Fast fluidized bed reactor and method of operating the reactor

Claim 3

A method as claimed in claim 1, in which the granular material and reaction gases removed from the upper region (18) are separated in a cyclone separator (24).

Claim 4

A method as claimed in claim 2, in which the granular material separated from the reaction gases in the cyclone separator (24) is received by a fluidized bed trap (25), and granular material overflows from the fluidized bed trap (25) back into the lower region (11) of the reactor chamber, the fluidized bed trap (25) containing a solid partition (28) for preventing cross flow of gases between the reactor chamber (10) and the cyclone separator (24).

Claim 7

A method as claimed in claim 4, in which the granular material is returned from the annular chamber (30) directly into the lower region (11) of the reactor chamber by gravity flow.

Claim 10

- A method as claimed in claim 1 or claim 4, in which the total pressurized air supplied to the reactor chamber is in excess of the stoichiometric amount needed for combustion of the matter fed into the lower region (11).

Claim 11

A method as claimed in claim 1 or claim 4, in which the matter fed into the lower region (11) is solid or liquid fuel for gasification, and the total pressurized air supplied to the reactor chamber is less than the stoichiometric amount required for combustion.

Claim 12

A method as claimed in claim 1 or claim 4, in which at least 80% of the total pressurized air supplied to the reactor chamber at maximum operating capacity is supplied by the second stream of air, and the second stream of air is supplied at about ambient temperature.

Claim 13

A method as claimed in claim 1 or claim 4, in which at least 30% of the total pressurized air supplied to the reactor chamber at minimum operating capacity of the reactor is supplied by the second stream of air, and the second stream of air is supplied at a temperature in excess of 150°C.

Claim 14

A method as claimed in claim 1 or claim 4, in which the second stream of air is supplied at about ambient temperature.

Claim 15

A method as claimed in claim 12, in which at least 50% of the total pressurized air supplied to the reactor chamber at minimum operating capacity of the reactor is supplied by the second stream of air.

Claim 17

A method as claimed in claim 14, in which the second stream of pressurized air is supplied tangentially through a plurality of pairs of oppositely disposed openings (19) in the cylindrical internal surface.

Claim 18

A method as claimed in claim 15 when dependent on claim 4, in which at least one of the pairs of oppositely disposed openings (19) is situated above the annular gap (32).

Claim 19

A method as claimed in claim 15 or claim 16, in which the plurality of pairs of oppositely disposed openings are vertically aligned and spaced apart throughout the upper region of the-reactor chamber.

Claim 20

A method as claimed in claim 1 or claim 4, in which combustion of the matter fed into the lower region (11) takes place in the reactor chamber (10) at a temperature within the range of from about 500°C to about 1000°C.

Claim 23

A fast fluidized bed reactor comprising a reaction chamber (10) having an upper region (18) and a lower region (11) containing a bed of granular material, means (17) for feeding matter to be reacted into the lower region of the reaction chamber, means (14, 15) for supplying a first stream of pressurized air to the reaction chamber through a plurality of openings (12) in the lower region (11) at a velocity sufficient to fluidize the granular material in the fast regime, whereby at least a portion of the granular material will be continually entrained upwards into the upper region, and means for returning granular material from the upper region (18) to the lower region (11) of the reaction chamber, characterised in that the reaction chamber (10) is substantially upright and its upper region (18) has a. cylindrical internal surface containing at least one substantially tangentially directed opening (19) therein, that means (14, 21) is provided for supplying a second stream of pressurized air tangentially into the upper region of the reaction chamber through the opening or openings (19) so as to create a cyclone of turbulence in the upper region (18) which increases the rate of reaction in the chamber (10) and to maintain a Swirl number of at least 0.6 and a Reynolds number of at least 18,000 in the upper region, the second air stream supply means being arranged to supply at least 50% of the total pressurized air fed to the reaction chamber (10) at maximum operating capacity of the reactor, and that the means for returning granular material from the upper region (18) to the lower region (11) includes an exit port (22) for granular material and reaction gases from the upper region (18) situated adjacent the upper boundary of the cyclone of turbulence, and means (24) for separating the granular material from the reaction gases before the return of the granular material to the lower region (11).

Claim 24

A fast fluidized bed reactor comprising a reaction chamber (10) having an upper region (18) and a lower region (11) containing a bed of granular material, means (17) for feeding matter to be reacted into the lower region of the reaction chamber, means (14, 15) for supplying a first stream of pressurized air to the reaction chamber through a plurality of openings (12) in the lower region (11) at a velocity sufficient to fluidize the granular material in the fast regime, whereby at least a portion of the granular material will be continually entrained upwards into the upper region, and means for returning granular material from the upper region (18) to the lower region (11) of the reaction chamber, characterised in that the reaction chamber (10) is substantially upright and its upper region (18) has a. cylindrical internal surface containing at least one substantially tangentially directed opening (19) therein, that means (14, 21) is provided for supplying a second stream of pressurized air tangentially into the upper region of the reaction chamber through the opening or openings (19) so as to create a cyclone of turbulence in the upper region (18) which increases the rate of reaction in the chamber (10) and to maintain a Swirl number of at least 0.6 and a Reynolds number of at least 18,000 in the upper region, the second air stream supply means being arranged to supply at least 50% of the total pressurized air fed to the reaction chamber (10) at maximum operating capacity of the reactor, and that the means for returning granular material from the upper region (18) to the lower region (11) includes an exit port (22) for granular material and reaction gases from the upper region (18) situated adjacent the upper boundary of the cyclone of turbulence, and means (24) for separating the granular material from the reaction gases before the return of the granular material to the lower region (11).

Claim 25

A fast fluidized bed reactor as claimed in claim 20, in which the means for separating the granular material from the reaction gases exiting from the upper region (18) comprises a cyclone separator (24) having its inlet connected to the exit port (22) of the reaction chamber.

Claim 26

A fast fluidized bed reactor as claimed in claim 21, further characterised in that a fluidized bed trap (25) is connected to the cyclone separator (24) to receive therefrom the separated granular material and is arranged so that granular material overflows from the trap (25) through an inlet port (23) into the lower region (11), the fluidized bed trap containing a solid partition (28) for preventing cross flow of gases between the reaction chamber and the cyclone separator.

Claim 27

A fast fluidized bed reactor comprising a reaction chamber (10) having an upper region (18) and a lower region (11) containing a bed of granular material, means (17) for feeding matter to be reacted into the lower region of the reaction chamber, means (14, 15) for supplying a first stream of pressurized air to the reaction chamber through a plurality of openings (12) in the lower region (11) at a velocity sufficient to fluidize the granular material in the fast regime, whereby at least a portion of the granular material will be continually entrained upwards into the upper region, and means for returning granular material from the upper region (18) to the lower region (11) of the reaction chamber, characterised in that the reaction chamber (10) is substantially upright and its upper region (18) has a cylindrical internal surface containing at least one substantially tangentially directed opening (19) therein, that means (14, 21) is provided for supplying a second stream of pressurized air tangentially into the upper region of the reaction chamber through the opening or openings (19) so as to create a cyclone of turbulence in the upper region (18) which increases the rate of reaction in the chamber (10) and to maintain a Swirl number of at least 0.6 and a Reynolds number of at least 18,000 in the upper region, the second air stream supply means being arranged to supply at least 50% of the total pressurized air fed to the reaction chamber (10) at maximum operating capacity of the reactor, and that the means for returning granular material from the upper region (18) to the lower region (11) includes a closed annular chamber (50) concentrically surrounding at least the upper portion of the upper region (18) of the reaction chamber, an annular gap (32) located in the upper portion of the cylindrical internal surface of the upper region (18) and through which, in operation, at least a portion of the turbulently flowing granular material passes centrifugally from the upper region of the reaction chamber into the annular chamber (30), thereby separating the granular material from the reaction gases present in the upper region, and means for returning the separated granular material from the annular chamber to the lower region of the reaction chamber.

Claim 28

A fast fluidized bed reactor comprising a reaction chamber (10) having an upper region (18) and a lower region (11) containing a bed of granular material, means (17) for feeding matter to be reacted into the lower region of the reaction chamber, means (14, 15) for supplying a first stream of pressurized air to the reaction chamber through a plurality of openings (12) in the lower region (11) at a velocity sufficient to fluidize the granular material in the fast regime, whereby at least a portion of the granular material will be continually entrained upwards into the upper region, and means for returning granular material from the upper region (18) to the lower region (11) of the reaction chamber, characterised in that the reaction chamber (10) is substantially upright and its upper region (18) has a cylindrical internal surface containing at least one substantially tangentially directed opening (19) therein, that means (14, 21) is provided for supplying a second stream of pressurized air tangentially into the upper region of the reaction chamber through the opening or openings (19) so as to create a cyclone of turbulence in the upper region (18) which increases the rate of reaction in the chamber (10) and to maintain a Swirl number of at least 0.6 and a Reynolds number of at least 18,000 in the upper region, the second air stream supply means being arranged to supply at least 50% of the total pressurized air fed to the reaction chamber (10) at maximum operating capacity of the reactor, and that the means for returning granular material from the upper region (18) to the lower region (11) includes a closed annular chamber (50) concentrically surrounding at least the upper portion of the upper region (18) of the reaction chamber, an annular gap (32) located in the upper portion of the cylindrical internal surface of the upper region (18) and through which, in operation, at least a portion of the turbulently flowing granular material passes centrifugally from the upper region of the reaction chamber into the annular chamber (30), thereby separating the granular material from the reaction gases present in the upper region, and means for returning the separated granular material from the annular chamber to the lower region of the reaction chamber.

Claim 29

A fast fluidized bed reactor as claimed in claim 23, in which the lower end (31) of the annular chamber (30) opens into the lower region (11) of the reaction chamber so that the granular material returns from the annular chamber (30) by gravity directly into the lower region (11).

Claim 30

A fast fulidized bed reactor as claimed in any one of claims 20 to 24, further comprising heat exchanger means (29) situated in the lower region (11) of the reaction chamber for removing heat from the fluidized bed.

Claim 31

A fast fluidized bed reactor as claimed in any one of claims 20 to 23, further comprising a second fluidized bed (40) situated adjacent the lower region (11) of the reaction chamber and arranged to receive at least a portion of the granular material separated from the reaction gases for return to the lower region (11), means (43,44) for maintaining the second fluidized bed (40) in the bubbling regime so that granular material overflows from the bed (40) back into the lower region (11), and heat exchanger means (42) immersed in the second fluidized bed (40) for removing heat therefrom.

Claim 32

A fast fluidized bed reactor as claimed in any one of claims 20 to 26, in which the horizontal cross-sectional area of the upper region (18) of the reaction chamber is larger than that of at least the lower portion of the lower region (11).

Claim 33

A fast fluidized bed reactor as claimed in claim 27, in which the lower region (11) of the reaction chamber includes an inverted frusto- conically shaped portion.

Claim 34

A fast fluidized bed reactor as claimed in any one of claims 20 to 28, in which there are a plurality of openings (19) for tangentially supplying the second stream of pressurized air into the upper region (18) of the reaction chamber.

Claim 35

A fast fluidized bed reactor as claimed in claim 29, in which the plurality of openings (19) are arranged in oppositely disposed pairs in the cylindrical internal surface of the upper region (18).

Claim 36

A fast fluidized bed reactor as claimed in claim 30 when dependent on claim 23, in which at least one of the pairs of oppositely disposed openings (19) is situated above the annular gap (32).

Claim 37

A fast fluidized bed reactor as claimed in claim 30 or claim 31, in which the pairs of oppositely disposed openings (19) are vertically aligned and spaced apart throughout the upper region (18) of the reaction chamber.

Claim 38

A fast fluidized bed reactor as claimed in claim 25 or claim 26, further comprising boiler means operatively connected to the heat exchanger means (29 or 42).

Claim 39

A fast fluidized bed reactor as claimed in claim 26,. in which at least a portion of the lower region of the reaction chamber is quadran- gularly shaped in plan section.