For over 35 years Bronkhorst High-Tech has brought a revolutionary flow technology to the market, and in today’s blog I would like to discuss one such example, called MASS-STREAM™. This device leverages Constant Temperature Anemometer (CTA) thermal mass flow technology, though differently than conventional meters in this category. I will describe what CTA thermal mass flow meters are, the conventional type and their applications, and what makes MASS-STREAM™ technology different.
What is a conventional Constant Temperature Anemometer (CTA) thermal mass flow meter?
The constant temperature anemometer (CTA) thermal mass flow meter works with a sensor with probes, which are inserted into the gas stream in order to directly contact the flowing gas. One of the two sensors is designed as a heater, and the other one is designed as a temperature probe.
When the instrument is powered up a constant difference in temperature (ΔT) is created between the two sensor probes. The heater energy required to maintain this ΔT is dependent on the mass flow. The working principle is based on King’s Law of the ratio between the mass flow and heater energy. What that means is the higher the flow, the more energy is required to maintain the chosen.
A conventional CTA thermal mass flow meter is installed by inserting the long probes through the pipe wall and into the gas stream. The probes are passed through an insertion port (hole) in the pipe. The “head” of the instrument is above the outer wall of the pipe.
Common characteristics of CTA thermal mass flow meters are having no moving parts, a low pressure drop across the instrument, and no need for additional temperature or pressure compensation.
Where are conventional Constant Temperature Anemometer (CTA) thermal mass flow meters used?
As you might imagine, processes where gas flows in pipes are places one will find CTA thermal mass flow meters. The rugged nature, no moving parts, and low pressure drop are beneficial for measuring gas flow in industries like midstream Oil & Gas, upstream Oil & Gas, Wastewater treatment, and Steel.
The types of applications where these flow meters are used include applications with gases such as methane, propane, argon, compressed air, coal emissions, carbon dioxide, ammonia, and others as well.
Typically a CTA thermal mass flow meter is a good choice when the gas has the potential to be dirty or includes some moisture as the through flow nature of the technology can be more forgiving to contamination than other flow meter technologies.