Vortex Flow Meters

Vortex flow meters work by placing a strategic obstruction in the path of the flowing media. This obstruction is commonly called a bluff body. As the gas or liquid passes by, vortices are created. They form on either side and break away in an alternating pattern.

A good example of this type of behavior in everyday life is a flag that is attached to a flagpole. As the flowing wind contacts the flagpole, the flagpole itself creates the obstruction that causes the flag to billow in the wind in an alternating wave. Another example is a rock in the middle of a river. It is plain to see, via the eddy behind the rock and the subsequent flow, that vortices are being created by the rock.

In the formed vortices, pressure decreases when a vortex is formed and increases when it is shed. This is true on both sides of the bluff body and causes pressure pulsations. The frequency of the pressure pulsations is directly proportional to the flow rate. A sensing element picks up the shifts from side to side behind the bluff body, amplifies the signal, and converts it to a 4-20 mA signal.

For large pipe diameters, inline installations are not cost effective. Insertion vortex flow meters are an ideal solution for vortex flow measurement in larger pipes. They are installed by creating a hole in the process pipe with a connection and then inserting the probe into the hole via the connection on the meter. For insertion vortex flow meters, the probe should be inserted into the highest velocity part of the flow stream in the pipe.

Multi-variable vortex flow meters do not just measure the flow rate. They also employ temperature and pressure measurement to deliver a mass flow rate for gases, liquids, or steam. Because so many process parameters are being measured at one exact point in the process line, they can deliver a much more accurate measurement than stand-alone flow meters. Having three different types of measurement in one instrument saves money and decreases the complexity of installation and maintenance. KOBOLD carries the DVE Insertion Multi-Variable Vortex Flow Meter and the DVH Multi-Variable Flow Meter with inline installation capabilities through ANSI Flanged or Wafer-Types. Multi-variable vortex flow meters can deliver mass flow measurements.

• Food & Beverage
• Chemical & Petrochemical
• Energy Industries
• Metallurgy
• Pharmaceuticals
• Oils & Fuels
• Steam Measurement

• Water, Chilled or Hot
• Ultra-pure Water
• De-ionized Water
• Glycol Mixtures
• Solvents & Acids

• Versatile – for gas, liquids, or steam
• Low to medium initial set-up cost
• Minimal maintenance for clean media
• Reliable and accurate
• Longevity of service, no moving parts to wear
• Can be installed at any angle if the bluff body is submerged
• Unaffected by temperature, pressure, density, or viscosity of the media
• Do not require impulse line heat tracing like DP orifice meters do
• Low to medium pressure loss

• Not for high viscosity media or slurries
• Not for media that coats or crystalizes
• Strainers and filters may be necessary
• Not great accuracy for really high or really low velocity flow rates
• Not suitable for pulsating flow
• Straight pipe requirements can be high, espec
• Not generally suitable for applications requiring batching capabilities