JPH06101824A - Melting method for waste refuse - Google Patents

Abstract

PURPOSE:To provide a method for melting waste refuse having a better melting efficiency by a method wherein combustion air is supplied to a main combustion chamber in a pulsation manner and a balance of air volume for pulsation combustion supplied to each of main combustion chamber divided into each of zones is changed. CONSTITUTION:There are provided air supplying holes 29a, 29b and 29c so as to define an inner cylinder 21 of a main combustion chamber 23 into a central annular zone A, an annular zone B around the zone A and an annular zone C around the zone B. Each of entire volume of supplied air at each of pulse is made constant. Dampers 30a, 30b and 30c are controlled through solenoids 38a, 38b and 38c in response to data of air volume transmitted from a flow meter 36 and flow meters 32a, 32b and 32c. Air volume supplied from the air supplying device 31 to the air supplying holes 29a, 29b and 29c is varied. With such an arrangement as mentioned above, the air is blown into the zone C as indicated by an arrow in its circumferential direction, a turbulent flow is generated within the main combustion chamber 3 and a intensity of the turbulent flow is increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to incineration ash after incineration of sewage sludge, municipal waste, etc. after treating municipal wastewater, etc.
The present invention relates to a waste melting method for melting crushed incombustibles and converting them into slag.

[0002]

2. Description of the Related Art A conventional waste melting method will be described below with reference to the drawings. FIG. 4 is a sectional view of a conventional waste melting furnace. The waste melting furnace of this embodiment is a vertical cylindrical rotary furnace in which a main combustion chamber 3 is formed by an inner cylinder 1 and an outer cylinder 2, and a combustion device 4 is provided at the center of the inner cylinder 1 forming the ceiling. Are provided, and the air supply holes 5 are provided in a dispersed manner. Fuel such as kerosene is supplied from the fuel tank 6 to the combustion device 4, and air is supplied from the air supply hole 5 to burn,
It provides a heat source for burning and melting the melted material 7 such as sewage sludge, incineration ash, and crushed incombustible material contained in the main combustion chamber 3. A supply hopper 8 is provided in an upper portion between the inner cylinder 1 and the outer cylinder 2, and is configured to feed the melted material 7 into the main combustion chamber 3. In the lower part of the main combustion chamber 3, the secondary combustion chamber 9
And is configured to completely burn unburned gas. A combustion device 10 for secondary combustion is provided on a side wall of the secondary combustion chamber 9, and a flue 11 for exhausting combustion gas is provided. A slag conveyor 12 is installed below the secondary combustion chamber 9 and is configured to convey the molten slag out of the furnace.

In the above configuration, when the melted material 7 is supplied from the supply hopper 8 to the main combustion chamber 3, the inner peripheral surface side of the melted material 7 is dispersed from the air supply holes 5 and air is supplied. In, the high temperature combustion heat of the combustion device 4 efficiently burns and melts. The material 7 to be melted, which has been burned and melted, is turned into molten slag and continuously flows down from the slag port 13 at the bottom of the furnace together with the high temperature combustion gas. This molten slag is solidified in the pit below the secondary combustion chamber 9 and taken out by the slag conveyor 12 in a safe state. In the secondary combustion chamber 9, the unburned gas that has not been burned in the main combustion chamber 3 is completely burned, exhausted from the flue 11, treated by the smoke exhaust treatment device (not shown), and released to the outside air.

[0004]

However, in the conventional waste melting method as described above, when the combustion air is uniformly supplied to the entire main combustion chamber, the jet speed of the supply air into the furnace decreases, There was a problem that the turbulent flow in the furnace was reduced and the combustion efficiency was reduced.

Further, when supplying a substantially constant amount of combustion air required in the main combustion chamber, for example, if a large amount of air is supplied to the corners of the furnace, the air will be insufficient in the central part of the furnace. There was a problem that combustion efficiency declined due to excess supply and short supply.

[0006] The present invention has been made in order to solve such a conventional problem, and an object thereof is to provide a waste melting method having good combustion efficiency and therefore good melting efficiency.

[0007]

In order to solve the above problems, in the waste melting method of the present invention, combustion air is supplied in pulses to the main combustion chamber.

Further, in the waste melting method of the present invention, the main combustion chamber is divided into a plurality of zones, and in each pulse, the air amount balance in each zone is changed and supplied.

[0009]

With the above structure, the combustion air is supplied in a pulsed manner to the main combustion chamber and the turbulent flow is positively generated in the main combustion chamber, whereby the pyrolysis gas and the combustion air are sufficiently mixed in the furnace. Therefore, the combustion efficiency is increased. Further, by dividing the main combustion chamber into a plurality of zones and changing the amount of air in each zone, the turbulent flow intensity is increased and the combustion efficiency is further increased. As a result, the temperature in the main combustion chamber rises, and the melting efficiency of the material to be melted increases.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of a main part of a waste melting furnace of one embodiment in which the waste melting method of the present invention is performed, FIG. 2 is a plan view of the main part of the waste melting furnace ceiling, and FIG. It is a graph which shows the air supply pattern to a main combustion chamber. As shown in FIG. 1, the waste melting furnace of this embodiment has the same basic structure as the conventional waste melting furnace, and has a main combustion chamber 23 composed of an inner cylinder 21 and an outer cylinder 22 in the upper part. The supply hopper 24 is configured to feed the melted material 25 such as sewage sludge, incinerated ash, and crushed incombustible material into the main combustion chamber 23. Although not shown, a secondary combustion chamber similar to that shown in FIG. 4 is provided in the lower portion of the main combustion chamber 23, and a combustion device for secondary combustion is provided on the side wall of the secondary combustion chamber. A flue is provided to exhaust the burned combustion gas. A slag conveyor is installed below the secondary combustion chamber to convey the molten slag to the outside of the furnace.

The present embodiment is different from the conventional example in that, as shown in FIG. 1 or 2, in the inner cylinder 21 of the main combustion chamber 23, a central annular A zone and an annular B zone around it are provided. When,
Furthermore, so as to be partitioned into the annular C zone around it,
The point is that the air supply holes 29a, 29b, 29c are provided. Further, a plurality of combustion devices 27 having a fuel supply device 28 are installed between the A zone and the B zone, and provide a heat source for initiating and promoting combustion and melting of the melted material 25. There is. Air supply holes 29a, 29b,
29c is connected to the air supply device 31 via dampers 30a, 30b, 30c. In addition, the air supply hole 29a,
Flow meters 32a, 32b, 32c are provided between 29b, 29c and dampers 30a, 30b, 30c, which are connected to a converter 33 and then to a controller 34.
The air amount measured by the flow meters 32a, 32b, 32c is converted into an electric signal by the converter 33 and sent to the controller 34. The flow meter 3 is also provided in the air supply path 35 to the air supply device 31.
6 is connected to the converter 37 and then to the controller 34, and the amount of air measured by the flow meter 36 is
Is converted into an electric signal and sent to the control device 34. The control device 34 is connected to the dampers 30a, 30b, 30c via the solenoids 38a, 38b, 38c, and is based on the air amount data sent from the flowmeter 36 and the flowmeters 32a, 32b, 32c. 38a, 38
b, 38c to control the dampers 30a, 30b, 30c, and the air supply device 31 to supply the air supply holes 29a, 29c.
The amount of air supplied to b and 29c is changed.

The operation of the above structure will be described below.
Since the total amount of air required for combustion is almost constant, A, A,
The supply balance from the B and C zones is changed to supply. That is, the data of the total air amount obtained by the flow meter 36 is sent to the control device 34 through the converter 37, and the control device 34 uses the solenoids 38a, 38b,
By controlling the dampers 30a, 30b, 30c by 38c, the total amount of air supplied to each zone is made constant. Regarding the supply balance, in pattern 1, the combustion air amount supplied from the A zone, the combustion air amount supplied from the B zone, and the combustion air amount supplied from the C zone are increased in this order, and in pattern 2, the combustion air supplied from the B zone. amount,
The amount of combustion air supplied from the C zone and the amount of combustion air supplied from the A zone are increased in this order. In pattern 3, the amount of combustion air supplied from the C zone, the amount of combustion air supplied from the B zone, and the combustion supplied from the A zone. Increase the amount of air in this order. For this purpose, the flow meters 32a, 32b, 32
Data of the amount of air supplied to each zone by c and the converter 33 is sent to the control device 34, and the control device 34 controls the dampers 30a, 30b, 30c through the solenoids 38a, 38b, 38c based on the data. Changes the amount of air supplied to each zone. Air is supplied by repeating the pattern 1, the pattern 2, and the pattern 3 sequentially to burn and melt the melted material 25. Note that FIG.
The arrow in the C zone indicates that air is blown in in a substantially circumferential direction. By thus supplying air in a pulsed manner, a turbulent flow occurs in the melting furnace, and by changing the pattern and supplying air, the turbulent flow intensity is increased. As a result, the pyrolysis gas in the melting furnace and the air are sufficiently mixed, and the combustion efficiency is increased. Also, the combustion efficiency is increased by providing a plurality of combustion devices.

The air supply pattern is not limited to the above pattern and can be set arbitrarily.

[0014]

As described above, according to the present invention, the turbulent flow is generated in the main combustion chamber by supplying the combustion air in pulses to the main combustion chamber. Further, the turbulent flow intensity in the main combustion chamber is increased by changing and supplying the air amount in the plurality of zones of the main combustion chamber. As a result, the mixing and stirring of the combustion air and the pyrolysis gas in the main combustion chamber are promoted, and the combustion efficiency is increased. Therefore, the temperature in the main combustion chamber is raised, and the melt processing amount can be increased. Further, it becomes unnecessary to supply an excessive amount of combustion air, which was required in the conventional uniform air supply.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration of a main part of a waste melting furnace in which a waste melting method according to an embodiment of the present invention is performed.

FIG. 2 is a plan view showing a configuration of a ceiling part of the waste melting furnace of FIG.

FIG. 3 is a graph showing a combustion air supply pattern in the waste melting method of the present invention.

FIG. 4 is a sectional view of a conventional waste melting furnace.

[Explanation of symbols]

 23 Main combustion chamber 25 Molten material 27 Combustion device

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hirohito Yoshioka 1-247 Shikitsuhigashi, Naniwa-ku, Osaka-shi, Osaka Kubota Corporation

Claims (2)

[Claims] 1. In a waste melting method of melting the melted material by using heat of combustion of a combustion device provided in the main combustion chamber and combustion heat of burning the melted material as a heat source, the main combustion chamber is burned. A waste melting method characterized by supplying air in a pulsed manner. 2. The waste melting method according to claim 1, wherein the main combustion chamber is divided into a plurality of zones, and each pulse is supplied by changing the balance of the amount of air in each zone.