Zeus Control has implemented¬†automation projects in¬†the cement industry since its early years.
Zeus Control Cement department has a highly experienced group of technicians specialized in¬†cement production plant processes, from the preparation of raw materials to clinker grinding and cement silage. Specialists in grinding installations with vertical mills for raw materials, coal, clinker and slag.
Vertical mills are gradually replacing horizontal mills in cement plants due to¬†better energy efficiency in the grinding¬†process. Vertical milling is a more sophisticated technology and hence requires a control system that can accurately deal with a big number of¬†variables.
Truncated-cone rollers rolling on a table have been used for centuries in many different grinding processes. The cement industry has¬†significantly sophisticated¬†this ancient technology to¬†grind very hard materials and obtain the necessary fineness.
A hydraulic system amplifies the pressure exerted on the rotary table by the rolling rollers. A hot gas generator or other source of energy, such as a gas furnace, supplies¬†thermal energy to the gas flow that passes through the milling chamber thus¬†obtaining optimal grinding conditions. A dynamic classifier of particles placed in the transport circuit, between the mill and the bag filter, optimizes separation of final product.
To maximize efficiency in the¬†grinding process it is necessary to maintain¬†some key variables
within¬†narrow margins. The control system is¬†in charge of that. Key variables in the grinding process are: hydraulic pressure, gas flow, gas temperature, differential pressure in the mill,¬†pressure in the mill’s gas inlet to the mill and composition of materials that feed the grinding plant.
Coal mills have¬†an¬†additional requirement because there is a significant explosion hazard¬†in areas where¬†coal dust¬†is handled¬†and the¬†appropriate preventive measures must be taken.
Combustion can¬†start very easily in places where¬†coal dust is in the presence of oxygen. It is important to detect¬†combustion at the very¬†beginning to keep it from spreading and causing explosions. Gas analysis, particularly carbon monoxide analysis, in ducts where coal dust is processed allows to take preventive¬†measures. Significant concentration of carbon monoxide is a clear sign that the combustion process has started.
Electrical equipment, instruments and control technologies applied must meet¬†ATEX requirements for hazardous areas.
Zeus Control technicians have participated in projects of vertical mill facilities in many countries all over the world: Argentina, Bulgaria, Colombia, Spain, USA, France, Morocco, Mexico, Panama and Dominican Republic.