Coriolis mass flow meters detect the flow of all liquids along with moderately dense gases. There are many self-draining designs available for sanitary applications meeting clean-in-place requirements.
The operating principle of a Coriolis flow meter is really effective. A Coriolis flow meter has a tube that's energized by a fixed vibration. When a fluid, whether gas or liquid, passes through this tube and the mass flow momentum causes a change in the tube vibration, the tube twists leading to a phase shift.
Since the principle measures mass flow independent of what's within the tube, it'll be directly applied to any fluid flowing through it whereas the thermal mass flow meters are also dependent on the physical properties of the fluid.
Furthermore, you can also measure the actual change in natural frequency. This change in frequency is directly proportional to the fluid density, and a further signal output may be derived. Once you have measured both the mass flow rate & the density, you can easily derive the volume flow rate.
How to Use Coriolis Mass Flow meters?
Coriolis mass flowmeters are used to measure the mass flow of liquids like acids, water, caustic, chemicals, and gases/vapors. Since the mass flow is measured, measurement isn't really affected by fluid density changes. So make sure you are careful when using Coriolis mass flowmeters to measure gas/vapor flows as the flow rates sometimes get low in the flow range. In gas/vapor applications, the large pressure drops across the flow meter, and its associated piping can occur.
Typically, the flow meter is applied to cryogenic, sanitary, relatively clean, and corrosive liquids and gases/vapors in pipes that are smaller than 6-12 inches. You can also find some of its general applications in the water, mining, mineral processing, wastewater, pulp and paper, petroleum, power, chemical, & petrochemical industries. Generally, the materials of construction are limited to stainless steel. To measure the dirty or abrasive liquids, straight-tube designs are used.
Apart from that, you will also find many applications for Coriolis mass flowmeters in chemical processes where fluids are corrosive. The relative insensitivity to the density allows the Coriolis mass flowmeters to be applied in places where physical properties of the fluid aren't well known. These flowmeters can be used in chemical feed systems that are found in most of the industries.
Coriolis Mass Flowmeters Installation
Most of the manufacturers claim that their flow meters aren't adversely affected by the installation effects. This way, they shouldn't require large lengths of straight length pipework upstream or downstream of the flow meter. But still, the compliance with the manufacturer’s guideline is extremely important that may vary depending on flow tube design.
Coriolis Flow Meters aren’t normally affected by swirling fluid or non-uniform velocity profiles that result from upstream/downstream piping configurations. Therefore, it’s imperative to get along with good practice at all times simply by ensuring that the flow meter is installed with suitable upstream & downstream straight pipework.
Although it might not get extremely affected by the installation effects, Coriolis meters shouldn’t be installed close to valves that regularly opens & closes as it may cause pulsations as well as vibrations in the flow. Otherwise, it may lead to the significant mismeasurement of the mass flow, thereby putting a negative impact on all your calculations.