Overall solution of the hottest kiln head monitori

The overall solution of kiln head monitoring system

Abstract: Based on a large amount of data and experience of monitoring and detection of cement rotary kiln for many years, this paper proposes a cement rotary kiln monitoring system based on image recognition system, kiln brick simulation system and temperature transfer index law, which is in the same information platform

1. Overview

in the production of new dry process cement, real-time monitoring of calcination in cement rotary kiln has become increasingly important. This is because the calcination in the cement rotary kiln is directly related to the output, quality, raw fuel consumption and cost of cement clinker. Too high calcination temperature and too large thermal oscillation will not only consume a lot of fuel, but may even damage the kiln lining, and even the kiln carcass in serious cases. Too low calcination temperature will seriously affect the quality of cement clinker

the calcination situation in the cement rotary kiln can usually be understood in many ways by monitoring the surface temperature of the carcass, detecting the flame temperature in the kiln head, and observing the state of the flame and clinker in the kiln. At present, most new dry process kilns in China are equipped with kiln shell surface temperature monitoring system, kiln head flame television monitoring system and colorimetric pyrometer. Because these devices can only reflect the local information in different stages of the cement rotary kiln calcination process, and most of these devices are in mutually independent working platforms, it is not conducive for operators to make an overall understanding and judgment of the whole calcination process information

through the reasonable configuration of kiln carcass temperature measurement system, kiln head multimedia flame monitoring system and colorimetric pyrometer, the system builds a platform to organically combine the measurement information of these equipment, which can not only understand and master the calcination situation in the cement rotary kiln in real time, but also guide the operators to make corresponding operations by extracting, processing and analyzing the key information of each equipment

the surface temperature of the kiln carcass is the result of the joint action of various factors inside and outside the kiln. By monitoring the surface temperature of the carcass, the flame temperature in the kiln head and the state of the flame and clinker in the kiln, we can understand the distribution and changes of the surface temperature in real time, extract useful information to reveal the conditions in the kiln after processing and analysis, and guide the operators to take corresponding measures in time, which is an effective technical means to realize the economic operation of the kiln

2. Current situation of domestic application of kiln head monitoring system

at present, many domestic cement enterprises have realized that the detection of most of the detection quantities of kiln head will bring considerable economic benefits to enterprises. Kiln carcass surface temperature, TV fire watching and colorimetric pyrometer have been their necessary monitoring equipment

however, the above three kinds of equipment are still independent of each other, and they are not even provided by the same manufacturer. In this way, not only do users have large investment and many maintenance equipment, but also it is not conducive for operators to make an overall understanding and judgment

for many years, we have been committed to the inspection of key monitoring and measurement of cement kiln head, obtained a large amount of data and summarized valuable experience. We also have some understanding of the relationship and interaction between them. The development of multimedia technology provides us with opportunities. Therefore, on the basis of preliminary research and use, we have combined the three as a whole solution to the kiln head as a set of system. At present, we have achieved relatively good results

3. Performance index of the system

⑴ carcass surface temperature scanning: using the fast line scanner, the temperature values of 50 lines can be obtained every second. There are 256 ~ 512 points on each line, and the scanning angle is from 45 ° to 90 °. The scanning range is generally the whole kiln (less than 60m), the distance between scanning points is 15 ~ 30cm, and the accuracy of temperature value is ± 0.5%. The temperature distribution of the whole kiln surface will be obtained after one turn of the kiln

⑵ colorimetric high temperature: the American high-temperature two-color infrared thermometer with variable focal length is selected, and the visual target screw sight is equipped during debugging. The target is accurate and convenient for the production process of the first long carbon chain nylon. The temperature measurement range of the thermometer is 60. The universal laboratory machine for wood-based panel adopts the warming exchange servo system in the international market to realize position control of 0 ~ 2000 ℃, the accuracy is ± 0.5%, and the response time is 7.5ms, The temperature value is output in two ways: 4 ~ 20ma/rs485

⑶ multimedia fire Watching: use the high-temperature needle space lens to focus the objects in the range of 0.8m ~ ∝ on the CCD of the color camera within the field angle of 45 ° ~ 90 °. The color camera converts the electrical signal on the CCD into a video signal, and the signal with a signal-to-noise ratio of 50dB is connected to the video image acquisition through the coaxial cable

4. Composition of the system

the main equipment used in this monitoring system are: infrared scanner, kiln position encoder, two-color infrared high-temperature probe, video image card, various protective covers, and industrial computer

5. Working process of the system

the composition of this system is relatively complex, and there are many auxiliary equipment. In order to further simplify the system composition, the collection of kiln carcass surface temperature and flame temperature are directly transmitted by RS485 signals into the computer, without adding a single chip microcomputer as an intermediate transition link

⑴ kiln carcass surface temperature monitoring system:

kiln position encoder transmits the detected position signals of kiln rotation to the digital input card built into the computer. After the signal is received by the computer, it sends a temperature request signal to the line scanner, which sends a group of temperature signals currently sampled to the computer through serial RS485, Through the reference and position signals generated by the kiln synchronous trigger device and the kiln position encoder, the computer collects the surface temperature of the whole kiln repeatedly, reflects various situations in the kiln from multi-level, multi-directional and multi angle directions, and converts from a simple graphic qualitative description to a multi-functional display with both qualitative and quantitative description functions

the information provided to users includes: circumferential temperature curve, axial temperature curve, two-dimensional chromaticity expansion diagram, three-dimensional temperature curve, etc

⑵ multimedia fire viewing:

the camera converts the flame and clinker in the kiln head in real time. Considering that it will take a lot of CPU time to collect images in real time, and considering that there is a certain time for the movement of clinker, we set the collection of video signals transmitted by the camera at 3 seconds, that is, collect images every 3 seconds

the collected image passes the