Wednesday, April 27, 2016

Vortex Flowmeter Delivers High Performance in Harsh Process Conditions

Yokogawa vortex flowmeter
digitalYEWFLO Vortex Flowmeter
Courtesy Yokogawa
In the process measurement and control field, vortex flowmeters are noted for their ruggedness, versatility, comparatively high accuracy, and absence of moving parts. They are compatible with numerous applications requiring measurement of flow in gases, liquids, and steam. The Yokogawa digitalYEWFLO vortex flowmeter is an accurate and stable device, even in harsh process conditions, and has a highly reliable and robust design that can deliver improvements in plant efficiency and reduced operating costs. It is available in several versions, one of which is multivariable, providing a calculated mass flow rate output.

Operating Principle

When a shedder bar is placed in a flow, Karman vortices are generated on the downstream side of the bar. The Karman vortices are detected by two piezoelectric elements installed in the upper part of the shedder bar. The vortex frequency is proportional to the flow velocity in a specific range of Reynolds numbers. Therefore, flow velocity or flow rate can be determined by measuring vortex frequency.

Noise Reduction

Noise caused by strong piping vibration may affect the accuracy of vortex frequency detection. The two piezoelectric elements in the digital YEWFLO are installed in a configuration that is polarized, so they are not affected by vibration in the flow or vertical directions. The noise of vortex (lift)- direction vibration is reduced by adjusting the outputs of the piezoelectric elements. Combining these features with the Spectral Signal Processing (SSP) function provides optimum and stable measurement.

Share your process measurement challenges with a product application specialist. The sharing of ideas and information will produce the best outcome.