| 1.1 Lime Transportation Automatic Control System Structure Lime Transportation Automatic Control System is consisted of control stations, operating stations, the host computer and network systems. The Control Stations control the operation of the process equipment, detect the system status and process parameters from the production equipments, then control and regulate the equipments in accordance with the determined control principles. Main function of Operating Stations, operators monitor the site production status through the CRT real-time dynamic pictures, control and regulate the production process according to the actual site conditions, then analyze trends. Host computer is responsible for the recording, processing production data, printing reports and data communication. The means of communication among Control Stations, Operating Stations and Host Computer is Industrial Ethernet. The means of communication between Control Station and Remote IO rack is RIO network. Siemens S7-300 PLC are used for Main Control Station, which is responsible for collecting field data and driving devices, achieving the processing and transmission of data between the operating station and site. Base-Automatic Data transmission using point-to-point type and profibus-DP, with great performances at communication speed, stability and anti-interference ability. Therefore, Lime Transportation Automatic Control System is divided into two grading: the process grading and the basic control grading. The process-grading execute information processing, operations management, mathematical model, running expert systems as well as monitoring functions. The basic control-grading execute data acquisition, sequence control, process control and centralized operation equipment, include HMI and PLC systems. 1.2 Functions of the Lime Transportation Automatic Control System Processes of lime transportation: preparation system, injection system and auxiliary system. Functions of the control system are achieving the fully automatic preparation and injection, including logical chain control, security, real-time monitoring of equipment operating status, process parameters online, closed-loop control, alarm and setting operation, and so on. 1.3 Characteristic of Lime Transportation Automatic Control System □ Electrical & instrument equipment and control computer of the main process line form a unified information system, which control dispersed EIC integration system. □ The system uses computer grading control, which contains two grading, the basic automatic grading (equipment automatic control level) and process control grading (monitoring level), building the process production database and historical data records, creating the conditions to improve the production technology. □ The automatic system uses open architecture, has good scalability. □ The automatic control system focus on automatic operation, considering using kinds of CRT manual back-up means to make sure process production normally. □ Instruments and electrical equipments integrate, easy maintenance, least equipments. □ Low Cost Automation (LCA), basic automatic grading, use powerful Siemens S7300 PLC control system, the Advantech IPCs are used for process control grading, with universal software supporting, compact and effective functions. 1.4 Achievement □ Hebei SongTing Steel Company, lime transportation projects 1st and 2nd |