What is Coriolis Flow Meter and how it works?

What is Coriolis Flow Meter?

These days, most of the flow meters that are used happen to be volumetric. But a mass flow meter is needed in a few other applications, and a Coriolis flow meter is one such type. A Coriolis flow meter is a form of mass flow meter that is used for measuring the mass of gases as well as liquids. The first Coriolis patents for industrial usage can be traced back to the 1950s although it was not until the 1970s that the first Coriolis mass flow meters originated. It has a different design from differential or thermal mass flow meters, and works in a different manner as well.

How Does a Coriolis Flow Meter Work?

This type of sensor uses inertia to make a measurement of mass. A dense gas or liquid flows through a tube that is vibrated with the help of a tiny actuator. The acceleration generates a twisting force on the tube that can be measured and happens to be proportional to the mass. Coriolis meters that are more advanced in form make use of two curved tubes for reduced drop in pressure and superior sensitivity.

Such a flowmeter needs a force that acts over a tube that transports a fluid. The force helps deform the tube, and how much deformation is achieved is directly based on the mass flow rate via the tubes. The signals emitted by the sensors that gauge the deformation offer a direct hint at the mass flowrate. The flowmeter, in a Coriolis meter that measures the rate of mass flow, needs to rotate the fluid. These oscillate the fluid in a rotational manner in practice, which generates equivalent Coriolis forces. The tubes may be straight, S-shaped or U-shaped in form.

Coriolis Flow Meter and Motion Mechanics

It has to be understood that this kind of sensor has motion mechanics as its underlying working principle. Once the process fluid gets into the sensor, it gets split. A drive coil, at the time of operations, makes the tubes oscillate as opposed to the direction of the natural resonant frequency. As the tubes start oscillating, the current voltage that is produced from every pickoff leads to a sine wave creation. It shows that one tube’s movement is relative to that of another. Delta-T is the name given to the delay in time between two sine waves, and it is proportional directly to the rate of mass flow.

These kinds of meters are mainly utilized in scientific applications, where these can measure clean as well as corrosive liquids and gases. These can also be seen in use in Wastewater handling, chemical processing, Oil and Petroleum and Paper and Pulp processing industries. Coriolis flow meters that have tubes with a straight design can be cleaned with greater ease, which makes them ideal for pharmaceutical industry as well as for food and beverage applications. These can also be seen in use in mining operations, as these can also deal with slurries. Thus, these types of meters have diverse applications.