JP3494890B2 - Waste incineration equipment and incineration method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refuse incinerator equipped with a dioxin decomposing device and a refuse incineration method.

[0002]

2. Description of the Related Art When incinerating dust (paper waste, wood waste, waste cloth, vinyl chloride, etc.), in order to reduce the amount of dioxin emission, the combustion chamber is kept at a temperature of 800 ° C. or higher for at least 2 seconds with the exhaust gas blocked from the outside Therefore, it is known that an auxiliary combustion device is provided for this purpose, dioxin-reduced exhaust gas is cooled to 200 ° C. or lower, and soot and dust are removed from the cooled exhaust gas and released.

Japanese Unexamined Patent Publication (Kokai) No. 10-68515 discloses a high temperature in the middle of a combustion chamber of a refuse incinerator for incinerating refuse such as general waste and industrial waste, and a gas cooling facility installed downstream thereof. A reburn chamber is provided to reburn unburned gas,
In a refuse incinerator in which gas mixing means is provided at the bottom of the reburn chamber, a reflection wall provided at the top of the reburn chamber,
A first oxygen control unit for controlling the oxygen concentration and supply amount of the tertiary combustion air supplied to the reburn chamber or the gas mixing means so that the temperature in the reburn chamber is maintained within a preset specified range.
A dioxin removing device in a refuse incinerator, which is characterized by comprising a control means.

Further, in Japanese Patent Application Laid-Open No. 8-247423, the combustion efficiency of the incinerator in the combustion chamber of the refuse incinerator is increased, and the unburned gas is completely burned to generate toxic gases such as CO and NOx. A waste incinerator is described which reduces the amount of dioxin and thermally decomposes dioxins in exhaust gas to suppress the generation thereof.

[0005]

The combustion chamber has been kept at a high temperature in order to reduce dioxin emissions. For this reason, an auxiliary burner has been conventionally used. According to this method
Although it is possible to reduce the amount of dioxin emission, not only was the operating cost high because the combustion method by the burner burner was used to generate high temperature gas, but it was also supposed to generate NOx. .

In view of the above points, the present invention reduces operating costs in reducing dioxin emissions, and NO
It is an object of the present invention to provide a waste incineration facility and a waste incineration method that suppress the generation of x.

[0007]

According to the present invention, the exhaust gas is uniformly burned by a catalytic combustion method instead of a burner, and the exhaust gas is heated at 800 ° C. for 2 hours.
It is characterized by decomposing dioxin by allowing it to stay for a second. Further, the uniform combustion method homogenizes the temperature in the furnace and partially raises the temperature, thereby increasing NOx.
The feature is that it suppresses the occurrence of a condition that is generated.

Further, the present invention is characterized in that the exhaust gas is cooled all the way to 200 ° C. to prevent its regeneration and that the catalyst decomposes undecomposed dioxin.

That is, the dioxin decomposition catalyst method used in the present invention decomposes dioxin contained in gas into water and carbon dioxide by causing a chemical reaction when, for example, a titanium oxide catalyst and exhaust gas come into contact with each other. It is what makes me.

In the catalytic combustion method adopted in the present invention, fuel and air (oxygen) are brought into contact with each other on the surface of the catalyst by the action of the catalyst to perform complete combustion.
It is activated above ℃ and has the same function as a catalyst. Here, it is treated as a catalyst.

By doing so, uniform combustion can be achieved by the catalytic combustion method, and high-temperature gas of low NOx (8
00 ° C.) can be supplied to the secondary combustion chamber.

The present invention specifically provides the following apparatus and method.

According to the present invention, in a refuse incinerator in which waste is primarily burned and further secondary burned to decompose dioxin, dust is removed and exhaust gas is discharged, a primary combustion chamber for primarily burning the waste, A catalytic combustor that combusts unburned components from the primary combustion chamber by a catalytic action, a secondary combustion chamber that decomposes dioxin by secondary combustion with a gas whose temperature is raised by catalytic combustion, and the secondary combustion chamber is exited. There is provided a refuse incineration facility including a desuperheater for cooling the gas and a dust remover for removing dust from the cooled gas.

According to the present invention, in a refuse incineration facility in which waste is primarily burned and further secondary burned to decompose dioxin, dust is removed and exhaust gas is discharged, a primary combustion chamber for primarily burning the waste, An incinerator comprising a catalytic combustion chamber in which unburned components from the primary combustion chamber are burned by a catalyst, and a secondary combustion chamber in which a gas whose temperature has been raised by catalytic combustion is secondarily burned to decompose dioxin, and An exhaust gas treatment device including a flue portion integrally provided in the incinerator, a desuperheater provided in the flue portion, and a catalyst device for decomposing undecomposed dioxin Provide garbage incineration equipment.

According to the present invention, in a refuse incineration method in which waste is subjected to primary combustion and further secondary combustion to decompose dioxin, dust is removed and exhaust gas is discharged, primary combustion of the waste and primary combustion Provided is a waste incineration method including a step of catalytically burning unburned components in the step, and a secondary combustion step of secondary combustion with a gas whose temperature is raised by catalytic combustion to decompose dioxin.

The present invention is a refuse incineration method in which waste is primarily burned and then secondary burned to decompose dioxin, dust is removed and exhaust gas is discharged, and the unburned fuel is burned to burn unburned fuel. A step of forming the fuel, a step of burning the fuel while suppressing the NOx generation condition by the presence of a catalyst, a step of decomposing dioxin by retaining a combustion gas, and a step of cooling and discharging the exhaust gas. A waste incineration method that includes the above is provided.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the overall construction of the refuse incineration facility.
In the figure, the equipment includes a primary combustion chamber 2 and a secondary combustion chamber 3
An incinerator 1 having the above, a desuperheater 5 provided in a flue 4 through which exhaust gas exiting the secondary combustion chamber 3 passes, an exhaust gas treatment facility 7, and a chimney 10. The combustion residue remaining in the primary combustion chamber 2 is taken out and cemented in the ash cement solidifying equipment 11.

The exhaust gas drawn from the primary combustion chamber 2 through the bypass passage 12 is first of all the cyclone separator 1.
The dust is removed by 3 and is guided to the catalytic combustor 14. Here, the unburned gas is uniformly burned by the catalytic action. The catalytic combustion method enables uniform combustion, and high-temperature gas with low NOx (10
00 ° C.) is supplied to the secondary combustion chamber 3.

The secondary combustion chamber 3 is constructed as a combustion chamber capable of burning at 800 ° C. or higher, and can retain gas at 800 ° C. or higher for 2 seconds or longer. In this case, the outside air is cut off.

The desuperheater 5 has the ability to cool the combustion gas to 200 ° C. or less at a stroke, and prevents the regeneration of dioxin.

The exhaust gas treatment facility 7 is composed of a dust filter 8 and a catalyst layer 9, and removes dust in the exhaust gas and decomposes it with the undecomposed dioxin catalyst layer 7.

Dioxins in the exhaust gas are decomposed into CO ₂ and H ₂ O by the action of the catalyst used in the catalytic combustion method and the catalyst used in the exhaust gas treatment facility 7. The undecomposed dioxin discharged when the temperature temporarily drops is also decomposed and removed by the catalyst layer 9.

As described above, according to this embodiment, incineration of refuse requires high-temperature combustion and two-stage treatment with a catalyst, so that the amount of dioxin discharged is extremely small.

FIG. 1 is a diagram when a general refuse incinerator 1 is newly provided, while FIG. 2 is a diagram when the incinerator 2 is modified. In the figure, the primary combustion chamber 2 is larger than the secondary combustion chamber 3 when the incinerator 1 is already installed. The secondary combustion chamber 3 is modified so that the bypass passage 12 is provided from the primary combustion chamber 2 through the upper portion of the secondary combustion chamber 3. Other configurations are substantially the same as those in FIG. 1, and will not be described repeatedly.

FIG. 3 shows an equipment suitable for incinerating a large amount of refuse in another embodiment. Basically, it is the same as the equipment configuration shown in FIG. The incinerator 201 is the primary combustion chamber 20.
2. A secondary combustion chamber 203 is provided. An air supply device 204 and a dust throwing device 205 are connected to the primary combustion chamber 202. From the primary combustion chamber 202 to the cyclone separator 20
After passing through 6, the catalyst is combusted uniformly in the catalytic combustor 207 to reach a high temperature and is charged into the secondary combustion chamber 203. Catalytic combustor 207
Oil from the oil tank 208 is supplied to the pump 209 and the valve 2
10 through the air supply fan 211, the valve 21
It is put in by 2 and the performance of the catalyst is improved by its combustion.

The secondary combustible material 203 is kept at a temperature of 800 ° C. or higher for 2 seconds or more in a state of being shielded from the outside air to decompose dioxin.

Dioxin decomposed gas is flue 21
3 to the cooling device (cooling device) 214. Water from the cooling water tank 215 is showered in the cooling device 214, and the gas is cooled to 200 ° C. or less at once. The cooled gas passes through the flue 216 and is introduced into the catalyst tower (with a dust filter) 217, where undecomposed dioxin is decomposed. The gas reduced in dioxin due to the catalytic action passes through the flue 218 and is discharged from the smoke chamber 219 to the atmosphere.

The gas temperature 222 and the dioxin concentration (indirect measurement) by the CO meter 223 are input to the control panel 221, and the input oil and the supply air amount are controlled.

The incineration ash is discharged from the bottom of the primary combustion chamber 202, stored in the storage device 241, treated by the dust treatment device 242 at any time, and charged into the ash melting furnace 243 for treatment.

[0031]

EFFECTS OF THE INVENTION According to the present invention, since the high temperature gas which has been catalytically uniformly burned is supplied to the secondary combustion chamber, 80% of exhaust gas is supplied to the secondary combustion chamber without requiring special fuel.
At a high temperature of 0 ° C. or higher, it can be retained for 2 seconds or longer, so that dioxin can be effectively decomposed and the operating cost can be reduced. Moreover, low NOx can be maintained.

Further, according to the present invention, the undecomposed dioxin is decomposed by the catalyst before being discharged into the atmosphere, so that the dioxin released can be remarkably small.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing an overall configuration of an embodiment of the present invention.

FIG. 2 is an overall configuration diagram showing another example.

FIG. 3 is a system diagram of another embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Incinerator, 2 ... Primary combustion chamber, 3 ... Secondary combustion chamber, 4 ... Flue, 5 ... Desuperheater, 7 ... Exhaust gas treatment equipment, 8 ... Dust filter, 9 ... Catalyst layer, 10 ... Chimney, 11 … Ash cement and solidification equipment, 12… Bypass, 13… Cyclone separator,
14 ... Catalytic combustor.

Front Page Continuation (72) Inventor Takashi Kimura 3-2-2 Sachimachi Hitachi City, Ibaraki Prefecture Hitachi Engineering Service Co., Ltd. (72) Inventor Akira Kato 7-1-1 Omikacho, Hitachi City, Ibaraki Prefecture Co., Ltd. Hitachi, Ltd., Hitachi Research Laboratory (56) Reference JP-A-7-310914 (JP, A) JP-A-7-301410 (JP, A) JP-A-6-288521 (JP, A) JP-A-11-193909 ( (58) Fields surveyed (Int.Cl. ⁷ , DB name) F23G 5/16 F23G 5/027 F23G 5/14 F23G 7/06

Claims (4)

(57) [Claims] 1. A primary combustion chamber in which waste is primarily burned in a waste incineration facility in which waste is primarily burned and then secondary burned to decompose dioxin, and dust is discharged to release exhaust gas. A catalytic combustor that combusts unburned components from the combustion chamber by a catalytic action, a secondary combustion chamber that decomposes dioxin by secondary combustion with a gas whose temperature is raised by catalytic combustion, and a gas that exits the secondary combustion chamber. A waste incineration facility, comprising: a desuperheater for cooling the air, and a dust remover for removing dust from the cooled gas. 2. In a refuse incineration facility in which waste is primarily burned and then secondary burned to decompose dioxin, and dust is discharged to discharge exhaust gas, a primary combustion chamber for primarily burning the waste and the primary combustion chamber. An incinerator comprising a catalytic combustion chamber in which unburned components from the combustion chamber are burned by a catalyst, and a secondary combustion chamber in which secondary combustion is performed with a gas whose temperature has been raised by catalytic combustion to decompose dioxin, and the incinerator. The flue part that is integrally provided in
A waste incineration facility comprising an exhaust gas treatment device comprising a desuperheater provided in the flue portion and a catalyst device for decomposing undecomposed dioxin. 3. A refuse incineration method in which waste is subjected to primary combustion and further secondary combustion to decompose dioxin, dust is removed, and exhaust gas is discharged, and a step of performing primary combustion of waste and a step of primary combustion 2. A waste incineration method, comprising: a step of catalytically burning unburned components of the above, and a secondary combustion step of secondary burning with a gas whose temperature is raised by catalytic combustion to decompose dioxin. 4. In a refuse incineration method in which waste is primarily burned and then secondary burned to decompose dioxin, and dust is discharged to discharge exhaust gas, the waste is primarily burned to form unburned fuel. A step of combusting the fuel while suppressing NOx generation conditions in the presence of a catalyst, a step of retaining combustion gas to decompose dioxin, and a step of cooling and discharging exhaust gas. A waste incineration method characterized by being configured.