{"id":1752,"date":"2021-06-07T17:17:26","date_gmt":"2021-06-07T09:17:26","guid":{"rendered":"https:\/\/www.hjkir.com\/?p=1752"},"modified":"2024-01-12T14:51:05","modified_gmt":"2024-01-12T06:51:05","slug":"%e5%9c%a8%e7%ba%bf%e7%ba%a2%e5%a4%96%e7%83%ad%e6%88%90%e5%83%8f%e6%b5%8b%e6%b8%a9%e5%9c%a8%e5%9b%9e%e8%bd%ac%e7%aa%91%e8%bf%90%e8%a1%8c%e7%9b%91%e6%b5%8b%e4%b8%ad%e7%9a%84%e5%ba%94%e7%94%a8","status":"publish","type":"post","link":"https:\/\/www.hjkir.com\/industry\/en\/1752.html","title":{"rendered":"Application of on-line infrared thermography temperature measurement in rotary kiln operation monitoring"},"content":{"rendered":"

Kiln skin plays a key role in prolonging the life of refractory bricks in hazardous waste incineration rotary kiln. The on-line infrared thermal imaging temperature measurement system is applied to the real-time monitoring and analysis of the surface temperature of the rotary kiln. Based on the on-line infrared thermal imaging temperature measurement system, this paper collects and analyzes the production process data. The results show that the on-line infrared thermal imaging temperature measurement system can ensure the real-time and long-term temperature measurement of the shell surface of the rotary kiln, and monitor the establishment and operation of the kiln skin.<\/p>\n

Heat treatment is the most effective method to treat hazardous waste, and rotary kiln is the most effective equipment in hazardous waste treatment. The external surface temperature of the rotary kiln barrel is an important process parameter for the design and operation of the rotary kiln. The design of the external surface temperature of the rotary kiln barrel is too high, which is not conducive to the on-site operation of personnel and the improvement of the thermal efficiency in the kiln; The design of the outer surface temperature of the rotary kiln shell is too low. On the one hand, it increases the investment and operation cost. On the other hand, the acidic substances (sulfur dioxide, hydrogen chloride, etc.) in the flue gas generated by the incineration of hazardous waste mix with water vapor to corrode the refractory bricks and shell. The on-line infrared thermal imaging temperature measurement system can continuously monitor, analyze and predict the surface temperature of the rotary kiln shell in the metallurgical non-ferrous industry, prevent the damage of the kiln lining and kiln shell due to overburning and other reasons, and improve the production efficiency. Based on the on-line infrared thermal imaging temperature measurement monitoring system, this paper collects and analyzes the production process data. The results show that the on-line infrared thermal imaging temperature measurement monitoring system can ensure the real-time and long-term temperature measurement of the shell surface of the rotary kiln (RK), and monitor the establishment and operation of the kiln skin.<\/p>\n

1.<\/strong>Application of infrared thermography temperature measurement to rotary kiln operation<\/strong><\/h2>\n

1 . 1. Ensure the real-time and long-term temperature measurement of the shell surface of the rotary kiln<\/strong><\/p>\n

At present, the instrument commonly used to measure the outer surface temperature of the hazardous waste incineration rotary kiln is a hand-held portable infrared thermometer. This instrument is inspected manually on site, and the cost is low, but it is too dependent on manpower to measure comprehensively and timely. The on-line infrared thermal imaging temperature measurement monitoring system has the advantages of friendly interface, efficient data acquisition, permanent data storage, and diversified functions. As shown in Figure 1 to figure 4.<\/p>\n

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Figure 1 Interface of online infrared thermal imaging system<\/p>\n

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Figure 2 Sectional and regional picture of rotary kiln online infrared thermal imaging<\/p>\n

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Figure 3 Temperature curve screen of real-time monitoring of a certain area<\/p>\n

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Figure 4 Temperature picture of rotary kiln after one revolution<\/p>\n

1.2 Establishment of monitoring kiln skin<\/strong><\/p>\n

Most of the main facilities for incineration and disposal of industrial hazardous wastes draw on and adopt the rotary kiln equipment in the cement industry, which is very mature. At the same time, it also adopts its kiln skin hanging technology. In order to prolong the service life and operation cycle of refractory bricks and reduce the operation cost, it is necessary to add a solid protective layer on its surface, that is, to cover a layer of \"kiln skin\" on the brick surface, so as to prolong the service life and operation cycle of refractory bricks and reduce the operation cost. However, the establishment and operation of kiln skin rely on the on-site personnel to judge whether the kiln skin is established through the kiln tail mirror and the kiln tail temperature, and there is no quantifiable standard. Using infrared thermal imaging temperature measurement technology to monitor the surface temperature change of the rotary kiln shell has reference value for monitoring the establishment and operation of the rotary kiln skin.\"\u5efa\u7acb\u7a91\u76ae\u65f6\u56de\u8f6c\u7a91\u7b52\u4f53\u5916\u8868\u7ea2\u5916\u6d4b\u6e29\u66f2\u7ebf\u56fe,\u76d1\u63a7\u7a91\u76ae\u7684\u5efa\u7acb\"<\/p>\n

Figure 5 Infrared temperature measurement curve of rotary kiln shell surface when establishing kiln skin<\/p>\n

The establishment of rotary kiln should comprehensively consider the specific gravity, water content, pH value and other parameters of materials entering the kiln. Figure 5 shows the infrared temperature measurement curve of the outer surface of the rotary kiln shell when establishing the kiln skin. 11 groups of data are collected according to the time of establishing the kiln skin. The order of the first to eighth sections in Figure 5 is based on the segmentation principle from the kiln head to the kiln tail. The establishment of kiln skin mainly goes through the process of heating, melting and cooling. As can be seen from Figure 5, curves a, B, C and D are the temperature rise curves of the outer surface of the rotary kiln shell when establishing the kiln skin. In this process, the materials required for the establishment of kiln skin enter the rotary kiln evenly, and the injection of auxiliary fuel oil provides sufficient heat for combustion to continuously melt the materials. The melting of materials into kiln skin can be observed through the kiln tail mirror; Curve e is the curve of the highest point of the outer surface temperature of the rotary kiln shell when the kiln skin is established, and the highest section is the fourth section (293.2 \u2103). At this time, the materials required for the establishment of the kiln skin have stopped entering the rotary kiln; Curves F, G, h, I, J and K are the cooling curve of the outer surface temperature of the rotary kiln shell when the kiln skin is established. In this process, the consumption of auxiliary fuel is reduced until the kiln skin is formed. At this time, the kiln skin can be observed through the mirror. The eighth section is the kiln tail. Because the kiln tail is equipped with the kiln tail cooling fan and is the material burnout area, the shell surface temperature is the lowest.\"\u672a\u6295\u6599\u4e0e\u6295\u6599\u65f6\u56de\u8f6c\u7a91\u7b52\u4f53\u5916\u8868\u7ea2\u5916\u6d4b\u6e29\u66f2\u7ebf\u56fe\"<\/p>\n

Figure 6 Infrared temperature measurement curve of the shell surface of rotary kiln without feeding and when feeding<\/p>\n

The kiln skin has a protective effect on the rotary kiln shell and refractory materials. Figure 6 shows the infrared temperature measurement curve of the outer surface of the rotary kiln shell when it is not fed and when it is fed. It can be seen from Figure 6 that after the kiln skin is built, the highest section of the outer surface temperature of the rotary kiln shell when it is not fed is the fourth section (206.1 \u2103), and the lowest section is the eighth section (154.8 \u2103); After the kiln skin is built, the highest section of the shell surface temperature of the rotary kiln during feeding is the fourth section (202.9 \u2103) and it is a peak. It is speculated that the fourth section is the best combustion section of the material, and the lowest temperature section is the eighth section (149.5 \u2103). The eighth section is the kiln tail. The reason for the low surface temperature of the barrel is that the kiln tail is equipped with a kiln tail cooling fan. In addition, the kiln tail is the material burnout area, and the surface temperature of the barrel is low.<\/p>\n

1.3 Monitor the operation of kiln skin<\/strong><\/p>\n

Generally, the thinning of kiln skin is judged by operation time and manual observation through the rear-view mirror at the end of the kiln, but this method is only empirical judgment, which has limitations for production personnel. By accumulating the infrared thermography temperature measurement data of the outer surface of the rotary kiln shell, a method to judge the thinning of the kiln skin can be provided. Figure 7 shows the infrared temperature measurement curve of the shell surface during the normal operation of the rotary kiln after the kiln skin is established. It can be seen from Figure 7 that curve A is the infrared thermal imaging temperature measurement curve of the shell surface of the rotary kiln in normal operation after the kiln skin has just been built. The highest segment is the fourth segment (214.0 \u2103), and the lowest temperature segment is the eighth segment (150.6 \u2103). Curves B to G are the infrared thermal imaging temperature measurement curves of the shell surface within 20 days of the operation of the kiln skin. From curves B to g, it can be seen that with the increase of the operation time of the kiln skin, the temperature of each section of the shell surface of the rotary kiln shows an upward trend, indicating that the thickness of the kiln skin is gradually thinning with the increase of the operation time. The highest section of curve h is the fourth section (292.1 \u2103), which is not much different from the maximum temperature of the fourth section (293.2 \u2103) when the kiln skin is established; The lowest temperature section is the eighth section (196.6 \u2103), which indicates that the kiln skin has disappeared and needs to be rebuilt.\"\u56de\u8f6c\u7a91\u8fd0\u884c\u65f6\u7b52\u4f53\u5916\u8868\u7ea2\u5916\u6d4b\u6e29\u66f2\u7ebf\u56fe\"<\/p>\n

Figure 7 Infrared temperature measurement curve of cylinder surface during operation of rotary kiln<\/p>\n

2.<\/strong>Summary<\/strong><\/h2>\n

This paper introduces the real-time and long-term characteristics of on-line infrared thermography temperature measurement, and analyzes the relationship between the establishment and operation of the kiln shell and the surface temperature curve of the rotary kiln. The results show that in the process of establishing the kiln shell, the surface temperature curve of the kiln shell increases first and then decreases; During the operation of the kiln skin, the temperature curve of the shell surface changes to a gradually decreasing trend. The kiln skin has a protective effect on the rotary kiln shell and refractory materials, so the relationship between the external temperature curve of the rotary kiln shell and the establishment and operation of the kiln skin is worthy of further study.<\/p>\n

Based on the real-time and long-term nature of on-line infrared thermal imaging temperature measurement, the on-line infrared thermal imaging temperature measurement system can also be used to monitor and analyze the corrosion and thinning of the rotary kiln barrel or refractory bricks, and monitor the combustion conditions of the rotary kiln incinerated materials.<\/p>\n

Applicable Machine<\/h2>\n