Vortex flowmeter is a type of flowmeter that works on the principle of Karman vortex street which is used to measure fluid flow in volumetric flowrate. When the medium passes through an obstruction ( shedder bar ) whose flow rate has to be measured, it causes the medium to separate and form alternating pressure frequency of vortices around the backside of the shedder bar.
WHAT IS KARMAN VORTEX STREET:
This principle states, that when there is an obstruction in the flow path, a pattern of swirling vortices is generated continuously.
HOW IT WORKS:
The vortex flowmeter consists of a shedder bar which acts as an obstruction in the flow path. The piezoelectric crystal is a sensor which is located behind the shedder bar. It measures the frequency of vortices and converts them into an electrical signal. The electrical signal is directly proportional to the frequency of vortices. Then the electrical signal is sent to an electronic circuit in which the signal is amplified and processed to produce output which is shown on the flowmeter display and transmitted to the control system.
Vortex Flowmeter is also used to measure the process temperature by a temperature sensor that is placed within the shedder bar in which the shedder bar act as a thermowell for those temperature sensors. This eliminates the need for separate temperature measurements.
It is compatible with a wide range of applications and can withstand high temperatures and pressures.
The meter body is available in a variety of configurations and multivariable capabilities that measure the volumetric flow and also density depends on the process temperature and pressure. If volumetric flow rate and density are known then mass flow rate can be calculated.