JP2002333116A - Refuse-feeding method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refuse-feeding method and device capable of feeding refuse into a fluidized bed type gasifying furnace smoothly. SOLUTION: The refuse-feeding method uses a screw feeder 42 connected with the fluidized bed type gasifying furnace 12 to feed refuse into the gasifying furnace 12, and introduces a part of the furnace bottom ashes taken out from the gasifying furnace 12 to the screw feeder 42 from a furnace bottom ash introduction hole 54. Since the furnace bottom ashes are fine grains or powder having an ash content and carbon as principal components, they adhere to the inner wall surface of the cylinder 46 of the screw feeder 42 and the outer surface of the screw 48 so as to improve the slide of the refuse to the surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluidized bed gasifier for generating pyrolysis gas by pyrolyzing garbage while flowing the garbage in a fluidized bed in a furnace body. The present invention relates to a method and an apparatus for supplying refuse.

[0002]

2. Description of the Related Art Waste containing organic matter such as general waste and industrial waste can be pyrolyzed into gas and recovered as a combustible gas. For this reason, a fluidized-bed gasifier has been used as a waste gasifier. Fluidized bed gasifiers produce flammable pyrolysis gas by pyrolysis by supplying refuse into the furnace body and stirring and flowing the refuse with high-temperature air introduced from the air port. is there.

In order to increase the chemical energy per unit volume of the pyrolysis gas obtained by such a gasifier,
The refuse is accumulated in the hopper after being dried by the drying device. Then, a predetermined amount of dried refuse is taken out of the hopper as appropriate, and supplied to the inside of the gasification furnace by a screw feeder.

[0004]

However, since the dried refuse is in a cotton-like or sponge-like state, that is, in a compressible state containing a large amount of air, the above-described means using a screw feeder cannot be used for drying. The refuse is gradually compacted during transport, and may be clogged near the screw feeder discharge port, causing a state in which transport is impossible.

An object of the present invention is to provide a waste supply method and apparatus capable of smoothly supplying dry waste to a gasification furnace in order to solve such a problem.

[0006]

In order to achieve the above object, a waste supply method according to the present invention supplies waste to a gasification furnace using a screw feeder connected to a gasification furnace of a fluidized bed type. In addition, a part of the bottom ash taken out of the gasification furnace is introduced into a screw feeder.

The bottom ash is a fine granular or powdery material, and its main component is ash and carbon. Therefore, the bottom ash is located on the inner wall surface of the cylinder of the screw feeder and the contact surface between the outer surface of the screw and the dust. By intervening, the sliding of dust on the surface is made favorable. As a result, it is possible to avoid a situation where dust is clogged in the screw feeder.

[0008] In order to sufficiently exhibit such effects,
It is preferable that the furnace bottom ash is introduced into the screw feeder at a position upstream of the position where dust is introduced into the screw feeder.

Another aspect of the present invention resides in a refuse supply device for performing the above method, wherein a screw feeder connected to a gasification furnace, refuse introduction means for introducing refuse to the screw feeder, And a bottom ash introduction means for introducing a part of the bottom ash taken out of the furnace into the screw feeder.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a gasification furnace 12 to which a waste supply apparatus 10 according to the present invention is applied. The illustrated gasification furnace 12 is a conventionally known fluidized bed type for thermally decomposing refuse containing organic matter such as general waste and industrial waste to generate a flammable pyrolysis gas. A furnace body 14 having a shape is provided. An air port 16 for introducing high-temperature air for combustion and flow is provided at a lower portion of the furnace body 14, a refuse supply port 18 for supplying refuse at an intermediate portion, and a gas outlet 20 for discharging pyrolysis gas at an upper portion. Is provided. Further, an air distribution plate 22 for dispersing the air introduced from the air port 16 and flowing the air upward is provided at a lower portion inside the furnace body 14. A cyclone 26 as a solid-gas separation device is connected to a gas outlet 20 at an upper portion of the furnace main body 14 via a gas line 24. A return line 28 extends downward from the solid discharge port at the bottom of the cyclone 26, and the lower end thereof is connected to the side surface of the middle part of the furnace body 14.

In the illustrated gasification furnace 12, the refuse supplied into the furnace body 14 is preferably deposited in a fluidized bed 30, which is fluidized by air introduced through an air port 16, at a flow rate of about 90 μm.
The pyrolysis is performed at 0 ° C., and the furnace bottom ash generated by the pyrolysis is appropriately discharged from the bottom opening 32. The discharged bottom ash is conveyed to a melting furnace (not shown) while being cooled by a screw feeder 34 with a water jacket, and is melted there. Further, the flammable pyrolysis gas generated in the gasification furnace 12 is sent to the attached cyclone 26. In the cyclone 26, the solid particles and the gas are separated by centrifugal action, and the separated solid particles are returned to the furnace body 14 through a return line 28. (Not shown). The combustible pyrolysis gas that has been cleaned by passing through the gas treatment system is used as fuel for the melting furnace.

A refuse supply device 10 for supplying refuse to such a fluidized-bed gasifier 12 includes a hopper 38 for containing refuse previously dried by a drying device (not shown);
Transfer pipe 40 extending downward from the bottom opening of hopper 38
And the screw feeder 4 to which the lower end of the transfer pipe 40 is connected
2 is provided. The transfer pipe 40 is provided with an opening / closing damper 44 for controlling the supply and cutoff of the dry refuse from the hopper 38.

The screw feeder 42 includes a cylinder 46 disposed substantially horizontally, a screw 48 disposed coaxially therein, and an electric motor 50 disposed at one end of the cylinder 46 for driving the screw 48 to rotate. It is composed of In the vicinity of the end of the cylinder 46 on the side of the electric motor 50, a dust introduction port 52 is formed at an upper portion thereof, and the lower end of the transfer pipe 40 is connected thereto. In addition, cylinder 4
The other end of 6, that is, the waste discharge port is connected to a waste supply port 18 of the furnace body 14. In such a configuration, when the electric motor 50 is driven to rotate the screw 48, the hopper 3
The dried waste introduced from 8 into the waste introduction port 52 via the transfer pipe 40 is pushed by the screw 48 to the waste supply port 18, and is pushed into the furnace body 14 from the waste supply port 18.

Further, in the present embodiment, a furnace bottom ash inlet 54 is formed in the upper portion of the cylinder 46 of the screw feeder 42, preferably at a position upstream (toward the electric motor 50) of the dust inlet 52. I have. Above the bottom ash inlet 54, a hopper 56 that accommodates a part of the bottom ash taken out of the gasification furnace 12 is disposed.
The bottom opening and the bottom ash inlet 54 of the cylinder 46 are connected by a transfer pipe 58. An opening / closing valve 60 is interposed in the transfer pipe 58, and by controlling the opening / closing valve 60, the bottom ash in the hopper 56 can be sent to the screw feeder 42 in a desired amount.

Various means may be used for conveying the bottom ash to the hopper 56, including manual means. For example, the screw feeder 34 is provided with an opening 62 for taking out the bottom ash.
It is preferable that the furnace bottom ash discharged by opening and closing the furnace is automatically performed by a separately prepared conveyor (only shown by the line 64 in the figure).

In such a configuration, the electric motor 50
Is driven to operate the screw feeder 42, the bottom ash introduced into the screw feeder 42 from the hopper 56 is transported to the gasification furnace 12 together with the dried refuse.

The bottom ash taken out of the gasification furnace 12 is a granular material or a powdery material, and the particle size or the powder size is very fine, about 50 to 3000 μm. Further, the main components are ash and carbon, and since water and oil are almost 100% removed, if they are interposed on the contact surface between the inner wall surface of the cylinder 46 and the outer surface of the screw 48 and the dust during transportation, The sliding of the dry refuse on that surface will be greatly improved. Furnace bottom ash also penetrates into the dried refuse, in which case it has the effect of making it easier to loosen, and prevents the dry refuse from being excessively compacted. Therefore, the problem that the dried refuse is smoothly transported by the screw feeder 42 and that the refuse is clogged in the cylinder 46 is solved.

In this embodiment, the furnace body 14 is used.
The waste supply port 18 is located at an intermediate portion of the fluidized bed 30 in the vertical direction, and the dry waste is directly fed into the fluidized bed 30. This is because a pyrolysis gas having stable properties can be generated more efficiently than when dust is introduced into the free board portion 64 above the fluidized bed 30. When the dry refuse is fed into the fluidized bed 30 as described above, the screw feeder requires a great deal of power in the conventional general refuse supply apparatus. Requires less power because it is smoother.

Although the preferred embodiments of the present invention have been described in detail, it goes without saying that the present invention is not limited to the above embodiments.

For example, the furnace bottom ash is introduced into the screw feeder 42 preferably at an upstream side of the dust inlet 52 in order to spread the furnace bottom ash to almost the entire area of the screw feeder 42. It may be located on the downstream side, for example, at a position where dust is easily clogged, or may be supplied in the middle of the transfer pipe 40 from the hopper 38.

The means for introducing dust into the screw feeder 42 and the means for introducing hearth ash are of a dropping type comprising hoppers 38 and 56 and transfer pipes 40 and 58, respectively. Other types may be used.

Further, in the above embodiment, the refuse is sent to the intermediate portion of the fluidized bed 30 in the furnace main body 14, but may be introduced to the free board portion 64 above the fluidized bed 30.

[0024]

As described above, according to the present invention, when supplying dust to the gasifier using the screw feeder, the supply of the dust can be made smooth and the dust can be prevented from being clogged in the screw feeder. . Therefore, the number of maintenance operations such as stopping the operation and cleaning the screw feeder is reduced, and the waste disposal efficiency is improved.

Further, since the garbage can be easily fed, the load on the driving source of the screw feeder is reduced, and an energy saving effect can be achieved.

Further, since the bottom ash generated in the gasification furnace is used as a powder for facilitating the supply of waste,
There is also an effect that cost increase can be minimized.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing a fluidized-bed gasifier to which a waste supply device according to the present invention is connected.

[Explanation of symbols]

10: refuse supply device, 12: gasifier, 14: furnace body,
18: refuse supply port, 30: fluidized bed, 38: hopper (refuse introduction means), 40: transfer pipe (refuse introduction means), 42: screw feeder, 44: open / close valve, 46: cylinder,
48: screw, 50: electric motor, 52: refuse inlet, 54: hearth ash, 56: hopper (hearth ash introduction means),
58: transfer pipe (furnace bottom ash introduction means), 60: open / close valve,
62: an opening for taking out the bottom ash;

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F23G 5/44 F27B 15/08 4K046 F27B 15/08 F23C 11/02 311 F term (reference) 3F040 BA01 DA11 EA01 3K061 AA01 AB02 AB03 AC01 BA01 EA01 EB07 EB14 3K064 AA20 AB03 AD01 AD08 AE15 3K065 AA11 AB02 AB03 AC01 BA01 EA06 EA14 EA23 EA44 4G068 AA01 AB21 AC01 AC09 AD33 AD49 AF01 AF20 4K046 HA11 JE01 KA01

Claims (4)

[Claims] 1. A refuse supply method for supplying refuse to a fluidized-bed gasifier that thermally decomposes refuse while flowing refuse to generate a pyrolysis gas, wherein the refuse is connected to the gasification furnace. A method of supplying refuse to the gasifier using a screw feeder, and introducing a part of the bottom ash taken out of the gasifier to the screw feeder. 2. The refuse supply method according to claim 1, wherein furnace bottom ash is introduced into the screw feeder at an upstream side of a refuse introduction position with respect to the screw feeder. 3. A refuse supply device for supplying refuse to a fluidized-bed gasifier that thermally decomposes and generates pyrolysis gas while flowing the refuse, wherein the refuse supply device is connected to the gasification furnace. A screw feeder, a refuse introduction unit for introducing refuse into the screw feeder, and a bottom ash introduction unit for introducing a part of the bottom ash taken out of the gasifier into the screw feeder. And garbage supply equipment. 4. The waste supply apparatus according to claim 3, wherein a bottom ash inlet of the screw feeder is provided upstream of a waste inlet of the screw feeder.