JPH0933028A - Ash melting furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a practical molten state in an ash melting furnace to be clearly monitored by a method wherein an infrared-ray camera is fixed in a through-pass hole formed in a furnace body and a melting state in the furnace is remotely monitored through the infrared-ray camera. SOLUTION: An infrared ray camera 2 is fixed to a through-pass hole arranged at a side wall of a main body 1 of a furnace. A lens tube 4 is fixed to a camera case 2a enclosing the infrared ray camera 2, a jacket 5 fixed to the lens tube 4 is fixed to a side wall of the main body 1 of the furnace. A filter 3 is fixed to a front side of the infrared ray camera 2 within the camera case 2a, cylindrical tube 4 having its extremity end closed is fixed to the front side of the filter 3, and a plurality of lenses 4a are stored in the lens tube 4. A cylindrical jacket 5 having its extremity end being released with a clearance 5a left between it and the lens tube 4 is fixed to and outer circumference of the lens tube 4, and the jacket 5 is inserted into an fitted to the through-pass hole at the side wall of the main body 1 of the furnace. Then, the infrared ray camera 2 is connected to a monitor 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ash melting furnace capable of remotely monitoring the melting condition inside the furnace. When various types of waste such as municipal waste, sewage treatment sludge, and industrial waste are incinerated in an incinerator, they are captured by incineration ash remaining in the incinerator and a dust collector installed in the exhaust gas treatment system of the incinerator. Fly ash is generated.
Usually, these incinerated ash and fly ash are melt-processed in an ash melting furnace such as an arc furnace, a plasma furnace, a resistance furnace, and a burner furnace in order to stabilize and reduce their volume. The present invention relates to an ash melting furnace capable of remotely monitoring the melting state in the furnace when the incineration ash or fly ash as described above is melt-processed.

[0002]

2. Description of the Related Art When incinerating ash or fly ash is melt-processed in an ash melting furnace, it is very convenient if the actual melting condition in the furnace can be visually observed in order to reliably and safely perform the melting process. Conventionally, as such an ash melting furnace, a furnace in which a peep window is provided in a part of the furnace body and a melting state in the furnace can be monitored through the peek window is generally used. However, when incineration ash or fly ash is melted in an ash melting furnace, the inside of the furnace is heated to its own high temperature, and a large amount of dust floats in the atmosphere inside the furnace. Even if you try to monitor the melting status of, you cannot actually monitor the melting status clearly.

On the other hand, it has been proposed that a visible light camera is attached so as to face the molten slag discharge port opened in the furnace body, and the discharged state of the molten slag is monitored through this visible light camera (actually). Kaihei 5-64700). Therefore, in order to monitor the melting state in the furnace, a visible light camera is attached to the above-mentioned viewing window, or a through hole is provided in the furnace body, and a visible light camera is attached to this through hole. It is conceivable to monitor the melting status in the furnace via a visible light camera, but even in this case, the melting status cannot actually be clearly monitored, as described above regarding the sight glass.

[0004]

The problem to be solved by the present invention is that, in the conventional ash melting furnace, the melting state in the furnace cannot be clearly monitored.

[0005]

According to the present invention, however, a furnace body is provided with a through hole, and an infrared camera is attached to the through hole.
The present invention relates to an ash melting furnace, characterized in that the melting state in the furnace is remotely monitored via the infrared camera.

The ash melting furnace to which the present invention is applied is an arc furnace, a plasma furnace, a resistance furnace, a burner furnace or the like. These ash melting furnaces usually include a furnace body as a furnace body and a lid body attached to the furnace body. In the present invention, such a furnace body is provided with a through hole, and an infrared camera is attached to the through hole. The through holes are provided at one or two or more locations in the furnace body, and one or more infrared cameras are attached to one through hole. The infrared camera is connected to a monitor, and the melting status in the furnace is displayed on this monitor.

The infrared camera preferably has a water-cooled or air-cooled lens tube so that the lens is not directly exposed to the high temperature atmosphere in the furnace. A cylindrical lens tube having a closed tip surrounding the lens is attached to the front of the infrared camera, and a jacket through which cooling water or cooling air can flow is attached to the outer circumference of the lens tube. Above all, in order to prevent dust in the furnace atmosphere from adhering to the tip of the lens tube, there is a gap between the lens tube and the jacket, and the purge gas is blown out from the tip of the lens tube through this gap. Preferred are

In order to more clearly monitor the melting condition in the furnace, the infrared camera uses the peak wavelength range of infrared rays emitted from the surface of the molten slag in the furnace and the average particle size of dust floating in the atmosphere in the furnace. It is preferable that it has sensitivity in a long wavelength range and does not have sensitivity in a peak wavelength range of infrared rays emitted from a heat source in the furnace.

In order to more clearly monitor the melting condition in the furnace, it is necessary to use an infrared camera having sensitivity in the peak wavelength range of infrared rays emitted from the surface of the molten slag in the furnace. For example, when incineration ash or fly ash of municipal waste is melted in an arc furnace, the surface of the molten slag in the furnace is generally about 1200 to 1400 ° C, and the peak wavelength range of infrared rays emitted from such surface is 1.3 to Since it is about 2.0 μm, an infrared camera having a sensitivity wavelength range of 1.3 to 2.0 μm is used as far as this limit is concerned.

In order to more clearly monitor the melting state in the furnace, an infrared camera having sensitivity in a wavelength range longer than the average particle size of dust floating in the atmosphere in the furnace is used. This is because infrared rays in a wavelength range shorter than the average particle size of dust are absorbed by the dust. Dust floating in the atmosphere in the furnace, especially when the concentration is high,
In some cases, they interfere with each other to actually absorb or reflect infrared rays in a wavelength range longer than the average particle size of the dust. Therefore, it is more preferable for the infrared camera to have sensitivity in a long wavelength region with some margin left over the average particle size of dust. For example, when incineration ash or fly ash of municipal waste is melt-processed in an arc furnace, generally, the average particle size of dust floating in the furnace atmosphere is 1.0 to 1.2 μm in terms of weight.
It is about 1.3 μm, leaving room for this limit.
An infrared camera having a sensitivity wavelength range is used above.

In order to more clearly monitor the melting state in the furnace, an infrared camera having no sensitivity in the peak wavelength range of infrared rays emitted from the heat source in the furnace is used. This is because if it has sensitivity in the peak wavelength range of infrared rays emitted from the heat source in the furnace, it will cause halation. For example, when incineration ash or fly ash of municipal waste is melt-processed in an arc furnace, the electrode part which is a heat source is generally 5000 to 60.
Since it becomes about 00 ° C. and the peak wavelength range of infrared rays emitted from such an electrode part becomes about 0.3 to 0.5 μm,
As far as this is possible, an infrared camera having a sensitivity wavelength range outside the peak wavelength range is used.

The type of waste that is the raw material for incineration ash and fly ash,
Although it is affected by the method of charging the incineration ash and fly ash to the ash melting furnace, the type of ash melting furnace, etc., in order to more clearly monitor the melting status in the furnace, 1.3 to 3. It is preferable to use an infrared camera having a sensitivity wavelength range of 0 μm,
It is more preferable to use an infrared camera having a sensitivity wavelength range of 1.5 to 2.0 μm. An example of such an infrared camera is one using lead sulfide as an infrared detection element.

Even if the infrared camera itself has a sensitivity wavelength range wider than the above range, a filter is attached in front of the infrared camera to remove infrared rays having a wavelength range longer than 3.0 μm, for example. Or
Or remove infrared rays in the wavelength range shorter than 1.3 μm,
As a result, it is possible that only infrared rays in the preferable wavelength range enter the infrared camera.

[0014]

1 is a vertical sectional view showing an embodiment of the present invention. 1 is a furnace body, 2 is an infrared camera, 2a is a camera case, 3 is a filter, 4 is a lens tube, 4
Reference numeral a denotes a lens, 5 denotes a jacket, and 6 denotes a monitor. An arc furnace (not shown) includes a furnace body 1 and a lid attached to the furnace body 1, a through hole is provided in a side wall of the furnace body 1, and an infrared camera 2 is attached to the through hole. There is.

The infrared camera 2 is surrounded by a camera case 2a, a lens tube 4 is attached to the camera case 2a, a jacket 5 is attached to the lens tube 4, and the jacket 5 is attached to a side wall of the furnace body 1. Installed. A filter 3 is attached to the front of the infrared camera 2 in the camera case 2a, and a cylindrical lens tube 4 having a closed end is attached to the front of the filter 3, and a plurality of lenses are provided in the lens tube 4. 4a is stored. On the outer periphery of the lens tube 4, there is attached a cylindrical jacket 5 having an open end with a gap 5a between the lens tube 4 and the lens tube 4, and the jacket 5 is provided on the side wall of the furnace body 1. It is inserted into the through hole. The infrared camera 2 is connected to the monitor 6.

The infrared camera 2 uses lead sulfide as an infrared absorbing element, and the filter 3 removes infrared rays in a wavelength range shorter than 1.3 μm. While flowing cooling water in the jacket 5 according to the solid line arrow in the figure,
When purging gas is introduced according to the broken line arrow in the figure,
The purge gas is blown into the furnace from the tip of the lens tube 4 through the gap 5a. The lens tube 4 is indirectly water-cooled and protected, and at the same time, dust floating in the furnace atmosphere is prevented from adhering to the tip of the lens tube 4.
In this state, the melting state in the furnace is displayed on the monitor 6 along the path of the lens tube 4 → lens 4a → filter 3 → infrared camera 2 → monitor 6 and monitored remotely.

[0017]

As is apparent from the above, the present invention described above has an effect that the melting condition in the furnace of the ash melting furnace can be clearly monitored.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

[Explanation of symbols]

1 ... Furnace body, 2 ... Infrared camera, 3 ... Filter, 4 ... Lens tube, 5 ... Jacket,
6 ... Monitor

Claims (4)

[Claims] 1. An ash melting furnace characterized in that a through hole is provided in a furnace body, an infrared camera is attached to the through hole, and a melting state in the furnace is remotely monitored through the infrared camera. . 2. The ash melting furnace according to claim 1, wherein the infrared camera has a water-cooled or air-cooled lens tube. 3. The infrared camera is sensitive to a peak wavelength range of infrared rays emitted from the surface of the molten slag in the furnace and a wavelength range longer than the average particle size of dust floating in the atmosphere in the furnace. The ash melting furnace according to claim 1 or 2, which is not sensitive to the peak wavelength region of infrared rays emitted from the heat source in the furnace. 4. The ash melting furnace according to claim 4, wherein the infrared camera has sensitivity in a wavelength range of 1.3 to 3.0 μm.