Turbine wheel flow meter
The turbine wheel flow meter (also turbine wheel gas meter ) can be used not only for gases, but also for low- viscosity liquids. Since it does not have a measuring chamber, it is one of the indirect volume counters .
functionality
The turbine wheel flow meter consists of a piece of pipe into which a turbine wheel is built. This turbine wheel serves as a measuring element. The flow of the medium, usually the gas flow, is led into an annular gap by a displacement body. In this annular gap it is guided past the turbine wheels and drives the turbine wheel. Since the flow rate increases with increasing gas volume, the speed of the turbine also increases. The speed is proportional to the flow velocity, with which the flow rate can be determined. The speed is determined without contact, with a magnetic coupling or an induction coil. The speed is then recorded outside by a counter. The flow rate can be determined by the number of turbine wheel revolutions per period.
The design allows it to be installed in lines with high pressures because the speed transmission does not have any mechanical connection to the outside that would have to be sealed. Due to the separate construction between measuring wheel and measuring device, it can also be used for measuring flammable and aggressive gases. In the latter case, the turbine wheel must be able to withstand the aggressive medium.
The turbine wheel flow meter needs a certain amount of flow in order to work accurately. The direction of flow cannot be determined with a pulse measuring method of the speed. For measuring small amounts of gas and for intermittent supply with gas flow standstill, “wet gas meters” such as the drum gas meter are preferred instead of the turbine wheel gas meter .
swell
- European teaching materials Chemical Engineering , 6th Edition 1997 ISBN 3-8085-7046-6 page 187