JPH04313615A - Method for adjusting basicity of incineration ash in incineration ash-melting furnace - Google Patents

Abstract

PURPOSE:To reduce the cost of fuel for an incineration ash-melting furnace which melts incineration ash discharged from a fluidized-bed type thermal decomposition furnace for incinerating waste. CONSTITUTION:A fluidized-bed type thermal decomposition furnace 1 is connected with an additive-feeding line 1a in a setup to feed a basicity-adjusting agent (a) to the fluidized-bed type thermal decomposition furnace 1 through the additive-feeding line 1a so that together with the basicity-adjusting agent (a) the incineration ash is sent to an incineration ash-melting furnace 4. This method makes the incineration ash mixed well with the basicity-adjusting agent (a) and through adjustment of the basicity of the incineration ash its melting point is effectively lowered. Thus a reduction in the cost of fuel can be achieved in the melting of incineration ash.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a method for adjusting the basicity of incinerated ash, which is a material to be melted, and more specifically to an incinerated ash melting furnace that can reduce the fuel consumption required for an incinerated ash melting furnace that melts incinerated ash. The present invention relates to a method for adjusting the basicity of incinerated ash.

0002

[Prior Art] As is well known, materials to be incinerated such as municipal waste, sludge, and industrial waste are incinerated in an incinerator, but incineration ash produced by incineration of materials to be incinerated is melted in an ash melting furnace. After the volume is reduced and stabilized through treatment, it can be used effectively as construction materials, etc., or it can be disposed of in landfills.

By the way, the basicity (CaO/SiO2) of the incinerated ash has an extremely important meaning in the melting process of the incinerated ash. In other words, if the basicity of the incinerated ash is appropriate, the melting point of the incinerated ash will be low, and the effect of reducing the thermal energy required for the incinerated ash melting furnace, that is, it will be extremely advantageous economically in terms of fuel consumption.

For example, the relationship between the basicity and the melting point of sludge incineration ash is shown in the relationship diagram (inorganic sludge incineration ash is marked with a white circle,
In addition, organic sludge incineration ash is indicated by black circles) in Figure 3.
As shown in , it has been shown that the melting point of sludge incineration ash is lowest in the range of about 1.0 or less.

[0005] Therefore, an addition line for a basicity regulator is connected to an incineration ash pneumatic transport supply line that communicates with an incineration ash melting furnace, and the basicity regulator is supplied from this addition line. By mixing it into the incineration ash to adjust the basicity of the incineration ash, the melting point of the incineration ash is lowered.

[0006] In order to determine the amount of basicity regulator added, it is necessary to know the basicity of the incinerated ash.
A well-known method of measuring according to JISM8221 is adopted.

[0007]

However, since the basicity regulator is added to the incinerated ash shortly before it enters the incinerated ash melting furnace, the incinerated ash and the basicity regulator are not sufficiently mixed, and the incinerated ash becomes Even though a basicity regulator was added to the incinerated ash, the melting point of the incinerated ash was not lowered, and it often did not contribute to reducing the thermal energy required for the incinerated ash melting furnace.

Therefore, the present invention provides a method for adjusting the basicity of incinerated ash in an incinerated ash melting furnace, which can reduce the fuel consumption required for the incinerated ash melting furnace by properly mixing incinerated ash and a basicity regulator. For the purpose of providing.

[0009]

[Means for Solving the Problems] The present invention has solved the above problems because mixing the incinerated ash and the basicity regulator more uniformly is effective in adjusting the basicity.
Therefore, the gist of the method for adjusting the basicity of incinerated ash in an incinerated ash melting furnace according to the present invention is that the incinerated ash of the incinerated material produced by decomposition and incineration in the fluidized bed pyrolysis furnace is supplied to the incinerated ash melting furnace. A method for adjusting the basicity of incinerated ash in an incinerated ash melting furnace in which a basicity regulator is added to the incinerated ash in order to reduce the basicity of the incinerated ash, characterized by supplying the basicity regulator to a fluidized bed pyrolysis furnace. shall be.

0010

[Operation] According to the method for adjusting the basicity of incinerated ash in an incinerated ash melting furnace according to the present invention, since the basicity regulator is supplied to the fluidized bed type pyrolysis furnace, the incinerated ash produced in the fluidized bed type pyrolysis furnace is The time for which the basicity regulator is present is longer than before.

[0011]

[Embodiment] An embodiment of the present invention will be described below with reference to FIG.
The case of sludge incinerated ash will be described as an example with reference to FIG. 2, which is a diagram showing the relationship between the furnace wall temperature of the incinerated ash melting furnace and the amount of incinerated ash processed.

Reference numeral 1 shown in FIG. 1 is a fluidized bed type pyrolysis furnace.
The sludge put into the fluidized bed pyrolysis furnace 1 is thermally decomposed and incinerated, and the incineration ash produced by the incineration is sent from the fluidized bed pyrolysis furnace 1 to the cyclone 2, and then to the cyclone 2.
The incinerated ash is supplied to the incinerated ash melting furnace 4 through the pneumatic transport supply line 3 communicating with the incinerated ash, where it is melted and turned into slag, which is discharged from the incinerated ash melting furnace 4.

On the other hand, the exhaust gas containing unburned gas generated by the thermal decomposition of sludge in the fluidized bed type pyrolysis furnace 1 is sent from the cyclone 2 to the secondary combustion chamber 5 and completely combusted, and the combustion exhaust gas generated thereby is Air preheater 6, 6a, exhaust gas treatment device 7
It is then discharged into the atmosphere from a chimney 8.

Furthermore, the air preheated by the air preheater 6 is supplied to the fluidized bed type pyrolysis furnace 1 and the secondary combustion chamber 5 through the air preheater 6a.
The preheated air is sent to the incinerated ash melting furnace 4, where it serves to thermally decompose the sludge, completely combust the exhaust gas, and combust the fuel that becomes the heat source for melting the incinerated ash. That is, the configuration described above is exactly the same as the conventional incineration material processing equipment.

In the conventional incineration material processing equipment, the addition line 3a (indicated by a broken line) for adding a basicity regulator to the incinerated ash was connected to the pneumatic transport supply line 3, but in this embodiment An addition line 1a was connected to the pyrolysis furnace 1, and the basicity regulator was supplied to the pyrolysis furnace 1 through the addition line 1a.

The mode of operation of this embodiment will be explained below. Since the basicity regulator is supplied from the addition line 1a to the fluidized bed type pyrolysis furnace 1, it is thermally decomposed and burned in the fluidized bed type pyrolysis furnace 1. The incinerated ash of the sludge generated by the sludge is supplied from the cyclone 2 to the incinerated ash melting furnace 4 through the pneumatic transport supply line 3 while being mixed with the basicity adjusting agent.

[0017] In this way, the time for the basicity adjuster to accompany the incinerated ash is longer than in the past, and since it is stirred in the cyclone 2 and the pneumatic transport supply line 3, the incinerated ash and the basicity adjuster are uniformly distributed. now mixed into

Incidentally, the difference in effect due to the difference in the mixing of the incinerated ash and the basicity regulator will be explained based on FIG. 2. In addition, Figure 2
The case according to this embodiment is shown by a white circle, and the conventional case is shown by a black circle, and the amount of fuel used is the same in both cases.

According to the figure, although the amount of fuel used is the same, the furnace wall temperature of the incinerated ash melting furnace 4 is higher in this embodiment than in the conventional case. This indicates that the thickness of the slag layer adhering to the furnace wall of the incinerated ash melting furnace 4 becomes thinner as the effect of lowering the melting point increases. In other words,
This suggests that less fuel is needed to maintain the same internal temperature of the incinerated ash melting furnace as in the past.

[0020] In this way, since the position where the basicity adjuster is added is simply moved to the previous process, there is no increase in equipment costs, and the incineration ash and the basicity adjuster are mixed more uniformly and reliably. It becomes possible to reliably reduce the fuel consumption required for the ash melting furnace 4.

[0021]

[Effects of the Invention] As detailed above, in the conventional method for adjusting the basicity of incinerated ash, the effect of adding the basicity adjusting agent may not be expected due to poor mixing of the incinerated ash and the basicity adjusting agent. Ta. However, according to the method for adjusting the basicity of incinerated ash according to the present invention, since the basicity regulator is supplied to the fluidized bed pyrolysis furnace, the basicity of the incinerated ash produced in the fluidized bed pyrolysis furnace is adjusted. Since the time that the agent is accompanied by the agent is longer than before, the incinerated ash and basicity adjuster can be mixed more reliably, which has an extremely large effect on reducing the fuel consumption required for the incinerated ash melting furnace. You can expect it.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a system of incineration material processing equipment equipped with an incineration ash melting furnace.

FIG. 2 is a relationship diagram between the furnace wall temperature of the incinerated ash melting furnace and the amount of incinerated ash processed.

FIG. 3 is a relationship diagram between basicity and melting point of sludge incineration ash.

[Explanation of symbols]

1...Fluidized bed pyrolysis furnace 1a...Addition line 2...Cyclone 3...Pneumatic transportation supply line 4... Incineration ash melting furnace 5...Secondary combustion chamber 6, 6a...Air preheater 7...Exhaust gas treatment device 8...Chimney a...Basicity regulator

Claims (1)

[Claims] Claim 1: In order to lower the melting point of the incinerated ash produced by decomposition and incineration in the fluidized bed pyrolysis furnace supplied to the incinerated ash melting furnace, a basicity regulator is added to the incinerated ash. A method for adjusting the basicity of incinerated ash in an incinerated ash melting furnace, wherein the basicity adjusting agent is supplied to a fluidized bed type pyrolysis furnace.