JP4064163B2 - Waste incinerator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a waste incinerator, and particularly to a secondary air supply portion.
[0002]
[Prior art]
In general, the combustion gas generated when garbage is burned in a waste incinerator contains unburned components such as carbon monoxide, hydrocarbons, and soot, which are precursors of dioxins. In order to suppress the generation of odors, it is necessary to completely burn the unburned matter.
[0003]
By the way, conventionally, in order to completely burn the unburned matter, a method of jetting air containing oxygen necessary for combustion as secondary air into the secondary combustion chamber and sufficiently stirring (mixing) the combustion gas is used. It has been.
[0004]
For example, as disclosed in Japanese Patent No. 3052967, a plurality of secondary air supply pipes are arranged in parallel to each other in the secondary combustion chamber of the incinerator so as to cross the flow path of the combustion gas. Some of these air supply pipes are formed with a large number of air outlets at predetermined intervals along the axial direction of the pipe.
[0005]
[Problems to be solved by the invention]
According to the above configuration, when a plurality of air supply pipes are arranged in parallel, that is, in the same horizontal plane, the flow area when the combustion gas flows from the lower side to the upper side in the secondary combustion chamber becomes narrower. There was a problem that the passage time was shortened and the combustion gas was not sufficiently stirred (mixed).
[0006]
Then, an object of this invention is to provide the refuse incinerator which can fully stir combustion gas in a secondary combustion chamber.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, the waste incinerator of the present invention is arranged with a secondary air supply pipe for supplying secondary air to the center of the secondary combustion chamber , and this secondary air supply pipe is A horizontal support pipe disposed at the center position between the front and rear wall parts constituting the secondary combustion chamber and supported at both ends by the left and right wall parts, and suspended downward from the center part of the support pipe And a secondary air supply pipe in the vertical direction in which a plurality of secondary air outlets are formed at predetermined intervals in the vertical direction,
Further, a secondary air introduction pipe for guiding secondary air is connected to one end side of the support pipe, and one end portion opens to the other end side of the support pipe from the center to the other end in the support pipe. A secondary air guide pipe having the other end connected to the upper end inlet of the secondary air supply pipe is disposed in a double tubular shape with a gap ,
Further, a part or all of the secondary air supplied to the secondary air supply pipe body is used as combustion exhaust gas.
[0008]
According to the above configuration, secondary air from the secondary air outlet provided in the center of the secondary combustion chamber and along the flow of the combustion gas, or secondary air partially containing combustion exhaust gas, or combustion Since the exhaust gas is ejected and the combustion gas is agitated, it is not necessary to make the ejection speed so fast and the cross-sectional area of the flow path is also larger than when multiple air supply pipes are arranged in the horizontal direction. Since it does not become so narrow, that is, the passage speed of the combustion gas does not become too fast, the combustion gas generated in the secondary combustion chamber can be sufficiently stirred. Therefore, complete combustion of the unburned content is promoted, and the concentration of the precursor of dioxins such as carbon monoxide can be reduced.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the refuse incinerator in embodiment of this invention is demonstrated based on FIGS. 1-3.
[0010]
This waste incinerator is of a stoker type, and as shown in FIG. 1, at the bottom of the furnace body 1, from one end side to the other end side, that is, from the front to the rear, the dust supply unit 2, the drying A stage grate part 3, a combustion stage grate part 4 and a post combustion stage grate part 5 are provided, and a combustion chamber 6 serving as a main combustion zone is formed immediately above the combustion stage grate part 4. A secondary combustion chamber 7 serving as a secondary combustion region is formed above the combustion chamber 6. Based on the flow direction of the combustion gas, it can be said that the secondary combustion chamber 7 is disposed downstream of the combustion chamber 6.
[0011]
And in order to stir (mix) the combustion gas in the said secondary combustion chamber 7 while injecting secondary air (air | atmosphere) into the center part of this secondary combustion chamber 7 to perform secondary combustion. Secondary air supply pipe body 8 is provided.
[0012]
As shown in FIGS. 1 and 2, the secondary air supply pipe body 8 is disposed at a central position between the front and rear wall portions 1a and 1a constituting the secondary combustion chamber 7, and the left and right wall portions 1b and 1b. A horizontal support pipe 11 supported at both ends thereof, and a vertical direction in which a plurality of secondary air jets 12 are vertically formed at predetermined intervals while being vertically suspended from the center of the support pipe 11 Secondary air supply pipe 13.
[0013]
The secondary air is supplied to the secondary air supply pipe 13 through the support pipe 11. That is, a secondary air introduction pipe 14 that guides secondary air is connected to one end side of the support pipe 11, and one end of the support pipe 11 extends from the center toward the other end of the support pipe 11. A secondary air guide pipe 15 having an opening on the other end side and having the other end connected to the upper end inlet of the secondary air supply pipe 13 is arranged in a double tubular shape. Of course, an annular gap a in which the secondary air can move is provided between the secondary air guide tube 15 and the support tube 11. Although not shown, a heat-resistant material is provided on the outer surfaces of the support tube 11 and the secondary air supply tube 13 exposed to the combustion gas in the furnace body 1 to protect them from high temperatures. Although not shown, the front and rear walls of the furnace body 1 are provided with an original secondary air supply nozzle, and secondary air is supplied as shown by an arrow b.
[0014]
In the above configuration, when secondary air is introduced into the support tube 11 from the secondary air introduction tube 14, the support tube 11 is cooled while moving from one end side to the other end side, and then the secondary air guide tube 15 is cooled. And enters the secondary air supply pipe 13, and secondary air is jetted into the secondary combustion chamber 7 from a plurality of secondary air outlets 12 formed above and below the secondary air supply pipe 13. . Of course, the secondary air supply pipe 13 itself is also cooled by the secondary air.
[0015]
As described above, since the secondary air is jetted in the front-rear direction in the central portion of the secondary combustion chamber 7 and from a plurality of locations, the combustion gas is agitated. Compared with the case where a plurality of air supply pipes are arranged in the horizontal direction, the flow passage cross-sectional area is not so narrow, that is, the passage speed of the combustion gas does not become too fast. The combustion gas generated in can be sufficiently stirred. When the combustion gas is sufficiently agitated, complete combustion of unburned matter is promoted, and the concentration of dioxin precursors such as carbon monoxide can be reduced.
[0016]
Here, FIG. 3A and FIG. 3B show the results of comparing the equiconcentration surface of carbon monoxide between the case according to the present embodiment and the case according to the conventional example. As can be seen from FIG. 3, the equivalent concentration surface (100 ppm, 10 ppm) appears at a lower position in the case (a) according to the present embodiment than that according to the conventional example, and carbon monoxide is in an early stage. It can be seen that the number is decreasing. Further, when comparing the concentration (maximum value) of carbon monoxide at the outlet of the secondary combustion chamber 7, it was 3.9 ppm in the case of this embodiment, whereas it was 12 in the case of the conventional example. 0.0 ppm.
[0017]
By the way, in the said embodiment, although the secondary air jet nozzle 12 was formed in the front-and-back surface of the secondary air supply pipe | tube 13, as shown in FIG. 4, for example, the secondary air jet nozzle 12 is made into the same height position. The two provided before and after and the four provided at every 90 degrees at the same height position are alternately arranged, and the phase is set to 45 with respect to the two provided four. It may be designed to be deviated. Also in this case, as shown in FIG. 5, it can be seen that carbon monoxide is reduced at an early stage as in the above embodiment.
[0018]
In addition, about the number of the secondary air ejection ports 12 and the ejection direction, various arrangement forms other than the above are conceivable, and anyway, secondary air can be ejected around and the combustion gas can be stirred more effectively. Any arrangement can be used.
[0019]
By the way, in the above-described embodiment, it has been described that the secondary air is supplied to the secondary air supply pipe body. However, for example, the combustion exhaust gas discharged from the secondary combustion chamber is mixed into the secondary air. In some cases, instead of the secondary air, that is, the whole may be combustion exhaust gas (in this sense, the secondary air supply pipe body may be simply referred to as a fluid supply pipe body).
[0020]
【The invention's effect】
As described above, according to the configuration of the waste incinerator of the present invention, the secondary air or a part of the combustion exhaust gas is discharged from the secondary air outlet provided in the center of the secondary combustion chamber and along the flow of the combustion gas. When the combustion air is agitated by ejecting secondary air containing combustion gas or combustion exhaust gas, it is not necessary to make the ejection speed too fast, and when multiple air supply pipes are arranged in the horizontal direction Compared to the above, the cross-sectional area of the flow path is not so narrow, that is, the passage speed of the combustion gas does not become too fast, so that the combustion gas generated in the secondary combustion chamber can be sufficiently stirred.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a schematic configuration of a waste incinerator according to an embodiment of the present invention.
FIG. 2 is a perspective view showing a schematic configuration of a secondary air supply pipe body in the waste incinerator.
FIG. 3 is a perspective view showing an equi-concentration surface of carbon monoxide in a combustion chamber in the waste incinerator.
FIG. 4 is a perspective view of a secondary air supply pipe according to a modification of the waste incinerator.
FIG. 5 is a perspective view showing an equi-concentration surface of carbon monoxide in a combustion chamber when the secondary air supply pipe according to the modification is used.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Furnace body 6 Combustion chamber 7 Secondary combustion chamber 8 Secondary air supply pipe body 11 Support pipe 12 Secondary air outlet 13 Secondary air supply pipe 14 Secondary air introduction pipe 15 Secondary air guide pipe

Claims (2)

A secondary air supply pipe that supplies secondary air is arranged at the center of the secondary combustion chamber , and this secondary air supply pipe is arranged at a central position between the front and rear walls constituting the secondary combustion chamber. And a horizontal support pipe whose both ends are supported on the right and left wall parts, and a plurality of secondary air jets formed vertically at predetermined intervals while being suspended downward from the center part of the support pipe. Composed of a secondary air supply pipe in the vertical direction,
Further, a secondary air introduction pipe for guiding secondary air is connected to one end side of the support pipe, and one end portion opens to the other end side of the support pipe from the center to the other end in the support pipe. In addition, a secondary air guide pipe having the other end connected to the upper end inlet of the secondary air supply pipe is disposed in a double tubular shape with a gap . The waste incinerator according to claim 1 , wherein a part or all of the secondary air is used as combustion exhaust gas.

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