JP2010216733A - Waste treatment facility and waste treatment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To economically and easily melt waste. <P>SOLUTION: This waste treatment facility including a burning section 1 for burning waste, and a melting section 2 for melting the burned ash discharged from the burning section 1, further includes an unburned material adjusting means for adjusting the amount of carbon in the unburned material included in the burned ash in the burning section 1, and a water content adjusting means for adjusting the water content of the burned ash to be the water content suitable of water gasification reaction before melting at the melting section 2. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a waste processing facility and a waste processing method provided with an incineration unit for incinerating waste and a melting unit for melting incineration ash discharged from the incineration unit.

  Conventionally, incineration and melting treatment of waste while suppressing the amount of fuel used, the incineration unit has unburned carbon adjustment means for adjusting the amount of unburned carbon contained in the incineration ash, and includes unburned carbon. It has been considered to use the exothermic energy of unburned carbon as melting energy by melting the incineration ash in the melting part (see, for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 64-79509

  The conventional processing equipment described above has a drawback in that a large amount of air is required to burn unburned carbon in the melting part, and the amount of exhaust gas increases. Moreover, oxygen did not reach unburned carbon buried in the lower part of the incinerated ash, and unburned carbon was sometimes burned out with molten slag in a carbon state without burning. In addition to not being able to effectively use the exothermic energy of carbon, the quality of the molten slag will be adversely affected.

  An object of the present invention is to provide an equipment that effectively uses unburned carbon contained in incinerated ash and efficiently melts it, and furthermore, economical melting that can reduce fuel consumption and exhaust gas emissions. To provide facilities.

  A first characteristic configuration of the present invention is a waste treatment facility provided with an incineration unit for incinerating waste and a melting unit for melting incineration ash discharged from the incineration unit, and incineration at the incineration unit It has unburned matter control means for adjusting the carbon content of the unburned matter contained in the ash so that the water content of the incinerated ash becomes a moisture amount suitable for the water gasification reaction before melting in the melting part. There is a means for adjusting the amount of water to be adjusted.

According to the first characteristic configuration of the present invention, the moisture amount adjusting means adjusts the moisture amount of the incinerated ash to a moisture amount suitable for the water gasification reaction, and then puts it into the melting part. A gasification reaction is easily induced, and the amount of hydrogen gas generated increases. Since the produced hydrogen gas burns immediately, melting is efficiently promoted, and fuel in the melted portion can be saved.
In addition, since the water gasification reaction does not require oxygen to reach unburned carbon in the incineration ash, it is not necessary to blow a large amount of air, and the amount of exhaust gas emitted can be suppressed.
In addition, even if unburned carbon is burned and used as an auxiliary fuel, it cannot be used effectively because it cannot be burned because the portion buried in the lower part of the incinerated ash is not in contact with oxygen. However, the problem can be solved by inducing a water gasification reaction.
In addition, unburned carbon that does not burn has a higher melting point than incinerated ash, so there is a problem that it is carried out together with molten slag in the state of carbon, but the problem is solved by the water gasification reaction.

  According to a second characteristic configuration of the present invention, the unburned matter adjusting means converts the unburned ash into a quantity of unburned carbon based on a heat reduction amount of the incineration ash, and the moisture amount adjusting means includes the unburned amount adjusting means. The number of moles of fuel carbon is adjusted to the same number of moles or more.

According to the second characteristic configuration of the present invention, the amount of unburned carbon can be adjusted by adjusting the amount of heat loss that is easier to measure than the amount of unburned carbon, so that the operation management becomes easy. Since the correlation between the amount of heat loss and the amount of unburned carbon is obtained in advance, the water amount can be adjusted to a water amount equal to or more than the number of moles of the amount of unburned carbon converted from the measured amount of heat loss. The control of the chemical reaction can be made easy and reliable.

  According to a third characteristic configuration of the present invention, the moisture content of the incinerated ash by the moisture amount adjusting means is adjusted to be 10 to 40%.

  According to the third characteristic configuration of the present invention, the incineration ash can be melted better. In other words, the incinerated ash whose water content has been adjusted by the water content adjusting means is likely to scatter when the moisture content is less than 10%, and if it is more than 40%, it becomes difficult to convey or forms a bridge in the melting furnace for melting treatment. Therefore, the lower limit of the moisture content of the incinerated ash is set to 10% and the upper limit is set to 40%. By adjusting the moisture content within this range, it becomes possible to perform processing without scattering and bridge formation.

  According to a fourth characteristic configuration of the present invention, the unburned matter adjusting means adjusts the heat loss of the incinerated ash to 15 to 30%.

According to the 4th characteristic structure of this invention, not only the operation management in an incineration part and a fusion | melting part becomes easy, but an incineration part and waste gas treatment equipment can be made small.
Conventionally, the amount of heat reduction of incineration ash has been naturally reduced to 5% or less, but operation management is difficult, and the incinerator has been forced to operate inefficiently. By limiting the heat loss of incineration ash to 15% or more, not only operation management becomes easier, but also the incinerator and exhaust gas treatment equipment can be made smaller, greatly reducing construction and maintenance costs. can do. For example, in the stoker furnace, the post-combustion part can be omitted. Conversely, if the combustion is adjusted to a value where the amount of heat loss exceeds 30%, the incinerated ash contains coarse unburned material, which may impede the treatment in the melting part. Therefore, the operation management in the incineration section and the melting section is facilitated by adjusting the heat loss of the incineration ash to 15 to 30%.

  A fifth characteristic configuration of the present invention is a waste treatment facility provided with an incineration unit for incinerating waste and a melting unit for melting incineration ash discharged from the incineration unit. The first step of adjusting the amount of unburned carbon contained in the incinerated ash discharged at the time of incineration, and before melting the incinerated ash in the melting part, the water content of the incinerated ash is the number of moles of the unburned carbon amount And a second step of adjusting the amount of water so that the number of moles is equal to or greater than the number of moles.

  According to the fifth characteristic configuration of the present invention, like the first and third characteristic configurations, the fuel consumption and the exhaust gas emission are reduced, and the operation management in the incineration unit and the melting unit is facilitated. it can.

  In addition to the fifth feature configuration, the sixth feature configuration of the present invention obtains in advance a correlation between the amount of heat reduction of the incineration ash and the amount of unburned carbon, and the heat of the incineration ash in the first step. The reduction in weight is measured, and the reduction in heat is converted into the amount of unburned carbon contained in the incinerated ash based on the correlation.

  According to the sixth characteristic configuration of the present invention, it is possible to easily and reliably control the water gasification reaction.

Schematic diagram of waste treatment facility explained in the embodiment Graph showing the relationship between thermal loss and unburned carbon Graph showing the relationship between heat loss and moisture content

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

  In this embodiment, as shown in FIG. 1, a waste treatment facility provided with an incineration unit 1 for incinerating municipal waste, which is general waste, and a melting unit 2 for melting incineration ash discharged from the incineration unit. It is configured.

  The incinerator 1 is provided with a stalker-type municipal waste incinerator, and unlike the conventional incinerator, the post-combustion unit is omitted. The incineration unit 1 is provided with an unburned material adjusting device 3 for adjusting the amount of unburned carbon in the incinerated ash.

The unburnt substance adjusting device 3 is composed of a combustion time adjusting device, a combustion temperature adjusting device, a combustion air supply amount adjusting device, and the like, and these can be used in combination.
The amount of heat loss of the incinerated ash can be adjusted to 5% or more by the control by the unburnt substance adjusting device 3, but it is preferable to adjust to 10% or more because of easy operation management. Furthermore, when using a stoker furnace without a post-combustion part in an incinerator, it is more preferable to adjust to 15% or more.
Incineration ash from municipal waste often has a water content of more than 40% after adjustment to a water content suitable for a water gasification reaction when the amount of heat loss exceeds 40%. Incinerated ash having a moisture content of more than 40% may form a bridge in the conveyance path or the melting furnace and cause an obstacle to the melting treatment, so that the heat loss is preferably adjusted to 40% or less. Furthermore, if the amount of heat loss exceeds 30%, the incinerated ash contains coarse unburned material, which causes a hindrance to the melting treatment, so it is more preferable to adjust the amount of heat loss to 30% or less.

The incineration ash taken out from the incineration unit 1 is transferred to the moisture control device 4 and the moisture content of the incineration ash is adjusted to a moisture content suitable for the water gasification reaction, but the lower limit of the moisture content is 10% and the upper limit is 40%. As adjusted. This is because the incinerated ash is likely to be scattered when the moisture content is less than 10%, and when it exceeds 40%, it becomes difficult to convey and supply into the melting furnace as described above.
Depending on the moisture adjusting device 4, the efficiency of the water gasification reaction in the subsequent melting portion 2 is improved by equalizing the moisture before charging the incinerated ash into the melting portion 2. The moisture control device 4 also serves as a fire extinguishing facility for incineration ash.

The incinerated ash whose water content has been adjusted is transferred to the pretreatment device 9 where iron scraps and wastes are removed and then poured into the melting section 2. The pretreatment device 9 is appropriately arranged according to the substance to be removed, and may be a known device. The exhaust gas from the incinerator is processed by the exhaust gas processing device 5. The separated incineration fly ash is put into a melting furnace.
In the melting furnace, a slag discharge part 6 in which incinerated ash is melted and an exhaust gas path 7 are connected in series, and the exhaust gas path 7 is provided with an exhaust gas treatment part 8 for removing chloride, collecting dust, and the like. It is.

Next, a method for adjusting the water content of the incineration ash to be equal to or more than the number of moles of unburned carbon in the incineration ash will be described. Measuring the amount of unburned carbon in incinerated ash is time-consuming, so it is suitable for daily operation management to measure the thermal loss of incinerated ash and convert it to the amount of unburned carbon based on the measured value. ing.
At the start-up of the incinerator, the unburned material control device 3 changes the operating conditions to incinerate the waste, and measures the thermal reduction and unburned carbon amount of each incinerated ash to create a correlation equation Become. In addition, the correlation between the heat loss of incineration ash and the amount of unburned carbon varies depending on the type of garbage, the collection time, the collection form, etc., and will be reviewed as appropriate in consideration of the situation.
Table 1 shows the results of analysis of heat loss and unburned carbon in municipal waste.

In this analysis result, there is a part where the amount of unburned carbon is larger than the amount of heat loss. Although this is due to analysis errors, the amount of heat loss and the amount of unburned carbon cannot be analyzed at the same time on the same sample, so sample variations, that is, variations in the amount of unburned carbon in the incineration ash, etc. also affect the analysis results. It is estimated that
The analytical value is plotted on a graph with the horizontal axis representing the amount of heat loss and the vertical axis representing the amount of unburned carbon, and an approximate straight line or approximate curve is drawn to obtain a correlation equation. FIG. 2 plots the analysis results shown in Table 1 and draws a straight line passing through the origin, and the slope is 1.1. In other words, the correlation equation is unburned carbon amount (%) = 1.1 × heat loss reduction (%) Equation 1
This is an example of setting. Although it is theoretically impossible for the slope to be 1.0 or more, it is set on the safe side in consideration of the influence of the analysis error and the like as described above.
Calculate the amount of unburned carbon from Equation 1 and the amount of water in the same number of moles as the amount of unburned carbon contained in 1 kg of dry ash (hereinafter, the amount of water in the same number of moles as the amount of unburned carbon converted from heat loss) Table 2 shows the results of determining the water content of ash adjusted to the required water content. Moreover, the graph which shows the relationship between a moisture content and a heat loss is shown in FIG.

  For example, when the amount of heat loss is 2%, the amount of unburned carbon is 2.2% from Equation 1 (unburned carbon amount (%) = 1.1 × heat loss reduction (%). ) The amount of unburned carbon in 1 kg of dry ash is 1000 g × 2.2% = 22 g. The required moisture content of 22 g of carbon is 22 g × 18/12 = 33 g (= 0.033 g), and the moisture content is 33 g ÷ (1000 g + 33 g) = 3.19%.

In this way, if the correlation between the heat loss of incinerated ash and the amount of unburned carbon, the required water content, and the moisture content are determined in advance, the required water content can be easily obtained by analyzing the heat loss in daily operation of the incinerator. The amount and moisture content to be adjusted are required.
The method for measuring the amount of heat loss may be performed periodically once a day, but it is sufficient to analyze it when changing the operating conditions.
Since the correlation between the amount of heat loss and the amount of unburned carbon is stored in the control unit of the moisture adjusting device 4, and when the analyzed amount of heat loss is input to the control unit, the required water amount is calculated and the required water amount is automatically added. is there.
In addition, although heat loss was analyzed by the following method, it is not limited to this. What is necessary is just to unify by the method used when creating the correlation formula of the amount of heat loss and the amount of unburned carbon.
(1) Tools and equipment to be prepared (a) Electric furnace: one that can be adjusted to 800 ° C ± 25 ° C.
(B) Crucible: Made of porcelain. After igniting at 800 ° C. ± 25 ° C. for about 1 hour, it is allowed to cool in a desiccator and the mass is measured to the order of 1 mg.
(2) Operating method (a) Weigh 5 g or more of the dried incineration ash into a porcelain crucible to the order of 1 mg.
(B) After igniting at 800 ° C. ± 25 ° C. for about 2 hours using an electric furnace, it is allowed to cool in a desiccator and the mass is measured to the order of 1 mg.
(C) Calculate heat loss (%) by the following formula.
Heat loss (%) = (α−β) / α × 100
(Α: mass of dry incinerated ash collected (g) β: mass of dry incinerated ash after ignition (g))

[Another embodiment]
Other embodiments will be described below.

<1> When obtaining the correlation between the amount of heat loss and the amount of unburned carbon, the control unit for obtaining the correlation between the operating condition of the unburnt substance adjustment device 3 and the amount of heat reduction in advance and storing the correlation is provided. 3 may be provided. This control unit is configured to calculate the thermal loss from the operating condition of the unburnt substance adjusting device 3 and to output the calculation result to the control unit of the moisture adjusting device 4. By setting it as such an installation, the moisture adjustment apparatus 4 can add a required moisture amount automatically based on the driving | running conditions of the unburned substance adjustment apparatus 3. FIG.
<2> In the present embodiment, the moisture control device 4 and the fire extinguishing equipment are combined, but they may be provided separately. For example, it is also possible to dispose the incinerator ash taken out from the incineration unit 1 with a fire extinguishing equipment, and to dispose iron scraps and waste in the pretreatment device 9 and to arrange the moisture adjusting device 4 in the subsequent stage. In this case, the fire extinguishing equipment can use equipment extinguishing by means other than water, such as an apparatus for spraying nitrogen gas.
<3> Although incineration fly ash is directly charged into the melting furnace in the present embodiment, it may be mixed with the incineration ash treated by the pretreatment device 9 and transferred to the moisture adjusting device 4. When the incineration ash is adjusted to a water content suitable for the water gasification reaction, when operating with a heat loss that exceeds 40%, the incineration ash is mixed to lower the water content of the incineration ash. It can be avoided that the incinerated ash causes troubles in the transport route and the melting furnace.
<4> The incineration unit 1 and the melting unit 2 are configured as separate furnaces, but may be configured as a single integrated processing furnace.
<5> A method of adding a necessary amount of moisture by human operation without using a control unit in the moisture amount adjusting device 4 may be used.

  In addition, as mentioned above, although the code | symbol was written in order to make contrast with drawing convenient, this invention is not limited to the structure of an accompanying drawing by this entry. In addition, it goes without saying that the present invention can be carried out in various modes without departing from the gist of the present invention.

  The waste treatment facility of the present invention can be applied to the treatment of industrial waste and sewage sludge in addition to general waste.

1 Incineration section 2 Melting section

Claims (6)

Establish an incineration unit to incinerate waste,
A waste treatment facility provided with a melting section for melting incineration ash discharged from the incineration section,
Having unburned matter adjusting means for adjusting the carbon content of unburned matter contained in the incinerated ash in the incineration section,
A waste treatment facility provided with water content adjusting means for adjusting the water content of the incinerated ash to a water content suitable for the water gasification reaction before melting in the melting part. The unburned matter adjusting means is for adjusting the amount of unburned carbon based on the heat loss of the incinerated ash,
The waste treatment facility according to claim 1, wherein the moisture amount adjusting means adjusts the number of moles of the unburned carbon to the same number or more. The waste treatment facility according to claim 1 or 2, wherein the moisture content of the incinerated ash by the moisture amount adjusting means is adjusted to be 10 to 40%. The waste treatment facility according to any one of claims 1 to 3, wherein the unburned matter adjusting means adjusts the heat loss of the incinerated ash to 15 to 30%. Establish an incineration unit to incinerate waste,
In the waste treatment facility provided with a melting part for melting the incinerated ash discharged from the incineration part,
A first step of adjusting the amount of unburned carbon contained in the incinerated ash to be discharged at the time of incineration of waste in the incineration unit;
Before melting the incinerated ash in the melting part, having a second step of adjusting the moisture content so that the moisture content of the incinerated ash is equal to or greater than the number of moles of the unburned carbon amount,
A waste treatment method for adjusting the moisture content of the incinerated ash to 10 to 40%.   A correlation between the amount of heat loss of the incinerated ash and the amount of unburned carbon is obtained in advance, the amount of heat loss of the incinerated ash is measured in the first step, and the amount of heat loss is calculated based on the correlation. The waste disposal method according to claim 5, wherein the amount of unburned carbon contained in the incinerated ash is converted into the amount of unburned carbon.

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