Direct mass flow measurement of gases
The story of Development of Thermal Dispersion Mass Flow Meter by Manas.
The Thermal Dispersion Mass Flow Meter is a comparatively new concept. In India, nobody was manufacturing it with indigenous technology. Even today, it is mostly imported in India from the US or some other European countries. The cheaper versions are also available from China. It is consuming a lot of foreign exchange of the country.
Right from the beginning, Manas has worked on the strategy of developing and manufacturing the technology products in India. This was the main reason for going after the development of the Thermal Mass Flow Meter.
The most important issue was how to test the meters under development or even a developed meter. A flow calibration laboratory was essential for this reason. The Thermal meter being a mass Flow Meter, the laboratory also required the capability of calibrating in terms of mass measurement.
So, the first challenge was, setting up a calibration laboratory. The calibration lab was designed, fabricated, and installed by Manas engineers only. It was designed with world-class Master elements like sonic nozzles and Coriolis type flow meter. The calibration lab was designed as per DS/EN/ISO 9300.
Then came the design and development of the flow meter. In the development phase, whatever equations of Thermodynamics and Fluid mechanics were necessary, were derived from fundamental principles. The same was converted to software and was embedded in the controller to read the correct mass flow.
We thus designed and developed the Thermal Mass Flow Meter with our own technology. We can therefore make continual improvements in the product as we don’t depend on any outside technology for it.
Is Thermal Mass Flow Meter better than Coriolis Mass Flow Meter?
While every flow meter design has its advantages and disadvantages, there are certain areas where Thermal Mass Flow Meters score:
- Thermal mass flowmeters are immune to vibrations.
- Coriolis meters are not immune to vibrations. They do not work in pipelines with vibration.
- Both measure mass flow.
- Coriolis meters must address one more parameter, like zero stability. This depends on position and years of use. As it contains moving parts like vibrating tubes, the chances of deterioration with time are higher.
- Thermal mass flow meters do not have any moving parts. Once the zero is set on-site, usually no change occurs. Hence, in terms of the stability of readings, it is more reliable.
- The usual accuracy of the Thermal Mass flow meter is about 2% of reading + 0.5% of F.S. It can be trimmed between 1 and 1.5% of the reading.
- The accuracy of Coriolis meters is 0.5%, but it must provide for zero stability variations over and above this accuracy. Also, the accuracy deteriorates over time.