JP2761187B2 - Garbage incinerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waste heat boiler for generating steam from heat generated by incineration of refuse, a combustion type superheater for superheating the steam generated in the waste heat boiler, and a combustion type superheater.
The present invention relates to a refuse incinerator provided with a power generator for generating power using superheated steam generated by a vessel and supplying cooling gas to a furnace wall surface facing a combustion zone of refuse to form the furnace wall as an air-cooled wall.

[0002]

2. Description of the Related Art A refuse incinerator equipped with such a combustion-type superheater can increase power generation efficiency by superheating steam generated from a waste heat boiler, and can reduce waste disposal conditions. Even with a change in the amount of steam from the waste heat boiler that fluctuates, stable power generation can be performed, for example, by performing water supply and steam supply operations using a combustion type superheater . On the other hand, with respect to the furnace wall, by supplying a cooling gas to the furnace wall surface and forming it as an air-cooled wall, it is possible to effectively prevent the clinker from adhering to the furnace wall surface, and furthermore, to prevent the furnace center from being located inside the wall. By blowing the cooling gas to the side, the position of the flame in the combustion zone can be controlled. Conventionally, as such furnace wall cooling gas, outside air has been suctioned from outside the furnace and used.

[0003]

However, according to the above-mentioned prior art, since air containing about 20% of oxygen is used as a cooling gas, thermal NOx due to this oxygen component is easily generated. Accordingly, it is an object of the present invention to provide a refuse incinerator that can effectively prevent clinker from being caught on a furnace wall and generates less NOx.

[0004]

In order to achieve the above object, a refuse incinerator according to the present invention is characterized in that exhaust gas discharged from a combustion type superheater is used as a cooling gas as a cooling gas on the surface of the furnace wall. In that it has an exhaust gas introduction path leading to the exhaust gas. Further, in the above-described structure, it is preferable that the combustion superheater is fired superheater for the natural gas and fuel gas.

[0005]

The exhaust gas exhausted from the combustion type superheater is guided to the furnace wall surface via the exhaust gas introduction passage, and cools the furnace wall at this location. When considering the air-cooling configuration of the furnace wall, in order to prevent the clinker from adhering, if the furnace wall surface can be maintained at a temperature of about 1000 ° C. or less, the purpose of air cooling can be achieved, and the clinker does not adhere. Since the exhaust gas temperature of the combustion type superheater is generally about 150 ° C., a sufficient air cooling effect can be obtained by introducing the exhaust gas to the furnace wall surface through the exhaust gas introduction passage. Furthermore, these exhaust gases have a relatively low oxygen content because they are gases after combustion,
As a result, it does not contribute to the generation of NOx in the furnace. Furthermore, when the combustion type superheater is a combustion type superheater using natural gas as a fuel gas, the exhaust gas from the combustion type superheater is very clean, and does not adversely affect the furnace wall. .

[0006]

As a result, it is possible to provide a refuse incinerator which can effectively prevent the clinker from being caught on the furnace wall and generates less NOx from the furnace.

[0007]

Embodiments will be described below. As shown in FIG. 3, the refuse incinerator is provided with a pusher 2 at the bottom of the hopper 1 for depositing the municipal garbage, which is the incineration material deposited on the hopper 1, and the trash supplied by the pusher 2 is stored in a stoker type. A drying zone 3, a combustion zone 4, and a post-burning zone 5, which are transported by the transport mechanism S, are provided in series, an ash pit 6 for accumulating incinerated trash is provided, and a flue 7 is provided above the combustion zone 4. A waste heat boiler 8 that forms a secondary combustion region and recovers waste heat from exhaust gas exhausted from the flue 7 to generate steam;
An exhaust gas treatment device 9 for removing harmful substances from the exhaust gas passing through the waste heat boiler 8 and a chimney 10 for exhausting the treated exhaust gas are provided.
There is provided a generator 11 for generating power by the steam generated in the above. Here, between the waste heat boiler 8 and the generator 11, L
A combustion type superheater 80 using NG as a fuel gas is provided, and the steam generated from the waste heat boiler 8 is superheated and supplied to the generator 11, thereby improving the thermal efficiency of the power generation system. Have been. Furthermore, this combustion type superheater 8
Numeral 0 is provided with a steam enrichment mechanism (not shown), and when the steam amount from the waste heat boiler 8 is reduced according to the operation state of the furnace, steam is replenished to generate a constant load power generation over time. The configuration is such that it can be performed stably.

[0008] Blower fan 1 for sucking air from outside the furnace
5, a supply path 16a for supplying the sucked air from below the drying zone 3, the combustion zone 4, and the post-combustion zone 5 as air for primary combustion, and a damper 17 for adjusting the supply amount to these. A primary combustion air supply mechanism A is provided.

As shown in FIGS. 1 and 2, the combustion zone 4
Cooling wall 12 divided into two stages in the transport direction along
a, 12b are arranged to form a furnace wall 12, and each air cooling wall 12
For each of the cooling walls 1 and 12b, the combustion exhaust gas from the combustion type superheater 80 is used as a cooling gas by the blower fan 150.
A supply path 16b for supplying the cooling gas to the air cooling walls 12a and 12b is provided, and dampers 13a and 13b are provided as first flow rate adjusting means 13 for adjusting the inflow of the cooling gas. Passage 12c,
Dampers 14a and 14b are provided as second flow rate adjusting means 14 for adjusting the flow rate of the cooling gas into the furnace via 12d. That is, a part or all of the exhaust gas from the combustion type superheater 80 is guided to the furnace wall surface 120 depending on the adjustment state of the first flow rate adjusting means 13 and the second flow rate adjusting means 14, and this wall surface is placed inside the furnace. A configuration that cools down from above is adopted. At this time, the furnace wall surface 120 is
The flow path for guiding the exhaust gas as the cooling gas is referred to as an exhaust gas introduction path. Here, the temperature of the cooling gas blown to the furnace wall surface 120 has dropped to about 150 ° C., and since this gas is a gas after combustion, its oxygen concentration is very low. Therefore, the cooling effect prevents the clinker from adhering to the furnace wall, and the N
Ox generation can be reduced, and the life of the furnace wall can be extended.

[0010] In the drying zone 3, the dust introduced by the pusher 2 is conveyed while being dried by the air supplied by the primary combustion air supply mechanism A. In the combustion zone 4, the dust is conveyed from the drying zone 3. The refuse is transported while being burned with the combustion air from the primary combustion air supply mechanism A. In the post-combustion zone 5, the refuse transported from the combustion zone 4 is solid-burned and completely incinerated. I do.

Above the furnace wall 12, a burn-out position detecting means 1 for detecting a burn-off position of the refuse in the combustion zone 4 (meaning a transition point from gas combustion to gas combustion).
A plurality of photoelectric sensors 7 are disposed along the direction of transporting the dust, and detect the burn-out position, that is, the transition point from gas combustion to solid combustion, based on the output level of each sensor. A plurality of other temperature sensors, gas sensors, and the like are arranged in the upper space such as the combustion zone 4 and the like, and their detection data is input to input the amount of dust from the pusher 2 and the dust generated by the transport mechanism S. Transport speed, and
The waste heat boiler 8 is controlled to control a supply amount of combustion air from the primary combustion air supply mechanism A to generate a predetermined power generation amount while incinerating a predetermined amount of dust within a predetermined combustion temperature range. A control means C for adjusting the amount of steam generated in the above is provided.

The burn-out position control for effectively utilizing the garbage incineration area in the combustion zone 4 by adjusting the burn-out position to an appropriate position in order to enhance the refuse incineration efficiency will be described in detail. When the burn-out position is detected by the burn-out position detecting means 17 to be on the upstream side of the combustion zone 4, the control means C controls the air cooling wall 1 on the upstream side.
2a, the first flow rate adjusting means 1
3a to increase the cooling gas inflow and enhance the cooling effect, and to prevent excess cooling gas from flowing out into the furnace through the air passage 12c. To reduce the outflow of cooling air, while increasing the transport speed of refuse in the combustion zone 4 and maintaining the supply of combustion air supplied from below the combustion zone 4,
Alternatively, the burn-off point is moved downstream while maintaining the combustion state by reducing the amount. That is, a part of the control means serves as a flow control means.

Another embodiment will be described below. In the above embodiment, the air cooling wall is divided into two stages before and after. However, the present invention is not limited to this. The cooling wall may be divided into two or more stages.

Further, an example has been described in which dampers are used as the first flow rate adjusting means and the second flow rate adjusting means. However, the present invention is not limited to dampers, and other known mechanisms may be used.

Although the means for detecting the burn-out position of the dust in the combustion zone using the photoelectric sensor has been described above, the invention is not limited to this, and other known mechanisms may be used. For example, the detection may be performed by performing image processing via an industrial television camera, or a plurality of temperature sensors may be arranged in the transport direction.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part.

FIG. 2 is a sectional view of a main part.

FIG. 3 is a schematic configuration diagram of an incinerator.

[Explanation of symbols]

Reference Signs List 4 combustion zone 8 waste heat boiler 11 generator 12 furnace wall 12a, 12b air cooling wall 16b, 12c, 12d exhaust gas introduction path 80 combustion type superheater 120 furnace wall surface

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Satoshi Kuroishi 1-1-1, Hama, Amagasaki-shi, Hyogo Prefecture Inside Kubota Research Institute of Technology (72) Inventor Hiroaki Nikaido 1-1-1, Hama, Amagasaki-shi, Hyogo Shares (56) References JP-A-5-332501 (JP, A) JP-A-53-21301 (JP, A) JP-A-2-122926 (JP, U) (58) Investigated Field (Int.Cl. ⁶ , DB name) F23G 5/44 F22B 1/18 F22G 1/16 F23C 9/08 F23G 5/46

Claims (2)

(57) [Claims] 1. A waste heat boiler (8) for generating steam from heat generated by incineration of refuse, a combustion type superheater (80) for heating steam generated by the waste heat boiler (8), A generator (11) for generating electric power by superheated steam generated by the combustion type superheater (80), and a cooling gas supplied to a furnace wall surface (120) facing a refuse combustion zone; A refuse incinerator in which a wall (12) is configured as air-cooled walls (12a) and (12b), wherein exhaust gas discharged from the combustion type superheater (80) is used as the cooling gas as the cooling gas surface (120). A waste incinerator provided with exhaust gas introduction paths (16b), (12c), and (12d) leading to the exhaust gas introduction path. 2. The refuse incinerator according to claim 1, wherein the combustion type superheater (80) is a combustion type superheater using natural gas as a fuel gas.