JP2007263829A - Leakage monitoring method of co gas - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a leakage monitoring method of CO gas capable of safely monitoring leakage of the CO gas over a wide range. <P>SOLUTION: A monitoring object is imaged by an infrared camera 1A through an infrared filter 4A, having infrared transmission characteristics of a wavelength zone absorbed by CO gas, and the monitoring object is imaged by an infrared camera 1B through an infrared filter 4B, having an infrared transmission characteristic of a wavelength zone that is not absorbed by CO gas. Then, two images acquired by the infrared cameras 1A, 1B are composited by an image compositing device 2, and the composited image is reflected on a monitor television 3, to thereby monitor the leakage of CO gas. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for monitoring leakage of CO (carbon monoxide) gas generated in a gas pipe such as a converter gas recovery pipe.

Conventionally, as a method for detecting CO gas leakage, as described in Patent Documents 1 and 2, CO gas leakage is directly detected using a CO sensor such as a constant potential electrolytic sensor or a catalytic combustion sensor. And a method of indirectly detecting CO gas leakage by detecting a leakage sound generated at the time of leakage with an ultrasonic sensor.
However, the former method described above has a problem that it is difficult to detect the leaked CO gas by the CO sensor when the CO gas leak location is high or away from the CO sensor installation location. is there. In addition, even if the leaked CO gas can be detected, it is impossible to grasp the leak point. In order to find the leak point of CO gas, it is necessary to equip an air line mask or the like to find the leak point. is there. Furthermore, when CO gas leaks from an aging gas pipe, there is a problem that it takes a long time to find a leak point.

On the other hand, the latter method has a problem that it is difficult to specify the location when CO gas stays. In addition, when the CO gas leakage does not involve a certain flow velocity, there is a problem that it is difficult to accurately detect the CO gas leakage, and further, the fluid other than the CO gas (for example, air, steam, etc.) There is also the problem of reacting to leaks.
Japanese Patent No. 3289137 JP 2002-850341 A

  The present invention has been made paying attention to the above-described problems, and an object of the present invention is to provide a CO gas leakage monitoring method capable of safely monitoring CO gas leakage over a wide range.

  In order to solve the above-described problem, a CO gas leakage monitoring method according to the present invention images an object to be monitored with an infrared camera through an infrared filter having infrared transmission characteristics in a wavelength region absorbed by CO gas, and the CO gas After the object to be monitored is imaged with an infrared camera through an infrared filter having infrared transmission characteristics in a wavelength range that is not absorbed by gas, the two images obtained by the infrared camera are synthesized, and the synthesized image is displayed on the monitor screen. The CO gas leakage is monitored.

  According to the CO gas leakage monitoring method according to the present invention, the CO gas leaked from the monitoring object such as the converter gas recovery pipe is displayed on the monitor screen as a visible image. It can be monitored safely.

  FIG. 1 shows a first embodiment in which the CO gas leakage monitoring method according to the present invention is applied to a combustible gas recovery piping monitoring system of a steelworks. In the figure, reference numerals 1A and 1B are infrared cameras as monitor cameras for monitoring combustible gas recovery pipes such as converter gas recovery pipes, and 2 is an image synthesis apparatus for synthesizing images obtained by the infrared cameras 1A and 1B. Reference numeral 3 denotes a monitor television for displaying an image synthesized by the image synthesizing apparatus 2. Of the infrared cameras 1A and 1B, for example, the infrared camera 1A has an infrared transmission characteristic (for example, a center passing wavelength) absorbed in the CO gas. An infrared filter 4A having a region of 4.705 μm and a half-value width of 0.170 μm is mounted in front of an objective lens (not shown), and the infrared camera 1B has infrared transmission characteristics in a wavelength region that is not absorbed by CO gas (for example, a central passing wavelength region). (3.480 μm, half-width 0.152 μm) is mounted in front of an objective lens (not shown). That. In this example, an infrared camera having an infrared detection band of 1.8 to 5 μm was used as an infrared camera for monitoring the combustible gas recovery pipe.

  In such a configuration, when CO gas leaks from a combustible gas recovery pipe as a monitoring target, infrared light having a wavelength range of about 4.7 μm is absorbed by the CO gas, and therefore enters the infrared camera 1A through the infrared filter 4A. The incident dose of infrared rays to be reduced is less than before leakage. For this reason, the image supplied from the infrared camera 1 </ b> A to the image composition device 2 is a dark image where the CO gas concentration is high.

On the other hand, since the incident dose of infrared rays incident on the infrared camera 1B through the infrared filter 4B is almost the same as the incident dose before leakage, the image supplied from the infrared camera 1B to the image synthesizer 2 is the image synthesizer from the infrared camera 1A. Compared with the image supplied to 2, the overall image is brighter.
Therefore, when the two images obtained by the infrared cameras 1A and 1B are synthesized by the image synthesizing device 2 and the synthesized image is displayed on the monitor television 3, an image capable of visually checking the CO gas is projected on the monitor television 3. Therefore, CO gas leakage can be monitored over a wide range and safely.

  As a method of visualizing CO gas by synthesizing two images obtained by the infrared cameras 1A and 1B by the image synthesis device 2, for example, an image obtained by the infrared camera 1A from an image obtained by the infrared camera 1B. The method of visualizing CO gas by subtracting and synthesizing, and the method of visualizing the CO gas by adding and synthesizing the image obtained by the infrared camera 1A after inverting the white and black of the image obtained by the infrared camera 1A Etc. can be adopted.

  In addition, when it is difficult to collate with the substance only by the CO gas image, the image of the monitoring object captured by the normal video camera 5 and the image synthesizing device 2 are used as in the second embodiment shown in FIG. The synthesized image is supplied to the image synthesizing device 6, and the image synthesizing device 6 superimposes the image from the image synthesizing device 2 on the image from the monitor camera 5 by, for example, coloring in red and superimposing it. A portion having a high CO gas concentration can be characterized and displayed in the.

In the first and second embodiments described above, leakage of CO gas is monitored using two infrared cameras. However, the monitoring target is monitored by one infrared camera while alternately replacing the infrared filters 4A and 4B. An object may be imaged, and the captured image of the monitored object may be stored in the image composition device 6 and synthesized.
Moreover, although the case where this invention was applied to the combustible gas collection | recovery piping monitoring system of a steelworks was illustrated in 1st and 2nd embodiment mentioned above, this invention is not limited to this, It is combustible. The present invention can also be applied to gas pipes other than the gas recovery pipe.

It is a figure which shows 1st Embodiment which applied the leakage monitoring method of the CO gas which concerns on this invention to the combustible gas collection | recovery piping monitoring system. It is a figure which shows 2nd Embodiment which applied the leakage monitoring method of CO gas which concerns on this invention to the combustible gas collection | recovery piping monitoring system.

Explanation of symbols

1A, 1B Infrared camera 2,6 Image composition device 3 Monitor TV 4A, 4B Infrared filter 5 Video camera

Claims (1)

  The monitoring object is imaged by an infrared camera through an infrared filter having an infrared transmission characteristic in a wavelength region absorbed by CO gas, and the monitoring object is passed through an infrared filter having an infrared transmission characteristic in a wavelength region not absorbed by CO gas. After capturing an image with an infrared camera, the two images obtained by the infrared camera are combined, and the combined image is displayed on a monitor screen to monitor the leakage of CO gas. Leakage monitoring method.

Images