What is Turbine Flow Meter and How It Works?

What is Turbine Flow Meter?

Turbine flow meters are a great way to measure the flow of natural gas and liquid. It is also referred to as an ‘Axial turbine’, and comprises of a turbine wheel put in the flow stream. The angled blades of the meter are pushed by the flow, which causes the rotation of the turbine. The flow rate can be gauged on the basis of the rate of rotation of the turbine when it gets steady. The rotation rate is generally picked up by the electronic coils which are connected to the housing of the meter, and finally transformed into readings that are obtained by users.

How Does It Work?

The meter comprises of a multi-bladed rotor that is mounted at an angle of 90° to the flow. It is suspended on a freely running bearing in the stream of the flow. The rotor’s diameter is a little less as compared to the metering chamber’s inner diameter, and the rotational speed is directly proportional to its volumetric rate of flow.

The rotor rotates as the fluid flows through the turbine meter. In case the impact of friction is not given importance, the rotor of the turbine will revolve at a speed that is proportional directly to the flowing fluid’s velocity.

There is an electrical pickup of the turbine meter, which can detect the rotor’s rotation and then changes the turbine rotor’s speed into pulses. The volume is proportional to the exact number of such pulses and the flow rate is also proportional to the pulse frequency.

How Do Various Turbine Flow Meters Work?

  • Single Jet – These have a set of blades that are directly set in the way of a jet or stream of water in a pipe. The jet or stream is created with the help of an orifice.
  • Multi-jet – These have the same working principle as the above flow meters. Water is directed onto blades from multiple orifices, in order to ensure their rotation around an axis in the middle. Both single jet and multi jet meters are used primarily for the purpose of billing in commercial and residential water supply operations.
  • Pelton Wheel – These have buckets connected to the outer side of the wheel. The wheel begins to rotate when liquid or waters hits the buckets. The setup of these flow meters is similar although in a frame that is more compact. It is used for the measurement of the flow of liquids of low viscosity that happen to flow at a slow rate.
  • Paddle Wheel – These consist of shafts positioned at an angle of 90° to the stream flow. It has a lightweight paddle wheel with shafts attached to it. As the shafts are moved by the flow, the wheel rotates. The paddle wheel rotational speed is proportional to the liquid flow speed.
  • Propeller – These types of flowmeters have 3 – 6 blades and are similar in appearance to wood propellers that can be found in boats. These have blades fixed around an axis in the middle, which rotate around the axis.