JP2001296011A - Gasifying device for refuse - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gasifying device for refuse into which refuse can be supplied continuously and stably. SOLUTION: Two dampers 8a and 8b vertically in two stages are situated at a chute 25 at the front stage of a gasifying furnace 9 to burn charged refuse. Refuse is charged during closing of the upper damper 8a and when the lower damper 8b is closed, the upper damper 8a is opened and refuse falls on the lower damper 8b side. After the upper damper 8a is closed, the lower damper 8b is opened and the refuse is charged in the gasifying furnace 9. In the above described formed gasifying device for refuse, an apron conveyor 24 is used to intermittently charge refuse to the closed state of the upper damper 8a, and refuse contained in one containing part partitioned at every given containing amount is charged during closing of the upper damper 8a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for reducing harmful substances such as dioxins and CO in exhaust gas generated when incinerating municipal waste and various industrial wastes (hereinafter, also simply referred to as "garbage"). Related to the gasifier used for
In particular, the present invention relates to a refuse gasifier that is characterized by a dust supply device that supplies refuse when gasifying.

[0002]

2. Description of the Related Art FIG. 5 schematically shows a conventional waste gasifier (equipment). The gasifier includes a gasifier 9, a melting furnace 14, a quenching reaction tower 16, a bag filter 18,
It is mainly composed of an induction ventilator 19 and a chimney 20. The garbage is put into the gasification furnace 9 and incinerated, slag and ash generated by the incineration are collected, and only the purified exhaust gas is discharged from the chimney 20 to the atmosphere. It is designed to release.

More specifically, refuse 1 such as municipal refuse is thrown into a hopper of a crusher 2 by a transporting means such as a conveyor or a refuse crane (not shown) and crushed. The crushed garbage is suspended on a conveyor 3 during the transport process by a magnetic separator 4.
The iron 5 in the refuse is removed by the refuse, and the refuse is further dried by a refuse dryer 6 so that the moisture in the refuse becomes about 20% or more, and gasified by a refuse supply conveyor from a dust feeder 7 through a double damper 8. It is put into the furnace 9.

[0004] When pyrolysis gasification and melting of the input refuse are performed, fluidizing air is supplied from a diffuser 10 provided in the lower part of the gasification furnace 9 to form a fluidized bed 11 in the gasification furnace 9. Perform gasification. That is, refuse is charged into a slow fluidized bed 11 of 500 to 700 ° C. formed by fluidized air supplied from the air diffuser 10, burned, and gasified.
The fluidized medium is sequentially discharged from the fluidized bed 11 in the gasification furnace 9 from the medium discharger 12, and non-combustible substances such as metal chips contained in the fluidized bed 11 and the fluidized medium (silica sand) are separated by the vibrating sieve 13. The separated incombustibles are recovered, and the fluidized medium is returned into the gasification furnace 9 to keep the bed height of the fluidized bed 11 constant and stabilize the fluidized state.

The combustible gas generated in the gasifier 9 and the char and fly ash mixed in the combustible gas are guided to the melting furnace 14, where the combustible gas and char are fly while being burned at 1300 to 1400 ° C. in the melting furnace 14. Melt the ash. In this melting furnace 14, since combustion is performed at a high temperature of 800 ° C. or more, no dioxins are generated. Reference numeral 15 denotes an auxiliary burner. Further, the combustion exhaust gas generated in the melting furnace 14 is sprayed with cooling water from a spray nozzle 17 in a quenching reaction tower 16, cooled to 160 ° C. or lower, which is the processing temperature of the bag filter 18, and then sent to a bag filter 18 in a subsequent stage. Can be In the bag filter 18, slaked lime is sprayed as an ash gas treating agent to make HCl and SOx in the exhaust gas harmless, and the molten fly ash is collected by the bag filter 18. The exhaust gas from which these are collected is
The air is released from the chimney 20 into the atmosphere by the induction ventilator 19. The slag 21 generated in the melting furnace 14 falls into the water of the slag granulator 22 and is collected by the slag conveyor 29 as granulated slag.

[0006] As described above, in the refuse gasifier, refuse is treated so as not to discharge pollutants such as dioxin and CO.

[0007]

Incidentally, the above-mentioned refuse gasifier 9 is operated at a negative pressure and a low oxygen concentration of 1% or less, and the generated gas is a high-concentration CO (5 to 6%) or H
_2, since CH ₄ is combustible gas, such as, 1) when the charged waste in the gasifier 9, the air Komu leak into the gasifier 9, abnormal combustion occurs rapidly furnace pressure rise As a result, it becomes impossible to operate the device for safety.

[0010] 2) The temperature of the empty tower of the gasification furnace 9 is 900 to 1
The temperature rises to 000 ° C., and operation cannot be performed due to safety of the device.

3) Since the combustible gas burns in the gasifier 9, the calorific value of the combustion gas in the latter melting furnace 14 becomes insufficient, and it is necessary to increase the auxiliary combustion amount for melting.

[0010] Due to the above problems, the gasification furnace 9 is moved from the dust supply device to the gasification furnace 9.
It is necessary to minimize the leakage of air into the system.

Therefore, when the waste is supplied into the gasification furnace 9, the double damper 8 is used so that the waste is always charged while one of the waste is closed. That is, since the double damper 8 is operated in a batch mode, when dust is continuously supplied, the dust is caught between the plate of the damper and the plate receiving surface to deteriorate the sealing property, or the dust is reduced. The presence of the intervening space also causes a situation in which the chute is clogged and it becomes impossible to input refuse.

The present invention has been made in view of such problems of the prior art, and an object of the present invention is to provide a refuse gasifier capable of supplying refuse in a stable and continuous manner.

[0013]

In order to achieve the above object, the present invention is directed to a method of burning input refuse, in which a two-stage upper and lower damper is provided in a chute at a preceding stage of a gasification furnace, and when an upper damper is closed. Put garbage, open upper damper when lower damper is closed, drop it to lower garbage damper side, close upper damper, release lower damper, and throw garbage into gasifier In the gasification apparatus of (1), a means for intermittently introducing dust according to a closed state of the upper damper is provided.

In this case, the means for introducing the refuse is constituted by an endless transport body provided with a plurality of storage sections continuously partitioned into predetermined storage amounts, and one storage section is provided when the upper damper is closed. Make sure that the garbage stored in the section is thrown in. As the endless carrier, for example, an apron conveyor is used.

Further, there is further provided a means for measuring the weight of the refuse supplied to the means for introducing the refuse, and the control means controls the opening / closing time of the upper damper based on the refuse weight measured by the means for measuring the refuse. It can also be done.

In addition, it is preferable to provide a water cooling means for maintaining the chute at a temperature not higher than the temperature at which dust is fixed. Further, it is preferable to provide a means for scraping dust remaining on the chute surface in accordance with the opening / closing operation of the lower damper. As means for scraping dust, for example, the dust is suspended by the lower damper, and at least the lower end is opened and closed by the lower damper. A metal plate that slides on the chute surface in conjunction with the operation can be used.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram of a waste gasifier (equipment) according to an embodiment of the present invention. This embodiment is different from the conventional example shown in FIG. 5 in that a crusher 23 and an apron conveyer 24 are provided instead of the dust feeder 7 after the dust dryer 6 and before the double damper 8, and furthermore, the double damper A water cooling device 31 is provided on the side plate of the chute 25 downstream of 8, so that the chute 25 has a water-cooled structure, and the dust removal fitting 26 is hung on the lower damper (lower damper) 8b of the double damper 8. It is. Other configurations are the same as those of the conventional example shown in FIG.

With this configuration, the refuse dried by the refuse dryer 6 to 20% or more as described above can be crushed by the crusher 2.
At 3, it is crushed to a predetermined size (length), and one batch is dropped on the apron conveyor 24. This operation is repeated intermittently. On the other hand, on the dust input side of the apron conveyor 24, one batch of the apron conveyor 24 is input when the upper damper 8a of the double damper 8 is closed. Next, the upper damper 8a is opened, and one batch of dust is received on the lower damper 8b. Then, after closing the upper damper 8a, the lower damper 8b is opened. Thus, one batch of refuse is thrown into the chute 25 from the lower damper 8b. At this time, the upper damper 8a, the lower damper 8b and the apron conveyor 2
The operation timing of No. 4 is shown in FIG. This timing is set by a CPU of a control device (not shown) based on a damper open / close detection signal from a sensor that detects the open / close state of the upper and lower dampers 8a and 8b. The sensor only needs to detect at least the closed state of the upper and lower dampers 8a and 8b. As described above, when the lower damper 8b is opened and dust is thrown into the chute 25, the upper damper 8a is closed, so that no air leaks and the dust is removed when the lower damper 8b is opened. Metal fitting 26 is shot 25
Since the inner surface slides, dust attached to the inner surface of the chute 25 is reliably removed. In addition, the treatment of refuse after charging the gasification furnace is the same as that of the above-described conventional example, and the description is omitted.

When the upstream side of the gasification furnace 9 is constructed as described above, the refuse introduced into the double damper 8 is crushed by the crusher 23 to a predetermined length or less.
It is possible to prevent clogging caused by garbage being trapped inside the garbage and accumulating garbage around the garbage.

Further, an apron conveyor 24 is provided upstream of the double damper 8, and dust can be dropped from the apron conveyor 24 in a state where the upper damper 8a of the double damper 8 is closed, so that the upper damper 8a and the lower damper 8b Dust can be prevented from being caught between the receiving plates. As a result, no space is created between the damper and the receiving plate, so that leakage of air into the gasification furnace 9 can be prevented.

Further, the clogging of the dust inside the chute 25 is performed by making the chute 25 a water-cooled structure and adjusting the temperature of the chute 25 side wall so as to be lower than the welding temperature of the dust, and providing a dust removal fitting 26 on the lower damper 8b. , Lower damper 8
Since the inner surface of the chute 25 is slid when the b is opened and closed, dust is scraped off.

FIG. 3 is a schematic configuration diagram showing a main part of another embodiment. In this embodiment, instead of the apron conveyor 24 and the double damper 8 in the embodiment shown in FIG. 1 described above, a centered-type conveyor 27 and a rotary valve 28 provided in two stages are used. Has the same configuration as that of the embodiment shown in FIG. 1 and the conventional example shown in FIG.

With this configuration, dust is dropped from the conveyor 27 onto the upper rotary valve 28a, and further from the upper rotary valve 28a to the lower rotary valve 28b. Thus, it is possible to input refuse in a state where air leakage is suppressed.

FIG. 4 is a schematic configuration diagram of a waste gasifier (equipment) according to still another embodiment. In this embodiment, a measuring device (belt scale) 3 for measuring the amount of conveyed refuse is provided downstream of the crusher 23 in the embodiment shown in FIG.
0 is provided, and the closing time of the upper damper 8a of the double damper 8 is controlled in synchronization with the increase and decrease of the dust. Other configurations are the same as those of the embodiment shown in FIG. 1 described above, and therefore, duplicate description will be omitted.

With this configuration, it is possible to set the charging timing in accordance with the amount of the refuse, and to control the opening and closing of the upper damper 8a in accordance with the charging timing. The amount of air to be introduced can be suppressed to a minimum.

[0027]

As described above, according to the present invention, there is provided a means for intermittently introducing refuse in accordance with the closed state of the upper damper, so that the refuse is stably injected into the gasification furnace at a predetermined timing. can do. Further, since the apparatus further includes means for measuring the weight of the refuse supplied to the means for introducing refuse, the opening / closing time of the upper damper is further controlled based on the refuse weight measured by the measuring means. Since the control means is provided, it is possible to stably input refuse and to minimize leakage of air into the gasification furnace.

Further, since the water cooling means for maintaining the temperature of the chute below the temperature at which the dust adheres is provided, the dust does not adhere to the inner surface of the chute. Since there is provided a means for scraping off the remaining dust, the fixed or adhered dust is scraped off, and the chute is not blocked by the dust, so that stable and continuous dust can be thrown.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a waste gasifier (equipment) according to an embodiment of the present invention.

FIG. 2 is a timing chart showing a relationship between a damper and an opening / closing state in the refuse gasifier of FIG. 1 and refuse input timing of a conveyor.

FIG. 3 is a schematic configuration diagram showing a refuse input section of a refuse gasifier according to another embodiment of the present invention.

FIG. 4 is a schematic configuration diagram showing a waste gasifier according to still another embodiment of the present invention.

FIG. 5 is a schematic configuration diagram showing a waste gasifier according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Dust 3 Dust transfer conveyor 7 Dust feeder 8 Double damper 8a Upper damper 8b Lower damper 9 Gasifier 14 Melting furnace 23 Crusher 24 Apron conveyor 25 Chute 26 Dust removal fitting 27 Conveyor 28 Rotary valve 28a Upper rotary valve 28b Lower rotary valve 30 Measuring device (belt scale) 31 Water cooling device

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) F23G 5/027 ZAB F23G 5/14 ZABF 4G068 5/14 ZAB 5/50 ZABG 5/50 ZAB ZABQ B01J 4/00 105A / / B01J 4/00 105 B09B 3/00 ZAB (72) Inventor Hideharu Mori 6-9 Takara-cho, Kure City, Hiroshima Prefecture Babcock Hitachi Inside the Kure Plant (72) Inventor Masaki Sato 6-9 Takara-cho, Kure City, Hiroshima Prefecture Babcock Hitachi Co., Ltd. Kure Office (72) Inventor Kazuki Kobayashi 3-36 Takaracho, Kure City, Hiroshima Prefecture Bubcock Hitachi Co., Ltd. Kure Research Laboratory F-term (reference) DB02 DB06 DB16 DB17 DB19 DB20 EA01 EB07 EB15 3K062 AA11 AA23 AB02 AB03 AC01 BA02 CB01 DA08 DA33 3K065 AA11 AA23 AB02 AB03 AC01 EA07 EA16 EA23 EA26 EA48 3K078 BA03 BA22 CA02 CA09 CA21 4D42 CA29 DA02 CA31 DA02 20 4G068 AA01 AB21 AC01 AD01 AF01 AF12 AF31

Claims (8)

[Claims] 1. A refuse is burned, and upper and lower two-stage dampers are provided on a chute at a preceding stage of the gasification furnace. The refuse is supplied when the upper damper is closed, and when the lower damper is closed, the upper damper is disposed. Open the dumper, drop it to the lower dumper, close the upper damper, open the lower damper, and put the waste into the gasifier. A garbage gasifier characterized by comprising means for introducing refuse. 2. The means for introducing garbage comprises an endless transport body having a plurality of storage sections divided for each predetermined storage amount, the storage sections being provided continuously when the upper damper is closed. The waste gasifier according to claim 1, wherein the stored waste is charged. 3. The garbage gasifier according to claim 2, wherein the endless transport body comprises an apron conveyor. 4. The refuse gasifier according to claim 1, further comprising means for measuring the weight of the refuse supplied to the means for charging the refuse. 5. The refuse gasifier according to claim 4, further comprising control means for controlling an opening / closing time of the upper damper based on the refuse weight measured by the measuring means. 6. The refuse gasifier according to claim 1, further comprising water cooling means for maintaining the chute at or below the refuse fixing temperature. 7. The refuse gasifier according to claim 1, further comprising means for scraping off refuse remaining on the chute surface in accordance with the opening / closing operation of the lower damper. 8. The method according to claim 1, wherein said means for scraping off dust is suspended from a lower damper, and at least a lower end is made of a metal plate material sliding on a chute surface in conjunction with the opening and closing operation of the lower damper. Item 7. A waste gasifier according to Item 7.