Measuring flow rates with differential pressure (DP) instruments has been a time-tested practice for decades. While still the most widely used flow measurement technology, other technologies have unique advantages for some applications.
In a Processing article, Controlling critical refining applications with Coriolis meters, Emerson’s Julie Valentine and Meha Jha share specific applications where Coriolis flow measurement provides opportunities for better control and more reliable operations.
Julie and Meha open the article noting that
…while dP flow meters have great application flexibility and repeatability, their accuracy can easily be impacted by changes in the composition or flow profile of the fluid flowing through them, or by changing process conditions such as pressure or temperature.
…dP flow meters require very regular maintenance as these technologies have impulse lines that can be prone to plugging depending on climate conditions and fluid properties. Like many mechanical meters, the accuracy of the device also degrades over time due to wear and tear on the orifice plate.
Coriolis flow meters, such as Emerson’s Micro Motion Coriolis flow meters, are well-suited for applications requiring greater accuracy and robustness. These meters:
…are multi-variable devices that provide a direct measurement of mass flow, density and temperature for liquids, slurries and gases. The technology is based on the Coriolis effect in which the inertia created by the fluid flow causes the meter’s tubes to twist proportional to the mass flow rate.
Julie and Meha highlight these refinery applications as a great fit for Coriolis flow measurements.
- Tank dewatering
- Crude blending
- Fuel blending
- Acid control in alkylation units
- Combustion control
Coriolis meters can be used to reduce acid consumption by online measurement and control of acid strength in sulfuric acid alkylation units. Density measurements from Coriolis meters can be measured and correlated to acid concentration at the interstage settlers, as well as the final spent acid settler. Monitoring the spent acid strength online allows for better optimization and control of fresh acid. Coriolis meters are also used to determine the acid-to-hydrocarbon ratio in the contactor, replacing high maintenance, low reliability sight gases.
Visit the Coriolis Flow Meters for Mass, Volume, & Density section on Emerson.com for more on how this flow measurement technology can be applied for your most critical flow measurement needs. You can also connect and interact with other flow measurement experts in the Measurement Instrumentation group in the Emerson Exchange 365 community.