JPH0886419A - Melting/solidifying apparatus for garbage incineration ash - Google Patents

Abstract

PURPOSE: To provide a compact and energy-saving type incineration ash melting/ solidifying apparatus which enables stabilizing of a poisonous substance. CONSTITUTION: This melting/solidifying apparatus for garbage 'incineration ash has a preheater for incineration ash, a melting furnace to melt the incineration ash preheated and a melted material solidifying cell to cool and solidify the melted material of the incineration ash melted with the melting furnace. The preheater of the incineration ash A is so arranged to be a fluidized layer heater 2 to fluidize and heat the incineration ash A by an exhaust gas D of the melting furnace 5 and a heating means of the melting furnace 5 employs a cyclic burner 6 with a heat storage device having a function of preventing clogging as caused by a heavy metal melted material. An outlet of the melting furnace serves as a port 7 for withdrawing a self film formation die while a cooling means of a melted material solidification layer employs a direct air cooled type heat exchanger.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for melting and solidifying waste incineration ash, and more particularly to an apparatus for melting and solidifying incineration ash (hereinafter simply referred to as incineration ash) incinerated from municipal waste or industrial waste. , Compact and energy-saving type melting and solidifying device for refuse incineration ash.

[0002]

2. Description of the Related Art An attempt has been made to melt waste incineration ash obtained by incinerating waste, which is increasing year by year, and reuse it as a raw material for tiles and the like. FIG. 4 is an explanatory diagram showing a schematic flow of such a conventional technique for melting and solidifying incineration ash.
Municipal waste or industrial waste is incinerated in an incinerator as general waste and collected as incinerated ash. The recovered incineration ash is partly accompanied by the exhaust gas and is introduced into the melting furnace together with the fly ash captured by the dust collector, where normal combustion heating means,
For example, it is heated to, for example, 1400 ° C. and melted by a liquid fuel burner or an electric heating means, and is recovered as molten slag. The recovered molten slag is partly entrained in the exhaust gas and scattered, and is used as a raw material for tiles, for example, together with the molten fly ash captured by the dust collector.

However, in the above-mentioned conventional apparatus for melting and solidifying waste incineration ash, a liquid fuel burner such as heavy oil or an electric heater is used as a heat source for melting the refuse incineration ash, resulting in poor energy efficiency and energy. There was a problem that the input amount became huge. In addition, there is a problem that the discharge port of the molten slag at the outlet of the melting furnace is included in the incineration ash, for example, it is frequently eroded by an alkali salt or clogged, and frequent maintenance is required, resulting in an increase in running cost. .

[0004]

SUMMARY OF THE INVENTION The object of the present invention is to solve the above-mentioned problems of the prior art, to cope with the quantitative increase and qualitative diversification of municipal solid waste, etc., and to reduce the final disposal amount of refuse incineration ash. In addition, it is to provide a compact and energy-saving incineration ash melting and solidifying apparatus capable of stabilizing harmful substances contained in the incineration ash.

[0005]

In order to achieve the above object, the invention claimed in the present application is as follows. (1) Using a fluidized bed heat exchanger that fluidizes and preheats incineration ash that is an object to be treated by using exhaust gas discharged from a melting furnace described later, and a heat storage type combustion device that switches preheated incineration ash at high speed Waste having a melting furnace for heating and melting by heating, a melt solidification treatment tank for cooling and solidifying by directly contacting air with the incineration ash melted in the melting furnace, and a discharge means for solidification waste Equipment for melting and solidifying incinerated ash. (2) The apparatus for melting and solidifying waste incineration ash according to (1), wherein the heat storage device of the high-speed switching heat storage type combustion device has a function of preventing clogging by a heavy metal melt. (3) The apparatus for melting and solidifying waste incineration ash according to (1) or (2), wherein a temperature control coil for forming a self-coating is provided at the melt outlet of the melting furnace.

[0006]

[Function] By providing a fluidized bed heat exchanger for flowing and heating incineration ash that is an object to be treated by using the exhaust gas discharged from the melting furnace, the exhaust gas of the melting furnace containing a large amount of heat and the incineration Since the ash uniformly contacts and mixes with the ash, the preheating efficiency is improved, and even incinerated ash containing water can be sufficiently dried. Therefore, melting in the downstream melting furnace is promoted. Further, by using a high-speed switching heat storage type combustion device as a heating means in the melting furnace, it is possible to perform uniform heating and melting by a high temperature combustion flame, which is smaller than the conventional technology.
It becomes a compact and highly efficient melting furnace. Further, as a cooling means for the molten incinerated ash slag, by providing a melt solidification treatment tank in which air is brought into direct contact with the melt to cool and solidify, cooling efficiency is improved and heating by cooling the molten slag is achieved. The recovered cooling air can be introduced into the fluidized bed heat exchanger and used as a fluidizing medium for incineration ash that is an object to be treated, and the recovered heat can be utilized.

In the present invention, the fluidized bed heat exchanger is
A fluidized bed of incineration ash that is an object to be processed is formed using exhaust gas discharged from a melting furnace as a fluidizing medium, and the incineration ash is preheated by the calorific value of the melting furnace exit exhaust gas in the fluidized bed. High-speed switching heat storage type combustion device (cyclic burner: High Cycle) installed in the melting furnace
Regenerative System) has, for example, a two-system heating device having a regenerator and a combustion burner, and combustion exhaust gas when one system burner burns flows through another system regenerator and burns another system burner. When burned, the combustion exhaust gas flows through the one-system heat storage unit, and this is repeated sequentially to store the heat quantity of the combustion exhaust gas of the burning burner in the heat storage unit of the burner that has stopped burning, and then the combustion. A combustion device that serves as a heat source for combustion air during combustion. It is preferable that the heat accumulator of the high-speed switching heat storage type combustion device has a function of preventing clogging by a heavy metal melt. Examples of the function of preventing clogging by the heavy metal melt include a metal melt trap column provided in the gas flow passage in the heat accumulator.

In the present invention, the direct air-cooling type heat exchanger provided in the melt solidification treatment tank means the inlet of the melt solidification treatment tank, that is, the opening of the slag outlet provided at the melting furnace outlet. Air is blown directly to cool the molten slag, and the air used is used as a part of the fluidized medium of the fluidized bed heat exchanger after being withdrawn from the melt solidification treatment tank.

In the present invention, it is preferable to provide a temperature control coil for forming a self-coating film at the outlet of the melting furnace. The self-coating temperature control coil is, for example, a coil-shaped cooler uniformly wound around the surface of the slag extraction outlet furnace material of the melting furnace,
For example, steam or air is used as the cooling medium.
The slag flowing out from the slag outlet is cooled to a temperature at which only the surface of the molten slag in contact with the furnace material forming the slag outlet is in a non-fluid state, for example, 1300 to 1000 ° C,
A coating made of slag itself is formed along the inner wall surface of the furnace material, and while the coating protects the inner surface of the furnace material, the slag in a fluidized state flows and is discharged inside the coating. Such a self-coating type discharge port is applied to, for example, a rocket nozzle temperature control method.

[0010]

EXAMPLES Next, the present invention will be described in more detail by way of examples. FIG. 1 is an explanatory view showing an apparatus for melting and solidifying refuse incineration ash showing an embodiment of the present invention, and FIGS. 2 and 3 are explanatory views showing the main parts of FIG. 1, respectively. In FIG. 1, this device is discharged from the melting furnace 5, and the mist catcher 1
3 and a fluidized bed heat exchanger 2 that uses the exhaust gas D that flows in through the exhaust gas flow path 14 to preheat and incinerate the incineration ash A that is the object to be processed, and is connected to the subsequent flow through the connecting portion 3.
The preheated incinerated ash A is heated and melted by using a high-speed switching heat storage type combustion device (hereinafter, referred to as cyclic burner) 6, and after the melting furnace 5 through a molten slag outlet 7. A melt solidification treatment tank 8 which is connected to a flow and in which the incinerated ash A melted in the melting furnace 5 is brought into direct contact with air B introduced through an air pipe 12 to be cooled and solidified.
And discharge means for discharging the cooled and solidified molten and solidified ash E. In addition, 1 is an incinerator ash A injection machine, 4 is an ash injection amount control machine, 9 is a bag filter provided in a flow path of the exhaust gas D flowing out from the fluidized bed heat exchanger 2, and 10 is a blower. Is.

FIG. 2 is an enlarged view of a main part of the melting furnace shown in FIG. In FIG. 2, a cyclic burner 6 is provided on the upper wall surface of the melting furnace 5, and the cyclic burner 6 includes a first combustion system 18 having a regenerator 20 and a combustion burner 21, a regenerator 22 and a combustion system. A second combustion system 19 having a burner 23, and the first combustion system 18 and the second combustion system 19.
Air pipe 11 for supplying combustion air B to the combustion system 19
And a four-way valve 2 provided at the tip of the air pipe 11.
4, connecting pipes 25 and 26 for connecting the four-way valve 24 to the first combustion system 18 and the second combustion system 19, respectively, a molten slag outlet 7 provided on the lower side wall of the melting furnace 5, and Furnace material 27 forming the molten slag outlet 7
And a temperature control coil 28 for forming a self-coating, which is arranged on the surface of the furnace material 27.

Further, FIG. 3 is an explanatory view of a heat accumulator provided in the cyclic burner 6 of FIG. 2 and having a function of preventing clogging by a heavy metal melt. In the figure, this heat storage device 22
Is a rotary refractory metal that has an exhaust gas inlet 33 and an outlet 34 and is provided in two stages with respect to the gas flow direction of the exhaust gas flow passage and only a part thereof is located in the exhaust gas flow passage. It mainly comprises a trapping column 36 and a low melting point metal trapping column 35, and the high melting point and low melting point metal trapping columns 36 and 35 are filled with a regeneration column 37.

In such a structure, the incineration ash A which is the object to be processed is passed through the incineration ash charging machine 1 and the fluidized bed heat exchanger 2
And is introduced through the exhaust gas passage 14 here,
The exhaust gas D discharged from the melting furnace 5 fluidizes to form a fluidized bed, which is dried and preheated. The preheated incinerated ash A is discharged by the ash input amount controller 4 and then flows into the melting furnace 5 through the connecting portion 3. Incinerated ash A flowing into the melting furnace 5
Is melted by being heated to, for example, 1400 ° C. by the cyclic burner 6.

The incineration ash A is heated by the cyclic burner 6 as follows (see FIG. 2). That is, the combustion burner 2 of the first combustion system 18 of the cyclic burner 6
1 fuel C, for example C heavy oil, is supplied to the air pipe 1
1, through the four-way valve 24, the connecting pipe 25, the first combustion system 1
8 and flows into the heat storage device 20 to be mixed and burned with the combustion air B heated to a predetermined temperature in the heat storage device 20, for example, 800 ° C., and the combustion flame 3
2, the incinerated ash A after preheating is heated to, for example, 1400 ° C. and melted.

The combustion exhaust gas D generated at this time circulates in the second combustion system 19 in the non-combustion state, and the second combustion system 19
Exhaust gas inlet 33 of the heat storage device 22 (see FIG. 3) arranged in the
From the high-melting-point metal trapping column 36 to the heat-accumulating body 22 and to apply heat to the heat-accumulating body 22, and a high-melting-point metal mist contained in the exhaust gas D, for example, a Cu mist having a melting point of 1000 ° C. or higher in the high-melting-point metal capturing column 36. The low-melting-point metal mist that has been captured but not captured by the high-melting-point metal capturing column 36, such as Zn mist, is captured by the low-melting-point metal capturing column 35 that is downstream.

The exhaust gas D from which the metal melt has been removed and which has heated the regenerator 22 in this way reaches a certain low temperature, for example, 300 ° C., flows out from the exhaust gas outlet 34, and passes through the connecting pipe 26 and the four-way valve 24. It flows into the exhaust gas passage 14. On the other hand, when the combustion burner 23 of the second combustion system 19 operates, the four-way valve 24 is switched, and the fuel C supplied to the combustion burner 23 passes through the air pipe 11, the four-way valve 24, and the connecting pipe 26 to the first A mixture of combustion air B that has flown into the two-combustion system 19 and has accumulated the amount of heat of the exhaust gas D and has been heated to a predetermined temperature, for example, 800 ° C., is burned, and the incineration ash A is combusted with a combustion flame, for example. 1400 ° C
Heat to melt.

The combustion exhaust gas D generated at this time is the first
After flowing through the flow path in the direction opposite to that of the combustion system 18 during combustion, the molten metal is similarly captured and removed by the heat storage device 20 of the first combustion system 18, and after heating the heat storage device 20, the low temperature exhaust gas is discharged. It becomes D and flows into the exhaust gas passage 14 through the connecting pipe 25 and the four-way valve 24. Such a first combustion system 18
And the combustion of the second combustion system 19 are, for example, 20 to 3
It is switched at 0 second intervals. The exhaust gas D flowing into the exhaust gas passage 14 is, for example, Cd, in the mist catcher 13.
After the Pb mist and the like are removed, it flows into the fluidized bed heat exchanger 2, where the incineration ash A that is the object to be processed is fluidized and preheated, and then flows out of the fluidized bed heat exchanger 2. After the exhaust gas treatment such as deoxidation and soot dust removal by the bag filter 9,
It is discharged outside the system.

On the other hand, the incinerated ash A heated and melted by the cyclic burner 6 in the melting furnace 5 is the molten slag 3
The molten slag solidification treatment tank 8 in the wake of the slag through the molten slag outlet 7 provided with the self-coating temperature control coil 28.
Flow into. At this time, for example, cooling water is circulated in the self-coating temperature control coil 28, and the surfaces of the slag extraction outlet furnace material 27 and the molten slag 30 are cooled to, for example, 1200 ° C. by the cooling water. A self-coating film 29 in which the molten slag 30 is in a non-flowing state is formed along the inner wall surface of the, and the molten slag 30 flows down inside the self-coating film 29 and is discharged. The thickness of the self-coating film 29 is adjusted by appropriately adjusting the cooling temperature.

The molten slag 30 discharged from the molten slag outlet 7 flows into the molten slag solidification treatment tank 8 where it comes into direct contact with the air B introduced through the air flow passage 12, and, for example, 150 to It is cooled to 50 ° C. and is discharged out of the system as molten and solidified ash E. According to the present embodiment, the incineration ash A is provided by providing the fluidized bed heat exchanger 2 that preheats the incineration ash A using the outlet exhaust gas D of the melting furnace 5 as a fluidizing medium.
Since it can be effectively preheated by using the exhaust heat, energy saving can be achieved for the entire apparatus.

Further, by using the cyclic burner 6 having the heat accumulators 20 and 22 as the heating means of the melting furnace 5, it is possible to achieve high temperature combustion in the melting furnace 5 and uniform temperature inside the furnace. Therefore, the melting furnace can be made smaller and more compact, and at the same time, energy efficiency can be improved. The metal mist in the exhaust gas that hinders the stable operation of the cyclic burner 6 is not only removed by the high melting point metal capturing column 36 or the low melting point metal capturing column 35 provided in the heat accumulators 20 and 22, but also the high melting point and Since the low melting point metal capturing columns 36 and 35 are of the rotary regeneration type, they can be washed and regenerated without stopping the main body of the cyclic burner 6, so that the heavy metal mist in the exhaust gas can be continuously captured. it can. Therefore, highly efficient operation of the cyclic burner 6 is ensured, and stable operation can be continued for a long time.

According to the present embodiment, the self-coating temperature control coil 28 is provided at the molten slag outlet of the melting furnace 5 to stabilize the extraction of the molten slag and prevent the melting furnace 5 from being blocked or damaged. The maintenance cost can be reduced. Further, by providing the melt solidification treatment layer 8 for cooling the molten slag 30 by directly introducing air into the outlet opening of the molten slag extraction outlet 7, the slag cooling efficiency is improved and the melt solidification treatment tank is provided. Since the exhaust gas of No. 8 can be used as a part of the fluidized medium of the fluidized bed heat exchanger 2, the heat utilization rate is improved.

According to this embodiment, since the bag filter 9 is provided at the exhaust gas outlet of the fluidized bed heat exchanger 2, the exhaust gas D can be effectively supplied by adding an alkaline agent to the upstream side of the bag filter, for example. Since it can be desalted, harmful chlorine compounds such as dioxins can be captured before being released into the atmosphere. The apparatus for melting and solidifying incinerated ash according to the present embodiment can be suitably used in, for example, a small-scale incineration treatment plant other than a large-scale treatment plant having an in-house power generation facility.

[0023]

According to the invention of claim 1 of the present application, the fluidized bed heat exchanger is used as the preheater for the incineration ash, and the high speed switching heat storage type combustion device is used as the heating means of the melting furnace. , While improving energy efficiency,
The entire device can be made compact and compact.

According to the second aspect of the present invention, by providing the heat storage of the high-speed switching heat storage type combustion device with the function of preventing clogging by the heavy metal melt, the metal melt contained in the exhaust gas can be continuously supplied. Therefore, in addition to the effects of the above invention, it is possible to prevent clogging of the heat accumulator and enable stable long-term operation of the melting furnace. According to the invention of claim 3 of the present application, by providing the temperature control coil for forming a self-coating film at the molten slag outlet, in addition to the effect of the invention, it is possible to prevent damage to the furnace material at the slag outlet. , Stable extraction is possible. This significantly reduces maintenance costs, for example.

[Brief description of drawings]

FIG. 1 is an explanatory view of an apparatus for melting and solidifying incineration ash showing an embodiment of the present invention.

FIG. 2 is a detailed view showing the melting furnace of FIG.

FIG. 3 is an explanatory view showing a heat accumulator portion of the high-speed switching heat storage type combustion device of FIG. 2.

FIG. 4 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Incineration ash charging machine, 2 ... Fluidized bed type heat exchanger, 3 ... Connection part, 4 ... Ash charging amount control machine, 5 ... Melting furnace, 6 ... Cyclic burner, 7 ... Molten slag outlet, 8 ... Melting Solidification treatment tank, 9 ... Bag filter, 10 ... Blower, 11, 12 ... Air flow path, 13 ... Mist catcher, 14 ... Exhaust gas flow path, 18 ... First combustion system, 19 ... Second combustion system, 20,
22 ... Regenerator, 21, 23 ... Combustion burner, 24 ... Four-way valve, 25, 26 ... Connection pipe, 27 ... Slag outlet furnace material,
28 ... Self-coating temperature control coil, 29 ... Self-coating, 3
0 ... Molten slag, 32 ... Flame, 33 ... Exhaust gas inlet, 34
... Exhaust gas outlet, 35 ... Low melting point metal capturing column, 36 ... High melting point metal capturing column, 37 ... Regeneration column.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kenichi Nagata, 1 Yachiman Kaigan Dori, Ichihara City, Chiba Mitsui Engineering & Shipbuilding Co., Ltd. Chiba Works (72) Ryoichi Tanaka 2-53, Shirate, Tsurumi-ku, Yokohama, Kanagawa Within Japan Furnace Industry Co., Ltd.

Claims (3)

[Claims] 1. A fluidized bed heat exchanger that fluidizes and preheats incineration ash that is an object to be treated by using exhaust gas discharged from a melting furnace described later, and a heat storage type combustion device that rapidly switches the preheated incineration ash. It has a melting furnace that heats and melts by using, a melt solidification treatment tank that directly cools and solidifies the incinerated ash melted in the melting furnace by air, and a discharge means that discharges the solidified material. A melting and solidifying device for incinerator ash that is a feature. 2. The apparatus for melting and solidifying waste incineration ash according to claim 1, wherein the heat storage unit of the high-speed switching heat storage type combustion apparatus has a function of preventing clogging by heavy metal melt. 3. The apparatus for melting and solidifying refuse incineration ash according to claim 1, wherein a temperature control coil for forming a self-coating is provided at the melt outlet of the melting furnace.