Analog vs Digital
Most of the machinery in the cement industry is operated by a computer which will be monitored by an operator. For example a sophisticated unloader where its performance and discharge rate are influenced on the balance between an operator, valve sequence, correct pressures and process control, it is of most importance that the operator is aware of each condition and/or status of the unloader during this process.
Previously we were limited to analog visualization of such process by the use of a fixed mimic process scheme, flashing bulbs, audio warnings, mechanic switches and the need of understanding the full operation and case of alarms followed by trouble shooting for fixing them.
A Programmable Logic Controller (PLC) or is a digital computer used for automation of the unloader process. Unlike a typical computer the PLC is designed for multiple inputs and output arrangements, extended temperature ranges, immunity to electrical noise, and resistance to vibration and impact. The program or ladder logic used to control the machine operation is stored in a battery-backed or non-volatile memory.
Nowadays we have the option to boost the available information and real-time visualization of each individual component by using and OIT or HMI.
The OIT or HMI (Human Machine Interface) is where the interaction between humans and the machine occurs. It provides critical feedback from the machine which aids the user in making the proper operational decisions. The OIT is a high visibility, high resolution touchscreen. The unloader also uses a redundant system with fixed controls so the machine can be operated in the event the screen fails or becomes damaged. The screen representations depicted are typical but may be modified depending on the application. These pages are representations of a typical unloader OIT control panel and may deviate from what is shown depending on the application.
The advantages by having such information visualization, is that the operator is guided by the computer, in case of failure, for the correct troubleshooting steps to reduce down time as much as possible. Besides this assistance another option is gaining a track record of the pressures throughout the system during the convey process. By analyzing these values, a clear indicator is provided of the “condition”, same as an electrocardiograph at humans.
A detailed explanation of this pressure monitoring analyses can be found here: http://www.lionbulkhandling.com/2017/06/27/heartbeat-pneumatic-ship-unloader/
The above examples are just a couple of the possibilities which can improve the performance and reduce downtimes on even existing “analog”systems by overhauling and/or retrofit them by the newest digital HMI.
In case you would like to see what can be improved on your equipment, please feel free to contact us for the variables.