Gasification melting facility

Abstract

This gasification melting facility includes: a fluidized bed gasification furnace that generates pyrolysis gas by thermally decomposing waste and discharges incombustibles; a vertical cyclone melting furnace that includes a pyrolysis gas duct through which the pyrolysis gas is introduced; a pyrolysis gas passage that connects the fluidized bed gasification furnace with the pyrolysis gas duct of the vertical cyclone melting furnace; pulverizer that pulverize the incombustibles into pulverized incombustibles so that the particle size of the incombustibles becomes fine; and airflow transporter that puts the pulverized incombustibles in the pyrolysis gas passage, and separating metal contained in the pulverized incombustibles by a difference in specific gravity while conveying the pulverized incombustibles together with airflow. The pyrolysis gas and the pulverized incombustibles are melted in the vertical cyclone melting furnace.

Claims

1. A gasification melting facility comprising: a fluidized bed gasification furnace that generates pyrolysis gas by thermally decomposing waste and discharges incombustibles; a vertical cyclone melting furnace that includes a pyrolysis gas duct through which the pyrolysis gas is introduced; a pyrolysis gas passage that connects the fluidized bed gasification furnace with the pyrolysis gas duct of the vertical cyclone melting furnace; a pulverizer that pulverizes the incombustibles, which are discharged from the fluidized bed gasification furnace, into pulverized incombustibles so that the particle size of the incombustibles becomes fine; an airflow transporter that conveys the pulverized incombustibles, which are generated by the pulverizer, together with airflow, puts the pulverized incombustibles in the pyrolysis gas passage, and separates metal contained in the pulverized incombustibles by a difference in specific gravity while conveying the pulverized incombustibles together with airflow; a classifier that classifies the incombustibles and a fluid medium that is discharged from the fluidized bed gasification furnace on a front stage of the pulverizer; a separator that separates iron and aluminum from the incombustibles that are classified by the classifier on the front stage of the pulverizer; and a fixed amount feeder that feeds the incombustibles, which have been subjected to the separation performed by the separator, to the pulverizer by a fixed amount on the front stage of the pulverizer, wherein the airflow transporter comprises: a pneumatic transport pipe that connects to the pyrolysis gas passage, the pneumatic transport pipe having an introduction portion into which the pulverized incombustibles containing the metal from the pulverizer are directly introduced, the introduction portion being directly connected to the pulverizer; a blower that generates airflow in the pneumatic transport pipe; and a metal removal pipe that extends downward from the pneumatic transport pipe, wherein the pneumatic transport pipe comprises a curved portion that is curved toward the downstream side in the airflow transporter, wherein the curved portion is bifurcated into a pulverized incombustibles transport pipe extending upward from the curved portion and the metal removal pipe extending downward from the curved portion toward the downstream side in the airflow transporter, wherein only the pulverized incombustibles from which the metals have been removed are conveyed upward along the pulverized incombustibles transport pipe by the airflow into the pyrolysis gas passage and mixed with the pyrolysis gas in the pyrolysis gas passage, and the mixed pulverized incombustibles and the pyrolysis gas are fed to the vertical cyclone melting furnace, and wherein the pyrolysis gas and the pulverized incombustibles are melted in the vertical cyclone melting furnace.

2. The gasification melting facility according to claim 1, wherein the particle size of the pulverized incombustibles is adjusted to a fine particle size of 0.1 mm or less.

3. The gasification melting facility according to claim 1, wherein the pyrolysis gas duct is provided with a premix burner.

4. The gasification melting facility according to claim 3, wherein a plurality of the pyrolysis gas passages and a plurality of the pyrolysis gas ducts are provided, and the pyrolysis gas and the pulverized incombustibles are blown into the vertical cyclone melting furnace to cause a swirling flow.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a view showing the structure of a gasification melting facility of an embodiment of the present invention.

(2) FIG. 2 is a schematic view of a pneumatic transport pipe of the embodiment of the present invention.

(3) FIG. 3 is a cross-sectional view taken along line A-A of FIG. 1.

DESCRIPTION OF EMBODIMENTS

(4) An embodiment of the present invention will be described below with reference to the drawings. An embodiment of the present invention will be described below with reference to the drawings.

(5) As shown in FIG. 1, a gasification melting facility 1 of this embodiment includes a fluidized bed gasification furnace 2 and a melting apparatus 4. The gasification melting facility 1 introduces pyrolysis gas 52, which is generated by the thermal decomposition of waste 51 in the fluidized bed gasification furnace 2, to the melting apparatus 4 through a pyrolysis gas passage 3.

(6) The fluidized bed gasification furnace 2 includes a gasification furnace body 5 having a rectangular cylindrical shape, and a waste inlet 6 including a waste discharge device 6a is provided on one side wall of the gasification furnace body 5. Further, a pyrolysis gas outlet 23 through which the pyrolysis gas generated in the gasification furnace is discharged is provided at the top portion of the gasification furnace body 5, and an incombustible outlet 7 is provided at the lower portion of the gasification furnace body 5. Furthermore, a fluid medium 8 (mainly, silica sand) is circulated and supplied to the bottom portion of the fluidized bed gasification furnace 2.

(7) Incombustibles and a fluid medium 53, which are discharged from the incombustible outlet 7, are fed to a sand classifier 9, and are separated into incombustibles 54 and a fluid medium 55. The fluid medium 55, which is separated here, is returned to the fluidized bed gasification furnace 2 by means such as a sand circulating elevator.

(8) The incombustibles 54, which are discharged from the sand classifier 9, are fed to a separation device (separator) that includes a magnetic separator 10 and an aluminum sorter 11. First, the incombustibles 54 are fed to the magnetic separator 10, and iron is then separated. Next, incombustibles 56, which are discharged from the magnetic separator 10, are fed to the aluminum sorter 11, and aluminum is separated. Accordingly, valuable metal including iron and aluminum is separated.

(9) Incombustibles 57, which are discharged from the aluminum sorter 11, are fed to a fixed amount feeding device 13 that includes a hopper 12. A fixed amount of the incombustibles 57, which are stored in the hopper 12, is cut out in the fixed amount feeding device 13. The cut incombustibles 58 are fed to a powdering machine 14 and are pulverized to have a particle size of 0.1 mm or less, so that the particle size of the incombustibles 58 is adjusted. Hereinafter, the incombustibles, which have been pulverized, are referred to as pulverized incombustibles 59. Since the particle size of the incombustibles 58 is adjusted to 0.1 mm or less, the incombustibles 58 are appropriately scattered by airflow when the pulverized incombustibles 59 are introduced into a pneumatic transport pipe 31 of an airflow conveyor 30 to be described below.

(10) The airflow conveyor 30 is provided below the powdering machine 14. The airflow conveyor 30 includes a pneumatic transport pipe 31 on which a curved portion 35 is formed, a blower 32 that generates airflow in the pneumatic transport pipe 31, and a metal removal pipe 33 that is provided on the curved portion 35. The blower 32 is installed so as to generate airflow toward the downstream side from an upstream end of the pneumatic transport pipe 31.

(11) As shown in FIG. 2, an introduction portion 34 and the curved portion 35 are formed on the pneumatic transport pipe 31 in this order from the upstream side. Since the introduction portion 34 is connected to an outlet of the powdering machine 14, the pulverized incombustibles 59 having been pulverized by the powdering machine 14 are introduced into the pneumatic transport pipe 31 from the introduction portion 34. The pneumatic transport pipe 31 is curved on the downstream side of the introduction portion 34, so that the curved portion 35 is formed. The pneumatic transport pipe 31 is curved upward at the curved portion 35. Further, the metal removal pipe 33 extends downward from the curved portion 35.

(12) The pneumatic transport pipe 31 is branched into two pipes on the downstream side of the curved portion 35. The pneumatic transport pipe 31, which is branched into two pneumatic transport pipes, is connected to branched pyrolysis gas passage 3 to be described below.

(13) Next, the detail of the melting apparatus 4 will be described.

(14) The melting apparatus 4 includes a vertical cyclone melting furnace 15, a secondary combustion chamber 17 that is connected to an upper portion of the vertical cyclone melting furnace 15 through a connecting portion 16, and a boiler portion 18 that is connected to a downstream portion of the secondary combustion chamber 17.

(15) The vertical cyclone melting furnace 15 has a circular cross-section, and a flue gas outlet 19 having a throttling structure is formed at the upper portion of the vertical cyclone melting furnace 15. In other words, the diameter of the vertical cyclone melting furnace 15 is reduced once at the flue gas outlet 19, and the vertical cyclone melting furnace 15 extends upward in a conical shape so as to be widened and is connected to the secondary combustion chamber 17. Further, a slag outlet 20 is provided at the lower portion of the vertical cyclone melting furnace 15.

(16) As shown in FIG. 3, the vertical cyclone melting furnace 15 includes a substantially cylindrical furnace wall 15a and a pair of pyrolysis gas ducts 21 through which the pyrolysis gas 52 is introduced are horizontally provided on the cross-section of the furnace wall 15a at predetermined positions in the up and down direction. The pyrolysis gas ducts 21 are disposed so that the pyrolysis gas 52 introduced from the pyrolysis gas ducts 21 is ejected in the tangential direction of a circle C formed in the vertical cyclone melting furnace. Furthermore, premix burners 22 are installed at portions of the pyrolysis gas ducts 21 that are connected to the vertical cyclone melting furnace 15.

(17) Combustion air is blown into the premix burners 22 from nozzle holes that are formed on the circumferential surfaces of the premix burners 22. Air, oxygen, oxygen-enriched air, or the like may be used as the combustion air. In this case, an air ratio of the combustion air may be in the range of 0.9 to 1.1, and preferably about 1.0. It is possible to stably maintain the temperature in the furnace high by setting the air ratio as described above.

(18) Since the pyrolysis gas 52 and the combustion air are blown into the vertical cyclone melting furnace 15 after being mixed with each other in the premix burners 22 in advance in this way, the pyrolysis gas 52 and the combustion air are sufficiently mixed with each other. Accordingly, it is possible to instantly combust the pyrolysis gas 52 in the furnace.

(19) The secondary combustion chamber 17 is formed to have a square cross-section. The connecting portion 16 of which the diameter is reduced toward the flue gas outlet 19 of the vertical cyclone melting furnace 15 is provided at the lower end portion of the secondary combustion chamber 17. Since the boiler portion 18 is provided on the flue gas-downstream side of the secondary combustion chamber 17, heat is recovered by a superheater (not shown) or the like installed on a flue. Flue gas 62, which has passed through the boiler portion 18, passes through a reaction dust collector, a catalytic reaction device, and the like, which are provided on the rear stage, and is discharged to the atmosphere through a chimney.

(20) Next, the pyrolysis gas passage 3, which connects the fluidized bed gasification furnace 2 with the vertical cyclone melting furnace 15, will be described in detail.

(21) As described above, the pyrolysis gas 52 is introduced into the vertical cyclone melting furnace 15 through the pyrolysis gas passage 3. Specifically, the pyrolysis gas outlet 23 of the fluidized bed gasification furnace 2 and the pyrolysis gas ducts 21 of the vertical cyclone melting furnace 15 are connected to each other through the pyrolysis gas passage 3. The pyrolysis gas passage 3 is branched into two passages at a predetermined position from the upstream side (the fluidized bed gasification furnace 2) toward the downstream side (the vertical cyclone melting furnace 15), and the two branched pyrolysis gas passages 3 are connected to the pair of pyrolysis gas ducts 21, respectively.

(22) Further, the two branched pneumatic transport pipes 31a are connected to the two branched pyrolysis gas passages 3 as described above. Accordingly, the pulverized incombustibles 59 are introduced into the vertical cyclone melting furnace 15 together with the pyrolysis gas 52.

(23) Next, the function of the gasification melting facility 1 of the embodiment will be described.

(24) The waste 51, which is put in from the waste inlet 6, is fed to the fluidized bed gasification furnace 2 through the waste discharge device 6a in a fixed amount and then is thermally decomposed and gasified. Accordingly, the waste 51 is decomposed into gas, tar, and char (carbide). Tar is a component that is liquid at room temperature, but is present in the form of gas in the gasification furnace. Char is gradually and finely powdered in a fluidized bed, and is introduced into the melting apparatus 4 as the pyrolysis gas 52 together with gas and tar.

(25) In addition, a fluid medium is classified from the incombustibles and the fluid medium 53, which are discharged from the incombustible outlet 7 of the fluidized bed gasification furnace 2, by the sand classifier 9, iron is separated by the magnetic separator 10, and aluminum is separated by the aluminum sorter 11. After that, the incombustibles 57, which are put in the hopper 12, are cut out by the fixed amount feeding device 13 and are introduced into the powdering machine 14.

(26) When the pulverized incombustibles 59, which are pulverized by the powdering machine 14 to have a particle size of 0.1 mm or less, are introduced into the pneumatic transport pipe 31 from the introduction portion 34, the pulverized incombustibles 59 are conveyed toward the downstream side together with airflow. After that, the pulverized incombustibles 59 reach the curved portion 35, and are conveyed upward along the curved portion 35 as shown by an arrow 59a. In this case, materials having a high specific gravity, such as metals, to be mixed in the pulverized incombustibles 59 fall without being conveyed together with airflow, and fall along the metal removal pipe 33 as shown by an arrow 59b. Accordingly, metals are removed from the pulverized incombustibles 59, and only the pulverized incombustibles 59 from which metals have been removed are introduced into the pyrolysis gas passage 3.

(27) After being mixed with the pyrolysis gas 52 fed from the fluidized bed gasification furnace 2, the pulverized incombustibles 59 introduced into the pyrolysis gas passage 3 pass through the premix burners 22, are fed to the vertical cyclone melting furnace 15, and are converted into molten slag.

(28) According to the embodiment, the pulverized incombustibles 59 are conveyed together with airflow and metals contained in the pulverized incombustibles 59 are separated while being conveyed together with airflow. Accordingly, for example, a device that removes metal such as a vibrating screen does not need to be provided, so that it is possible to construct a gasification melting facility at lower cost.

(29) Further, since the pyrolysis gas 52 and the pulverized incombustibles 59 pass through the premix burners 22 and are fed to the vertical cyclone melting furnace, it is possible to sufficiently preheat the pyrolysis gas 52 and the pulverized incombustibles 59. Furthermore, since the particle size of the pulverized incombustibles 59 is adjusted to 0.1 mm or less, smooth melting can be performed.

(30) Moreover, since the pyrolysis gas 52 and the pulverized incombustibles 59 are introduced from the two pyrolysis gas ducts 21, a swirling force of a gas flow in the vertical cyclone melting furnace 15 can be increased. Further, it is possible to prevent the pulverized incombustibles 59 from carrying over in the flue gas without being caught in the vertical cyclone melting furnace 15 by the throttling structure of the flue gas outlet 19 of the vertical cyclone melting furnace 15.

(31) In addition, the scope of the invention is not limited by the above-mentioned embodiment, and the invention may have various modifications without departing from the gist of the invention. For example, the number of the branches of the pyrolysis gas passage and the number of the pyrolysis gas ducts are not limited to two, and may be three or more.

REFERENCE SIGNS LIST

(32) 1: gasification melting facility

(33) 2: fluidized bed gasification furnace

(34) 3: pyrolysis gas passage

(35) 9: sand classifier (classifier)

(36) 10: magnetic separator (separator)

(37) 11: aluminum sorter (separator)

(38) 13: fixed amount feeding device (fixed amount feeder)

(39) 14: powdering machine (pulverizer)

(40) 15: vertical cyclone melting furnace

(41) 19: flue gas outlet (throttling structure)

(42) 21: pyrolysis gas duct

(43) 22: premix burner

(44) 30: airflow conveyor (airflow transporter)

(45) 31: pneumatic transport pipe

(46) 32: blower

(47) 33: metal removal pipe

(48) 51: waste

(49) 52: pyrolysis gas

(50) 59: pulverized incombustibles