Flow measurement is an essential aspect of many industrial processes, and accuracy is critical to successfully operating these processes. Different flow measurement technologies are available, but Coriolis flow meters have become increasingly popular recently.
Flow measurement technologies are used in various industries, including oil and gas, chemical, food and beverage, and pharmaceuticals. Accurate flow measurement is critical in these industries to ensure the efficiency and safety of operations.
In this article, we will compare Coriolis flow meters to other flow measurement technologies, highlighting the benefits and drawbacks of each.
Different flow measurement technologies are available, each with advantages and limitations. This article compares Coriolis flow meters to other flow measurement technologies to help you make an informed decision.
Flow Measurement Technologies
Several flow measurement technologies are available, including differential pressure flow meters, magnetic flow meters, ultrasonic flow meters, vortex flow meters, and Coriolis flow meters. Let us briefly describe each of these technologies.
Differential Pressure Flow Meters
Differential pressure flow meters measure the difference in pressure across a constriction in the flow path. They don’t measure mass but only volume. The constriction causes an increase in fluid velocity, and the pressure difference is proportional to the flow rate. These flow meters are relatively simple and inexpensive but have limited accuracy.
Magnetic Flow Meters
Magnetic flow meters use Faraday’s law of electromagnetic induction to measure the flow rate of conductive fluids, mostly water based fluids..They don’t measure mass but only volume These flow meters do not have any moving parts, making them ideal for applications that involve corrosive or abrasive fluids. However, they have limited accuracy at low flow rates.
Ultrasonic Flow Meters
Ultrasonic flow meters use sound waves to measure the flow rate of fluids.They don’t measure mass but only volume. These flow meters can measure the flow rate of liquids and gasses, making them versatile. Since they are mostly installed outside the pipe, they are subject to insulation material consideration, rusting or corrosion pipes, etc. They can also be affected by external noise and require a straight pipe section for accurate measurements.
Vortex Flow Meters
Vortex flow meters measure the frequency of vortices created by a bluff body inserted into the flow path. The frequency of vortices are proportional to the flow rate. Vortex meters are ideal for steam measurement as other technologies have problems in steam. However, they can be affected by changes in fluid viscosity and density.
Coriolis Flow Meters
Coriolis flow meters measure the mass flow rate of fluids by detecting the Coriolis effect. The Coriolis effect is the apparent deflection of an object in motion due to the rotation of the Earth. These flow meters are highly accurate and can measure the flow rate of fluids with varying properties.
Comparison of Flow Measurement Technologies
Let us compare the different flow measurement technologies based on their accuracy, turndown ratio, installation, maintenance, and cost.
Turndown Ratio
Turndown ratio refers to the ratio of the maximum flow rate to the minimum flow rate that a flow measurement technology can measure accurately. Coriolis flow meters have the highest turndown ratio, ranging from 20:1 to 100:1. Ultrasonic flow and magnetic flow meters have turndown ratios of up to 10:1, while differential pressure flow meters and vortex flow meters have turndown ratios of up to 5:1.
Installation
The installation of flow measurement technologies can affect their accuracy and performance. Coriolis flow meters do not require a straight pipe section before and after the meter to ensure accurate measurements. With the exception of Positive Displacement flow meters all other flow meters require a straight pipe section, making Coriolis meters installation easy.
Maintenance
Flow measurement technologies require regular maintenance to ensure their accuracy and longevity. Coriolis flow meters have no moving parts, making them low maintenance. Magnetic flow meters also have no moving parts, but their electrodes can become coated with deposits, affecting their accuracy. Ultrasonic and vortex flow meters can experience sensor fouling and require periodic cleaning. Differential pressure flow meters require regular calibration to maintain their accuracy.
Cost
The cost of flow measurement technologies varies depending on their accuracy, turndown ratio, and features. Coriolis flow meters are the most expensive flow measurement technology if the user needs only volumetric flow outputs. Ultrasonic and magnetic flow meters are less expensive but are not as accurate and need straight run requirements. provide good accuracy. Differential pressure and vortex flow meters are the least expensive but have limited accuracy and turndown ratio. For straight-run requirements of various flow meters pleaser go to: http://smartmeasurement.com/wp-content/uploads/2021/02/Straight-Run-Requirements-of-Various-Flow-Technologies.pdf
Applications of Flow Measurement Technologies
Different flow measurement technologies are used in various industries, depending on their accuracy, turndown ratio, and suitability for different fluids. Let us briefly describe some of the applications of flow measurement technologies.
Oil and Gas Industry
Flow measurement technologies are widely used in the oil and gas industry to measure the flow rate of crude oil, natural gas, and other fluids. Coriolis flow meters are commonly used in this industry due to direct mass flow measurement, high accuracy and ability to measure fluids with varying properties. Magnetic flow meters are also used in applications involving corrosive fluids but limited to conductive fluids and petrochemical products are NOT conductive.
Chemical Industry
Flow measurement technologies are essential in the chemical industry to ensure accurate measurements of various chemicals and fluids. Coriolis and magnetic flow meters are commonly used in this industry due to their high accuracy and suitability for measuring corrosive fluids.
Food and Beverage Industry
Flow measurement technologies are used in the food and beverage industry to measure the flow rate of various fluids, such as water, milk, and juices. Coriolis and magnetic flow meters are commonly used in this industry because they measure hygienic fluids and withstand frequent cleaning.
Conclusion
Flow measurement is critical in various industries to ensure the efficiency and safety of operations. Coriolis flow meters are the most accurate flow measurement technology and can measure fluids with varying properties. Other flow measurement technologies have advantages and limitations, such as magnetic flow meters, ultrasonic flow meters, vortex flow meters, and differential pressure flow meters. The choice of flow measurement technology depends on the application requirements, fluid properties, and budget.
FAQs
What is the most accurate flow measurement technology?
Coriolis flow meters are considered the most accurate flow measurement technology, with an accuracy of up to 0.1% of the measured value.
Can Coriolis flow meters measure fluids with varying properties?
Yes, without recalibration, Coriolis flow meters can measure fluids with varying properties, such as viscosity, density, and temperature.
Do magnetic flow meters require a straight pipe section?
Yes, magnetic flow meters require a straight pipe section to ensure accurate measurements. The recommended straight pipe section length is typically 5-10 pipe diameters upstream and 2-5 pipe diameters downstream of the meter.
What are the advantages of ultrasonic flow meters?
Ultrasonic flow meters have several advantages, including non-invasiveness, no pressure drop, no moving parts, and suitability for a wide range of fluid types and flow rates. They are also highly accurate and can measure bidirectional flow.
Which flow measurement technology is the least expensive?
Variable area flow meters, or rotameters, are generally the least expensive flow measurement technology. However, their accuracy is limited and may not be suitable for all fluid types and flow rates.
