JP2004255329A - Apparatus for treating exhaust gas - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for treating exhaust gas which can reduce the amount of chemicals for removing harmful components in the exhaust gas, the amount of cement and chemicals for solidifying collected ashes and the amount of final materials of solidified ashes. <P>SOLUTION: The apparatus for treating the exhaust gas is provided with a dust filtering collector for an incinerator removing dust in the exhaust gas in an incinerator, an ash melting furnace melting the ash incinerated in the incinerator and the ash collected by the dust filtering collector for the incinerator, and a dust filtering collector for the ash melting furnace removing dust in the exhaust gas in the ash melting furnace. The apparatus for treating the exhaust gas is installed with a dust filtering collector for removing dust and a dust filtering collector for removing harmful gases in this order as the dust filtering collectors for the incinerator, and installed with a means for supplying, to the ash melting furnace, the ash collected in the dust filtering collector for removing dust and a means for making a melting furnace treated gas from the dust filtering collector for the ash melting furnace join the incinerator exhaust gas of upstream of the dust filtering collector for removing the harmful gases, and a means for supplying chemicals to the joined exhaust gases for removing the harmful gases. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an exhaust gas treatment device, and more particularly to an exhaust gas treatment device suitable for a waste incineration facility provided with an ash melting furnace.
[0002]
[Prior art]
2. Description of the Related Art In recent years, regarding waste disposal, reuse (recycling) for protecting a living environment has been increasing as a social demand. Due to the tightness of landfill sites, waste that cannot be reused is incinerated as much as possible to extend the life of the landfill site. Furthermore, in incineration facilities, there is an increasing demand for reducing harmful substances emitted from chimneys and detoxifying and recycling incinerated ash.
As a method for detoxifying and recycling incinerated ash, a method is employed in which incinerated ash is melted to suppress elution of harmful substances, taken out as molten slag, and reused as roadbed material (for example, Patent Document 1). .
[0003]
FIG. 5 is a system diagram of a conventional exhaust gas treatment apparatus.
This exhaust gas treatment device comprises an incinerator filter dust collector 21 for removing dust in incinerator exhaust gas from the incinerator 1, an incinerator ash 14 of the incinerator 1, and a filter dust collector 21 for the incinerator. An ash melting furnace 8 for melting the collected ash 22 collected, a ash melting furnace filter / dust collector 10 for removing dust in the smelting furnace exhaust gas from the ash melting furnace 8, and an incinerator filter / collector. It mainly comprises a chemical supply pipe 7 for supplying a chemical for removing harmful components in the exhaust gas to the exhaust gas upstream of each of the dust collector 21 and the filter dust collector 10 for the ash melting furnace.
[0004]
In such a configuration, the waste is supplied to the incinerator 1 and incinerated, and the incinerator exhaust gas generated at this time is supplied to the incinerator filter / dust collector 21 via the gas cooling device 2. In the incinerator filter dust collector 21, dust and solidified harmful components in the incinerator exhaust gas are collected and removed. Since the incinerator exhaust gas contains harmful gases such as sulfur oxides and hydrogen chloride, chemicals such as slaked lime are usually supplied from the chemical supply pipe 7 to the incinerator exhaust gas upstream of the incinerator filter / dust collector 21. Then, the harmful components in the exhaust gas from the incinerator are reacted with a chemical to solidify, and collected as dust ash 22 together with the dust. The processing gas from which the dust and reactants have been removed is discharged from the chimney 6 to the outside of the system via the induction ventilator 5.
[0005]
On the other hand, the collected ash 22 collected by the incinerator filter dust collector 21 is supplied to the ash melting furnace 8 together with the incinerated ash 14 of the incinerator 1, and is melted. Is discharged. The incinerated ash 14 and the collected ash 22 are melted in the ash melting furnace 8 at a high temperature of about 1300 to 1400 ° C., though depending on their components. Instead of being contained therein, it is entrained in the melting furnace exhaust gas discharged from the ash melting furnace 8. Therefore, as in the case of the incinerator exhaust gas, a chemical is introduced from the chemical supply pipe 7 into the melting furnace exhaust gas after passing through the gas cooling device 9 before being introduced into the ash melting furnace filter dust collector 10. The gas is solidified, and the melting furnace processing gas 13 is combined with the incinerator processing gas downstream of the incinerator filter dust collector 21 by the fan 11 and discharged out of the system. The collected ash collected by the ash melting furnace filter dust collector 10 is not supplied to the ash melting furnace 8 because the harmful gas concentration in the melting furnace exhaust gas gradually increases when the ash is again supplied to the ash melting furnace 8. The ash is supplied to an ash solidification device 18 and solidified by a cement / chemical 19 and discharged as a final product.
[0006]
In the above exhaust gas treatment equipment, harmful gases such as sulfur oxides and hydrogen chloride gas contained in the incinerator exhaust gas and the melting furnace exhaust gas are respectively reacted with reactive agents such as slaked lime powder to solidify harmful components, and filtered for the incinerator. The dust is collected and removed by the dust collector 21 and the filtration dust collector 10 for the ash melting furnace. This solidification reaction is a so-called solid-gas reaction between a solid drug and a gaseous component, and the reaction is not sufficiently performed only by supplying an equivalent amount of the drug. Five to three times the amount of drug is dispensed. The introduced unreacted chemicals are collected by the ash melting furnace filter dust collector 10 as the collected ash 17, so that the amount of the collected ash 17 increases. There is a problem that the amount of the drug increases and the final solidification treatment cost increases. There is also a problem that the unreacted drug cannot be reused and is wasted. Further, since the chemicals are separately injected into the exhaust gas from the incinerator and the exhaust gas from the melting furnace, it is difficult to adjust the amount of the injected chemical, and it is difficult to reduce the amount of the injected chemical.
[0007]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 9-173742
[Problems to be solved by the invention]
The object of the present invention is to solve the above-mentioned problems of the prior art and reduce the amount of chemicals used for removing harmful components in exhaust gas, the amount of cement and chemicals for solidifying collected ash, and the amount of final ash solidified material. It is an object of the present invention to provide an exhaust gas treatment device that can perform the treatment.
[0009]
[Means for Solving the Problems]
The present inventors have conducted intensive studies on the above-mentioned problems, and as a result, installed a filtration dust collector for an incinerator in two stages, and collected ash collected by a filtration dust collector for removing dust in the preceding stage in an ash melting furnace. The processing gas from which the dust is removed from the melting furnace exhaust gas is combined with the incinerator exhaust gas between the pre-stage and post-stage filtration dust collectors to remove harmful components from the combined exhaust gas. So that the collected ash collected by the harmful gas removal filter dust collector at the subsequent stage is mixed with the exhaust gas of the melting furnace upstream of the filter dust collector for the ash melting furnace. By doing so, the inventors have found that the above-mentioned object can be achieved, and have reached the present invention.
The invention claimed in this application to achieve the above object is as follows.
[0010]
(1) Filtration precipitators for incinerators for removing dust in exhaust gas from incinerators, and ash melting for melting incineration ash from the incinerators and collected ash collected by the filtration precipitators for incinerators In an exhaust gas treatment apparatus provided with a furnace and a filter and dust collector for an ash melting furnace for removing dust in exhaust gas from the ash melting furnace, Means for sequentially installing a filter and a harmful gas removal filter dust collector, a means for supplying collected ash collected by the dust removal filter dust collector to the ash melting furnace, and the harmful gas removal filter dust collector. Means are provided for joining the processing gas of the melting furnace from the ash melting furnace filter / dust collector to the upstream incinerator exhaust gas, and harmful gas is removed from the combined exhaust gas upstream of the harmful gas removal filter / dust collector. An exhaust gas treatment device provided with a means for introducing a chemical for performing the treatment.
(2) A means for mixing all or a part of the collected ash collected by the harmful gas removal filter dust collector with the melting furnace exhaust gas upstream of the ash melting furnace filter dust collector is provided. The exhaust gas treatment device according to claim 1, wherein:
[0011]
(3) Filtration precipitator for incinerator for removing dust in exhaust gas from incinerator, and ash melting for melting incineration ash of the incinerator and collected ash collected by the filtration precipitator for incinerator In an exhaust gas treatment apparatus provided with a furnace and a filter dust collector for an ash melting furnace that removes dust in a flue gas of the melting furnace of the ash melting furnace, the filter for dust removal is used as the filter dust collector for the incinerator. A dust collector and a harmful gas removal filtration dust collector are sequentially installed, and a means for supplying collected ash collected by the dust removal filtration dust collector to the ash melting furnace; and a harmful gas removal filtration collector. Means for mixing the collected ash collected by the dust collector with the exhaust gas of the melting furnace upstream of the filter dust collector for the ash melting furnace, and providing the exhaust gas of the incinerator upstream of the filter dust collector for harmful gas removal. An exhaust gas treatment device comprising means for introducing a chemical for removing harmful gas.
[0012]
[Action]
In the present invention, as shown in FIG. 1 described later, a filter dust collector 3 for removing dust and a filter dust collector 4 for removing harmful gas are sequentially installed via a duct 12 as a filter dust collector for an incinerator. Then, the collected ash 15 collected by the filtration dust collector 3 for dust removal is supplied to the ash melting furnace 8 to be melted, and the dust in the exhaust gas of the melting furnace is collected by the filtration dust collector 10 for the ash melting furnace. Removed, the melting furnace processing gas 13 is combined with the exhaust gas from the incinerator of the duct 12, and a chemical is supplied from the chemical supply pipe 7 connected to the duct 12 to remove harmful components in the combined exhaust gas. This makes it possible to carry out the introduction of the medicine in one place, thereby facilitating the adjustment of the introduction amount of the medicine, reducing the amount of the medicine, and reducing the amount of the collected ash 17 collected by the ash melting furnace filter dust collector 10. Reduction of cement and chemicals 19 necessary for solidifying the collected ash 17 Reduction of and the final solidified product becomes possible.
[0013]
Further, as shown in FIGS. 2 to 4 described later, all or a part of the collected ash 16 collected by the harmful gas removing filter dust collector 4 is transferred to the upstream of the ash melting furnace filter dust collector 10. By mixing with the melting furnace exhaust gas, the unreacted chemical contained in the collected ash 16 can be reacted with the harmful gas in the melting furnace exhaust gas, and the input chemical can be effectively used. That is, since the reactant for removing the harmful gas is blown in an amount of 1.5 to 3 times the equivalent ratio, the unreacted agent having an equivalent ratio of 0.5 to 1.5 times is collected. The collected ash 16 containing such unreacted chemicals is blown into the exhaust gas of the melting furnace in front of the filter dust collector for the ash melting furnace, so that the collected ash 16 in the collected ash 16 is collected. The unreacted chemical can be reacted with the harmful gas in the exhaust gas of the melting furnace, and the input chemical can be effectively used. In addition, since the amount of chemicals for removing harmful gas is reduced, the amount of collected ash 16, 17 collected by the filter dust collector 4 for the incinerator or the filter dust collector 10 for the ash melting furnace is reduced, The supply amount of the cement / drug 19 for solidifying the collected ashes 16 and 17 may be small, and the final solidified amount is also small. Further, the melting furnace treatment gas 13 from which corrosive gases such as sulfur oxides and hydrogen chloride gas in the melting furnace exhaust gas have been removed is joined to the upstream or downstream of the incinerator filter / dust collector 4 in order to join them. Due to corrosive gas in ducts and the like is prevented.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings, but the present invention is not limited thereto.
FIG. 1 is a system diagram of an exhaust gas treatment apparatus showing one embodiment of the present invention.
1 is different from FIG. 5 in that a filter dust collector 3 for removing dust and a filter dust collector 4 for removing harmful gas are sequentially connected via a duct 12 instead of the filter dust collector 21 for the incinerator. The collected ash 15 collected by the filter dust collector 3 for removing dust is supplied to the ash melting furnace 8 through a duct, and the processing gas of the melting furnace from the filter dust collector 10 for the ash melting furnace is supplied. 13 is merged with the incinerator exhaust gas from the duct 12 upstream of the harmful gas removing filter / dust collector 4 through the duct, and the chemical supplied from the chemical supply pipe 7 is supplied to the combined exhaust gas from the duct 12. Another point is that the collected ash 16 collected by the harmful gas removing filter dust collector 4 is supplied to the ash solidifying device 8.
According to such an exhaust gas treatment apparatus, the medicine can be injected at one place, and the adjustment of the amount of injected medicine becomes easy. It is possible to reduce the amount of collected ash 17 collected, the amount of cement and chemicals 19 required for the solidification of the collected ash 17, and the amount of final solidified material.
[0015]
FIG. 2 is a system diagram of an exhaust gas treatment apparatus showing another embodiment of the present invention.
2, the difference from FIG. 1 is that the collected ash 16 from the harmful gas removing filter dust collector 4 is combined with the exhaust gas of the melting furnace upstream of the ash melting furnace filter dust collector 10 via a duct. It is the point that it did.
With such a configuration, in addition to the above effects, the unreacted chemical contained in the collected ash 16 can be reacted with the exhaust gas from the melting furnace, and the effective use of the injected chemical and the reduction of the amount of the injected chemical can be achieved. Therefore, it is possible to further reduce the collected ash 17, the supply amount of the cement / chemical 19 for the solidification treatment, and the final solidified material. Further, since the melting furnace processing gas 13 from which the harmful gas has been removed is combined with the upstream of the incinerator filter / dust collector 4, corrosion due to a harmful gas (corrosive gas) such as a duct for merging can be prevented. .
[0016]
When the behavior of the harmful gas in the exhaust gas from the incinerator was investigated in the above-mentioned apparatus, about 10% of the harmful gas was adsorbed on the collected ash 15 of the filter dust collector 3 for removing dust, and about 90% of the remaining about 90% was collected. It has been clarified that the harmful gas passes through the dust collector 3 and is introduced into the harmful gas filter 4. In addition, a highly reactive slaked lime is used as a chemical that reacts with the harmful gas, and about 1.5 times the amount of the chemical with an equivalent ratio to the harmful gas is blown from the chemical supply pipe 7 so that the filter dust collector 4 for harmful gas removal can be used. The measurement results revealed that the concentration of harmful gas in the outlet gas satisfied the required value. From these results, about one-third of the drug supplied from the drug supply pipe 7 is contained in the collected ash 16 as an unreacted component, and the collected ash 16 is filtered by the filter dust collector for the ash melting furnace. The unreacted chemicals can be effectively used by blowing the gas into the exhaust gas (including the above harmful gas of about 10%) in the upstream of the melting furnace. Even in the test using this apparatus, the amount of harmful gas in the exhaust gas from the incinerator upstream of the harmful gas removal filter and dust collector 4 was reduced to about 90%. The amount, the amount of cement and chemicals used for collecting and solidifying ash, and the amount of final solidified material could be reduced by about 10%.
[0017]
FIG. 3 is a system diagram of an exhaust gas treatment apparatus showing still another embodiment of the present invention.
3 is different from FIG. 2 in that a part of the collected ash 16 from the harmful gas removal filter dust collector 4, for example, an amount of ash trapped in a surplus furnace exhaust gas that is necessary to remove harmful gas components. The ash collector 16 is combined with the melting furnace exhaust gas upstream of the ash melting furnace filter dust collector 10, and the remaining collected ash 16 is supplied to an ash solidifying device 18.
With such a configuration, in addition to the above-described effects, the amount of the collected ash 16 can be adjusted according to the amount of harmful gas contained in the exhaust gas of the melting furnace. Processing efficiency can be improved.
[0018]
FIG. 4 is a system diagram of an exhaust gas treatment apparatus showing still another embodiment of the present invention.
4 is different from FIG. 2 in that the melting furnace processing gas 13 processed by the ash melting furnace filtration dust collector 10 is combined with the processing gas downstream of the harmful gas removal filtration dust collector 4. It is a point that did. With such a configuration, the processing efficiency of the harmful gas removing filtration dust collector 4 can be improved.
[0019]
【The invention's effect】
According to the first aspect of the present invention, the filter dust collector for the incinerator is installed in two stages, and the processing gas of the exhaust gas of the melting furnace is combined with the exhaust gas of the incinerator from which the dust has been removed. By adding the removing agent, it becomes easy to control the amount of the agent, and the amount of the agent is reduced, the amount of collected ash is reduced, the amount of cement and agent for solidifying the collected ash is reduced, and the amount of the final solidified material is reduced. Therefore, the life of a landfill site can be extended.
According to the second or third aspect of the invention, in addition to the above-mentioned effects, it is possible to effectively use the unreacted drug for removing the harmful gas, and it is possible to further reduce the harmful gas removal drug and the like.
[Brief description of the drawings]
FIG. 1 is a system diagram of an exhaust gas treatment apparatus showing one embodiment of the present invention.
FIG. 2 is a system diagram of an exhaust gas treatment apparatus showing another embodiment of the present invention.
FIG. 3 is a system diagram of an exhaust gas treatment apparatus showing still another embodiment of the present invention.
FIG. 4 is a system diagram of an exhaust gas treatment apparatus showing still another embodiment of the present invention.
FIG. 5 is a system diagram of a conventional exhaust gas treatment apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Incinerator, 2 ... Gas cooling device, 3 ... Filter dust collector for dust removal, 4 ... Filter dust collector for harmful gas removal, 5 ... Induction ventilator, 6 ... Chimney, 7 ... Chemical supply pipe, 8 ... ash melting furnace, 9 ... gas cooling device, 10 ... filter and dust collector for ash melting furnace, 11 ... fan, 12 ... duct, 13 ... melting furnace exhaust gas, 14 ... incineration ash, 15, 16, 17 ... collection ash , 18: Ash solidification device, 19: Cement / drug, 20: Melt slag, 21: Filtration dust collector for incineration path, 22: Ash collected.

Claims (3)

An incinerator filter dust collector for removing dust in exhaust gas of an incinerator, and an ash melting furnace for melting the incineration ash of the incinerator and the collected ash collected by the incinerator filter dust collector, In an exhaust gas treatment device provided with a filter dust collector for an ash melting furnace that removes dust in exhaust gas from the ash melting furnace, the filter dust collector for an incinerator is provided with a filter dust collector for removing dust. A gas removing filter dust collector is installed in order, a means for supplying the collected ash collected by the dust removing filter dust collector to the ash melting furnace, and a means upstream of the harmful gas removing filter dust collector. A means for joining the melting furnace processing gas from the ash melting furnace filter dust collector to the incinerator exhaust gas is provided, and a harmful gas is removed from the combined exhaust gas in front of the harmful gas removal filter dust collector. An exhaust gas treatment device comprising a means for introducing a drug. A means for mixing all or a part of the collected ash collected by the harmful gas removal filter dust collector with the melting furnace exhaust gas upstream of the ash melting furnace filter dust collector is provided. The exhaust gas treatment device according to claim 1. An incinerator filter dust collector for removing dust in exhaust gas of an incinerator, and an ash melting furnace for melting the incineration ash of the incinerator and the collected ash collected by the incinerator filter dust collector, In an exhaust gas treatment device provided with a filter dust collector for an ash melting furnace that removes dust in exhaust gas from the ash melting furnace, the filter dust collector for an incinerator is provided with a filter dust collector for removing dust. A gas removing filter dust collector is installed in order, and the collected ash collected by the dust removing filter dust collector is supplied to the ash melting furnace and collected by the harmful gas removing filter dust collector. Means for mixing the collected ash with the exhaust gas of the melting furnace upstream of the filter dust collector for the ash melting furnace, and removing harmful gas from the exhaust gas of the incinerator upstream of the filter dust collector for harmful gas removal. Exhaust gas treatment device provided with means for introducing a chemical for use in the treatment.

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