JPH06213423A - Incinerator - Google Patents

Abstract

PURPOSE:To reduce NOx and to suppress generation of dioxin by expediting mixing of burning gas generated from a combustion zone and reducible gas generated from a dry zone and mixing of the mixture gas and secondary combustion air. CONSTITUTION:A mixing chamber A is formed above a dry zone 6, and a guide chamber B for guiding combustion gas generated from a combustion zone 7 is provided above the zone 7. A nozzle C for injecting secondary air toward the chamber A is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an incinerator for municipal waste, for example, a drying zone for drying an incineration object placed in the oven while it is conveyed, and an incineration conveyed from the drying zone. An incinerator having a primary combustion region having a combustion zone for burning an object, and a secondary combustion region for complete combustion by supplying a secondary combustion gas to the combustion gas generated in the primary combustion region .

[0002]

2. Description of the Related Art The incinerator described above is called a reduction two-stage combustion type and is constructed for the purpose of reducing the generation of nitrogen oxides NO _x , and it has a high temperature in the primary combustion region (around 1000 ° C.). ) The nitrogen oxide NO _x generated by combustion is reduced by the reaction with the reducing gas (for example, NH ₃ ) generated from the dry zone, and the temperature is lower than the primary combustion region (around 800 ° C.).
Nitrogen oxides NO _X is incinerator to completely burn so as not to generate in the secondary combustion zone of the. As such an incinerator, as shown in FIG. 2, a flue 12 is formed above the combustion zone 7 located on the transport lower side of the drying zone 6, and the secondary combustion of air or the like is performed in the flue 12. Although the secondary combustion region R2 for mixing the working gas to achieve complete combustion is formed,
Since the combustion gas formed in the combustion zone 7 directly rises in the flue 12, even if the secondary combustion gas is supplied to the rising combustion gas, the combustion gas and the secondary combustion gas are separated from each other. In some cases, unmixed gas such as carbon monoxide CO was not completely removed due to insufficient mixing and stirring. Further, since the nitrogen oxide NO _x and the reducing gas generated from the dry zone could not be sufficiently stirred, the reduction reaction was not as expected, and therefore the nitrogen oxide NO _x could not be sufficiently removed. . It has been conventionally known that the flue gas is mixed with the combustion gas and the secondary combustion gas well to eliminate the above-mentioned drawback and to sufficiently perform combustion in the secondary combustion region. One of them is the invention disclosed in Japanese Patent Application Laid-Open No. 4-240308, and the gist thereof is as follows. That is, a flue that forms a secondary combustion region is provided above the primary combustion region, and is configured so that air for secondary combustion is introduced from the peripheral wall of this flue, and on the lower side of this air supply means, It is provided with a damper means for adding a stirring action to the secondary combustion gas rising in the flue and promoting mixing.

[0003]

However, in the above-mentioned prior art, since a new means called a damper means is formed to promote mixing, there is a drawback that the equipment structure becomes complicated. In addition, no consideration is given to the fact that the combustion gas generated in the combustion zone and the reducing gas generated in the dry zone in the primary combustion region are not sufficiently mixed, and the nitrogen oxide NO _x cannot be sufficiently removed. It's still left behind. The object of the present invention is to improve the structure of the upstream side of the secondary combustion region by mixing and stirring the reducing gas generated from the dry zone and the combustion gas generated from the combustion zone, and the secondary combustion gas. By sufficiently promoting the mixing and stirring with and before reaching the secondary combustion region, complete combustion is achieved in the secondary combustion region, and carbon monoxide CO, and thus the generation of dioxin, which correlates with the amount of carbon monoxide CO generated. The point is to provide an incinerator that can suppress the above.

[0004]

A characteristic feature of the present invention is that the upper side of the secondary combustion region is located above the dry zone.
Forming a mixing region for mixing the reducing gas generated from the dry zone and the combustion gas generated from the combustion zone, and forming guide means for guiding the combustion gas generated from the combustion zone to the mixing zone. There is a point. In particular,
A supply means for the secondary combustion gas is provided on the upstream side of the secondary combustion area, and the combustion gas guided by the guide means blows into the mixing area in the ejection direction of the secondary combustion gas of the supply means. It is preferable to apply it to an incinerator, which is set in such a guiding direction.

[0005]

In other words, the reducing gas generated from the dry zone is introduced into the mixing zone and the combustion gas generated from the combustion zone is prevented from rising by the guide means and the combustion gas is forced. The gas is introduced into the mixing zone by being guided above the dry zone, and collided with the reducing gas generated in the dry zone to sufficiently stir and mix before reaching the secondary combustion zone, thereby promoting the reduction reaction. At that time, by agitating the secondary combustion gas in a direction that further promotes the introduction of the combustion gas into the mixing region by the guide means, the stirring and mixing in the mixing region is further promoted. Mixing with the secondary combustion gas can be sufficiently achieved before reaching the combustion zone, and sufficient time for the combustion reaction in the secondary combustion zone can be secured.

[0006]

Since the mixing area is formed before reaching the secondary combustion area and the guide means for introducing the combustion gas is provided therein, it is possible to prevent the combustion gas from directly entering the flue and It is possible to promote the mixing and stirring of the reducing gas and the mixing and stirring of the mixed gas and the secondary combustion gas, and by promoting the mixing and stirring, the generation of nitrogen oxide NO _x is suppressed and the carbon monoxide CO And suppress the generation of dioxin,
It has become possible to provide an incinerator that can achieve clean combustion.

[0007]

EXAMPLES Examples will be described below. As shown in FIG. 1, the incinerator for municipal waste is provided with a hopper 3 for storing the incinerated waste, a combustion chamber 2 for incinerating the waste, an ash pit 4 for collecting the incinerated ash, and the like. Configured. The combustion chamber 2 has a drying zone 6 for drying the dust introduced by the pusher 5 provided at the lower end of the hopper 3 and heating it to the vicinity of the ignition point, and a drying zone 6 below the drying zone 6 for burning the dry dust. The combustion zone 7 and the post-combustion zone 8 for ashing the dust burned in the combustion zone 7 are arranged in a stepwise manner from the upper side to the lower side. There is provided a stoker means 1 for transporting the dust to the ash pit 4 while stirring the dust by sliding the fired grate 9 diagonally up and down. Below the combustion chamber 2, there is provided a supply path 11 for supplying the heated air sent by the blower 10 to the combustion chamber 2 as drying / combustion air.
The dry zone 6, the combustion zone 7, and the post-combustion zone 8 are separately supplied. The combustion gas generated in the combustion chamber 2 reaches the waste heat boiler 13 via the flue 12, and the waste heat boiler 13 generates steam to become the energy of the power generator 14,
It passes through the exhaust gas treatment facility 15 and is released to the atmosphere.

Above the drying zone 6 in the combustion chamber 2.
On the other hand, when a mixed area A having a constant space is formed,
Then, tilt the ceiling wall upward from the combustion zone 7 to the dry zone 6.
It is formed on a slanted inclined surface and starts from the post combustion zone 8 and the combustion zone 7.
In the guide means B for guiding the produced combustion gas to the mixing area A
Configured. In this combustion chamber 2, the combustion from the dry zone 6
When the burning zone 7 and the post-combustion zone 8 constitute the primary combustion region R1
Both are mixing regions provided immediately after the primary combustion region R1.
Introduce combustion gas from combustion zone 7 and post-combustion zone 8 to A
Then, the reducing gas generated from the dry zone 6 is mixed with stirring.
Opposite the mixing area A, which is the inlet throat to the flue 12
Secondary to supply secondary air as secondary combustion gas to the wall
The air supply means C is formed, and the secondary air supply means C is emptied.
The secondary air is mixed with the air supply direction toward the mixing area A.
It As a result, unburned gas such as carbon monoxide CO
And secondary air to promote agitation and to mix the mixed combustion gas
It is introduced into the flue 12 and the primary combustion region R1
Nitrogen oxide NO _XWhile suppressing the occurrence of
Secondary combustion is performed to completely burn unburned gas.
In this way, the secondary combustion region R2 is formed in the flue 12.
The tip of the ceiling wall of the combustion chamber 2 as the guide means B described above.
Is on the dry zone 6 side of the boundary between the combustion zone 7 and the dry zone 6.
Combustion gas from the combustion zone 7
Are prevented from flowing directly into the flue 12. And
Above the protruding portion of the ceiling wall, the secondary air supply means
Since there is C, it is possible to suppress the inclusion of the combustion gas.

Another embodiment will be described below. (A) As the secondary combustion gas, combustion exhaust gas, water vapor, or combustible gas can be applied in addition to air. (B) As the guide means B, the ceiling wall of the combustion chamber 2 is used as it is, but a dedicated guide body may extend from the ceiling wall. (C) As the secondary air supply means C, nozzles may be inserted from a plurality of directions and the ejection directions of the nozzles may be arranged so as to generate a vortex flow. (D) In the case of treating the incineration object, the combustion zone 7 and the post-combustion zone 8 are arranged on the lower transfer side of the drying zone 6 for processing, but it is located on the lower transfer side of the drying zone 6. The combustion zone 7 alone may be used. Alternatively, the combustion zone 7 may be divided into a plurality of parts. The guide means B guides the combustion gas generated from the combustion zone 7 and thereafter in accordance with the configuration of the combustion zone 7 and the post-combustion zone 8 arranged on the transport lower side of the combustion zone 7 configured as described above. You may

It should be noted that reference numerals are given in the claims for convenience of comparison with the drawings, but the present invention is not limited to the structures of the accompanying drawings by the entry.

[Brief description of drawings]

[Fig. 1] Overall configuration of the incinerator

[Fig. 2] Conventional configuration diagram of incinerator

[Explanation of symbols]

 6 Dry Zone 7 Combustion Zone A Mixing Area B Guide Means C Secondary Combustion Gas Supply Means R1 Primary Combustion Area R2 Secondary Combustion Area

Claims (2)

[Claims] 1. A drying zone (6) for drying an incineration object thrown into a furnace while conveying it, and a combustion zone (7) for burning the incineration object conveyed from the drying zone (6). An incinerator having a primary combustion region (R1) provided therein and a secondary combustion region (R2) in which the combustion gas generated in the primary combustion region (R1) is completely burned by supplying a secondary combustion gas. The dry zone (6) on the upper side of the secondary combustion region (R2)
A mixing region (A) for mixing the reducing gas generated from the dry zone (6) with the combustion gas generated from the combustion zone (7), and from the combustion zone (7). An incinerator in which a guide means (B) for guiding the generated combustion gas to the mixing area (A) is formed. 2. The upstream side of the secondary combustion region (R2),
A secondary combustion gas supply means (C) is provided, and the combustion gas guided by the guide means (B) in the jet direction of the secondary combustion gas in the supply means (C) is mixed in the mixing area (A). The incinerator according to claim 1, which is set in a direction in which the air is blown into the furnace.