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Flow Research has been covering vortex flowmeters since our
first study on them in 2001. Our
latest report, The World Market for Vortex
Flowmeters, 6th Edition, shows that this useful and affordable meter is
still strong and continuing to experience steady market growth.
Vortex flowmeters, introduced to the market 50 years ago,
are versatile, reliable and accurate in measuring liquids, gases, and steam at a
competitive price -- and with equal ease. They are widely used for steam flow
measurement, and can handle the high temperatures of both saturated and
superheated steam.
Many vortex meters today offer accuracy better than one
percent, depending on the fluid and application.
They also have very favorable costs of acquisition, commissioning and
ownership.
With more suppliers entering the market and a growing
demand for gas flow measurement, we believe vortex flowmeters are uniquely
positioned for strong growth.
Since vortex flowmeters were first introduced to the market in 1969, the number of worldwide suppliers has grown to at least 35 and many changes have taken place in the market. Today there is a wide diversity of choices for customers to make when specifying or purchasing vortex flowmeters. Technical innovations include anti-vibration software and electronics, multivariable flowmeters, reduced bore meters, plastic vortex flowmeters, and much more.
What’s
new
Despite what has been slow growth in the vortex flowmeter market, there are signs that this flowmeter is breaking out of its slump. One sign is the major product enhancements that have occurred in the past five
years.
In addition, the American Petroleum Institute’s approval of its API 14.12 draft standard for using vortex flowmeters in single phase gas and steam custody transfer applications has boosted market growth as suppliers develop products that conform to the standard.
Reduced bore meters
Due to their design, vortex flowmeters have traditionally
had trouble measuring low flowrates. Suppliers have now introduced smaller bore
flowmeters that provide a stronger signal at the point of measurement and allow
the meter to more effectively and accurately measure low flows. Our study found that both single-line size and double-line size reduced
bore vortex flowmeters have become increasingly popular in the last few years.
Advantages of multivariable vortex flowmeters
Sierra Instruments (now part of TASI
Group) introduced the first multivariable vortex flowmeter in 1997. This flowmeter
included an RTD temperature sensor and a pressure transducer. By using information from these sensors, together with detection of vortices generated, the flowmeter can output volumetric flow, temperature, pressure, fluid density, and mass flow. Multivariable flowmeters measure more than one process variable, and typically use this information to compute mass flow. This makes the flowmeter measurement more accurate in
fluctuating temperature and pressure conditions.
In the past 10 years, a number of suppliers have also
introduced multivariable vortex flowmeters that use sensors to determine a
variety of factors: volumetric flow, temperature, pressure, fluid density, and
mass flow. While somewhat more
expensive than their single-variable, volumetric counterparts, multivariable
vortex flowmeters provide significantly more information. They are particularly
attractive for steam and gas flow measurement and are contributing to vortex
flowmeter market size growth.
Other suppliers that have introduced multivariable vortex
flowmeters include include ABB. Yokogawa, KROHNE, and Endress+Hauser.
Redundancy is increasingly important
In response to user demands for increased reliability and
certainty, manufacturers have introduced two redundant configurations: 1) a
single shedder bar with dual sensors and 2) dual vortex meters calibrated and
installed in tandem directly in the flowstream. Although the traditional installation with a single shedder bar and
sensor still dominates the market, our study determined that users see the value
of measurement redundancy.
Vibration Issues solved
One perennial problem with vortex flowmeters has been susceptibility to vibration error. Vibrations in the line can cause a vortex flowmeter to falsely generate a vortex signal, or to incorrectly read an existing vortex. Suppliers have responded to issues surrounding vibration by implementing software and electronics, including digital signal processing, that have reduced the susceptibility of vortex meters to interference from vibration.
How they work
Vortex flowmeters operate on a principle called the von Karman effect. This principle concerns the behavior of fluids when an obstacle is placed in the path of flow. Under the right conditions, the presence of the obstacle generates a series of alternative vortices called the von Karman street. This phenomenon occurs in liquid, gas, and steam, and has been observed in many diverse contexts including cloud layers passing an island and whitewater rapids.
In vortex flowmeters, the obstacle takes the form of an object with a broad, flat front called a bluff
body that is mounted at right angles to the
flowstream. Flow velocity is proportional to the frequency of the vortices and
flowrate is calculated by multiplying the area of the pipe times the velocity of the flow.
In order to compute the flowrate, vortex flowmeters count the
number of vortices generated by the bluff body using a variety of techniques.
The majority of vortex flowmeters use a piezoelectric sensor to detect vortices,
however some use a capacitive or ultrasonic sensor.
Previous Vortex Flowmeter Studies
The World Market for Vortex Flowmeters, 5th Edition
Previous Study -
December 2014
The World Market for Vortex Flowmeters, 4th Edition
Previous Study - July 2010
The World Market for Vortex
Flowmeters, 3rd Edition
Provides historical perspective
The World Market for Vortex Flowmeters, 2nd Edition
Provides historical perspective
The World Market for Vortex Flowmeters, 1st Edition
Provides historical perspective
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