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Omega Tube Design Extends the Usability of Coriolis Technology in Mass Flowmetering Applications. Presented by John Daly NA Sales Manager Rheonik USA. Introduction.
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Omega Tube Design Extends the Usability of Coriolis Technology in Mass Flowmetering Applications Presented by John Daly NA Sales Manager Rheonik USA
Introduction The objective of this session is to introduce Omega Tube Coriolis technology, comparing it to conventional Coriolis technologies currently available and describe why challenging and extreme flow applications can be solved using it • Topics Covered: • Coriolis technology in general • Working principles and design goals • Engineering elements of the Omega Tube Design • Features of the Omega Design • Examples and solutions of challenging applications
Overview Coriolis Mass Flowmeters have been available commercially for about 20 years Over the past decade, they have been one of the fastest growing flow measurement technologies. Growth has been driven by a unique ability to directly measure mass as well as many other general advantages
Why is Mass so Good? 1 kg = 1 kg = 1 kg For most critical measurements, mass or normalized volume is of interest – volume alone is insufficient for many applications In the Mountains On the Beach Out in Space
Advantages of Coriolis Meters • No moving parts – essentially no wear • No flow profile issues like those seen with turbine, ultrasonic and other “velocity” measuring meters • No effect from changing viscosity • No effect from density • Easy to install
Different Coriolis Designs Coriolis meter technology is offered by around a dozen suppliers, each having their own design. Here is a sample of some of the different types: Cantilevered Triangles Parallel Straight Tube S-Shaped Tubes Torsional Loops All work using the same Coriolis Principle but different designs are more suited to specific applications; i.e. straight-through designs may be more suitable for hygienic applications
Coriolis Meter Operating Principle M = Mass of moving element (liquid or gas) in pipe F = Coriolis force v = velocity of mass moving w = rotation speed / angular velocity F = 2 * M * v * w
Operating Principle - continued Measured time difference / phase shift (t) is proportional to flow
Meter Design Goals No ideal design possible – simplified considerations: • Preferred Design Features • Long easily bendable pipe system • Large distance between oscillation and excitation point • Thin wall tube to keep spring constant small • High energy excitation to create large oscillation amplitudes • Conflicting Factors • Long pipes may create unacceptable pressure drop • High pressure, abrasive and/or corrosive media requires thick wall tubing • High energy input may be conflict with hazardous area requirements • Excessive excitation may lead to fatigue failure in tubing
Omega Tube Design Offers Some Solutions Semi-circular Measurement Tube Carefully balanced oscillation system consisting of rods and cross bar counter weight Flow Supply Section
De-coupled Measurement Section • No deformation at increasing pressures • De-coupled from the Process Flow Supply Section
Independent Tunable Oscillation System • Stable and highly energized oscillation • Large amplitude / great signal to noise ratio • Adaptable to different tube sizes, thicknesses and materials
Bitumen – High Pressure and Temperature • Process Conditions • 3” Line Size • 1350psi / 93 bar • 680°F / 360°C • Hazardous Area • Hot, viscous liquid Thick wall tubing required to meet pressure rating. Without Omega Tube torsion rod/cross bar system, it would not be possible to provide sufficient oscillation for reliable meter operation
Large Volume Fuel Oil Custody Transfer Flow • Process Conditions • 12” Line Size • Heated to improve flow • Extremely viscous liquid Turbine and PD meters not ideal due to abrasive nature of fuel oil Ultrasonic meters not accurate enough due to flow profile issues
Gas Flow at Extremely High Pressure • Process Conditions • 900 bar / 13,000psi • Turndown of 100:1 required • H2 dispensing for alternative automobile fuelling requires very accurate metering over a wide range of flowrates Omega Tube Design can accommodate thick wall tube to meet pressure requirements while providing high accuracy across a range of 0.25 kg/min to 50 kg/min
Flow Measurement of Highly Corrosive Materials • Process Conditions • 3” Line Size • HCl Flow • Highly corrosive to Stainless Steel and other Alloys The Omega Tube Design lends itself to variations in material of tube construction. Because of the torsion rod/mass weight design, tubes manufactured from exotic materials such as Tantalum can be accomodated without requiring meter redesign
Cryogenic Gas Flow Measurement • Process Conditions • -425°F / -253°C • H2 Gas Omega Tube Design Mass Flowmeters are resilient to extremes of temperature due to remote electronic mounting
Summary • The Omega Tube Coriolis Mass Flowmeter design differentiates from others by its unique construction with torsion rods and cross bar. • With these design elements, the meters operate with large oscillation movements (providing measurement performance) without putting undesirable bending stress on the tubing. • The design allows for the accommodation of exotic materials and thick wall tube without compromising performance. • Extreme applications with temperatures from -250°C up to 400°C and pressures up to 900 bar can be solved, as well as high volume/throughput requirements up to 1500 t/hr.
Thank you for your attention…….. the Mass Flowmetering Experts For more information on Omega Tube Coriolis Mass Flowmeters, please come to the South Fork Instruments Table www.rheonik.com