JP2000117224A - Ash treatment for waste melting treatment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of treating ash in a waste melting treatment device by which harmful components generated from ash fed into a waste melting furnace is reduced and also the quantity of a reaction catalysis and ash conveyed to a final treating facility are reduced. SOLUTION: In this method of treating ash for a waste melting treatment device, a waste melting furnace 1, a combustion chamber 2, a waste heat boiler 3, a waste gas temperature controller 4, and dust collectors 5, 6 are provided in the above-listed order. Waste gas from the waste gas temperature controller 4 is subjected to dust collection in the dust collector of the first stage 5, and slaked lime is blown into the waste gas introduced to the dust collector of the second stage 6 from the dust collector of the first stage 5, and the collected ash in the dust collector of the second stage 6 is discharged to outside the system together with part of the collected ash in the dust collector of the first stage 5 after being subjected to the make harmless treatment. The mixture of the balance of the ash collected in the dust collector of the first stage 5 and the ash collected from the combustion chamber 2, the waste heat boiler 3, and the waste gas temperature controller 4 is discarded into the waste melting furnace 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waste melting treatment facility for melting waste such as general waste and industrial waste in a waste melting furnace, comprising a combustion chamber, a waste heat boiler, an exhaust gas temperature controller and The present invention relates to a method for treating ash discharged from a dust collector.

[0002]

2. Description of the Related Art As one of the disposal methods of general waste, industrial waste and the like, the waste is dried, thermally decomposed, burned and melted in a shaft furnace type waste melting furnace to form slag and metal. There is a waste melting process. In this waste melting process,
Waste can be gasified, melted at high temperature, and processed at once.

[0003] As a method of treating ash generated in a waste melting facility, Japanese Patent Application Laid-Open No. 6-226236 discloses a method for increasing the concentration of heavy metals that can be recovered as valuables in ash generated from a waste melting furnace. After washing the ash with water and removing the water-soluble chlorine compounds, the ash is circulated into a waste melting furnace to reduce the amount of generation, and to remove the HCl in the exhaust gas introduced into the dust collector, the exhaust gas It describes that a reaction aid such as slaked lime is blown into the inside and dust is collected by a dust collector.

[0004]

In the ash processing method,
A wastewater treatment facility for treating the ash-washed water is required,
In addition, since granulation and drying equipment for handling the ash after washing are required, the cost is high. Therefore, it is desirable to put the waste into a waste melting furnace without washing with water.

[0005] However, the collected ash collected in the first stage of the dust collector contains a reaction aid after the reaction of capturing the harmful components, and the harmful components are gasified again in the waste melting furnace. as a result,
As the concentration of harmful components in the exhaust gas increases, a large amount of a reaction aid is required, and as a result, there is also a problem that the cost of chemicals is greatly increased.

[0006] The present invention provides a method for treating ash in a waste melting facility, which reduces the content of harmful components in the ash fed into the waste melting furnace.

[0007]

SUMMARY OF THE INVENTION An ash treatment method for a waste melting treatment facility according to the present invention comprises a waste melting furnace, a combustion chamber, a waste heat boiler, an exhaust gas temperature controller, and a dust collector which are sequentially connected. In the ash treatment method of the melting treatment equipment, the exhaust gas from the exhaust gas temperature controller is collected by a first-stage dust collector,
Slaked lime is blown into the exhaust gas introduced from the first-stage dust collector into the second-stage dust collector, and the ash collected by the second-stage dust collector is collected by the first-stage dust collector. After detoxifying the ash together with part of the ash, the ash is discharged out of the system. The remaining ash collected in the first-stage dust collector, the ash mixed with the ash from the combustion chamber, the waste heat boiler, and the exhaust gas temperature controller are used. Into a waste melting furnace.

[0008] In the above configuration, part of the ash collected in the second-stage dust collector is blown into the exhaust gas introduced into the second-stage dust collector, so that unreacted slaked lime can be reused. it can.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to a waste melting treatment facility, in which two stages of dust collectors are provided, and ash in exhaust gas is collected by a first stage dust collector. HCl at the entrance,
SO _X, in order to remove harmful gases, such as organic halogen compounds, supplying slaked lime, a reaction aid such as activated carbon, for use as a reactor. The only ash to be put into the waste melting furnace is the collected ash from the first-stage dust collector with low harmful component content. Can be. In addition, it is possible to suppress an increase in the amount of the reaction assistant introduced at the entrance of the second-stage dust collector.

Further, since a large amount of collected ash collected by the first-stage dust collector can be introduced into the melting furnace, Si, Al and the like in the ash can be effectively turned into slag.

[0011] Further, since the reaction assistant charged at the inlet of the second-stage dust collector is often discharged without being reacted, it is discharged to the inlet of the second-stage dust collector by a circulation device such as a conveyor. By transporting and charging the mixture, an increase in the amount of the reaction aid used can be suppressed.

[0012]

1 is an ash treatment system diagram of the present invention. A combustible gas containing ash generated in a waste melting furnace 1 is sent to a combustion chamber 2 for combustion. The flue gas generated by the combustion is sent to a waste heat boiler 3 where heat is recovered, and the flue gas temperature controller 4, 1.
The air is discharged from the chimney 8 through the stage dust collector 5, the second stage dust collector 6, and the induction blower 7.

The exhaust gas introduced from the first-stage dust collector 5 to the second-stage dust collector 6 is blown with a reaction aid such as slaked lime or activated carbon to collect ash in the second-stage dust collector. After being detoxified together with a part of the collected ash in the first-stage dust collector 5, the ash is discharged outside the system, the remaining portion of the collected ash in the first-stage dust collector 5, the combustion chamber 2, and the waste heat boiler 3 and the mixed ash with the ash from the exhaust gas temperature controller 4 are charged into the waste melting furnace 1.

Further, a part of the ash collected in the second-stage dust collector 6 is circulated to the second-stage dust collector 6 by the reaction aid circulating device 9 and is blown into the exhaust gas so that unreacted reaction aid is obtained. Since the agent can be reused, an increase in the amount of the reaction assistant can be suppressed.

FIG. 2 and FIG. 3 show test results when a certain waste was treated. FIG. 2 shows the return rate of the collected ash of the first-stage dust collector to the waste melting furnace and the ash to the final disposal site. A graph showing the relationship between the amount (b) and the amount of slaked lime blown at the inlet of the second-stage dust collector required for removing harmful gases in the exhaust gas (a),
If the circulation rate is high, the ash amount (b) going to the final disposal site decreases, and even if the circulation rate is changed, the slaked lime blowing amount (a) does not increase much.

On the other hand, the return rate of the collected ash of the single-stage dust collector shown in FIG. 3 to the waste melting furnace, the ash amount (b) going to the final disposal site, and the harmful gas From the graph showing the relationship with the dust collector inlet slaked lime blowing amount (a) required for removal, the circulation rate increases and the slaked lime blowing amount (a) also increases.

Therefore, according to the ash treatment method of the present invention,
The amount of slaked lime used can be greatly reduced as compared with the case of a conventional single-stage dust collector.

In the present embodiment, slaked lime is used as a reaction aid introduced at the inlet of the second-stage dust collector. However, the present invention is not limited to this. For example, activated carbon is used as another reaction aid. You can also.

[0019]

According to the present invention, the following effects can be obtained.

(1) Since the increase in the amount of the reaction aid injected at the entrance of the second-stage dust collector can be suppressed, the amount of dust ash carried out to the disposal site can be reduced, and the increase in chemical cost can be suppressed.

(2) By circulating and using the reaction aid collected by the second-stage dust collector, the amount of the reaction aid used can be reduced, so that the amount of dust ash carried to the disposal site is reduced, and the cost of chemicals is reduced. Can be reduced.

(3) A large amount of ash in the exhaust gas can be put into the melting furnace, and Si and Al content in the ash can be effectively turned into slag, so that the amount of dust ash carried to the disposal site can be reduced.

[Brief description of the drawings]

FIG. 1 is a ash processing system diagram of the present invention.

FIG. 2 is a graph showing the relationship between the rate of return of the collected ash of the present invention to the waste melting furnace, the amount of ash going to the final disposal site (b), and the amount of slaked lime blown into the inlet of the second stage dust collector (a). It is.

Fig. 3 Relationship between the rate of return of the collected ash to the waste melting furnace in the first stage dust collector, the amount of ash going to the final disposal site (b), and the amount of slaked lime blown into the dust collector inlet (a) FIG.

[Explanation of symbols]

Reference Signs List 1 Waste melting furnace 2 Combustion chamber 3 Waste heat boiler 4 Exhaust gas temperature controller 5 First stage dust collector
6 Second-stage dust collector 7 Induction blower 8 Chimney 9 Reaction assistant circulation device

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3K061 NB06 3K070 DA02 DA05 DA07 DA12 DA16 DA27 4D004 AA36 AA37 AA46 AB06 AB10 CA29 CA50 CC11

Claims (2)

[Claims] 1. An ash treatment method for a waste melting treatment facility in which a waste melting furnace, a combustion chamber, a waste heat boiler, an exhaust gas temperature controller, and a dust collector are sequentially connected, wherein the exhaust gas from the exhaust gas temperature controller is removed. Dust is collected by the first-stage dust collector, slaked lime is blown into the exhaust gas introduced from the first-stage dust collector into the second-stage dust collector, and the ash collected by the second-stage dust collector is collected. , After detoxifying a part of the ash collected in the first-stage dust collector, and then discharging the ash out of the system, the remaining ash collected in the first-stage dust collector, the combustion chamber, and a waste heat boiler. An ash mixed with ash from an exhaust gas temperature controller and a waste melting furnace. 2. The waste melting treatment equipment according to claim 1, wherein a part of the ash collected in the second-stage dust collector is blown into exhaust gas introduced into the second-stage dust collector. Ash treatment method.