Chemical Engineering Newsfront: Go With the Flow

Added capabilities of modern flowmeters help chemical processors increase efficiency and uptime, and reduce costs

Joy LePree

Click here for full pdf version of this article - includes all graphs, charts, tables, and author information

 

According to experts in flow measurement, any chemical processors seeking to optimize its processes in an effort to offset the rising prices of natural gas, electricity and raw materials may want to look at improving measurement and control via the added capabilities of modern flow technologies. Increasing productivity and process optimization very often involves system automation, says Jens Goebel from Siemens Industry Automation Division of Siemens Corp. (New York, N.Y.). "Increased use of flowmeters can contribute significantly in reaching that goal, as flowmeters are of paramount importance when it comes to process control and monitoring," he says. "More specifically, flowmeters ensure improved accuracy, which contributes to an enhanced quality, minimized waste and costs for disposal. The great reliability of the measurements also results in improved billing ability."

...

Magnetic Flowmeters 

As processors continually tighten their belts, new loop-powered magnetic flowmeters (sometimes called mag) are also showing up as a cost-cutting alternative to other measurement methods in the CPI. "Traditionally, magnetic flowmeters were the choice if there were solids involved because the design is free of obstructions," explains Bob Harvey, director of sales and marketing with Yamatake America Inc. (Phoenix, Ariz.). "But, being four wire devices, they were overlooked by chemical processors because of costly installation issues and hazard risks in chemical plants with explosive environments."

However, use of the loop-powered mag eliminates the need for the additional, and potentially hazardous, wiring. "In a new installation a loop-powered mag can have a dramatic savings in conduit costs over a four-wire mag," says Harvey. "When you can eliminate 50 ft of conduit times 10 magmeters on a project, the savings really begin to snowball."

Thanks to the new two-wire models, magnetic flowmeters are now being considered as potential replacements in situations where more traditional metering devices were used. High accuracies and turndown capabilities of loop-powered magnetic flowmeters can lead to reduced costs and dramatically increased uptime.

"Mag meters are free flowing, so there are no issues with solids coming down the line, which reduces maintenance costs associated with older style meters that seize when jammed by solids," says Harvey. "We have situations where people were spending $200 to 300 a couple times a year rebuilding turbine and other meters. Then they spend $1,800 to $2,100 on a two-wire mag, eliminate maintenance expenditures and the payback is fast." He adds that the accuracy, ability to handle solids, reduced mechanical wear and reduced need for calibration can quickly provide further savings.

Harvey notes that Yamatake's MagneW Two-Wire PLUS  loop-powered electromagnetic flowmeter has become a very strong product because the explosion-proof installation allows it to be placed in a lot of CPI applications where traditional magmeters couldn't have been used.