Showing posts with label Niagara. Show all posts
Showing posts with label Niagara. Show all posts

Thursday, March 22, 2018

What Are Turbine Flow Meters?

Turbine Flow Meter
Turbine Flow Meter (Niagara WPX)
Turbine flow meters are process instruments used in a variety of industrial applications to measure the flow of a fluids. These types of flow meters operate under the simple principle that the rotation of the turbine will be constant as the turbine is acted upon by a fluid passing through the flow meter.

Turbine flow meters use the mechanical energy of the fluid to rotate a turbine blade in the flow stream and provide precise and accurate flow measurement. The flow impinging upon the turbine blades causes the rotor to spin. The angular velocity of a turbine flow meter is proportional to flow rate. The rotational velocity of the turbine is interpreted as an electrical frequency output through the use of magnetic pick-ups. As each turbine blade passes by the magnetic pick-up coil, a voltage pulse is generated which is a measure of the flow rate. The total number of pulses gives a measure of the total flow which can be totalized with a maximum error of a single pulse.

The relationship of the angle of the turbine meter blades to the flow stream governs the angular velocity and the output frequency of the meter. The sharper the angle of the turbine blade, the higher the frequency output.

Easy to maintain while also boasting reliability, turbine flow meters are known to be cost-effective solutions that make an ideal device for measuring flow rate. Aside from excellent rangeability, they also provide high response rate and high accuracy compared to other available types of flow meters. Turbine flow meters are sturdy, need very little maintenance, and seldom exhibit much deviation in performance.

These meters are used in multiple industries to reliably measure the velocity of a variety of liquids, gases and vapors over a very broad range of flow rates, temperatures, and viscosities. Turbine flow meters are used to provide measurement information in crude oil production, chemical processing, blending systems, tank storage, product off-loading, product loading, and many other applications across many industries.

Advantages
  • Simple and durable structure
  • Easy to install and maintain
  • Low pressure drop
  • Operate best in applications with fast, steadyflows
  • Operate under a wide range of temperatures and pressures
Disadvantages
  • Require straight run of pipe upstream and downstream
  • Need constant back-pressure
  • Best for lower fluid viscosity
  • Bubbles in liquids affect accuracy
  • Bearing wear
(877) 768-1600

Friday, March 31, 2017

Introduction to Flowmeters

magnetic flowmeters
Magnetic flowmeters
(courtesy of Siemens)
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.

Turbine flow meter
Turbine flow meter
internal view
(courtesy of Niagara)
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 add gather measurements through the pipe wall without any contact with the flowing media.

Because they are needed for a variety of uses and industries, there are multiple types of flowmeters classified generally into four main groups: mechanical, inferential, electrical, and other.
Variable Area Flowmeters
Variable Area Flowmeters
(courtesy of Siemens)

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.

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

For any flowmeter application or question, visit Ives Equipment at www.ivesequipment.com or call (877) 768-1600.

Sunday, January 22, 2017

Basics of Turbine Flowmeters

Turbine flow meter
Turbine flow meter
internal view
(courtesy of Niagara)
Turbine flowmeters are displacement devices which mechanically measure fluid flow, specifically clean liquids and gases. Turbine flowmeters, so named for the axially mounted turbine these measuring instruments employ, measure the velocity of fluids flowing through the instrument. Additional processing of the fluid velocity measurement can be used to determine volumetric and mass flow.

In a single turbine flowmeter, there is a paramagnetic bladed turbine rotator which spins proportionally to the velocity of the subject fluid flowing through the pipe. Directly above the rotator and isolated from the fluid is a pickup coil, comprised of fine wire windings and a magnet. As the fluid flows and makes the suspended rotator spin, the rotator blades pass through the magnetic field of the pickup coil, generating a sinusoidal electrical signal. This signal is processed into a final calculation of total metered volume, as well as instantaneous flow rate and mass flow, based on the counts of turbine blade passage.

Turbine flow meter
Turbine flow meter
(courtesy of Niagara)
Known for their accuracy and comparatively large turndown ratio, turbine flowmeters also accommodate a wide range of temperature and pressure combinations. Little maintenance is required and installation is generally simple to accomplish. Use of turbine flowmeters should be avoided with corrosive fluids, as well as those with high viscosity. Adequate protection, in the form of a properly sized strainer, should be provided upstream of the device. The mechanical nature of the turbine requires the support bearings to remain lubricated and in a condition that does not impede the movement of the rotor, as this would result in a reading below the actual flow rate. When applied with liquids, operators must assure that the entire cross section of the pipe in the measuring section is filled with the measured liquid.

Turbine flowmeters advantages additionally include low pressure drop and a compact design. Available sizes and materials of construction can accommodate a wide variety of applications in oil and gas, wastewater, utility, chemical, and food and beverage industries.

Proper instrument selection and configuration goes hand in hand with a proper installation toward successful project completion. Share your fluid measurement challenges with instrumentation specialists, combining your process knowledge with their product application expertise to develop effective solutions.