Flexibility with Fieldbus

Plant rebuilt in record time

For Harald Liebisch, team leader for automation at Basell in Frankfurt, an exciting phase started in December 2005 when the polymerization plant had to be rebuilt in record time: “Once the initial decisions regarding the new plant had been made at the end of the year, things moved very quickly”, Liebisch summarizes. “We were able to update the plant within three months and equip it with Foundation fieldbus lines.”

Liebisch had already had some initial experience with multibarriers, though he was not entirely satisfied with the results. When the Turck solution was presented, the decision was made very quickly: “We were immediately impressed by the full galvanic isolation of the Turck multibarriers,” the automation manager explained, “it was exactly this feature that was missing before.”

Multibarriers with full galvanic isolation

The Turck MBD-49-T415/Ex multibarrier allows for the installation of Ex-i drop lines up to 120 m in length. The full galvanic isolation is provided both between the trunk line and the output circuits as well as between the four output circuits. This prevents compensation currents from developing due to potential differences. The integrated short-circuit protection is activated if a short-circuit occurs at a fieldbus node. Only the output affected is disconnected – the trunk line and the other outputs of the affected fieldbus segment remain in operation.

Actual planning was able to be completed just as quickly as the decision process, thanks to the configuration tool from Turck. “We used the tool to make a preliminary plan of the segments. The length of the fieldbus lines, the division of the fieldbus barriers, the assignment of inputs to multibarriers – the configuration tool allowed us to define all these points very quickly,” Liebisch explained.

Broad base

A total of nine fieldbus lines are currently in operation at the Basell polymerization plant. Power conditioners connected upstream from each one are ­provided for supplying the fieldbus segments. The scope of this project also includes plans for expanding the Foundation Fieldbus network to 15 segments. “We are very happy with the Turck products,” Harald Liebisch says. “In addition to the galvanic isolation, their reliability and simple operation are outstanding. Since we have completely migrated to Turck, we have not had any more difficulties. We therefore also intend to implement the next expansion stage using Turck products.”

Conclusion

The changeover to fieldbus technology has enabled the installation planners at Basell in Frankfurt to create the basis for a flexible response to market requirements. The speed at which the installations can be adapted has already been put to the test with the first FF project. The installation in the polymerization plant had to be made operational as quickly as possible without a test phase.