Application of the hottest infrared temperature sc

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Application of infrared temperature scanning system in Guangzhou Zhujiang Cement Plant

1 Introduction

our factory has introduced a complete set of production equipment and production technology from Smith Company in Denmark. There is one φ four point seven five × 75m dry production kiln with double series five stage cyclone preheater and calciner. The daily output of clinker is 4000 tons

for such a large-scale new dry process plant, the kiln body and its refractories are one of the main investments, and the damage and maintenance of refractories greatly reduce the operation rate of the rotary kiln. Therefore, in order to protect the refractory lining and the kiln barrel and prolong the operation cycle of the rotary kiln, the infrared scanning system is included in the whole imported automatic control system

carry out statistical analysis in groups. Due to insufficient understanding of the application of infrared temperature scanning system in the cement industry, it is considered that this system can only be used to detect hot spots and replace human eyes to find the location of "red kiln". Obviously, this purpose is only a part of the system function, and its function also has a broader content

2 working principle of infrared temperature scanning system

the scanner is set at a position 30 ~ 100 meters away from the kiln, and scans rapidly along a line parallel to the kiln axis with a scanning angle of 90 °, scanning the whole kiln length range 8 times per second. Generally, the kiln produces more than 200 ~ 300 complete scans per revolution (depending on the rotation speed). The coverage of each radiation point is generally 25 ~ 40 cm in diameter, and the scanner outputs a current signal representing the temperature of the point. The computer reads out the kiln speed at the same time. After preprocessing the scanning signal, it stores it in the specific memory of the computer with a temperature array, and makes each temperature value represent the temperature of a specific small rectangular area on the kiln surface. According to the basic information of the temperature array system, Dai rujun, general manager of Heilongjiang Xinda enterprise group, said at the signing ceremony: "Xinda has a unique technical barrier in the field of biological materials and bio based composites. It can produce graphic functions and point functions for operation and management personnel.

3 main graphic functions and their experience of use.

because the kiln lining and kiln skin produce heat transfer resistance from the kiln interior to the external environment, the surface temperature of the kiln body reveals the state of the kiln lining and kiln skin.

the following graphics can be selected from the computer terminal:

3.1 level The average distribution diagram

the average distribution diagram is a graph made with the radial average temperature of the kiln barrel as a function of the kiln axis position. It provides the following two kinds of information: the surface temperature of the kiln shell at that time and the position and thickness of the kiln skin at that time

the characteristic slope of the temperature curve of the firing zone indicates the growth position of the kiln skin. The lower the temperature, the thicker the kiln skin. The measured map and distribution map intuitively prove this

3.2 maximum and minimum distribution diagram

it is a graph made with the maximum and minimum values of the radial temperature of the kiln barrel as a function of the position of the kiln axis. It provides the following three kinds of information: the location of the "red kiln" point; Predict which potential hot spots will produce "red kilns"; Irregularity and axial position of kiln skin and kiln lining, whether the kiln skin has nodules, pits and material rings

3.3 grey diagram

it is the temperature distribution diagram of the whole kiln shell surface. With the help of different colors, it shows the temperature level of each area. Therefore, it can more intuitively reveal the situation in the kiln, reflect the uniformity of kiln skin and kiln lining, and the position of deep peeling of bricks or refractory bricks

3.4 inverse three-dimensional image

is the same as the gray diagram. It is the temperature distribution diagram of the surface of the kiln barrel, but the difference is that the peak and valley represent the temperature of each region. The peak represents the low temperature area and the valley represents the high temperature area. According to the inverse three-dimensional image, the following two kinds of information can be obtained: "red kiln" point position and geometry; Uniformity of kiln skin of firing belt and accurate stereogram of kiln skin. Inverse three-dimensional image has the advantages of more intuitive and more specific

3.5 summary

using the infrared scanner system to continuously measure the temperature and draw the temperature distribution map can help find the best state of the kiln, kiln skin and refractory lining, that is, the kiln skin is correct, uniform, firm and of appropriate thickness, while the kiln and refractory lining are in better working conditions. At the same time, this optimal state can be used as a reference for optimizing the operation and management of the kiln in the future

compare the temperature distribution map every day to master the formation and spalling of kiln skin, as well as the thickness and wear of refractory bricks

the preset alarm temperature provides dangerous temperature rise information. The operator should immediately carry out preventive control to prevent its further development. At the place where the burning belt peels off the fallen bricks or refractory bricks deeply, the protective kiln skin should be added to protect the kiln shell from heat damage

we must take advantage of the planned shutdown opportunity to actually measure the situation in the kiln, record the growth of the kiln skin, including length, position, uniformity and thickness, record the thickness of each refractory brick section, and calculate the wear rate. And compared with the drawings printed out before the kiln is stopped, so that we can more accurately understand the functional graphics, and understand the changes of kiln skin and kiln lining from the change of graphics

four aspects of control can be achieved by using this system:

preventive control to avoid bad conditions of kiln lining

carry out corrective control to produce protective kiln skin on the damaged lining while the kiln is running

repair plan control, plan the scope of kiln lining repair before shutdown

start control, monitor the kiln when starting the kiln to achieve the correct preheating and heating state

preventive control and corrective control are achieved through kiln control and adjustment. The main adjustment methods are:

adjust the feeding rate of the kiln. A lower feeding rate will produce a thicker kiln skin

by adjusting the composition of the raw material into the kiln, a higher lime saturation coefficient and silicon rate will produce a thinner kiln skin in the firing zone and form fewer circles

adjust the flame characteristics and air volume. A larger flame will produce a thicker kiln skin, and the performance standard of anchoring agent mt143.1 ⑵ 011. A higher excess air will produce a more stable kiln skin

fan cooling, air cooling is adopted at the hot spot, which is conducive to the production of protective kiln skin at this position

4 conclusion

infrared temperature scanning system has been used more and more widely in the cement industry in the world. Practice has proved that it extends the life of lining, protects the kiln barrel from damage, and achieves obvious economic results. Due to the short time of commissioning in our plant, the brick consumption per unit clinker cannot be calculated at present

in order to better develop and apply this technology, we need to constantly accumulate experience in application, which is conducive to the application and popularization of this technology

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