Research And Application Of Automatic Control System In Cement Industry Based On Fieldbus

Automation is very important in the cement manufacturing, especially in modern cement production line. Only applying automatic system to supervise and control the condition of the equipments in real time can make the whole system effectively run. This paper introduces the application of Fieldbus technology in cement manufacturing and also introduces author's valuable working experience extracted from automation rebuilding design of HuBei Baoshi Cement Manufacturing Group.Firstly, this paper presents the background and content of the project, describes the technique procedure, equipments characteristic, universal controlling method of cement manufacturing and technologies related with Fieldbus.Taking automation rebuilding design of HuBei Baoshi Cement Manufacturing Group as the paper's main research object, author presents the Fieldbus technology merged with DCS (Distributed Control System) system and PLC (Programmable Logic controller ) controlling on the basis of analyzing cement technique trait and automation system status, Which can represents the digital, intelligent and open characteristic of Fieldbus technology, good programming computation and easy configuring of DCS, and flexible configuration and inexpensive price of PLC.According to the technique procedure, equipments peculiarity, automation demands of the production line of No. 4 kiln of HuBei Baoshi Cement Manufacturing Group, the paper analyzes the control scheme, and presents applying Filed Bus control scheme to the concentrate measuring and controlling points, such as the pre-heater of kiln tail, the cooler of kiln head, the vertical mill and distributing balance of raw material and so on. As for the distributed measuring and controlling points, the traditional DCS controlling method was used. Therefore the advantage and characteristic of Fieldbus can be put into practice, which could greatly reduces insulator, terminal box, I/O modules, cable and cable bridges, improves measuring, transmitting and controlling accuracy of the spot signal, and elevates running reliability of the system. At the same time, the original instruments and equipments of the DCS system could be economically saved.Moreover, this paper introduces the analysis and design of automation system of the production line at length, including the spot controlling unit, the central controlling unit, hardware and software, communication connecting and electricalcontrol. Also introduces the technique analysis and controlling method design of the raw material preparation, rotating kiln system and coal powder preparation. Describes the system design in detail, such as the main control interface, the system main interface, the system flow diagram, group start and stop, equipments selecting, emergency and fault reset, alarming picture, tendency picture, speed setting, raw material feeding, feeding operation, production reporting table and so on.At last, the paper summarizes the application of automation rebuilding project of No. 4 kiln of HuBei Baoshi Cement Manufacturing Group, and prospects the automation technology development of the cement manufacturing.