JPH0221120A - Garbage incineration method - Google Patents

Abstract

PURPOSE:To reduce the damage on a furnace wall in an unburnt substance combustion chamber and improve durability by supplying partial combustion air to the lower side of a fire grate and carbon combustion air to the bottom of an unburnt substance combustion furnace respectively, and increasing/decreasing the quantity of both the partial combustion air and the carbon combustion air. CONSTITUTION:When a waste A is thrown into a partial combustion chamber 13 of a primary combustion furnace 1, air is supplied from an air supply port 16, and the waste A is ignited by an ignition burner 25, unburnt substances, such as carbon drop from a fire grate 12 consecutively into an unburnt substance combustion chamber 14 as the partial combustion advances. When the temperature in a combustible gas outlet 4 rises gradually, in keeping with the progress in the partial combustion, a flow rate control valve 24 for an air supply pipe 18 is opened by way of a control unit 20 so as to supply air to the bottom of the unburnt substance combustion chamber 14. Therefore, an unburnt substance B in the combustion chamber 14 starts carbon combustion. When the temperature is increased to a certain degree inside the chamber 14, the flow rate control valve is closed so as to inhibit the carbon combustion of the unburnt substances. It is, therefore, possible to prevent the generation of clinkers inside the unburnt substance combustion chamber and improve durability as well.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an incinerator for incinerating industrial and municipal wastes containing synthetic resins, rubber, and the like.

[Problems to be solved by conventional technology and inventions] When incinerating industrial/municipal waste containing synthetic resins, rubber, etc., it has recently become necessary to achieve almost complete lean reduction of harmful gases generated during incineration; In order to improve the durability of the combustion furnace by lowering the combustion temperature, the waste is
It is partially combusted and gasified in the primary combustion furnace, and then
The so-called dry distillation gasification and incineration method is used, in which the combustible gas generated in the primary combustion furnace is guided into the secondary combustion furnace, where it is completely combusted by mixing with secondary combustion air. .

The conventional primary combustion furnace used in this dry distillation gasification and incineration method, for example, as described in Japanese Patent Publication No. 55-44283, has a rostre formed at the bottom of the primary combustion furnace. Air for combustion was supplied to the lower part of the combustion chamber, and the waste was partially combusted on the rostrum, and after the partial combustion, the unburnt material was combusted with carbon.

However, this system simultaneously supplies the air necessary for partial combustion of waste and the air necessary for carbon combustion of unburned material after partial combustion to the bottom of the rostle. Following the progress of partial combustion of the waste, carbon combustion of the unburned material occurs after this partial combustion, so that the partial combustion of the waste and the carbon combustion of the unburned material are mutually promoted, resulting in a significantly high temperature. As a result, incombustible materials such as glass and metals contained in waste condense, and so-called clinker, which condenses incineration ash by melting alkali salts contained in waste, rapidly grows. Combustion is often inhibited, and the durability of the primary combustion furnace is reduced. Moreover, a phenomenon occurs locally where partial combustion of waste and carbon combustion in unburned materials are mutually promoted. However, in the layer of waste fed into the primary combustion furnace, cavities are formed in areas where partial combustion of waste and carbon combustion of unburned materials are mutually promoted locally, and eventually combustion occurs. Since the air used for combustion blows through this cavity, it becomes impossible to control the combustion of the waste to a state of partial combustion.

Therefore, Japanese Patent Publication No. 58-24473 discloses that when waste such as rubber is partially combusted in the secondary combustion furnace and then carbon combustion of the unburned material after this partial combustion is performed, Providing eight rostles in the partial combustion chamber in the upper part and the unburnt combustion chamber in the lower part,
Partial combustion of the waste in a partial combustion chamber on the rostol,
It is proposed that the unburned materials after this partial combustion be sequentially dropped into the unburned materials combustion chamber below the rostre, so that carbon is burned in this unburned materials combustion chamber. Since the partial combustion and the carbon combustion of unburned materials are performed separately, the phenomenon in which the combustion is mutually promoted is reduced, and the occurrence of cavities can be reduced.

However, on the other hand, in this case, the air necessary for combustion, that is, the air necessary for partial combustion of the waste section and the air necessary for carbon combustion of unburned materials, is collected and brought together into the unburned material combustion chamber. The air required for carbon combustion of unburned materials and the air required for partial combustion of waste are simultaneously supplied into the unburned materials combustion chamber. The carbon combustion of unburned materials becomes active due to the air for partial combustion, and the combustion temperature during carbon combustion becomes significantly high. During the carbon combustion of unburned materials, clinker grows rapidly and Not only does this hinder the combustion of the fuel, but it also makes it extremely difficult to remove the residual ash.Furthermore, the high temperature of the unburned combustion chamber increases the damage to the furnace wall in the unburned combustion chamber, which can cause serious damage to the furnace wall. This resulted in a decrease in durability.

In addition, the amount of air required for partial combustion of waste and the amount of air required for carbon combustion of unburned materials are different for wastes such as synthetic resins where the gasification component is less than the carbon component, and for wastes such as rubber. This is different in the case of waste containing more carbon than gasified components, so as mentioned above, the air necessary for partial combustion and the air necessary for carbon combustion of unburned materials are simultaneously supplied to the unburned material combustion chamber. Another problem with the type of fuel that is supplied to the bottom of the waste is that if the component ratio of the waste changes, it is difficult to optimize the partial combustion state and carbon combustion state according to the component ratio. there were.

The present invention aims to solve the problems of the conventional dry distillation gasification incinerator.

[Means to solve the problem]

To achieve this object, claim 1 provides a primary combustion furnace for partially burning and gasifying waste, and a secondary combustion furnace for completely burning the combustible gas gasified in the primary combustion furnace. An incinerator is provided in the primary combustion furnace, the inside of the primary combustion furnace being divided into a partial combustion chamber in the upper part and an unburned material combustion chamber in the lower part. an air supply means for partial combustion to the lower surface of the rostre;
It is composed of an air supply means for carbon combustion to the bottom of the unburned material combustion chamber.

In addition to the above-mentioned claim 1, a second aspect of the present invention provides that, in addition to the first aspect, the air supply means for partial combustion to the lower surface of the rosttle is configured such that when the outlet temperature of the secondary combustion furnace becomes high, an amount of air is increased to the lower surface of the rosttle. A control means configured to reduce the amount of air supplied to the bottom of the unburned combustion chamber for carbon combustion is provided with a control means configured to reduce the amount of air supplied to the bottom of the unburned combustion chamber when the temperature of the unburned combustion chamber becomes high. A configuration is adopted in which each control means is provided to reduce the amount.

[Action/effect of the invention]

As in claim 1, the air necessary for partial combustion of waste is supplied to the bottom of the rostre, while the air necessary for carbon combustion of unburned materials after partial combustion is supplied to the bottom of the unburnt combustion chamber. When supplied, the air required for partial combustion does not pass through the point where the carbon of the unburnt material is combusted, and in other words, the carbon combustion of the unburned material is not promoted by the air required for the partial combustion. , since carbon combustion of unburned materials can be performed only by the carbon combustion air supplied to the bottom of the unburned material combustion chamber, the temperature during carbon combustion of unburned materials is lower than that of the air for partial combustion. It is possible to avoid rising to

Moreover, the air for partial combustion is supplied to the bottom of the rostor, and the air for carbon combustion is supplied to the bottom of the unburned material combustion furnace, and the amount of air for both can be increased or decreased separately. In the case of waste that has more gasified components, such as resin, by increasing the amount of air for partial combustion and decreasing the amount of air for carbon combustion. In the case of waste with a large amount of carbon, reduce the amount of air for partial combustion and increase the amount of air for carbon combustion.
The state of partial combustion and the state of carbon combustion can be accurately adjusted according to the component ratio of the waste.

According to claim 1, since it is possible to suppress the increase in combustion temperature during carbon combustion of unburned materials, damage to the furnace wall in the unburned materials combustion chamber can be reduced and its durability can be improved. At the same time, it is possible to prevent the generation of talin force during carbon combustion of unburned materials, avoid the inhibition of carbon combustion due to the generation of talin carbon, and improve the ease of removing the incineration ash. Since the state of carbon combustion and the state of carbon combustion can be adjusted accurately according to the component ratio of waste, when the component ratio of waste changes, the state of partial combustion and carbon combustion corresponding to the component ratio can be adjusted accurately. In other words, it has the effect of being able to reliably respond to changes in the component ratio of waste.

On the other hand, according to claim 2, if the amount of combustible gas generated increases due to the partial combustion of waste in the partial combustion chamber in the primary combustion furnace and the outlet temperature of the secondary combustion furnace becomes high, the lower surface of the rostor By reducing the amount of air for partial combustion, the partial combustion of waste is suppressed, and the outlet temperature of the secondary combustion furnace can be prevented from increasing further, improving the durability of the secondary combustion furnace. In addition, when the heat contained in the exhaust gas from the secondary combustion chamber is recovered by a heat recovery device such as a boiler, fluctuations in the heat load on the heat recovery device can be reduced. During carbon combustion of unburned materials in the combustion chamber, if the temperature of the unburned materials combustion chamber increases, the amount of air for carbon combustion at the bottom of the unburned materials combustion chamber decreases, suppressing carbon combustion. , Since the temperature of the unburned material combustion chamber can be prevented from becoming higher than that, it is possible to prevent the generation of coal in the unburned material combustion chamber;
And it is possible to more effectively achieve the improvement of the durability of the unburnt combustion chamber.

〔Example〕

Hereinafter, embodiments of the present invention will be explained with reference to the drawings. In the drawings, reference numeral 1 indicates a primary combustion furnace equipped with a waste inlet 3 and a combustible gas outlet 4 at the upper part, and reference numeral 2 indicates a secondary combustion furnace. Each secondary combustion furnace is shown including a burner 26 and a secondary combustion air supply nozzle 6 from the blower 5, and the primary combustion furnace l
The combustible gas outlet 4 in the upper part of the secondary combustion furnace 2
The combustion gas output lower connected to the upper part of the secondary combustion furnace 2 and the lower part of the secondary combustion furnace 2 is connected to the chimney 11 via a dust collector 8, a heat recovery device 9 such as a boiler, and an exhaust blower 10. . Note that a shutter 3 is provided at the waste input port 3.
a and a lid 3b, and by opening the lid 3b with the shutter 3a closed and introducing waste into the input port 3, and then opening the shutter 3a with the lid 3b closed,
The waste is configured to fall into the primary combustion furnace 1.

A movable rotor 12 that swings and rotates is provided approximately in the middle of the primary combustion furnace 1, so that the inside of the primary combustion furnace 1 can be divided into a partial combustion chamber 13 above the rostrtle 12 and a partial combustion chamber 13 above the rostrtle 12. 12 and an unburned material combustion chamber 14 below.

An air supply port 16 for partial combustion from the blower 15 is opened at the bottom of the rostre 12, while an air supply pipe 18 for carbon combustion from the blower 17 is opened at the bottom of the unburned material combustion chamber 14. will be established.

The air supply port 16 for partial combustion has a flow rate control valve that is controlled to open and close via the control unit 20 based on the temperature Tl detected by a thermometer 19 attached to the lower combustion gas outlet from the secondary combustion furnace 2. 21 will be provided. Further, in the air supply pipe 18 for carbon combustion, a thermometer 22 attached to the combustible gas outlet 4 in the primary combustion furnace 1 and a thermometer 23 attached to the upper part of the unburned material combustion chamber 14 are connected. A flow rate control valve 2 whose opening and closing are controlled via a control unit 20 according to the detected temperature.
4 will be provided.

Waste A is put into the partial combustion chamber 13 of the primary combustion furnace 1, and when the waste A is ignited with the ignition burner 25 while air is supplied from the air supply port 16 for partial combustion, the waste A The gasified components in the inside are gasified by partial combustion to generate combustible gas, and this combustible gas is led into the secondary combustion furnace 2 via the combustible gas outlet 4, and the secondary combustion furnace 2 After being mixed with secondary air from the air supply nozzle 6 in the air supply nozzle 6 and almost completely combusted by the secondary combustion burner 26, the combustion gas is removed from the lower dust collector 8.
, the exhaust gas is discharged to the chimney 11 via the heat recovery device 9 and the exhaust blower lO, and in this case, the temperature at which the outlet temperature T1 at the combustion gas output lower is reached (for example, about 100
0° C.), the flow rate control valve 21 in the air supply port 16 for partial combustion closes its opening via the control unit 1-20 to suppress partial combustion of the waste A. Accordingly, the outlet temperature T1 at the combustion gas output lower is automatically controlled so as not to become higher than this.

On the other hand, as the partial combustion of the waste A progresses in the partial combustion chamber 13, unburned materials such as carbon sequentially fall from the rostrum 12 to the unburned material combustion chamber 14 located below it.

As this partial combustion progresses, the temperature T2 at the combustible gas outlet 4 from the primary combustion furnace 1 gradually increases. By swinging and rotating the
20, the flow rate control valve 24 for the carbon combustion air supply pipe 18 is automatically opened and operated.

Then, since air is supplied to the bottom of the unburned material combustion chamber 14, the unburned material B that has fallen into the unburned material combustion chamber 14 starts carbon combustion. Temperature T3 at which the temperature inside the combustion chamber 14 becomes (for example, about 60
0°C), via the control unit 20,
Flow control valve 2 for the air supply pipe 18 for carbon combustion
4 is closed to suppress carbon combustion of unburned materials, the temperature T3 of the unburned material combustion chamber 14 is automatically controlled so as not to rise any higher.

Then, when the partial combustion and carbon combustion further progress,
By swinging and rotating the rostol 12, unburned materials are dropped and there is no waste on the rostrum 12, so when there is little left, new waste can be thrown into the partial combustion chamber 1 from the input port 3. , new waste is partially combusted by the heat of carbon combustion in the unburned material combustion chamber 14.

Note that new waste is introduced before and after the time when the control valve 24 for the air supply pipe 18 for carbon combustion is operated according to the temperature T2 at the combustible gas outlet 4 from the primary combustion furnace 1. You can do it like this.

[Brief explanation of the drawing]

The drawings are diagrams showing embodiments of the invention. 1...Primary combustion furnace, 2...Secondary combustion furnace, 3...
...Waste inlet, 4...Combustible gas outlet, 6...
・Air supply nozzle for secondary combustion, 11...Chimney, 12
...Rostle, 13...Partial combustion chamber, 14...
... Unburned material combustion chamber, 16... Air supply port for partial combustion, 18... Air supply pipe for carbon combustion, 19, 22
．． 23...Thermometer, 20...Control unit, 2
1.24...Flow rate control valve.

Claims (2)

[Claims] (1) Consisting of a primary combustion furnace for partially burning and gasifying waste, and a secondary combustion furnace for completely burning the combustible gas gasified in the primary combustion furnace, the primary combustion furnace In an incinerator, the incinerator is provided with a rostre that divides the inside of the primary combustion furnace into a partial combustion chamber in the upper part and an unburned material combustion chamber in the lower part, the supply of combustion air into the primary combustion furnace. A waste incineration apparatus characterized in that the means is comprised of an air supply means for partial combustion to the lower surface of the rostre and an air supply means for carbon combustion to the bottom of the unburned material combustion chamber. (2) Consisting of a primary combustion furnace for partially burning and gasifying waste, and a secondary combustion furnace for completely burning the combustible gas gasified in the primary combustion furnace, the primary combustion furnace In an incinerator, the incinerator is provided with a rostre that divides the inside of the primary combustion furnace into a partial combustion chamber in the upper part and an unburned material combustion chamber in the lower part, the supply of combustion air into the primary combustion furnace. The means includes an air supply means for partially burning waste to the lower surface of the roost and an air supply means for burning unburned carbon to the bottom of the unburned combustion chamber, The air supply means for partial combustion to the bottom of the unburnt combustion chamber is provided with a control means that reduces the amount of air to the bottom of the rooster when the outlet temperature of the secondary combustion furnace becomes high. A waste product characterized in that each of the air supply means for carbon combustion is provided with a control means that reduces the amount of air to the bottom of the unburned combustion chamber when the temperature of the unburned combustion chamber increases. Incinerator.