet in the standpipe, the outlet being located upstream from the inlet of the sealpot. The drain device is configured to remove the excess gas from the flow of solids within the standpipe to increase the solids-to-gas ratio of the flow prior to the solids entering the sealpot.

An apparatus for controlling flow of a material includes an inlet for receiving the material from a source, and a seal mechanism connected to the inlet, the seal mechanism having a fluidizing bed configured to receive the material from the inlet, a first discharge passageway and a second discharge passageway. The fluidizing bed includes a first transport zone associated with the first discharge passageway and a second transport zone associated with the second discharge passageway, wherein the first and second transport zones are configured to receive transport gas from a transport gas source. The transport gas is controllable to selectively divert a flow of the material into the first discharge passageway and the second discharge passageway.

The invention relates to an improved method for chemical-looping combustion of a solid hydrocarbon-containing feed using a particular configuration of the reduction zone with: a first reaction zone R1 operating under dense fluidized bed conditions; a second reaction zone R2; a fast separation zone S3 for separation of the unburnt solid feed particles, of fly ashes and of the oxygen-carrying material particles within a mixture coming from zone R2; fumes dedusting S4; a particle stream division zone D7, part of the particles being directly recycled to first reaction zone R1, the other part being sent to an elutriation separation zone S5 in order to collect the ashes through a line 18 and to recycle the dense particles through a line 20 to first reaction zone R1. The invention also relates to a chemical-looping combustion plant allowing said method to be implemented.

The invention relates to an improved method for chemical-looping combustion of a solid hydrocarbon-containing feed using a particular configuration of the reduction zone with: a first reaction zone R1 operating under dense fluidized bed conditions; a second reaction zone R2; a fast separation zone S3 for separation of the unburnt solid feed particles, of fly ashes and of the oxygen-carrying material particles within a mixture coming from zone R2; fumes dedusting S4; a particle stream division zone D7, part of the particles being directly recycled to first reaction zone R1, the other part being sent to an elutriation separation zone S5 in order to collect the ashes through a line 18 and to recycle the dense particles through a line 20 to first reaction zone R1. The invention also relates to a chemical-looping combustion plant allowing said method to be implemented.

The present invention provides a circulating fluidized bed boiler, comprising: furnace side walls; a ceiling; an air distribution plate provided at a bottom of a furnace; and at least one air distribution cone provided on the air distribution plate, wherein each air distribution cone extends upwards from the air distribution plate into an interior of the furnace and has a shape gradually tapered in an extending direction, cone side walls which form the air distribution cone are provided with secondary air ports, the cone side walls are separated from the furnace side walls, and a furnace combustion space is formed and surrounded by the ceiling, the furnace side walls, the air distribution plate, and the cone side walls. The present invention further relates to an air distributor for a circulating fluidized bed boiler, the air distributor being provided on an air distribution plate of the boiler, wherein the air distributor is in a form of an air distribution cone, which extends upwards from the air distribution plate into an interior of a furnace to form a shape gradually tapered in an extending direction, and secondary air ports are formed in air distribution cone side walls forming the air distribution cone. The present invention also relates to an air distributor assembly for a circulating fluidized bed boiler.

The present invention provides a circulating fluidized bed boiler, comprising: furnace side walls; a ceiling; an air distribution plate provided at a bottom of a furnace; and at least one air distribution cone provided on the air distribution plate, wherein each air distribution cone extends upwards from the air distribution plate into an interior of the furnace and has a shape gradually tapered in an extending direction, cone side walls which form the air distribution cone are provided with secondary air ports, the cone side walls are separated from the furnace side walls, and a furnace combustion space is formed and surrounded by the ceiling, the furnace side walls, the air distribution plate, and the cone side walls. The present invention further relates to an air distributor for a circulating fluidized bed boiler, the air distributor being provided on an air distribution plate of the boiler, wherein the air distributor is in a form of an air distribution cone, which extends upwards from the air distribution plate into an interior of a furnace to form a shape gradually tapered in an extending direction, and secondary air ports are formed in air distribution cone side walls forming the air distribution cone. The present invention also relates to an air distributor assembly for a circulating fluidized bed boiler.

The present invention demonstrates a solid fuel grade gasification-combustion dual bed poly-generation system, comprising a combustion system, a gasification system, a synthesized gas cooling and purifying system and a synthesized gas methanization system. The combustion system is connected with the gasification system through a circulating material return system. The gasification system mainly adapts the circulating fluidized-bed combustion mode. The gasification system adapts the fluidized-bed incomplete gasification method and the generated semi-coke is returned to the combustion system for re-utilization. The synthesized gas purifying and cooling unit adapts water cycling and combustible recycling. The by-products, CO.sub.2 and steam, in the methanization unit can be recovered, so the maximum utilization rate of energy in this system is realized.