When a Danish manufacturer of speciality vegetable oils and fats decided to build a new processing plant, it opted for state of the art control technology. The result is an efficient, simple to run installation.
Danish firm Aarhus Oliefabrik has been producing refined vegetable oils and fats since 1871. Its main production unit in Aarhus, Denmark, uses state of the art plants to produce a wide range of specialty vegetable oils. As part of its growth programme, the company decided to build a completely new vegetable oil processing plant.
In planning the best possible automation system for the new plant, Aarhus engineers researched the latest technologies. Based on their findings, they specified the use of fieldbus technology, open architecture, easy programming, fast commissioning and high functionality for operators. In addition the engineers defined the module library, faceplates, and other automation tactics to secure a uniform structure across the plant.
After evaluating a number of suppliers, Aarhus chose PlantWeb digital plant architecture from Emerson Process Management, with the DeltaV digital automation system, and Foundation fieldbus communications technology.
"We found that the Emerson PlantWeb architecture supplies all imaginable requirements for an innovative automation system in the food and beverage processing industry,“ explained Aarhus automation engineer Jens Quist.
Now fully commissioned, the new plant features a central control room for two operators, each equipped with double DeltaV system monitors (Fig.1). There is an additional operator desk in the hazardous area of the plant, and seven distributed DeltaV controllers. AMS predictive maintenance software within the DeltaV system communicates with intelligent field devices over the Foundation fieldbus-based network, providing installation setup and configuration plus ongoing monitoring of field device and process health.
The Foundation fieldbus installation has 16 segments that connect instrumentation and valves. Typically four field devices are connected into each junction box in the extraction plant. Fig. 2 shows one such hazardous area installation where a Micro Motion Coriolis meter, a Fisher control valve with FIELDVUE digital valve controller, and a Rosemount temperature transmitter connect to the junction box (top left). Instrumentation from other suppliers is also linked to the Foundation fieldbus network. This installation approach and use of AMS software produced savings in plant commissioning, testing and documentation.
By introducing PlantWeb digital plant architecture, Aarhus has achieved its objective of a uniform automation structure across the plant. Since the DeltaV system within PlantWeb conforms to IEC1131-3, the different application software development contractors involved have been able to do their programming in one common platform, and access the modules, faceplates and standard programs provided.
The company also chose to utilise the DeltaV system because of its interfacing capabilities, demonstrated first by the connection to a Profibus-DP network to monitor several frequency converter inputs, and second by compatibility with legacy DCS systems installed from 1973 onwards. The integration capabilities allow extension of the DeltaV automation throughout the plant, enabling upgrade of additional plant areas.
At the business management level, PlantWeb architecture with the DeltaV digital automation system offers increased availability to data from the field instrumentation. Operators and higher level business systems within the plant are provided with improved plant efficiency by means of improved production surveillance, optimisation and resource planning.
Boy Konstmann, managing director for Emerson Process Management Denmark and Sweden, highlighted further key differentiation features that are an integral part of the PlantWeb offering: "The DeltaV system allows downloading of new programs and the application of new functions during plant operation, an important consideration for a continuously operating plant. Control options available including Fuzzy logic, Autotune and Neural- plus DeltaV Inspect and optimisation and simulation tools were all valued by Aarhus engineers. These tools were important not only during the engineering start-up phase, but also during plant operation, as they enabled the process to be monitored and optimised.“
Foundation fieldbus provides Aarhus with the optimal conditions for transmitting parameter and operational data from the plant. With all this vital data from field instrumentation available for diagnostics, calibration and configuration, it is easy to reduce maintenance costs by initiating a predictive maintenance scheme.
AMS software enables the Aarhus maintenance organisation to monitor status for all field units, and base its maintenance schedules on this information. This will allow a reduction in both scheduled and unintentional operation shutdowns.
The company is now putting all these new tools to good use in the new plant. Its next project will be to extend PlantWeb architecture to include the boiler plant.
This extension will include one central and three local operator control stations, running five controllers for steam production. The experience gained and best practices established through implementing digital plant architecture and the fieldbus technology will continue to enable improvements in manufacturing operations efficiency.
More information is available from Emerson Process Management, tel +44 (0)151 604 3045, fax +44 (0)151 604 1222, email Emerson.Process@respond.uk.com, www.EmersonProcess.com
