Portland cement manufacturing involves the following technological stages: raw materials extraction; raw meal preparation and preheating, clinker burning, and cement grinding with additives. There are several methods of Portland cement manufacturing: wet, dry, semi-dry, and combined depending on how raw materials are mixed and prepared for burning. In the wet process the raw materials are crushed with the addition of water. The components are mixed and ground to a fine consistency of slurry which is a liquid creamy substance with water content of about 32-50%. After that, the slurry is pumped to the rotary kiln. In the dry process, the raw materials are reduced to a very fine powder known as raw meal. The raw meal is blended, corrected, and fed to the rotary kiln for burning.
Advantages of industrial automation integration:
Process automation of clinker manufacturing involves the following operations and equipment (one of DYCKERHOFF plants is taken as an example):
The scope of works performed:
Industrial automation systems that control the electric drives are configured on the basis of electrical machinery and software products produced by Siemens. Two-level integrated automation system is powered by Industrial Ethernet fiber optic loop. Simatic PCs are used as workstations, and Simatic S7-400 programmable logical controllers are applied as basic computing and control devices. Controllers are equipped with ЕТ200М distributed i/o stations based on Profibus DP fiber optic looped networks. The system also includes OSM and OLM optic switching modules.
Visualization and process control are based on Cemat software which is preconfigured for cement industry and makes part of Simatic Process Control System 7. Terminal Data server integrates information about all the processes and systems. Adjustable electric drives work on the basis of Schneider-made Altivar frequency converters controlled with the help of Profibus DP bus. All meters and sensors that measure temperature, pressure, flow, and consumption are Siemens products
Depending on the customer’s requirements, we can also develop applications based on electric drives, controls, and actuators (automatic breakers, electric contactors, thermal relays) produced by Ukrainian manufacturers.
Our other implemented projects use applications based on electric drives and actuators (automatic breakers, electric contactors, thermal relays) manufactured either by Siemens and Schneider or by Ukrainian producers, depending on the customer’s requirements.
Visualization systems rely either on Siemens-made WinCC software or on InTouch software developed by Wonderware.
Electric drives and actuators run under several control modes:
The amount of raw materials fed into the kiln;
The amount of gas fed into the burner;
The speed of the rotary kiln;
The performance of clinker coolers controlled by frequency converters via the open-loop automatic control system.
The operating modes are selected at the computer and confirmed at the local control panels.
The system calculates the following parameters from the beginning of the control period (e.g. shift, day, month, year) or for the entire control period:
Safety functions (blocking)
In case of emergency, the following safety measures are taken: