Turbine Flowmeters

                                                 The turbine flowmeter consists of a multiblade rotor or propeller mounted on a spindle complete with bearings and supporting webs so that it is free to rotate. The fluid drives the rotor at a velocity proportional to the fluid velocity. The tips of each blade pass a pick up device and each pulse represent a certain volume of flow. Further instrumentation is required to convert the pulses into volumetric flowrate.

Advantages:

1. Accurate over wide turndown

2. Able to operate over wide range of pressure and temperature

3. Most effective in application with steady, high speed flow

Disadvantages:

1. Wear or fouling of surface will lead to a need for recalibration.

2. The major disadvantage is that the rotor bearings must allow the rotor to spin at high speed and must operate at fairly high temperatures. Thus rotor bearing life is the main limiting factor of reliability.

3. Susceptible to the effect of swirl.

4. Require constant backpressure in order to avoid cavitation.