Coriolis mass flow meter is one of the popular option for metering mass flow rate and density of oil and gas applications. Coriolis flow meters allow the direct measurement of mass flows. Direct mass flow measurement eliminates inaccuracies caused by the physical properties of measured medium. The measurement does not affect pressure, temperature, viscosity, and density. Hence, no compensation is needed.
Mass Flow
Many industrial processes ie oil and gas, chemical, food and beverages, cosmetic, pharmaceutical industry etc. are mass related. The unit of measurement for mass flow is expressed in kg/h (kilograms per hour) or g/s (grams per second).
Examples:
- Custody transfer applications in oil and gas relies on the mass of the measured medium to determine the price
- Batching process in chemical manufacturer may also rely on the masses of reactants to determine the right mass ratio
- Food and beverages formulation often requires consistent measurement of ingredients to form a certain taste or colour
Advantage of Coriolis
- Not affected by variations in pressure and temperature
- Flow profile and speed are nonfactors with Coriolis measurement
- Higher accuracies with better repeatability
- Ability to measure undefined or variable mixture
- Do not require any inlet or outlet straight runs in pipes
- No need for (re)calibration in the field – fluid independent flow measurement and control
- Materials that are sold by weight rather than volume benefits from Coriolis measurement
- Oil and gas measurements are highly suited for Coriolis flow measurement since the value of petroleum products is based on the heating units rather than the volume
Working Principal
Coriolis mass flow meter working principle is based on the Coriolis Effect. The Coriolis force is the forces of inertia that affect tube oscillations. Coriolis mass flow meter has 2 tubes oscillating at their resonant frequency using a driver coil. Whenever flow passes through these tubes, we observe a change in the oscillations of these 2 oscillating tubes.
A fixed vibration energizes a tube. When the fluid passes through the mass flow momentum will cause a change in the vibration. Both ends of the tube inside a Coriolis mass flow meter consist of two pick-up sensors. These motion sensors capture the oscillations. Thus, the oscillating tubes will have a phase shift according to the fluid flow. It is recommended that the Coriolis mass flow meter should be installed away from interference sources such as a pump, control valves or sound generator, which may cause vibration in the pipe.
