Entrained Gas Management (EGM)

Without entrained gas, the measuring tubes in the Coriolis mass flowmeter have the desired regular oscillation. Gas entrained in the liquid dampens this regular oscillation, and as the gas content increases, the oscillation can come to a complete stop.

To overcome this, KROHNE has developed powerful control algorithms for the OPTIMASS series of Coriolis flowmeters, and implemented them in a synthesised drive control.

The difficulty of measuring a liquid with entrained gas increases with the gas volume fraction (GVF). A number of other process factors such as temperature, increased viscosity, pressure, and the relative velocity between liquid and gas also affect the resulting flow regime.

EGM technology allows the flowmeter to maintain the oscillation with complex flow regimes. Even during a complete transition from a pure liquid phase to a gas phase and back, i.e. from 0 to 100% gas content, the device will continue to operate.

Typical applications for OPTIMASS flowmeters with EGM are:

• Production of polyurethane foams

• Crude oil production

• LNG loading/unloading

• Spinach production

• Ice cream production

• Yoghurt production

• Mayonaise production

• Beer production

Density measurement of single-phase fluids is common practice, but for traditional meters it becomes challenging with entrained gas. In many applications where entrained gas is present, OPTIMASS flowmeters with EGM show excellent performance and repeatability for process control, batching, loading, unloading and transfer measurement.