Coriolis Flowmeter Finds 'Vanishing' Product in Specialty Chemical Batch Processing
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The Foxboro Measurements & Instruments Division of Invensys Process Systems (www.foxboro.com/instrumentation) is providing advanced digital Coriolis technology to assist Great Lakes Chemical Corporation
(e1.greatlakes.com/corp/common/jsp/index.jsp) in accurately reading flow in their chemical batch process, reducing material loss and increasing productivity. Great Lakes Chemical is the world's leading producer of certain specialty chemicals for applications such as water treatment, household cleaners, flame retardants, and performance chemicals.
Foxboro, MA May 19, 2006 -- The Foxboro Measurements & Instruments Division of Invensys Process Systems (www.foxboro.com/instrumentation) is providing advanced digital Coriolis technology to assist Great Lakes Chemical Corporation (e1.greatlakes.com/corp/common/jsp/index.jsp) in accurately reading flow in their chemical batch process, reducing material loss and increasing productivity. Great Lakes Chemical is the world's leading producer of certain specialty chemicals for applications such as water treatment, household cleaners, flame retardants, and performance chemicals.
At the Great Lakes Chemical facility in Manchester, UK, a Foxboro CFT50 digital Coriolis transmitter was installed to address particular trouble with a batch line that makes a variety of water treatment chemicals for heating systems and desalination. The application involves combining three feeds into a tank, blending and pH balancing the batch, and pumping it into a storage tank. With some batches the product needs to be filtered when it is pumped from the tank, which reduces the flow and increases metering problems.
Accurate flow measurement at the beginning and end of batch runs is a common problem in industries ranging from chemical to food processing. Typically the flow meter starts empty, suffers the "hit" from the onset of process fluid, meters the bulk of the fluid, and then encounters slugs and two-phase flow at the end of the batch. While no flowmeter technology performs especially well in these conditions, Coriolis meters, which are most accurate when full of fluid, are especially vulnerable to start and end conditions.
"We had huge discrepancies between the metered inputs and the output, and it was clear that the Coriolis meters were not 'seeing' all the product passing through," says Roger Marsden, director of Westmeade Services Limited, who provides technical support for Great Lakes Chemicals. Depending on the flowrate, up to 200 kg of product was missing. And in situations where the product had to be filtered, as much as a 1000 kg went unmetered. "We have other clients with similar problems, and we pride ourselves in supporting the latest technology. Upon learning of the Foxboro CFT50 digital Coriolis flowmeter, we arranged a trial," says Marsden.
Great Lakes Chemicals implemented the Foxboro CFT50 digital Coriolis transmitter at the Manchester site and recent trials indicate that the transmitter can resolve the problem. The instrument has demonstrated what engineers at Westmeade say is a "remarkable ability" to meter accurately during the difficult start and end stages of the batch.
The Foxboro CFT50 was installed in series with the existing meter on the outlet to properly compare performance. A chart recorder was used to capture data, with a two second update time. Data collected included the start and end of a typical batch, the two mass flow readings, and the Foxboro CFT50 density reading to indicate the percentage of air in the fluid.
Prior to the onset of flow, both meters showed a zero reading, while the density reading indicated that the meters were "wet and empty." Once the flow began, at 18 seconds, the CFT50 started up immediately, whereas the other meter required some 16 seconds to register the flow, allowing approximately 4 kg of material to pass through unmetered. Once the batch was in full flow the two meters matched each other. At the end of the batch, some two hours later, both meters registered the drop in flow at 130 minutes, but as the flowtubes drained the traditional Coriolis meter stalled. It failed to register the final blow-though of product.
"Based on proven performance, we now trust the CFT50, so the other meter will be pulled out," says Mark Wilkinson, I+E manager (instrumentation and electrical) at Great Lakes, who funded the trial. "We will be recommending the CFT50 to our clients for batching applications where entrained air is an issue," adds Roger Marsden. "This is a significant extension of Coriolis capability."
For more information on the CFT50 mass flow transmitter or other advanced Foxboro measurement and instrument devices, readers can contact their local Invensys/Foxboro representative, visit the Foxboro Measurements and Instruments Web Site at www.foxboro.com/instrumentation or call 866-746-6477 (508-549-2424 outside the U.S. and Canada). The CFT50 mass flow transmitter can also be purchased on-line at buyautomation.com.
About Invensys
Invensys is the world leader in industrial asset performance management. In addition to its rapidly expanding Global Solutions and Performance Management services groups, Invensys' automation businesses includes industry-leading brands such as Foxboro, Triconex, SimSci-Esscor, Wonderware, and Avantis, whose products are installed in more than 100,000 plants across the world. These range from small hybrid and batch plants to the world's largest upstream projects, refineries, gas plants, petrochemicals plants, power plants, and pulp and paper mills.
For more information on Invensys' process automation businesses, please visit www.invensys.com/ps. For more information on Invensys' groundbreaking InFusion enterprise control system, please visit www.infusionecs.com.
The Invensys Group (www.invensys.com) is headquartered in London and is listed on the London Stock Exchange, with approximately 30,000 employees working in 60 countries.
