JPH09243337A - Method for monitoring gate of waste fusion furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automate the monitoring of a gate and eliminate the individual difference to stabilize the measure to the blocking of the gate by photographing the thermal image of the gate by a thermal image camera set obliquely under the gate, and monitoring the blocking of the gate by the degree of reduction in area of a high luminance part. SOLUTION: A thermal image camera 7 is set obliquely under a gate 6 to photograph the thermal image of the gate 6. The thermal image by the camera 7 is processed by an image processing computing element 10 through an image converter 8, and displayed on an image processing monitor 11. The average luminance of the whole thermal image is reduced by the growth of solidified slug, and returned when the solidified slug is fallen from the gate 6. However, it is not improper for automatic monitoring of the gate 6 as it is since the vertical movement is vigorous. Thus, the computing element 10 analyzes the thermal image by luminance since the area of the photographed part of a high temperature furnace inner part in the thermal image is gradually reduced when the blocking of the gate 6 is progressed by sedimentation of solidified slug, and counts the number of picture elements in the high luminance part to extract only the high luminance part corresponding to the high temperature part within the thermal image.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for monitoring the gate of a waste melting furnace for melting waste to form slag.

[0002]

2. Description of the Related Art In recent years, waste such as sewage sludge incineration ash is melted in a waste melting furnace such as a swirling melting furnace to form slag, thereby reducing the volume of the waste and containing it in the waste. Attempts have been made to contain heavy metals in slag.
In such a waste melting furnace, the high temperature molten slag generated in the furnace is discharged from the sprue,
Molten slag may accumulate around the sprue, and the sprue may be gradually closed as shown in FIG. Further, as shown in FIG. 2, the slag adhering to the sprue may grow downward and become a long solidified slag like stalactite, which may reach the equipment below.

For this reason, conventionally, an operator frequently monitors the condition of the sprue visually and removes the slag with a heat-resistant rod before the sprue is blocked or the solidified slag is excessively grown. However, such an operator's visual observation method has large individual differences, and there are cases in which the slag is removed more frequently than necessary with heat-resistant rods, or the timing of removing slag with heat-resistant rods is delayed.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems and automates the sprue monitoring,
It is made in order to provide a method for monitoring the gate of a waste melting furnace, which enables stabilization of coping by eliminating individual differences among workers.

[0005]

[Means for Solving the Problem] The above-mentioned problem is solved by taking a thermal image of the sprue with a thermal image camera installed obliquely below the sprue of the waste melting furnace, and reducing the area of the high-intensity part in this thermal image. This can be solved by the method of monitoring the gate of the waste melting furnace, which monitors the blockage of the gate depending on the degree. The above-mentioned problem is that the thermal image of the sprue is taken by a thermal image camera installed diagonally below the sprue of the waste melting furnace, and the average of the intermediate brightness part excluding the high brightness part and the low brightness part in this thermal image is taken. This can be solved by the method of monitoring the gate of the waste melting furnace, which monitors the growth of solidified slag hanging from the gate depending on the degree of decrease in brightness. In any case, it is preferable to install a thermal image camera on the back surface of the sprue on the side where the slag flows down to take an image.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below. In FIG. 3, 1 is a waste melting furnace,
Here, a swirl type melting furnace is shown. In this waste melting furnace 1, waste such as sewage sludge incineration ash is tangentially injected into the slanted primary combustion chamber 2 and melted by a burner 3 while swirling to be slag, and further an auxiliary burner 4, It is heated by 5 and flows down from the sprue 6 to a cooling section (not shown) below. Therefore, in the illustrated furnace, the solidified slag is likely to be deposited and the solidified slag is likely to grow mainly on the left side of the sprue 6.

In the present invention, a thermal image camera 7 is installed diagonally below the gate 6 to capture a thermal image of the gate 6. At this time, the thermal image camera 7 is preferably installed on the back surface of the sprue 6 on the side where the slag easily flows down as shown in FIG. The reason for this is that if the thermal image camera 7 is installed on the opposite side, even if the solidified slag grows, the hot slag flow is photographed from the sprue 6 regardless of this, so it is difficult to clearly capture the growth of the solidified slag. . The thermal image of the thermal image camera 7 is subjected to image processing by the image processing calculator 10 via the image converter 8 and displayed on the image processing monitor 11.

FIG. 4 is a diagram schematically showing changes in the thermal image of the thermal image camera 7, and FIG. 5 is a graph showing measured values of changes in average luminance of the entire thermal image. As can be seen from this graph, the average brightness of the entire thermal image decreases due to the growth of the solidified slag, and it returns when the solidified slag falls from the sprue 6. However, if it is left as it is, the vertical movement is severe and it is not suitable for automatic monitoring of the gate. Therefore, in the present invention, the thermal image of the thermal image camera 7 is image-processed by the following algorithm.

[First Invention] In the first invention, when the closure of the sprue 6 progresses due to the accumulation of solidified slag, the area of a portion of the thermal image captured by the thermal image camera 7 in the high-temperature furnace is reduced. Focusing on the gradual decrease, only the high-luminance portion corresponding to the high temperature portion in the thermal image is extracted. For this purpose, the thermal image may be analyzed by brightness and the number of pixels in the high brightness portion may be counted.

FIG. 6 is a graph showing the results of such image processing. As the closure of the sprue 6 progresses, the area of the high-intensity part in the thermal image decreases, and when the solidified slag falls, the sprue 6 is formed. The situation in which it opens but then the obstruction progresses again is clearly captured. As described above, according to the first aspect of the present invention, by grasping the change in the area of the high-intensity part in the thermal image as a process variable, the blockage of the sprue 6 is automatically and accurately monitored, and a worker or an automatic slag removing device is provided. Can be issued for appropriate action.

[Second Invention] Next, in the second invention, when the solidified slag hanging from the sprue 6 grows, FIG.
Paying attention to the fact that the area of the solidified slag in the thermal image increases as shown in, the average brightness of the intermediate part excluding the high brightness part and the low brightness part in the thermal image is measured. Since the surface of the solidified slag on the side of the thermal image camera 7 is cooled by the outside air, it has a low luminance portion in the thermal image, and reduces the average luminance of the thermal image. In particular, in the present invention, by removing the high-intensity part (the part in the high-temperature furnace visible from the sprue 6) and the low-brightness part (the part such as the outer wall of the furnace) in the thermal image, the area of the part that easily changes is accurately determined. Can be captured.

FIG. 7 is a graph showing the result of such image processing. As the solidified slag hanging from the spout 6 grows, the average brightness of the intermediate portion in the thermal image decreases, and when the solidified slag falls. The situation of returning to the original state is clearly captured. As described above, according to the second aspect of the present invention, the growth of the solidified slag of the sprue 6 is automatically detected by capturing the change in the average luminance of the portion excluding the high-luminance portion and the low-luminance portion in the thermal image as a process variable. Can be accurately monitored and signaled to workers and automatic slag removers for appropriate action.

[0013]

As described above, according to the first invention, it is possible to automatically and accurately monitor the closure of the sprue due to the accumulation of the solidified slag, and according to the second invention. Growth can be monitored automatically and accurately. Therefore, unlike the conventional method in which the worker visually monitors the situation of the sprue, it is possible to eliminate individual differences and stabilize the handling.

[Brief description of drawings]

FIG. 1 is a cross-sectional view schematically showing the closure of a sprue.

FIG. 2 is a cross-sectional view schematically showing growth of solidified slag.

FIG. 3 is a partial sectional view showing a relationship between a waste melting furnace and a thermal image camera.

FIG. 4 is a diagram schematically showing a change in a thermal image of a thermal image camera.

FIG. 5 is a graph showing measured values of changes in average luminance of the entire thermal image.

FIG. 6 is a graph showing a change in area of a high brightness portion in a thermal image.

FIG. 7 is a graph showing a change in average luminance of a portion excluding a high luminance portion and a low luminance portion in a thermal image.

[Explanation of symbols]

1 waste melting furnace, 2 primary combustion chamber, 3 burners, 4
Auxiliary burner, 5 auxiliary burner, 6 gate, 7 thermal image camera, 8 image converter, 10 image processing calculator, 11
Image processing monitor

Claims (3)

[Claims] 1. A thermal image of the sprue is taken by a thermal image camera installed diagonally below the sprue of the waste melting furnace, and the blockage of the sprue is monitored by the degree of reduction of the area of the high-intensity part in the thermal image. A method for monitoring the gate of a waste melting furnace, characterized by: 2. A thermal image of the sprue is taken by a thermal image camera installed diagonally below the sprue of the waste melting furnace, and the average brightness of the intermediate brightness part excluding the high brightness part and the low brightness part in this thermal image. A method for monitoring the gate of a waste melting furnace, which is characterized by monitoring the growth of solidified slag hanging from the gate depending on the degree of decrease in the amount. 3. The method for monitoring the gate of a waste melting furnace according to claim 1 or 2, wherein a thermal image camera is installed on the back surface of the sprue on the side where the slag flows down and the image is taken.