The Vortex flow meter is the only type of flow meter that can measure all three fluid phases – liquid, gas, and steam. Vortex flowmeters make use of the only flow measurement technology capable of performing steam flow measurement in one integrated package; this ability makes it the best and most economical solution for steam flow measurement. The vortex meter can also be offered with integrated pressure and temperature measurement for both compressed gas and steam flow measurement in order to allow the meter to compensate for variations in pressure and temperature that will affect volumetric flow rate of compressible media. The vortex meter’s no-moving-parts design provides users with reliable, maintenance-free operation and long service life even in dirty and contaminated media applications.
The primary application for vortex flow meters is steam because no other flow meter can measure steam with only one sensor. Other technologies, such as DP flow meters, must measure flow, temperature and pressure in order to determine standard steam flows. The SmartMeasurementTM ALVT standard vortex meter measures steam flow at a fixed pressure and temperature. In applications where pressures and/or temperatures are not constant, our ALVT-mass Vortex flow meters are ideal because they incorporate fully integrated pressure and temperature sensors to compensate for dynamic process changes. These meters are also ideal for gas mass flow measurement. The ALVT vortex meter’s no-moving-parts design provides users with reliable, maintenance-free operation with long service life, even in dirty and contaminated media applications.
Vortex flow meters from SmartMeasurement have been successfully installed in a wide variety of industries and applications including:
The primary source of energy is using fossil fuel plants that use steam to generate electricity. Smart Measurement’s ALVT Vortex flow meters are ideal for steam measurement and offer many advantages including easy installation without impulse lines, no moving parts to maintain or repair, less leak potential, and a wide flow turndown range. Vortex meters also offer very low power consumption compared to other flow measurement devices. For steam measurement, the only alternative to vortex meters is a differential pressure flow measuring device which requires several sensors in order to provide an equivalent output to a vortex flowmeter. In applications where process conditions such as pressure and/or temperature are not constant, Smart Measurement offers a fully compensated ALVT-Mass flow meter with an integrated pressure and temperature sensing device. Vortex flowmeters are the flow measurement technology of choice for steam applications.
SmartMeasurement’s Multi Variable Vortex Flow Meters automatically adjust for changes in density, making it easy to accurately measure mass and corrected volume flows in steam and gas applications. Steam measurement accuracy requires the highest degree of safety and reliability and our proprietary all-cast design, gasket- free, sealed meter body eliminates leak points and offers users ease of mind. Moreover, having no moving parts or need to install impulse lines means fewer process disturbances and smoother operations.
Please visit our industrial measurement applications section to find more detailed information about where our Vortex flow meters have been successfully used.
Request a quote for vortex flow meters for your application, or contact SmartMeasurement to learn more.
Smart vortex meters employ the vortex flow measurement technique combined with a microprocessor-based flow computer which automatically corrects for insufficient straight pipe conditions inside its flow body as well as diagnostic information which can identify problems with both the meter and with the application.
Mass flow vortex meters include integrated pressure and temperature sensors to detect process pressure and temperature in addition to the vortex frequency. With the ability to measure the media pressure, temperature, and flow velocity, the mass flow vortex meter is able to determine the density and the mass flow rate. Typical accuracies for this style of meter are 1.25% of reading for measuring the compensated mass flow of liquids and a 2% of reading for gasses and steam. The multi-parameter capability of this meter provides an additional benefit for applications where knowledge of process temperature and pressure measurement is required or is of value for other reasons. In those situations, a mass flow vortex meter provides a convenient, less costly alternative to installing separate transmitters.
Steam measurement is the most popular application for vortex flow meters as they are far more economical and easier to install versus other flow measurement technologies that have the ability to measure steam. However, the vortex meter has low flow and low-pressure limitations for compressed gasses. For liquids, some vortex meter manufacturers are unable to cancel out electrical noise, which can be considerable in liquid applications. Moreover, batch control applications must be avoided as it takes approximately 30 seconds or more to stabilize a flow rate reading. This is because vortex sensing meters count the number of vortices in a moving average technique in order to determine an instantaneous flow rate.
When fluids pass through a bluff body on the side of the bluff body where the vortex is initially formed, fluid velocity is higher, and pressure is lower. As the vortex moves downstream, it grows in strength and size, and then eventually detaches or sheds itself. (This is why vortex meters are sometimes referred to as vortex shedding meters.) Alternating vortices are formed on each side of the bluff body 180 degrees apart and are spaced at equal distances. In fluid mechanics, these vortices are referred to as a Karman Vortex Street. The frequency with which the vortices are formed, as well as the magnitude & length of the vortices, are directly proportional to the velocity of the flowing media. The animation below illustrates this phenomenon. This phenomenon can also observe as wind hits a flagpole and the flag moves from side to side. In this analogy, the flagpole acts as a bluff body causing the vortex formation and the rippling of the flag is the response to the vortices’ formation. In a closed pipe, the vortex effect is dissipated within a few pipe diameters downstream of the bluff body. The vortex meter counts the vortices in much the same way that a turbine flow meter counts rotations of a turbine’s blades, by making use of commonly available electronic components such as a piezoelectric sensor.
Vortex flow meters’ principle of operation is based on the work of early 20th-century Hungarian-American physicist Theodore von Karman. Von Karman discovered that when a non-streamlined obstruction (also referred to as a bluff body) is placed in the path of a flowing media, the fluid will alternately separate from the object on its two downstream sides. As this phenomenon occurs, the boundary layer becomes detached and curls back on itself and the fluid forms vortices (also called whirlpools or eddies). Von Karman also noted that the distance between the vortices was constant and depended solely on the size and geometry of the bluff body causing the vortices’ to be formed.
The frequency of the vortex formation and shedding depends on several factors: velocity of the fluid (V), width of the shedder (d), and Reynolds number (Re). The relationship of velocity with flow and frequency can be given as f = S × V/d, where S is the Strouhal number.
Bluff body geometries (square, rectangular, t-shaped, trapezoidal) and dimensions will vary from manufacturer to manufacturer; these design differences will provide for certain performance trade-offs. The bluff body’s width must occupy a large enough portion of the overall pipe diameter that the entire flow profile will participate in the vortex shedding process. It also must have protruding edges on the upstream face in order to fix the lines of flow separation, regardless of the flow rate. The bluff body’s length along the direction of the flow must be a certain minimum multiple of the bluff body width.
There are a number of different ways that a vortex meter may detect and count the vortices’ formation. The majority of vortex meters use piezoelectric or capacitance-type sensors which detect the pressure oscillation around the bluff body. The sensor detects pressure oscillation with a low voltage output signal which has the same frequency as the oscillation. These replaceable sensors can operate over a wide range of temperatures in order to accommodate all types of flow measurement applications ranging from cryogenic liquids to superheated steam. Sensors can be located inside or outside of the bluff body. Wetted sensors (outside the bluff body) sense the vortex pressure fluctuations and are enclosed in hardened cases to avoid corrosion and erosion effects. External sensors, typically piezo-electric strain gages, sense the vortex shedding indirectly through the force exerted on the shedder bar. External sensors are preferred for highly erosive/corrosive applications in order to reduce maintenance costs, while internal sensors provide better rangeability and low flow sensitivity. The internal sensor is also less sensitive to interference from ambient pipe vibrations.
The primary materials of construction for the Vortex flowmeter are typically either 304 or 316 stainless steels. Components fabricated from the stainless alloy would include the flow body, the bluff body, and the flanged process connections. Other key components include the sensor which counts the vortices, which is typically a piezoelectric type, and a display/transmitter module which can be mounted integrally or remotely. The vortex meter is typically offered as an inline meter with either flanged or wafer-type process connections, but it may also be provided as an insertion style probe. Vortex meters are sensitive to low Reynolds numbers and to velocity profile distortion.
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Our Vortex meters provides a cost-effective, reliable, low maintenance solution that can measure all three phases of a fluid; gas, liquid and steam.
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