by Walt Boyes

It is interesting to look at the flow control industry from time to time and see just what, if anything, is new. We go to the shows, and we look at the new product releases, and we often wonder if anybody is spending R&D money on flowmeters and flow controls.

Then somebody comes along and shows you what a little enterprising inventiveness can do.

The “Best of Show” product at ISA 2002 in Chicago is an example of this point. It is called “Digital Coriolis” and is a new, digital transmitter from the Foxboro division of Invensys.

Mike Jost of Foxboro said, in his acceptance speech, “In simple terms, what Digital Coriolis does is extend the applicability of Coriolis flowmeters. It solves problems associated with void fraction and entrained air. For any industry where flow is involved — oil and gas, food processing, chemicals and pharmaceuticals, for example — Digital Coriolis will improve productivity tremendously.”

While the product extends the Foxboro line significantly, the most innovative feature of their new transmitter is that it can be applied to any Coriolis primary element, from any manufacturer. This means that they’ve extended their reach outside their own customer base and made a really neat new product at the same time.

This is advanced thinking from an “old line” company.

There are many issues in flow control that can be addressed by innovative thinking. Another example is the use of multipath transit time ultrasonic flowmeters for custody transfer in the hydrocarbon industry. Multipath transit time meters are incredibly accurate and precise and with multichannel digital transmitters, can be used for mass flow, density and volumetric flow. The major problem with the current designs is how expensive they are. Typical units sell for tens of thousands of dollars.

What might happen if somebody designed a transit time ultrasonic flowmeter that was as accurate as an AWWA class turbine meter and sold for the same price? The only reason that mechanical meters are still used in water service is the fact that they are extremely inexpensive. A 6” cast iron turbine meter sells for less than half of the price of a 6” transit time meter. Even a transit time clamp-on meter is more expensive. An inexpensive transit time flowmeter might very well eliminate the Woltman-style turbine meter in water service.

For many years, Fischer and Porter, on-again off-again, manufactured the Swirlmeter. This device was a “vortex precession” flowmeter. It was one of the direct ancestors of the vortex shedding flowmeters of today. The Swirlmeter could work with no straight run, had an excellent accuracy, repeatability and turndown. But it was expensive to make and couldn’t compete, by itself, against vortex shedding flowmeters. In a highly innovative move, however, ABB (the successor to Fischer and Porter) has combined the Swirlmeter and its vortex shedding flowmeter. The sensor and transmitter are identical. The only thing that changes is the flow element body itself. For some applications, the vortex shedding spoolpiece is supplied. If there are problems with straight run or other flow profile disturbances, the Swirlmeter spoolpiece is furnished. Because each spoolpiece is the same laying length, if a vortex meter is installed and has problems in operation related to flow profile or a higher turndown is needed, ABB can swap out the spoolpiece to make the application work.

So, if these innovative solutions are still being done, in the economic climate of the first years of the 21st century, what other innovations in flow control can we expect to see?

How about a flowmeter with an embedded web server, and its own IP address?

In the mid-1990s, there was a flurry of excitement about a tiny single chip web server connected to the Internet by a graduate student at MIT. It wasn’t big enough to do anything, except prove the concept.

Now, several companies — including the one that this graduate student founded, Ipsil Inc. (www.ipsil.com) — are driving toward making it possible for even a paddlewheel flowmeter that sells for under $500 to have an embedded web server and be entirely Internet enabled.

What does this mean? Well, for one thing, it means a significant reduction in overhead in the control system. A sensor, control valve, or controller that is already IP-enabled and is designed to communicate directly to a browser or similar tool can be interrogated or operated by something as unsophisticated as a CGI script on an SSL encrypted Web site. Adding in an XML schema, it is apparent that most of the overhead of a conventional HMI goes away.

Combine this with wireless Ethernet, and it gets even more interesting. One of the significant cost savings of industrial fieldbus is the significant savings on wiring. Imagine the savings produced by a whole plant whose sensors and final control elements were wireless, with their own IP addresses, and communicated with each other and the plant management regardless of location!

Walt Boyes is a is a principal in Spitzer and Boyes LLC, offering engineering, expert witness, development, marketing, and distribution consulting for manufacturing and automation companies.