01 June 2002

Fieldbus solving chemical maker's growth problems

By Mark Vick

Growing chemical company gets more devices in current space

Bulk pharmaceutical ingredients maker Boehringer Ingelheim Chemicals faced serious expansion problems at its 200-acre site in Petersburg, Va.

The fast-growing manufacturer was running out of electrical equipment room space in its motor control center. At the same time, it needed more devices with improved reliability and accuracy. Adding to its challenges, the bosses were talking future expansion.

In short, BI Chemicals required a solution that accommodated its current space, worked as a jumping-off point for future expansion, and also handled the tremendous documentation requirements faced by all U.S. pharmaceutical industry suppliers.

A Foundation fieldbus (FF) network proved to be the answer, solving those issues while also lowering costs.

In conjunction with new production bays and environmental facilities, FF helped increase BI Chemicals' manufacturing capabilities and, perhaps more importantly, helped improve its documentation procedures for ISO 9002 compliance and maintain the company's Drug Enforcement Agency license for C-II controlled substances.

Plant runs 24/7

BI Chemicals ranks itself the world's largest private producer of active pharmaceutical ingredients and advanced intermediates used in drugs such as Alupent, Atrovent, and Mucosolvan. Its Petersburg, Va., site operates 24 hours a day, seven days a week. The facility includes a multipurpose inorganic chemicals plant, a hydrogenation plant, and a production building for controlled substances and high-potency compounds.

The specialty chemical maker's production environment is a combination of Class I/Division 1 and Division 2 hazardous areas, so any new system installation had to include intrinsically safe procedures and equipment. BI Chemicals also wanted to plan for the future, which meant using cutting-edge technology to both prevent obsolescence and improve production efficiency.

A collaborative effort among BI Chemicals, supplier Carotek, and integrator Control Dynamics, the BI Chemicals FF installation was a learning experience for all three companies.

BI Chemicals discovered it could reclaim some space in its control room. In addition, FF enabled all three parties to develop new technical solutions.

Because BI Chemicals' older process installation primarily used industrial programmable logic controllers for control, the switch to FF required an entirely new operating system. FF would control a variety of devices, ranging from automated valves to level meters and flowmeters, which meant the system would have to interpret both discrete and analog signals.

An Allen-Bradley system and Emerson Process Management's DeltaV were considered. Ultimately, BI Chemicals selected a DeltaV designed for use with intelligent FF devices that also offered batch control capabilities. The system's graphical interface eased integrating it into the production process with a modest amount of retraining.

In addition, previous experiences with Pepperl+Fuchs (P+F) equipment led BI Chemicals to contact Carotek to supply intrinsically safe isolators, repeaters, and barriers for the new FF installation. The repeaters saved costs by enabling BI Chemicals to maximize using DeltaV's native FF H1 (31.25 kilobits per second) I/O card. This meant it needed fewer H1 cards to maintain system capacity, reducing up-front equipment investment while speeding system completion.

A standard DeltaV H1 FF segment accommodates up to 16 field devices of varying types. However, in the intrinsically safe environment used at BI Chemicals, the FF segments must be limited to less than 70 mA, which means using only three or four valves and transmitters, each drawing approximately 17.5 mA, with each card.

With the repeaters and their built-in intrinsic safety equipment, it was possible to load up to 16 devices on a segment and still maintain the critical intrinsically safe signal levels. Currently, the BI Chemicals installation averages 10 to 12 field devices per segment.

Timing problems

Some issues arose at start-up. First was that devices were not communicating on the segment back to the controller.

Emerson certifies devices for use with DeltaV, which guarantees compatibility and durability and gives customers a great deal of confidence in their product and devices used with it. Unfortunately, at the time, the P+F repeaters had not been certified, adding to the troubleshooting difficulties. Emerson suggested using another company's product that had been certified but found it had no effect on the problem.

Tom Maxwell of Control Dynamics said: "Replacing the repeaters didn't change that problem."

During the repeater changeover, it was discovered the P+F repeaters had been wired incorrectly. But fixing the wiring and installing another supplier's repeaters did not solve the problem. But the company found performance actually improved once the P+F equipment was reinstalled. The problem ended up being a mechanical issue.

The diagnostics associated with FF allow users to monitor system checks so they can make adjustments to speed the operation of the discrete valves. The TopWorx FF units located on discrete valves were plug and play with the DeltaV system. This allowed easier commissioning/decommissioning of devices and built-in diagnostics.

Taking advantage of FF's extended capabilities, Control Dynamics installed a professional station in the

BI Chemicals maintenance shop. The station gives technicians a complete graphical overview of the entire system and enables them to remotely commission and configure all devices on the network, with full access to the digital diagnostic information available in FF devices.

The professional station also takes full advantage of DeltaV's diagnostic and calibration abilities. It allows BI Chemicals to have a device audit trail, a record of each device's commissioning date, date and time of each calibration, and calibration specifications. The audit trail includes a large amount of information, virtually eliminating calibration errors. New devices can be installed on the network, and the system automatically adds them to the database. This kind of documentation is especially useful for validation purposes, vital in the pharmaceutical industry.

"The professional station makes remotely configuring and calibrating the system very easy," Maxwell said. "With [the professional station], they can watch the entire plant from the maintenance room. They can do remote calibration and diagnostics, and the devices will even indicate when they are in need of recalibration. It really reduces the amount of time a technician has to spend in the field."

BI Chemicals said P+F/Elcon power supplies selected to power their network provide diagnostic abilities that complement those of the DeltaV system. Like the professional station, the power supplies improved reliability and reduced maintenance requirements.

"When their traditional power supply units failed, they switched to a backup," said Carotek's Trygve Teigen. "But when that backup failed, the only way [the technicians] knew anything had happened to the power supply was the process suddenly stopped, and alarms started going off. Not good."

The new power supplies have built-in fault alarms to prevent such situations. They also feature load sharing, which reduces up-front costs because redundant supplies are not required. BI Chemicals also likes the fact the power supplies are hot swappable, allowing quick and easy replacements without interrupting production.

Training is key

Today, efforts focus on making the system as reliable and rugged as possible. Technician training is key in this process. However, the DeltaV system offers training tools: BI Chemicals "can try any system changes ahead of time on a simulator, right there in the maintenance room," Maxwell said. "Operators can be familiarized with the system before they start in the field, giving them hands-on training in a variety of real-world situations. And if they have problems, they can just plug it into a phone connection, and we can help them diagnose them remotely on our own simulator."

With the system up and running, customer service became a factor. Teigen said he believes service was a primary reason his company's products were selected for the project. "When [BI Chemicals] was having problems, P+F sent engineers to solve them. A lot of other companies would have sent salesmen. That's no way to get answers when things aren't working right."

Maxwell feels the same. "We are as interested in making things right as [BI Chemicals] is. Everybody learned a lot from this project, and that can only help in the future. Making sure they were satisfied with the system's performance was our No. 1 goal."

Ultimately, BI Chemicals found FF met its expectations. DeltaV software's processing power gave it additional tools to improve process and certification procedures, along with a convenient way to monitor the entire system. Combined with the rugged repeaters, barriers, sensors, and power supplies that form the system's backbone, BI Chemicals improved reliability, reduced operating costs, and created room to expand in the future. Customer support was just icing on the cake. WBJ