Diseño e Implementación de un Sistema de Control Automático Centralizado en el Área de Molienda de Puzolana Miag de la Planta Cemento Chimborazo.

Abstract

The desing and implementation of a Centralized Automatic Control System was carried at Pozzolana Milling area of Unión Cementera Nacional Planta Chimborazo Company. For implementing the system it was necessary to use a (PLC) Programmable Logic Controller as a main controller, an (HMI) Human Machine Interface for the startup, and for process monitoring, it was necesary to use PROFIBUS communication network with decentralized peripheral, as well as the use of electrical accesories for control and power circuits. To establish the start-stop sequence, the previous milling process was analyzed before its automation, in order to improve the production of pozzolana. GRAFCET tool (Sequential Fuctional Chart) was used in order to have a graphic representation of the system startup sequence by means of blocks, which fuction is established through input and output variables. The Programmable Logic Controller of the system was programmed by using fuction blocks and Simatic Manager Software. For the HMI (Human Machine Interface), it was necessary to use Wincc Flexible 2008 software, wich allowed creating a remote control for milling process. The new automatic control system was tested and resulted in 99% availability compared with the conventional system which allowed is now being used. It is concluded that the Centralized Automatic Control System is efficient in the pozzolana production and it reduces the MIAG mill breakdown due to electrical failure. It is recommended to carry out a maintenance program by the Production Technical Chief in order to improve the Automatic Control System.