摘要:
Various aspects provide for a multistage fluidized bed reactor, particularly comprising a volatilization stage and a combustion stage. The gas phases above the bed solids in the respective stages are separated by a wall. An opening (e.g., in the wall) provides for transport of the bed solids from the volatilization stage to the combustion stage. Active control of the gas pressure in the two stages may be used to control residence time. Various aspects provide for a fuel stream processing system having a pretreatment reactor, a combustion reactor, and optionally a condensation reactor. The condensation reactor receives a volatiles stream volatilized by the volatilization reactor. The combustion reactor receives a char stream resulting from the removal of the volatiles by the volatilization reactor.
摘要:
Described herein are embodiments of systems and methods for oxidizing gases. In some embodiments, a reaction chamber is configured to receive a fuel gas and maintain the gas at a temperature within the reaction chamber that is above an autoignition temperature of the gas. The reaction chamber may also be configured to maintain a reaction temperature within the reaction chamber below a flameout temperature. In some embodiments, heat and product gases from the oxidation process can be used, for example, to drive a turbine, reciprocating engine, and injected back into the reaction chamber.
摘要:
The invention concerns a method and a device in the cooling of the circulating material in a fluidized-bed boiler. In the method the fuel (A) is introduced into the circulating-powder combustion chamber (10) of the fluidized-bed boiler into the lower part of the circulating-powder combustion chamber (10) and an inert circulating material, which contains a proportion of unburned powdered fuel (A), is circulated from the top part of the circulating-powder combustion chamber (10) to the lower part of the circulating-powder combustion chamber (10). The flue gases are passed in the method from the powder separator (13) along the duct (15) into the exhaust-gas boiler (16), through whose heat exchanger (16a) thermal energy of the flue gases is transferred further to other useful use. In the method, part of the cooled flue gases are recirculated along the duct (20) into the circulating material and, by means of the cooled flue gases, the capacity of cooling of the fluidized-bed furnace is regulated by affecting the temperature of the circulating material.
摘要:
An ash control valve apparatus for use in a system that includes a fluidized-bed system which includes a housing, a seat in the housing for passage of particulate material, a plug dimensioned and configured for mating engagement with the seat, and apparatus for moving the plug from a first position wherein the plug is disposed in seated engagement with the seat to a second position wherein the plug is disposed in spaced relationship to the seat. The apparatus for moving the plug includes apparatus for mounting the plug that includes an elongated tube to which the plug is fixed. The apparatus for mounting includes a plurality of axially extending ribs disposed on the circumference of the elongated tube and a plurality of channels disposed in a bore in the plug. Apparatus in the plug cooperates with the plurality of channels to define a bayonet type receiving structure dimensioned and configured for receiving the plurality of axially extending ribs and allowing relative rotational movement between the plug and the ribs to produce locking engagement therebetween. In some forms of the apparatus the apparatus for cooling the tube includes a concentric hollow internal member for directing flow of a coolant along the axial extent of the tube. A portion of the tube may extend through a wall of the housing opposite the seat; and a bonnet assembly may surround the axial portion of the tube may extending through a wall of the housing, the bonnet assembly insures a dynamic seal between the tube and the bonnet assembly as the tube is moved axially from the first position to the second position.
摘要:
A method and apparatus are provided for operating a pressurized reactor system in order to precisely control the temperature within a pressure vessel in order to minimize condensation of corrosive materials from gases on the surfaces of the pressure vessel or contained circulating fluidized bed reactor, and to prevent the temperature of the components from reaching a detrimentally high level, while at the same time allowing quick heating of the pressure vessel interior volume during start-up. Superatmospheric pressure gas is introduced from the first conduit into the fluidized bed reactor and heat derived reactions such as combustion and gassification are maintained in the reactor. Gas is exhausted from the reactor and pressure vessel through a second conduit. Gas is circulated from one part of the inside volume to another to control the temperature of the inside volume, such as by passing the gas through an exterior conduit which has a heat exchanger, control valve, blower and compressor associated therewith, or by causing natural convection flow of circulating gas within one or more generally vertically extending gas passages entirely within the pressure vessel (and containing heat exchangers, flow rate control valves, or the like therein). Preferably, inert gas is provided as a circulating gas, and the inert gas may also be used in emergency shut-down situations. In emergency shut-down reaction gas being supplied to the reactor is cut off, while inert gas from the interior gas volume of the pressure vessel is introduced into the reactor.
摘要:
A stationary weakly expanded fluid bed for combustion of coal, refuse, sludge and the like has a free space above the fluid bed in which a so-called upper firing is effected with secondary air. The temperature of the secondary air is maintained above the temperature of the fluid bed to handle problems resulting from variations in fuel quality and varying loads and guarantees a stable upper firing.
摘要:
The invention relates to a method and a nozzle bottom for controlling the mixing of gaseous flows in fluidized bed reactors and circulating fluidized bed reactors. In the method, part of the combustion air is introduced into a reactor chamber through fluidizing nozzles (11) positioned in a nozzle bottom (4). In order to improve the controllability of a combustion process, the remaining part of the combustion air is according to the invention introduced through essentially vertically directed jet nozzles (12) positioned in the nozzles bottom (4), and the vertical penetration of the air jets applied through the jet nozzles (12) is maintained at a value essentially higher than the vertical penetration of the air jets applied through the fluidizing nozzles (11). The nozzle bottom (4) according to the invention thus comprises, in addition to the fluidizing nozzles (11), essentially vertically directed jet nozzles (12) the diameter of which is larger, preferably 5 to 20 times larger than the diameter of the fluidizing nozzles (11) and the number of which is essentially smaller than the number of the fluidizing nozzles (11).
摘要:
A parameter, especially the temperature of the bed in a fluidized-bed furnace, is maintained constant by a regulator (24) positioned in a line (20) that supplies fluidizing air to a trap (15), through which solids that have been precipitated out of the flue gas are recirculated into the fluidized bed (5). The servo mechanism (23) that drives the regulator is coupled to a temperature sensor (27) in the bed such that the volume of fluidizing air is increased when the measured bed temperature exceeds a prescribed level and decreased when it drops below that level.
摘要:
A system and method for controlling the sealing efficiency and recycle rate in a fluidized bed reactor in which air is introduced into two chambers found in a sealing vessel for receiving the separated solids from the separator. The air is introduced into two chambers in the sealing vessel in a direction opposite to that of the flow of the separated solids through the vessel. One of the chambers is located below the separator dipleg and in alignment therewith and the other chamber surrounds the first chambers. The air flow through each path can be separately adjusted as necessary.
摘要:
A method of discharging heat from a particulate material in a bed (28) of a combustor (12) in the event of an operational disturbance in a PFBC power plant. Gas from the combustor (12) is cooled in a cooling circuit (69) connected to the combustor (12) and is returned to the combustor (12) where it is allowed to pass through the bed (28). A device for carrying out the method comprises a cooling circuit (69), connected to the combustor (12), with a cooler (72) and a compressor or fan (76) which effects gas circulation through the cooling circuit (69) and the combustor (12).