Factors that Impact Accuracy, Conditioning and Flow Profile of a Thermal Mass Flowmeter

Written by: WILLKOMMEN BEI TRIGASDM Published by: TRIGASDM on 24/10/2018

The velocity profile is used to determine the flow rate of fluid flowing within a pipe. If the fully developed profile changes, the accuracy level of a thermal mass flowmeter decreases. Keep on reading to know the major application factors that affect the meter’s accuracy require consideration. One of these includes the upstream straight run distance, which changes the flow profile. In many cases, flow conditioning, a process of synthetically creating a more uniform flow profile, is necessary when upstream straight run lengths are not available to achieve a sufficiently developed flow profile. Thermal mass flowmeters measure the mass flow rate of gases and liquids directly. Volumetric measurements are affected by all ambient and process conditions that influence unit volume or indirectly affect pressure drop, while mass flow measurement is unaffected by changes in viscosity, density, temperature or pressure. Thermal mass flowmeter is often used in monitoring or controlling mass-related processes such as chemical reactions that depend on the relative masses of unreacted ingredients. In detecting the mass flow of compressible vapors and gases, the measurement is unaffected by changes in pressure and/or temperature. One of the capabilities of thermal mass flowmeter is to accurately measure low gas flow rates or low gas velocities much lower than can be detected with any other device.

Why Use of Thermal Mass Flowmeter is Growing Recently?
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Rugged Construction – Stainless Steel with available protective coatings
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Measure liquid & gas applications
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Unobstructed path for continuous flow and no pressure drop
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Wide turndown for wide flow ranges
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Back up sensors for extended life
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Sensors are protected and never come into contact with passing fluid
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Flow and total flow measured
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4-20mA output to data recorders, PLC’s etc
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Insertion probe available for simple installation and ease of cleaning

Thermal Mass Flowmeter for Measuring Landfill Gas

Landfill gas is a mixture of methane, Carbon dioxide, and Oxygen that is created by the decomposition of waste stored in landfills. According to sources, landfills are the 3rd largest generator of Methane Gas. Methane is the 2nd most prevalent gas to contribute to the Green house gas effect and for that reason it is important to contain and process the methane gas in a way that it doesn’t increase the level of GHG’s in the earth atmosphere.

Landfill operators use a combination of wellheads, pumps, and piping to funnel these gases to a central point where they can either be burned off by a flare system or converted into renewable energy. Many landfills now see this gas as a revenue source as they are able to contain it, send it to local power plants and create renewable energy. To that end, landfill operators are responsible for collecting and accurately measuring the gas in order to benefit both the environment and offset their operating costs.

Thermal mass flowmeters are the key tool in measuring the amount of landfill gas being produced in order to comply with the EPA Clean Air Act. The thermal mass flowmeter is the most versatile solution and is calibrated to the exact gas mixture and operating temperatures that landfill operators are working under. Obtaining quality checkups using superior thermal mass flowmeter in measuring gas flows is crucial in power plants to turn what was once waste into renewable energy of today.