Go with the flow
Added capabilities of modern flowmeters help chemical processors increase efficiency and uptime, and reduce costs
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.”
Apparently more processors are following this advice by taking advantage of improvements in flow technologies. “We are seeing a switch from the practice of changing out flowmeters on an as needed basis to seeing plant managers moving toward advanced technologies in an effort to save energy, improve productivity and optimize the plant,” says Thomas Swihart, director of industrial sales worldwide with Mc- Crometer (Hemet, Calif.).
But what are they switching to? According to the experts, orifice plate, venturi tube and other traditional methods have been used in the chemical process industries (CPI) for what seems like eons, but advances in other flowmeter methodologies are sending processors on a quest for more modern technologies with advanced features.
Recently, many flowmetering techniques that were previously overlooked for chemical processes have received updates that make them more suitable for these applications. In addition to bringing the benefits of advanced technologies, such as increased accuracy and reliability, many of these techniques can help boost efficiency and productivity, while reducing costs for electricity, natural gas and other raw materials.
Traditionally, the clamp-on attribute of ultrasonic measurement methods didn’t perform as well as chemical processors required, so the industry as a whole often passed it by. However, in the last few years there’s been a lot of advancement in the signal conditioning associated with taking a good reading in an application where you aren’t directly in contact with the process, says Jack Roushey, global product manager for flow products with Honeywell Process Solutions (Phoenix, Ariz.). “The software advancements in ultrasonics have really allowed this type of meter to take more reliable measurements.”
And, because the meter can be installed without having to cut into the pipeline, it saves processors time and money on installation. In addition, says Roushey, if a processor requires verification of the process line, they have to verify the process loop again when equipment is put directly into a line. “By clamping a meter to the outside, you aren’t impacting the process line itself, so it can save a lot of paperwork in addition to the actual physical cost of installation.”
Like other manufacturers of ultrasonics, Honeywell is giving its model a revamp. Its VersaFlow Sonic 1000 is an ultrasonic clamp-on flowmeter that can be mounted on the outside of a pipe to measure the flowrate of liquids. Installation takes only minutes and requires no special tools. Additionally, the converter is pre-installed on the rail at the factory, further reducing installation time. The unit’s design includes robust industrial construction, is insensitive to corrosive materials and provides accurate measurements independent of conductivity, viscosity, temperature, density and pressure.
Inline ultrasonic flowmeters are also realizing major technological improvements. For instance, the Innova-Sonic In-Line from Sierra Instruments (Monterey, Calif.), a state-of-the-art digital correlation transit-time ultrasonic flowmeter, offers an order-of-magnitude improvement in transit-time measurement technology over typical units, enabling superior response to changes in flows, as well as impressive low flow detection. The advanced technology allows the ultrasonic transit time-of-flight to be measured in picoseconds (10–12 s) for high resolution and extreme lowflow detection rather than the typical nanoseconds (10–9 s).