JPH09196353A - Site installed type melting furnace for dust combustion ashes - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a site installed type melting furnace in which some dust combustion ashes can be melted at a low cost and in a superior thermal efficiency while various kinds of advantages caused by application of a pure oxygen burner are being utilized at the most. SOLUTION: A pure oxygen burner for igniting oxygen gas having an oxygen concentration of 50% or more together with fuel is operated and soda ash (sodium hydroxide) is applied for melting into glass form. A melting chamber 1 for the dust combustion ash and a melting holding chamber 2 for the ash are defined and cooperatively arranged through a communication passage. A dust combustion ash feeding port 4 and a discharged gas discharging passage 5 are arranged above the melting chamber 1. A discharged gas discharging passage 6 is arranged above the melting holding chamber 2. A melted dust discharging port 7 is arranged below the discharging passage. There is provided each of at least one of pure oxygen burners 8a, 9a for igniting oxygen gas of oxygen concentration of 50% or more together with fuel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stationary melting furnace used for melting and treating incinerated ash of municipal waste, such as municipal waste including industrial waste, such as waste of synthetic resin products, or paper and wood. The present invention relates to a stationary melting furnace for refuse incineration ash in which residual ash obtained by incinerating flammable materials such as rubber (including metal articles) (metals remain as they are) is melted at high temperature.

[0002]

2. Description of the Related Art The amount of municipal waste treated depends on
Due to the changes in lifestyle, the amount of waste is one of the most important issues in the treatment of such waste, but on the other hand, the one that has recently become particularly problematic is However, the post-treatment of volume-reduced incinerated ash has become a problem. In other words, since municipal waste contains harmful substances, if the incinerated ash is directly disposed of (landfill, etc.), there is a risk of secondary pollution, and it cannot be simply disposed.

Generally, the residual incineration ash (including the one collected by a bag filter etc.) obtained by incinerating municipal waste is buried in a landfill site, or is also buried underground when concrete is placed in civil engineering foundation work. It was buried and processed afterwards. However, incineration ash is a fine powder that adsorbs dioxins, and also contains non-burnable heavy metals, and is highly likely to be scattered during its handling and transportation,
There is a problem that the transportation processing is troublesome. Also, if this incineration ash is simply buried in the soil, it may cause pollution problems due to runoff due to rain and groundwater, and its disposal must be done carefully.

However, the incineration ash is still enormous even after the incineration of garbage, and if the incineration ash is simply buried, the problem that residual harmful substances flow out due to rainwater etc. cannot be solved. Of. In view of such serious matters, recently, legislation concerning post-treatment of waste has been made, and it has been obliged to treat incinerated ash of waste through so-called secondary treatment. Therefore, recently, as a method of further reducing the volume of incinerated ash of garbage, decomposing harmful substances, and preventing it from flowing out at the time of burying, a method of dissolving this has been researched. Electromelting, high frequency electromelting, and other heating melting using a burner have been tried.

In the method of melting incinerated ash as described above, it is technically difficult to use an electric furnace because the object to be melted is mainly a non-ferrous substance, and plasma electric melting and the like are performed by an apparatus. However, there is also a problem that the equipment cost is large and the equipment cost is very high. Therefore, the heating method by the burner is used by using the solid, gas or liquid fuel which has been generally used conventionally. In particular, since the burner type heating means which has been developed in recent years has begun to spread from the viewpoint of high temperature, thermal efficiency, cost and easiness of control, this method is common.

In this burner system, LPG or NL
Although G and other fuels are used, the air for burning the fuels is supplied by an air compressor, for example, a pump such as a centrifugal turbine, and mixed with the fuels. This combustion method can obtain a high temperature enough to dissolve the incinerated ash, but since it is an air compression method, it is difficult to suppress the generation of CO, and this CO is present. It means that the generation of dioxin, which is said to have a close relationship with, cannot be suppressed. Whatever it is,
The idea is that the incineration of municipal waste, etc. and the dissolution treatment of the incineration ash are carried out as completely different processes, and not only two incineration plants are required, but also transportation and fuel cost for the treatment. Is very expensive. The incinerated ash and the like that has been simply dissolved is fragile after the slag is cooled, and this is simply thrown away in a landfill or the like and buried.

The present invention has already proposed a method and apparatus for incinerating and dissolving trash as a means for solving these problems. That is, dust is thrown by the dust throwing means from one opening of the rotary incinerator having openings at both ends,
From this opening, dust is incinerated at 800 ° C to 1200 ° C with an oxygen burner using fuel and oxygen with an oxygen concentration of 50% or more, and when the volume is reduced by incineration, the dust is reintroduced and then burned with an oxygen burner. After repeating the charging and incineration of the dust a plurality of times, the incinerator ash (residual substance) remaining in the rotary incinerator is melted at a high temperature of 1600 ° C or higher by the oxygen burner to be vitrified, While processing by eluting from the other opening of the rotary incinerator,
The exhaust gas generated during the incineration and melting is guided to the dust collector through the other opening of the rotary incinerator to remove the dust.

And in such a method and apparatus,
For more preferable vitrification and melting, it is preferable that at least soda ash (sodium hydroxide) is mixed and added at the time of melting, and powdery or lumpy at the time of waste incineration or prior to the dissolution of waste incineration ash. It has also been found that it is preferable to add at least one solid fuel of coke, coal or charcoal to assist heating and melting. According to this method and apparatus, when a predetermined amount stays while a large volume reduction is achieved by repeatedly charging and incinerating dust with an oxygen burner having an oxygen concentration of 50% or more in one rotary incinerator. It is possible to move to dissolution.

When incinerating this garbage, the oxygen concentration is 50%.
By using the above-mentioned oxygen burner, the oxygen concentration in the furnace can be increased, more complete combustion can be expected, and exhaust gas with a low CO concentration can be obtained, and dioxins can be decomposed at a high temperature of 800 ° C to 1200 ° C. It can be done. Therefore,
Even if the exhaust gas is exhausted through the dust collector, almost no dioxin is scattered and emitted.

[0012] Then, not only the volume of a large amount of dust is reduced by repeating the inputting and incineration of this dust, but also the flammable dust (especially, various synthetic resin wastes having a high calorific value).
By the combustion, the preheating up to the melting process of the rotary incinerator can be performed, and the fuel consumption required to raise the temperature of the rotary incinerator can be greatly saved. Then, the incinerated ash having reached a predetermined amount is heated to 1600 ° C. or higher by an oxygen burner capable of generating high temperature, and can be smoothly vitrified and dissolved by soda ash that is added together with dust.
Even during this melting, by using an oxygen burner with an oxygen concentration of 50% or more, the oxygen concentration in the furnace can be increased, and the CO contained in the exhaust gas becomes very small, and exhausted to the atmosphere via a dust collector. It is possible to prevent the pollution substances from being scattered. It should be noted that non-combustible substances other than incinerated ash, such as metals, are dissolved at a high temperature and are dissolved in the vitrified state in a mixed state.

Therefore, according to this method and apparatus, the amount of heat of incineration of dust can be utilized while reducing the volume by incinerating the dust by repeating the charging and incineration of dust a plurality of times in one rotary incinerator. Then, there is an advantage that the rotary incinerator is heated and the fuel consumption required for high temperature heating (about 1600 ° C) of the rotary incinerator required for the next melting step can be greatly saved. Further, since the dust is incinerated and melted by an oxygen burner having an oxygen concentration of 50% or more, not only complete combustion of the fuel (LPG, etc.) but also the oxygen concentration in the furnace is increased to eliminate the generation of CO and to prevent dioxins. In addition to preventing the generation of dioxin, it is possible to decompose dioxin by incineration and melting at high temperature and prevent the scattering of harmful substances. Further, there is also an advantage that the incineration ash and the like can be made into glass by the melting treatment at a high temperature (about 1600 ° C.) and the outflow of harmful substances due to rainwater due to burying etc. can be prevented in the post-treatment.

[0012]

However, such a method and apparatus have the following problems. In order to use the rotary incinerator, a certain amount of refuse incineration ash to be melted must be put in, and after melting, the rotary incinerator must be turned over (around the axis orthogonal to the axis of rotation) and tapped,
The problem is that so-called continuous melting cannot be performed because the incineration ash and the molten hot water cannot be continuously supplied. The structure that the rotary incinerator can be turned over (electric or hydraulic)
Therefore, there is a limit to increasing the size, and it is not suitable for mass production and continuous melting. Although the thermal efficiency of melting (stirring of the melt, rotation following and use of radiant heat of the inner surface of the rotary furnace) due to the rotary type is not greatly improved, the refractory material is consumed so much that the incinerated ash is melted into glass at high temperature. It is expensive to use as a furnace (higher temperature than casting).

In addition to the above, there are various problems, but the fact that the equipment (rotary furnace) is expensive and the inability to continuously operate are major problems that directly affect the melting cost. ) Is a problem regarding whether or not the dissolution treatment device is adopted. Therefore, as one means for solving these problems, a one-room stationary type refuse incinerator smelting furnace adopted in a conventional blast furnace or the like was considered. With this, unlike the previously proposed rotary melting furnace (batch type), the problem of continuous melting can be solved, but a melting furnace aiming for vitrification using this type of pure oxygen burner
Since the temperature is extremely high (1600 ° C to 1700 ° C or higher) and the temperature in the melting furnace is lowered when tapping hot water, there is a problem that fuel efficiency (thermal efficiency) is extremely deteriorated. In view of such conventional technology, the present invention provides a stationary melting furnace capable of melting waste incineration ash at low cost, while making maximum use of various advantages by using the pure oxygen burner described above. The purpose is to provide.

[0014]

In order to achieve the above-mentioned object, a stationary incinerator for refuse incineration ash according to the present invention uses a pure oxygen burner for burning oxygen gas having an oxygen concentration of 50% or more and a fuel. A stationary melting furnace for refuse incineration ash, which uses soda ash (sodium hydroxide) for vitrification and melting, including a melting chamber 1 and a melting holding chamber 2 for the dust incineration ash.
Are divided and connected via a communication passage 3, and a refuse incineration ash input port 4 and an exhaust gas discharge passage 5 are provided above the melting chamber 1, and exhaust gas discharge is provided above the melting and holding chamber 2. At least one pure oxygen burner 8a, which is provided with a passage 6 and a tap hole 7 below it, faces the melting chamber 1 and the melting holding chamber 2 and burns oxygen gas and fuel having an oxygen concentration of 50% or more. ，
9a is provided for each.

In the present invention, the communication passage 3 between the melting chamber 1 and the melting holding chamber 2 is formed at the bottom of the partition wall 10, and the melting holding chamber 2 is connected to the communication passage 3. A weir 11 is preferably provided between the passage 3 and the tap hole 7. Further, in the melting and holding chamber 2, the communication passage 3 and the weir 1 are provided.
1 and at least one pure oxygen burner 9
It is preferable that at least one pure oxygen burner 9a is provided with b facing between the weir 11 and the tap hole 7.

Further, in the present invention, the exhaust gas discharge passage 5 of the melting chamber 1 and the exhaust gas discharge passage 6 of the melting and holding chamber 2 are provided with a bag filter and a chemical reaction means via a cooling tower 12. It is preferably connected to the dust collector 13. The refuse incineration ash referred to in the present invention also includes incineration ash of municipal waste containing incombustible substances, incineration ash of industrial waste, sludge and the like. As a fuel for the pure oxygen burners 8a and 9a, LPG is used.
It is preferable to use other fuels, but other fuels that can be expected to generate a high calorific value can be appropriately used, and a solid fuel or the like may be used together with the refuse incineration ash. In addition, the dust collector 13
The chemical reaction means includes various known means such as quick lime spraying for dealing with sulfuric acid gas.

[0017]

According to the present invention, various advantages (use of high temperature vitrification and melting and suppression and decomposition of harmful substances) by using the pure oxygen burners 8a and 9a are directly inherited according to the present invention. Unlike the rotary melting furnace proposed in, the refuse incineration ash can be continuously charged and tapped continuously. Then, by arranging the melting holding chamber 2 in series with the melting chamber 1, the melting chamber 1 is substantially divided and tapping is performed from the melting holding chamber 2, so that the temperature of the melting chamber 1 is lowered due to tapping. It can be suppressed and the thermal efficiency of melting can be improved.

Unlike the rotary melting furnace proposed above, the melting furnace of the present invention is a stationary type that does not require a moving mechanism, so that the cost of the entire furnace and the operating cost can be reduced. Along with melting and thermal efficiency, melting cost reduction can be achieved. Further, in the present invention, the melting chamber 1
A communication passage 3 between the melt holding chamber 2 and the melt holding chamber 2 is formed at the bottom of the partition wall 10, and a weir 11 is provided in the melt holding chamber 2 between the communication passage 3 and the tap hole 7. In such a case, the molten metal surface of the melting chamber 1 does not immediately drop upon tapping, and the thermal efficiency can be further enhanced.

Further, in the melting and holding chamber 2, the communication passage 3
In the case where at least one pure oxygen burner 9b is provided between the weir 11 and the weir 11, and at least one pure oxygen burner 9a is provided between the weir 11 and the tap hole 7, By virtue of the presence of the pure oxygen burner 9b, the viscosity of the glassy hot water at the time of overflowing the weir 11 of the melting and holding chamber 2 can be prevented from decreasing, and the viscous hot water can smoothly flow into the tap hole 7. At the same time, the melt pooled between the weir 11 and the tap hole 7 can be smoothly tapped while maintaining its melting temperature due to the presence of the other pure oxygen burner 9a.

Further, in the present invention, the exhaust gas discharge passage 5 of the melting chamber 1 and the exhaust gas discharge passage 6 of the melting and holding chamber 2 are provided with a bag filter and a chemical reaction means via a cooling tower 12. When connected to the dust collector 13, the exhaust gas burned by the pure oxygen burners 8a and 9a and the combustion gas and fly ash (including harmful substances) discharged when melting the refuse incineration ash are included. Can be removed.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a refuse incineration ash stationary melting furnace according to the present invention will be described in detail below with reference to the drawings.
As shown in FIG. 1, the stationary incinerator of refuse incineration ash is divided into a melting chamber 1 and a melting holding chamber 2 for the refuse incineration ash through a communication passage 3, and the waste incineration ash is continuously provided. It is configured so that continuous charging can be performed by using separate chambers for charging and melting the molten metal and discharging molten glass-like material.

A communication passage 3 between the melting chamber 1 and the melting holding chamber 2 is formed at the bottom of the partition wall 10.
Moreover, in the melting and holding chamber 2, the communication passage 3 and the tap hole 7 are provided.
A weir 11 is provided between and. These melting chamber 1
And the inner wall of the melting and holding chamber 2 is coated with a heat-resistant material that can withstand 1800 ° C.

In the melting chamber 1, as shown in FIG.
Three sets of pure oxygen burners 8a, 8b, 8c for burning a so-called pure oxygen gas having an oxygen concentration of 50% or more and LPG as a fuel are provided, whereby refuse incineration ash is at least soda ash (sodium hydroxide). ) 10 to 20% weight ratio (the ratio is not limited to this range)
And is melted into glass at a high temperature of 1600 ° C to 1800 ° C.

Further, an input port 4 for waste incineration ash and an exhaust gas discharge path 5 are provided above the melting chamber 1. An opening / closing damper 15 is provided at the input port 4 for the refuse incineration ash, and a refuse incineration ash supply device 14 is provided so as to face the hopper above it. This garbage incineration ash supply device 14
Is a feeder for feeding the refuse incineration ash (and the additive, at least soda ash) conveyed by a truck or the like into the melting chamber 1. Further, a duct is connected to the exhaust gas discharge path 5 and is connected via a cooling tower 12 to a dust collector 13 equipped with a bag filter and a chemical reaction means.

Further, an exhaust gas discharge passage 6 is provided above the melting and holding chamber 2, and a tap hole 7 is provided below the exhaust gas discharge passage 6. A duct is also connected to the exhaust gas discharge path 6 so that the high temperature exhaust gas is cooled through the cooling tower 12 and guided to the dust collector 13 that can remove fly ash and the like with a filter (bag filter). Has been

As shown in FIGS. 2 and 3, the melt holding chamber 2 is provided with pure oxygen burners 9a and 9b similar to the pure oxygen burners 8a, 8b and 8c. This one unit 9a is provided between the weir 11 and the tap hole 7 so as to maintain a high temperature in the melt holding chamber 2, and the other one unit 9b is provided to the communication passage 3 and the weir 11. It is provided so as to face the gap between the glass plate and the weir, and the temperature of the glass-like body beyond the weir 11 is prevented from lowering, so that the fluidity is not lowered.

[0027]

EFFECTS OF THE INVENTION According to the present invention, stationary melting of a two-chamber structure is made while maximizing the various advantages of melting waste incineration ash into vitrification using the previously proposed pure oxygen burner. As a furnace, it has the remarkable effect that melting and continuous tapping of refuse incineration ash can be performed at low cost (fuel consumption), and the cost of the furnace itself is higher than that of the previously proposed rotary melting furnace. It is also possible to significantly reduce the size, and since it is not necessary to lay down the rotary mold when tapping hot water, it is possible to increase the size, and it is possible to increase the melting efficiency and reduce the running cost.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of a stationary incinerator of refuse incineration ash according to the present invention.

FIG. 2 is a plan view of a stationary melting furnace for refuse incineration ash according to the present invention.

FIG. 3 is a side view of a stationary melting furnace for refuse incineration ash according to the present invention.

[Description of sign]

 1 Melt Chamber 2 Melt Holding Chamber 3 Communication Passage 4 Waste Incinerator Ash Inlet 5 Exhaust Gas Discharge Channel 6 Exhaust Gas Discharge Channel 7 Outlet 8a Pure Oxygen Burner 9a Pure Oxygen Burner 10 Partition Wall 11 Weir 12 Cooling Tower 13 Dust Collector

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location F23J 15/00 F23J 15/00 J

Claims (4)

[Claims] 1. A stationary melting of refuse incineration ash using a pure oxygen burner for burning oxygen gas having an oxygen concentration of 50% or more and a fuel, and using soda ash (sodium hydroxide) for vitrification and melting. In the furnace, a refuse incineration ash melting chamber 1 and a melting holding chamber 2 are partitioned and connected via a communication passage 3, and a refuse incineration ash charging port 4 and exhaust gas discharge are provided above the melting chamber 1. A passage 5 is provided, an exhaust gas discharge passage 6 is provided at an upper portion of the melting and holding chamber 2, and a tap hole 7 is provided at a lower portion thereof.
, And at least one pure oxygen burner 8a, 9a, which faces the melting chamber 1 and the melting and holding chamber 2 and burns oxygen gas and fuel having an oxygen concentration of 50% or more, respectively. Stationary ash melting furnace. 2. A communication passage 3 between the melting chamber 1 and the melting and holding chamber 2 is formed at the bottom of a partition wall 10, and the melting and holding chamber 2 is connected to the communication passage 3 and the outlet. The stationary melting furnace for refuse incinerated ash according to claim 1, wherein a weir 11 is provided between the spout 7 and the sprue 7. 3. The melting and holding chamber 2 is provided with at least one pure oxygen burner 9b facing between the communication passage 3 and the weir 11, between the weir 11 and the tap hole 7. At least one pure oxygen burner 9a is provided.
Or the stationary melting furnace for garbage incineration ash in 2. 4. The exhaust gas discharge path 5 of the melting chamber 1 and the exhaust gas discharge path 6 of the melting and holding chamber 2 are connected to a dust collector 13 equipped with a bag filter and a chemical reaction means via a cooling tower 12. A stationary melting furnace for refuse incineration ash according to any one of claims 1 to 3.