Mass flowmeters are devices that measure the amount fluid passed to a process. Mass flowmeters are used where the composition of materials used are important, which ensures the quality of the product.
These are the different types of mass flowmeters:
1. Coriolis Mass Flow Meters
In this type, two parallel measuring tubes containing flowing fluid were oscillated in antiphase, acting as a tuning fork using strong electromagnets. The Coriolis forces produced in the measuring tubes cause a phase change in the oscillations of the tube.
The tubes stay standstill when there is no flow. (1)
2. Thermal Mass Flowmeters
3. Impeller-Turbine Mass Flow Meters
In this device, there are two rotating elements impeller and turbine. The impeller is driven by a synchronous motor at constant speed, through a magnetic coupling and imparts an angular velocity to the fluid as it flows through the meter.
The turbine located downstream of the impeller eliminates all the angular momentum of the fluid and, therefore, receives a torque proportional to the angular momentum. This turbine is constrained by a spring that deflects through an angle that is proportional to the torque that the fluid exerts on it, which gives a measure of mass flow.
4. Twin-Turbine Mass Flow Meter:
Each turbine is designed with a different blade angle; therefore there is a tendency for the turbines
to turn at different angular velocities. When the flow happens
Gyroscopic Mass Flow Meter:
It consists of a tube with a circle or square shape. A motor introduces an oscillating vibration at a constant angular velocity “ω” on the axis A.
When the fluid passes through the loop, a moment of precession type occurs on the B axis and is measured by the deviation of the sensor element. It can be shown that this deviation is directly proportional to the mass flow.