Worldflow Knowledge Base

Blogs

We hope you enjoy these posts from Jesse Yoder, president of Flow Research.

  • The History of Thermal Flowmeters

    By Jesse Yoder, PhD

    The history of thermal flowmeters is fascinating. Thermal flowmeters were born on the West Coast of the United States —the result of independent development by first two, then three separate companies. One company was Fluid Components International (www.fluidcomponents.com), which began by developing thermal flow switches that were used in the oil patch. The switches detected the movement of oil in oil well pipes, but they didn’t evolve into actual flowmeters until 1981.

    The second strain of early development in the flowmeter marketplace was a result of the collaboration of John Olin, Ph.D., and Jerry Kurz, Ph.D. Both Olin and Kurz worked for Thermo Systems Inc. (TSI) in Minnesota from 1968 until the early 1970s. They used hot-wire anemometers in their research on air velocity profile and turbulence. The anemometers consisted of a heated, thin-film element. While these anemometers worked well for research purposes, they were too light for industrial environments.  

    While Olin and Kurz were doing research using anemometers, they were more interested in developing measurement products for industrial environments. This would require a more rugged device than an anemometer.  They approached TSI about developing industrial products, but TSI wasn’t interested. As a result, Olin and Kurz decided to start their own company, incorporating Sierra Instruments (www.sierrainstruments.com) in Minnesota in 1973. In 1975, they moved the company to California , packing the business up into two trucks, driving it across the Continental Divide to set up shop in Monterey .

    In 1977, Sierra Instruments was making both air sampling products and thermal flowmeters. That year, Jerry Kurz decided to become independent and formed Kurz Instruments (www.kurzinstruments.com). Sierra kept the air sampling products, while Kurz Instruments kept the thermal flowmeters.  However, Sierra got back into the flowmeter market in 1983.

    In the early 1980s, Sierra, Kurz, and Fluid Components were the only companies manufacturing thermal flowmeters. However, over time, more thermal flowmeter manufacturers arrived in the area of Monterey . These include Eldridge Products, Fox Thermal Instruments, and Sage Metering Inc.  Eventually, some of the larger flowmeter companies entered the market, including Endress+Hauser and ABB.  Magnetrol, a manufacturer of level and flow switches, also entered the thermal flowmeter market.  

  • The difference between thermal dispersion and calorimetric flowmeters

    By Jesse Yoder, PhD

    I believe I now see a difference between the thermal dispersion and calorimetric flowmeters. Thermal dispersion flowmeters measure flow by in two ways. One is by measuring the amount of power required to keep a constant temperature difference between a HEATED sensor and another temperature sensor in the flowstream. This is called the Constant Temperature method. In the Constant Power method, the amount of power or current to a heated sensor is kept constant. Mass flow is based on the difference in temperature between the temperature of the HEATED sensor and a second temperature sensor that measures the temperature of the flowstream. This is called the Constant Power or Constant Current method.

    In the calorimetric method, there is also a heated sensor. But there is one temperature sensor upstream of the HEATED sensor and one temperature sensor downstream from the heated sensor. So this involves two temperature sensors, differently placed, and one heated element.

    I concede that both are thermal type flowmeters, but they employ different principles. Here is my thesis. Thermal dispersion flowmeters were invented by Sierra, Kurz, and FCI in the mid-1970s, Mass flow controllers were invented by Hastings and others in the early to mid 1970s, but they are not thermal dispersion flowmeters but a different technology altogether. Nonetheless, they employ thermal principles. Calorimetric flowmeters were invented by Gunther Weber and others in the 1970s. They employ a thermal principle, but not a thermal dispersion principle. Instead, the principle is based on the displacement of temperature profiles.

    I have written two articles on the history of thermal flowmeters for Flow Control. In each case, I have heard various people object to my analysis and say “We were first,” Well, say what you want, but the fact is that there are at least three distinct types of thermal flowmeters: thermal dispersion, mass flow controllers, and calorimetric. And If I write an article about thermal dispersion flowmeters, or about mass flow controllers, it is beside the point if people come out and say “We were first in developing some other technology that you weren’t writing about.”  Each of the three technologies should stand on its own and be treated historically as unique and different from the other technologies.

  • Filling in the Blanks in the Vortex Story

    By Jesse Yoder, PhD

    I’ve learned a lot since I first set out to determine who introduced the first working commercial vortex flowmeter. I found out that it was Yokogawa in Japan, who introduced insertion vortex meters for flare stacks. The development of this meter was done in Japan, and was based on university and academic research. This was Yokogawa’s main vortex meter until 1979, when it came out with the YEWFLO.

    The other company involved in this story at the time was Eastech. Eastech was formed in 1968 by Dr. Douglas F. White, Alan E. Rodely, and Charles L. McMurtrie. Rodely was from Austria and was granted a German patent on vortex meters in 1968. However, this patent was not recognized in the United States. In 1969 Rodely filed a patent in the US for a bluff body flowmeter. This was granted in 1971. In 1973, Rodely received another patent a vortex meter for use in controlling air pollution in internal combustion engines. In 1974, Theodore Fussell received two patents involving the use of shuttle balls to detect vortices.

    I have heard the same story from several independent sources, and the patents bear it out. Eastech first began designing vortex flowmeters using shuttle balls to detect vortices coming off a bluff body. When this didn’t work well, the Eastech engineers turned to the use of thermistors to detect differences in temperature in the vortices. The problem with this approach was that the thermistors were not rugged enough to handle the swirls coming off the bluff body, so this approach was also not successful. It wasn’t until the Eastech engineers began using piezoelectric sensors that they were successful in building a viable vortex meter.

    Since Eastech did not receive patents for the use of shuttle balls in detecting vortices until 1974, it would appear that the above sequence of events occurred from 1973 to the late 1970s. In the meantime, Eastech was sold to Neptune International, which at that time was busy making oscillating piston (positive displacement) meters. While Eastech did succeed in making some commercial vortex meters during this time, no sales figures are available. It is safe to say the number of vortex meters that Eastech actually sold, if any, was quite small. All these events occurred long after Yokogawa introduced its first insertion vortex meter in Japan for flare stacks.

    In 1983, Neptune Eastech was sold to G. Corson Ellis Jr. Associates. This is the same person who was involved in forming Kessler Ellis Products (KEP). Ellis called his vortex products “Neptune Vortex.” It is highly likely that it was Corson Ellis and an associate, possibly Theodore Fussell, that sold Neptune Vortex to Frank Sinclair in 2000. Sinclair retired the product line in 2001.

    In the meantime, Frank Sinclair purchased the ultrasonic product line from Badger Meter. He called his new company Eastech Flow Controls. Frank Sinclair received a patent for the cartridge meter, an ultrasonic meter designed to measure flow in partially filled pipes, in 2010. This is a product that Eastech Flow Controls still sells today. Badger Meter, meanwhile, got back into the ultrasonic business when it purchased Racine Federated in 2012.

    Dynasonics was the ultrasonic division of Racine. In 2016, Badger also absorbed the vortex meters of Nice Instrumentation, a company founded by Gerry Nice in 1985. Gerry Nice had worked for Neptune Eastech in the mid 1970s and then Kessler Ellis Products before forming Nice Instrumentation in 1985.
    The accompanying graphic shows the timeline for the development of Eastech’s vortex meters. For more information, go to http://www.flowresearch.com/vortex.

    In the meantime, Frank Sinclair purchased the ultrasonic product line from Badger Meter. He called his new company Eastech Flow Controls. Frank Sinclair received a patent for the cartridge meter, an ultrasonic meter designed to measure flow in partially filled pipes, in 2010. This is a product that Eastech Flow Controls still sells today. Badger Meter, meanwhile, got back into the ultrasonic business when it purchased Racine Federated in 2012. Dynasonics was the ultrasonic division of Racine.

    In 2016, Badger also absorbed the vortex meters of Nice Instrumentation, a company founded by Gerry Nice in 1985. Gerry Nice had worked for Neptune Eastech in the mid 1970s and then Kessler Ellis Products before forming Nice Instrumentation in 1985.

  • Did FMC Technologies have a Coriolis flowmeter?

    By Jesse Yoder, PhD

    After hours of research I have concluded the following:

    FMC sold a Coriolis flowmeter called the Apollo in the early 2000’s –a at least in 2004. This was for liquid measurement, and I don’t know who developed it.

    FMC partnered with Direct Measurement Corp. (DMC) on a straight tube Coriolis gas flowmeter. This meter was discontinued I believe in 2008.

    In 2003, FMC began offering 3 path and 6 path ultrasonic flowmeters called the MPU.

    In 2017, FMC was acquired by Technip and became TechnipFMC. About that time they started reselling the E+H Coriolis flowmeters, branded as the FMC 5000 Series.

    In 2023, FMC sold its Measurement Solutions business to One Equity Partners.

    There is much more to this story; however these are some of the measurement highlights. For those of you who don’t know, FMC stands for Food Machinery Corporation. FMC has a history of being involved with food production and food processing.

  • Calculating the Cross-Sectional Area of a Pipe

    by Jesse Yoder, PhD

    With all the sources of uncertainty in flow measurement, the last thing we need is another source of uncertainty based on the geometry of flow. Yet there is such a source of uncertainty that has to do with calculating the cross-sectional area of a pipe. Volumetric flow is defined as the actual volume of fluid that passes a given point in a pipe per unit time. This is determined by the following formula:

    Q = Av

    Here A is the cross-sectional area of the pipe and v is the average velocity of the fluid.

    The cross sectional area A is as follows:

    A = πr2

    Substituting for A in the formula for Q, we have:

    Q = Av = πr2 v

    Here Q = Volumetric flowrate

    A = the cross-sectional area of the pipe

    r = the internal radius of the pipe (also = D/2 where D is the internal diameter of the pipe)

    v = the average velocity of the flow

    It is really not possible to get around the use of π in this calculation because πr2 is the mathematical formula for calculating the area of a circle, and most pipes are round. Of course, this introduces another area of uncertainty in flow measurement, since not all pipes are perfectly round. They may be made “out of round,” or they may have build-up on the inside walls that makes them less than round. This is an important consideration for ultrasonic flowmeters, since it is important for ultrasonic flowmeters in computing flowrate to know the distance from one side of the pipe to the other. If a pipe is not exactly round, this may influence that distance.

    Most flow engineers are familiar with the use of π in calculating cross-sectional area. The value of π is the value of the ratio of the circumference of a circle to its diameter. While π has been computed to 105 trillion places, no exact value has ever been found, making π an irrational number with a nonrepeating decimal value. In place of π, when a value has to be assigned to it, most engineers use an approximate value, such as 22/7, 3.14, or 3.1416. As a result, they may choose to use a wavy equals sign (≈) to indicate that the two values are approximately, though not exactly, equal. This is exactly what engineers should do, since so far no one has found a way to precisely calculate the value of π.