Entrained gas can disturb the sensitivity of mass flow measurement of liquids, decreasing accuracy or even stopping measurement completely. New Coriolis mass flowmeter technology has come on the market that ensures both stable and uninterrupted measurements with high gas content. The new meters, including KROHNE’s OPTIMASS 6400, offer reliable indication of gas bubbles in the process by using a combination of various measurements to detect a twophase flow. With values between zero and one hundred percent gas or air content in the line, it maintains continuous mass density measurement and provides measured values at all times. At the same time, it can report the two-phase status and output a preconfigured alarm, in accordance with NAMUR NE 107 requirements.
Gas entrainment – what is it and why does it matter?
Gas entrainment refers to the presence of gas bubbles in a process. It can occur for many reasons and particularly in terms of sensitive dosing processes, it causes aggravation and headaches for users. Gas bubbles can form, for example, due to degassing, leaks upstream of, or in, a negative pressure area, excessive cavitation and levels falling below the minimum in supply containers, as well as agitators in tanks or long drop distances for media into tanks. However, they can also occur due to status transitions in process control, such as when starting or shutting down the system, or cleaning it.
Other examples include production processes in which gas bubbles are introduced deliberately and the gas flow is measured upstream of the sprayer. This can happen, for example, in the production of shower gels, or processes in which the bubbles are used for control purposes.