The Research On State Monitoring System For Rotary Cement Kiln Based On Infrared Temperature-measurement

In the cement industry, calcining cement clinker is the most important technicalprocedure in the whole production process. And the rotary kiln is the core of this technicalprocedure. The working condition of the rotary kiln is directly related to the output, quality,fuel consumption and costs of the process. Excessive temperature inside and excessivethermal oscillation of rotary kiln may damage the kiln lining, even the kiln cylinder. Whenthe rotary kiln operates, the kiln's inside condition should be always kept an eye on, and theappropriate measures should be taken in a timely fashion to prevent the damage of kiln liningand body. Only then, can the rotary kiln operate economically. In practice, unfortunately, it isdifficult to directly monitor the inner calcination and the variation in thickness of kiln body.However, there is a searing temperature field around the surface of kiln body. Thistemperature field is formed by various factors inside and outside the kiln, and contains a greatdeal of information about the kiln body. To a large extent, this information objectivelyreflects the kiln body's changes inside. Timely analysis of the kiln body's surface temperaturereceived from monitoring can infer the main condition of the kiln body and to provide theworkers with necessary reference, thus to ensure that the operators can take prompt andeffective measures to guarantee the normal production process.According to this method, this research project developed a rotary cement kilnmonitoring system based on infrared temperature-measuring. The kiln body surfacetemperature can be monitored in real-time and continuously by adding auxiliary devices and infrared temperature-measuring scanner. The measured data can be sent into computer foranalysis and treatment through PLC. This system receives data with Main Memory Databasecache to guarantee data instantaneity. According to the production process of rotary kiln, thissystem designs an appropriate kiln surface positioning method to determine the exactpositions of the monitored points on the kiln surface; and then according to the distribution ofthe monitored points, this system designs their coordinates on kiln surface, and thesecoordinates can help transmit the corresponding points' information into the monitoringimages, and furthermore, the data storage structures corresponding to the coordinates aredesigned. According to the monitored data's features, this system also designs the appropriatehistorical data storage method to analyze the data of specific position. This system usescomputer graphics technology to present the monitored point information to the users in theform of graphs and images. By these graphs and images, the users can know the distributionand change of temperature in the monitored field. According to the malfunction phenomenaof kiln body, the system uses the collected data to design a method which can automaticallyidentify kiln body malfunctions, and those malfunctions will be marked in the monitoringimages; thus, some common malfunctions of kiln body can be identified and pre-warnedintellectually. According to the characteristics of the system network structure, this systemalso designs the appropriate data distribution strategy and method to enable thecommunication between client-side and Web server.Through those aforementioned designs, the operators can thoroughly learn much moreinformation about the kiln body such as: the surface temperature distribution, temperaturechange of specific position, whether there exists inner kiln-ringing or the position ofkiln-ringing, whether the kiln skin or kiln lining drops or the position of drops, whether thekiln surface exists hot spot or the position of hot spot, and so on. All these information canhelp the workers to effectively improve the routine operation and maintenance toward rotarykiln, improve the stability of clinker calcinations, reduce the labor intensity and improve theeconomical working result of rotary kiln. In addition, the monitored data of kiln body can besent to the monitoring terminals, by which the users can obtain the real-time consistent withthe server-side and the data processing result. Moreover, the monitored data of kiln body canbe shown on the enterprise webpage, and thus the customers can know the productioncondition of rotary kiln, which can push the enterprise to become more competitive in themarket and enhance the social benefits.