The Azbil AX24R Reduced Bore Vortex Flowmeter

EXTENDED MEASURING RANGE FOR LOWER FLOW RATES

Much of the measuring range of a standard vortex flowmeter is at higher fluid velocities. Because of this, measurements at low flow conditions may be missed due to the low flow cutoff. To remedy this issue, users often install pipe reducers and a smaller than line size vortex meter to increase fluid velocities through the meter. The Azbil AX24R reduced bore vortex flowmeter has integrated reducing flanges, eliminating the need for separate pipe reducers and spool pieces. This integrated reduction extends the measuring range to capture lower flow rates.

CAPTURES STEAM FLOW IN BOTH HIGH AND LOW DEMAND SEASONS

Steam usage in heating systems can vary widely based on seasonal demands. These systems are commonly sized with the high demand season (colder weather) in mind, and little thought is given to the low demand season (warmer weather). This leads to a situation where steam flowmeters are oversized and may miss flow measurements at low flow conditions. AX24R reduced bore vortex flowmeters have an extended low flow measuring range, capturing both high and low demand seasons.

REDUCED INSTALLATION COSTS

Like most flowmeters, vortex flowmeters have requirements for unobstructed upstream and downstream piping lengths to ensure a proper flow profile through the meter. Adding pipe reducers adds cost and complexity to the piping design since those unobstructed piping lengths are required before and after the pipe reducers.

The AX24R reduced bore vortex flowmeter has integrated reducing flanges, eliminating the need for separate pipe reducers and spool pieces. Drastically reducing both the complexity and cost of the meter installation.

SAME FACE-TO-FACE DIMENSION AS A STANDARD VORTEX METER

AX24R reduced bore vortex flowmeters have the same face-to-face dimension as a standard AX24 flowmeter for pressure classes up to ANSI 600. So if process conditions change, the meter body size can be changed without any costly piping modifications. This is especially useful in project planning, as it allows for flexibility into the future.

For more information on the Azbil AX24R in New England, contact Piping Specialties / PSI Controls. Call 800-223-1468 or visit https://psi-team.com.

Reduced Bore Vortex Flowmeter Provides Better Measurement for Low Flow and Also Saves Cost

Azbil’s AX24 Multivariable Vortex Flowmeter offers accurate and reliable flow metering in a multivariable design. The multivariable design incorporates a high-accuracy velocity sensor, a precision platinum RTD temperature sensor, and a solid-state pressure transducer. The meter’s process connections match the line size but use integrated reducing flanges, and the meter body reduces in diameter, increasing the fluid velocity through the meter. Increasing the velocity in this fashion extends the meter’s measuring range to capture lower flow rates that a full line size meter might miss. 

READ HOW THE AZBIL AX24R EXTENDS MEASURING RANGE FOR LOWER FLOW RATES AND SAVES COST HERE

To learn more about the AX24R visit this page. 

For immediate action in New England, call Piping Specialties / PSI Control at 800-223-1468.

The Azbil AX Series of Vortex Inline Flow Meters

The AX Series of Vortex inline flowmeters measure flows of liquid, gas, and steam by measuring the rate at which vortices are alternately shed from a bluff body; this rate has been shown to be directly proportional to the flow velocity.

As flow passes a bluff body in the stream, vortices create pressure differentials which are measured by a piezoelectric crystal sensor, which converts these pulses into electrical signals. The meter uses an all-welded sensor design to create a strong unit and minimize potential leakage.

The Azbil AX Series can be configured to measure anything from simple volumetric flow of liquids and saturated steam up through multivariable measurements, including mass flow rate, pressure, temperature and density of liquids and steam.

Insertion style vortex meters measure fl ow by detecting the local velocity at a strategically located position within the pipe. Using local velocity, calculated by measuring the rate at which vortices are alternately shed from a bluff body within the sensor, the Azbil AX2300 uses parameters such as fluid type, pipe size, and Reynolds number to calculate accurate measurements.

Download the Azbil AX Series Vortex Flow Meter brochure here.

Azbil AX Series Vortex Flow Meters from Piping Specialties, Inc and PSI Controls

Operating Principles and Application of Vortex Flowmeters

Animation of vortices*

To an untrained ear, the term "vortex flowmeter" may conjure futuristic, potentially Star Wars inspired images of a hugely advanced machine meant for opening channels in warp-space. In reality, vortex flowmeters are application specific, industrial grade instruments designed to measure an important element of a fluid process control operation: flow rate.

Vortex flowmeters operate based on a scientific principle called the von Karman effect, which generally states that a fluid flow will alternately shed vortices when passing by a solid body. "Vortices" is the plural form of vortex, which is best described as a whirling mass, notably one in which suction forces operate, such as a whirlpool. Detecting the presence of the vortices and determining the frequency of their occurrence is used to provide an indication of fluid velocity. The velocity value can be combined with temperature, pressure, or density information to develop a mass flow calculation. Vortex flowmeters exhibit high reliability, with no moving parts, serving as a useful tool in the measurement of liquid, gas, and steam flow.

Photograph of vortices **

While different fluids present unique challenges when applying flowmeters, steam is considered one of the more difficult to measure due to its pressure, temperature, and potential mixture of liquid and vapor in the same line. Multiple types of steam, including wet steam, saturated steam, and superheated steam, are utilized in process plants and commercial installations, and are often related to power or heat transfer. Several of the currently available flow measurement technologies are not well suited for steam flow applications, leaving vortex flowmeters as something of a keystone in steam flow measurement.

Rangeability, defined as a ratio of maximum to minimum flow, is an important consideration for any measurement instrument, indicating its ability to measure over a range of conditions. Vortex flowmeter instruments generally exhibit wide rangeability, one of the positive aspects of the technology and vortex based instruments.

The advantages of the vortex flowmeter, in addition to the aforementioned rangeability and steam-specific implementation, include available accuracy of 1%, a linear output, and a lack of moving parts. It is necessary for the pipe containing the measured fluid to be completely filled in order to obtain useful measurements.

Vortex flowmeter
(Azbil)

Applications where the technology may face hurdles include flows of slurries or high viscosity liquids. These can prove unsuitable for measurement by the vortex flowmeter because they may not exhibit a suitable degree of the von Karman effect to facilitate accurate measurement. Measurements can be adversely impacted by pulsating flow, where differences in pressure from the relationship between two or more compressors or pumps in a system results in irregular fluid flow.

When properly applied, the vortex flowmeter is a reliable and low maintenance tool for measuring fluid flow. Frequently, vortex flow velocity measurement will be incorporated with the measurement of temperature and pressure in an instrument referred to as a multivariable flowmeter, used to develop a complete measurement set for calculating mass flow.

Whatever your flow measurement challenges, share them with a flow instrument specialist, combining your process knowledge with their product and technology expertise to develop effective solutions.

* Animation of vortex creation credit Cesareo de La Rosa Siqueira via Wikipedia.
** Photograph of vortices credit Jürgen Wagner via Wikipedia.

Magnetic Flowmeters: Principles and Applications

Magnetic Flowmeter (Azbil)

Crucial aspects of process control include the ability to accurately determine qualities and quantities of materials. In terms of appraising and working with fluids (such as liquids, steam, and gases) the flowmeter is a staple tool, with the simple goal of expressing the delivery of a subject fluid in a quantified manner. Measurement of media flow velocity can be used, along with other conditions, to determine volumetric or mass flow. The magnetic flowmeter, also called a magmeter, is one of several technologies used to measure fluid flow.

In general, magnetic flowmeters are sturdy, reliable devices able to withstand hazardous environments while returning precise measurements to operators of a wide variety of processes. The magnetic flowmeter has no moving parts. The operational principle of the device is powered by Faraday's Law, a fundamental scientific understanding which states that a voltage will be induced across any conductor moving at a right angle through a magnetic field, with the voltage being proportional to the velocity of the conductor. The principle allows for an inherently hard-to-measure quality of a substance to be expressed via the magmeter. In a magmeter application, the meter produces the magnetic field referred to in Faraday's Law. The conductor is the fluid. The actual measurement of a magnetic flowmeter is the induced voltage corresponding to fluid velocity. This can be used to determine volumetric flow and mass flow when combined with other measurements.

The magnetic flowmeter technology is not impacted by temperature, pressure, or density of the subject fluid. It is however, necessary to fill the entire cross section of the pipe in order to derive useful volumetric flow measurements. Faraday's Law relies on conductivity, so the fluid being measured has to be electrically conductive. Many hydrocarbons are not sufficiently conductive for a flow measurement using this method, nor are gases.

Magmeters apply Faraday's law by using two charged magnetic coils; fluid passes through the magnetic field produced by the coils. A precise measurement of the voltage generated in the fluid will be proportional to fluid velocity. The relationship between voltage and flow is theoretically a linear expression, yet some outside factors may present barriers and complications in the interaction of the instrument with the subject fluid. These complications include a higher amount of voltage in the liquid being processed, and coupling issues between the signal circuit, power source, and/or connective leads of both an inductive and capacitive nature.

In addition to salient factors such as price, accuracy, ease of use, and the size-scale of the flowmeter in relation to the fluid system, there are multiple reasons why magmeters are the unit of choice for certain applications. They are resistant to corrosion, and can provide accurate measurement of dirty fluids ' making them suitable for wastewater measurement. As mentioned, there are no moving parts in a magmeter, keeping maintenance to a minimum. Power requirements are also low. Instruments are available in a wide range of configurations, sizes, and construction materials to accommodate various process installation requirements.

As with all process measurement instruments, proper selection, configuration, and installation are the real keys to a successful project. Share your flow measurement challenges of all types with a process measurement specialist, combining your process knowledge with their product application expertise to develop an effective solution.

An Introduction to Industrial Flowmeters

Electromagnetic flowmeter
(courtesy of Azbil)

Flowmeters measure the rate or quantity of moving fluids, in most cases liquid or gas, in an open channel or closed conduit. There are two basic flow measuring systems: those which produce volumetric flow measurements and those delivering a weight or mass based measurement. These two systems, required in many industries such as power, chemical, and water, can be integrated into existing or new installations. For successful integration, the flow measurement systems can be installed in one of several methods, depending upon the technology employed by the instrument. For inline installation, fittings that create upstream and downstream connections that allow for flowmeter installation as an integral part of the piping system. Another configuration, direct insertion, will have a probe or assembly that extends into the piping cross section. There are also non-contact instruments that clamp on the exterior surface of the piping and gather measurements through the pipe wall without any contact with the flowing media.

Because they are needed for a variety of uses and industries,

Orifice plate
(Flow-Lin)

there are multiple types of flowmeters classified generally into four main groups: mechanical, inferential, electrical, and other.

Quantity meters, more commonly known as positive displacement meters, mass flowmeters, and fixed restriction variable head type flowmeters all fall beneath the mechanical category. Fixed restriction variable head type flowmeters use different sensors and tubes, such as orifice plates, flow nozzles, and venturi and pitot tubes.

Inferential flowmeters include turbine and target flowmeters, as well as variable area flowmeters also known as rotameters.

Thermal Mass Flowmeter

(Kurz)

Laser doppler anemometers, ultrasonic flowmeters, thermal mass, and electromagnetic flowmeters are all electrical-type flowmeters.

The many application classes throughout the processing industries have led to the development of a wide range of flow measurement technologies and products. Each has its own advantages under certain operating conditions. Sorting through the choices and selecting the best technology for an application can be accomplished by consulting with a process instrumentation specialist. The combination of your own process knowledge and experience with their product application expertise will develop an effective solution.

For more information regarding any type or style of flowmeter, visit http://www.psi-team.com or call 800-223-1468.