The EO system was first started up, together with ABB experts, at Adana Cement on 11 May 2009 for process optimisation of clinker production line 4, which has an average capacity of 4500 tpd, including the control of the rotary kiln, calciner and clinker cooler. In a second step the raw mill of line 4 and coal mill 2 were included in the EO system.
The rotary kiln line, raw mill and coal mill were being operated by a PLC based central automation system in the plant.
In general, it is quite difficult to ensure process control with such a conventional automation system, looking at long term stability and consistency, due to shift-to-shift variations. Therefore, many unexpected negative instances may occur in the process conditions, leading to higher production costs.
The EO system is able to analyse all required process data simultaneously with a high sampling rate, while an operator normally follows a limited amount of data within a much greater time period. The result of the higher sampling rate with a much broader range of information is that all necessary actions are realised in time by EO. This leads to a much more stable and consistent operation, with the result that unnecessary energy consumption is prevented and process efficiency increases.
First, the communication between EO and the existing Scada system, Siemens PCS7, was achieved by means of current Ethernet infrastructure. In this way, the starting of mutual data traffic was enabled between EO and PLCs. The first three months was the period during which EO acquired process recognition. Within this period, process parameters and related operators actions were verified and saved by EO in its database.
Then, a mathematical model was formed by means of using the data already stored by EO and through discussions between the operators and process engineers. Process target parameters were determined and the final mathematical model was implemented. Transition software for both operator mode and EO mode was prepared using the mathematical model.
Before running the mathematical model and in order to be sure about the system safety, EO online/ offline transitions were tested. Some probable communication problems and process upsets were created, and the reactions of EO were observed.
The aim of this exercise was to check the process parameters and the reaction of EO during the safety process flow. After being sure of the system’s safety, a trial run for mathematical model was realised to observe the actions as taken by the best operator over 24 hours.
The EO was designed to run separate strategy modules for the different process areas, which are independent from each other in their operation. This makes it a flexible system and new modules can be added at any time.
During the first phase of optimisation at the Adana plant, EO was designed to control the kiln, calciner and clinker cooler with three modules. After the performance tests and final acceptance of EO system for these process areas, two further modules were added for the raw meal mill and coal mill. In this manner, the system now runs five separate modules for five process areas.
It is up to the operators to set EO online by selecting any of those five modules independently.
As long as the system is online, all PID controls are executed by EO. The program determines the set values in accordance with the strategy selected by the operator and assigns them to PIDs. After each data sampling, EO compares the process changes that occurred with the predicted changes calculated by the system and determines the new set values between the minimum/maximum limits given by the operator.
Deviations on parameters of control strategy can be monitored with trends and with EO signs and tools. EO provides comprehensive and easy to use tools based on web browser technology to create rich graphical user interface.
The operator sets the system offline during unexpected cases like breakdowns, process stops, etc. until the process recovers and then the operator sets it back online. EO does not start up the kiln and takes control when the kiln feed is low or the instrumentation is not in good working order.
When required, the possibility exists to interfere with the EO system by the firm expert via ADSL remote connection.