CORIOLIS MASS FLOW METERS INCREASE FLOW ACCURACY AND PERFORMANCE AND REDUCE THE COST OF OWNERSHIP
Do you have any of these concerns?:
“We use Coriolis meters and they work great, but when they show an error message, it’s difficult to determine the cause because we have to go into the menu, hunt for an error code, and then look it up in the manual.”
Modern Coriolis meters which use transmitters have large, multi-line displays that show not only error codes, but also describe the errors in plain English, so steps can immediately be taken to diagnose and solve the problem. Furthermore, Coriolis meters supplied with USB or serial ports can be interrogated with license-free software to see detailed lists of the diagnostic error codes interpreted into plain English.
“My Coriolis meter has no display and when there is a fault, all I see is a red light. How can I quickly determine the problem with the unit?”
A software package with a full suite of features, such as RHECom, can be connected to the meter and used to review the cause of the error light, getting to the heart of the matter quickly. Units without displays are often inaccessible – tucked away in a cabinet or remote in the field, so connecting to such meters using either serial or Ethernet communications from a remote PC can help to quickly diagnose the problem and determine if it’s a meter or process issue. This helps to ensure that any trip out to the meter site can better address the problem, thanks to having the right people and equipment on hand.
“We are upgrading our process line by adding additional measurement and control capabilities, and I need to tightly control mass flow rate, but we are running low on I/O. How can I do that using a Coriolis meter?”
Some mass flow meters have a built in PID controller for direct mass flow control from the transmitter. High-end meters supplied by South Fork Instruments provide high accuracy mass flow measurement and can save on I/O count by directly controlling a valve with positioner mounted in the line. Connection to the control system can be analog, or to save on multiple I/O points, through a multidrop Modbus link.
“I’m filling vials with 2 g of material. We are using weigh scales, but the tare cycle for each vial is a substantial overhead due to the variable vial weight, and settling time for the scales prevents us from speeding up our production rate. Can I use a Coriolis meter for this, and will it be faster?“
Certain specialized transmitters have a fast fill function and can totalize 2 g of fill at quite high speeds to an uncertainty of no more than 0.2% (+/- 4mg). This special function takes advantage of the high-speed acquisition and processing capability of the 40 series transmitters to rapidly determine fill rate and when target end point is reached. Without the need to tare weigh each of the vials before filling, the production rate can be significantly increased.
"I’m controlling a mix of chemicals and must keep the feed ratio correct to avoid ruining the batch. Can Coriolis meters help me to achieve this?"
Coriolis meters are an ideal solution for ratio mixing control. Coriolis meters are highly accurate and have fast response to changing flow rates. These two factors can provide the basis for controlling feed rates in a strict ratio for proper formulation of the batch material.
“I use a Coriolis meter to measure a reactor fill line but under certain conditions, air gets sucked into the line by the pump, causing the meter to go into fault. We use the meter to totalize the amount of each fill, and because it fails like this, the meter often overdelivers, costing us money. Can Coriolis meters fix this?”
Better-quality Coriolis meters have specific features and functions to help resolve the effects of entrained air. The stable mechanical nature of a high-end flow sensor means that even with fairly high levels of air present, the meter will stay online and continue working. In fact, Coriolis flow meters can even be used to measure the flow of high-density foam! However, if aeration is extreme, the meter may go offline. In that case it can be configured to count down for a predetermined period of time before stopping completely. If the meter fails to reacquire a flow rate, a digital output can be triggered to signal that there is no longer a reading.
“I use a lot of orifice plate meters to measure flow, and while they work OK, we have to rework the plates every year to make sure they stay accurate. This takes a considerable amount of time, and because we send them out, we have to keep a lot of spares. I’d like to use Coriolis meters because we could dispense with the constant maintenance, but they are more expensive than plate meters.”
There are two costs to consider here: the original cost of purchase and installation and the ongoing maintenance cost. For orifice plate meters, the cost to purchase is very low. But as you say, the maintenance requirements are extensive, and your spares holding is high, so cost of ownership is very high. In addition, for installation, you must have an adequate length of straight pipe upstream and downstream to ensure the meters work accurately.
Coriolis meters on the other hand, are more expensive to purchase upfront, but once installed, need very little maintenance. They also typically don’t need upstream/downstream straight runs, making them easier to install. Calibration can be carried out on site with a master meter, so only one meter needs to go to the lab for periodic checking. Lastly, Coriolis meters hold their calibration for long periods of time. Frequently, calibration routines allow for longer intervals between checks as time goes on, if calibration factors do not change in the meters. Consequently, cost of ownership actually reduces over time!
“Coriolis meters are mass meters, but I can’t use them because I need volumetric flowrate in my application.”
A Coriolis meter will provide a volumetric flow value in a flowing stream based upon a calculation using mass flow rate and density. Additionally, having multiple parameters can tell you a lot more about your process stream than just volumetric flow rate alone.
“I need to measure a variety of different oil types in the same meter. It’s important that I can capture the total flow of each oil when flowing so I can maintain inventory. Can I do this using a Coriolis meter?”
A Coriolis meter is not density or viscosity dependent, so it will generate accurate measurements no matter what type of oil runs through it. Furthermore, if the different oils have different densities, it is possible to verify the right type is running through the meter by using the live density measurement feature. Totalized flow data from the meter can be apportioned to the specific oil type, so inventory can be maintained automatically.
“We store and transfer oil from different tanks as part of a pipeline system, and need to keep density somewhat consistent, which we do by taking samples at regular intervals. If density gets too high or too low, we recirculate the oil and blend it with oil from other tanks to bring it back into our preferred density range. Coriolis meters are mass meters, but can we use one as a densitometer instead?”
Coriolis meters provide continuous density measurement and flow measurement. The advantage of a Coriolis meter is that all the flow can be passed through it, rather than relying on a slipstream sample line or an insertion probe. This means that the reliability of the measurement is quite high, giving confidence that the density measurement is correct. Connecting the density output to a local supervisory control or SCADA system will provide at-a-glance information on flowing density at any time.
“I have an abrasive flow. Is a Coriolis meter suitable for this type of regime?”
Coriolis meters have no moving parts and will certainly work with abrasive flowing media but there are some caveats. Coriolis meters often utilize thin wall tube to increase sensitivity to flow. This can be a problem if abraded by the media, which can result in tube failure or leaks. Accuracy can also be affected over time, although this often manifests as a small zero shift. High-end Coriolis meters can be fitted with heavy wall measurement tubes to mitigate abrasion caused by flowing media, ensuring the meter continues to provide accurate measurements over a long period of time.
“We use mechanical meters to measure flow from our holding tanks into the plant. The process has a fluid that can agglomerate and create lumps that sink to the bottom of the tanks. When the tanks get low, we suck these lumps up and have found that they can gum up our meter mechanisms. Will using Coriolis meters solve this problem?”
Coriolis meters have no moving parts to gum up. Inside each Coriolis meter are one or two tubes through which all the flow passes. Provided the lumps are not big enough to block the tubes, there would be no problem using Coriolis meters in this application.
“I would love to use Coriolis meters, but my process needs pressure ratings in excess of 12,000 psi, so it’s not an option.”
Coriolis meters are an option! Using thicker wall internal tubes and higher tensile strength metals, highly specialized Coriolis meters can be supplied with operating pressure ratings of up to 20,000 psi. These high-pressure meters have the full functionality and feature capability of standard Coriolis meters, providing a lower-cost alternative to installing multiple instruments to achieve the same result.
“I’m deploying LACT skids and need to output standard volume to API standards. Currently I’m having to use a flow computer to achieve this but is there a more cost-effective way?”
Better quality Coriolis meters have broad capabilities, including API standard volume functionality. When installed, pressure and temperature can be supplied to the transmitter in a variety of ways, and the calculation is made in the transmitter itself.
Decoupled Measurement Section
- Semi-circular shape unaffected by pressure changes
- Unaffected by pipeline stresses from misalignment
Balanced Torsional Drive System
- Supports meter mechanism
- Low energy requirements – intrinsically safe
- Drives through external vibrations and “noise”
- Resilience to aeration and flow disturbances
Thick Wall Tube Measurement Tubes
- Allows high pressure applications – over 20000 psi in small meters
- Abrasion and corrosion allowance
- No requirement for meter body secondary pressure containment
HOW DOES A CORIOLIS MASS FLOW METER WORK?
The operation of a Coriolis meter is based on physics. See below for a detailed description of the operation of this type of meter.
MORE ACCURATE MEASUREMENTS WITH OMEGA TUBE TECHNOLOGY
The Rheonik Omega Tube meter mechanism consists of three distinct sections:
The Measurement Section
- Pickup Coils – Provide signals to the transmitter
- Measurement Tubes – Where measurement takes place
The Meter Drive System
- Mass Bars – Provide stability and support to the measurement tube oscillation
- Drive Coils – Provide power to maintain oscillations at constant amplitude
- Torsion Rods – Energize and guide oscillation
The Meter Connection System
- In/Out Section – Decouples measurement tubes from process line stress and misalignment
- Each section plays a specific role in ensuring that the meter performs at a high level when measuring flow.
EVERY SECTION OF THE OMEGA TUBE MECHANISM ENSURES THAT RHEONIK'S FLOW METERS PERFORM AT AN UNMATCHED LEVEL OF ACCURACY.
The following information briefly describes the role of the various components within the meter and how they interact to ensure accurate and reliable flow measurement, even in difficult conditions.
To receive more application information for Coriolis meters in your industry, please fill out our short form.
oil & gas
How can injection meter maintenance be reduced in unmanned offshore installations?
Chemical injection meters need to work at high pressure when monitoring the flow rate of chemicals (e.g. DRA, CI, SI, LHDI, etc.) being sent down into the wells. Gear meters have long been the meter of choice for this task due to their ability to withstand the high pressure. However, gear meters have moving parts, and consequently, a high maintenance overhead. With the advent of high pressure Coriolis meters capable of withstanding 20,000 psi, there is a trend away from gear meters, not only to reduce maintenance costs, but to also take advantage of the multifunction capabilities and detailed diagnostics that Coriolis meters provide.
Metering skids for export of produced oil from offshore oil installations take up a lot of real estate because of straight run requirements. How can accurate metering be achieved without using so much valuable space?
Coriolis meters do not require straight metering runs to condition flow profile in order to be accurate. Coriolis meters can be installed on bends or in short pipe sections and still provide accurate and reliable measurement. Large size Coriolis meters are ideal for produced oil export measurement.
Coriolis meters are mass flow meters, but all the measurements required in a LACT skid are volumetric to reference conditions. How can Coriolis meters be used on LACT skids and give me what I need?
Coriolis meters are multifunction devices that measure both mass flow and density, simultaneously. Combining mass and density together gives a volumetric measurement. Fully featured Coriolis transmitters have built-in functionality and I/O to allow temperature and pressure correction to reference conditions to be calculated in real-time, without the need for a separate flow computer. Furthermore, net oil calculations can be made in real-time in some transmitters on produced oil streams to indicate actual versus gross oil production.
The oil and gas industry demands the most accurate and repeatable specifications of all industries, and applications often have extreme conditions, resulting in some of the most challenging measurement scenarios in the world. Whether a hydrocracker at 400°C/300 bar, chemical injection lines at 1,000 bar, or a huge LPG export terminal – a Coriolis meter with robust construction and the very highest pressure and temperature ratings, and custody transfer accuracy and performance, is the obvious choice for any upstream, midstream or downstream flow measurement.
Our machinery automatically combines several chemicals to make the final product, but the feed ratios must be tightly controlled, otherwise the product is ruined. Can Coriolis meters help me do this?
Coriolis meters are an ideal solution for ratio mixing control. They are highly accurate and have fast response to changing flow rates. These 2 key factors provide precise measurements used to control feed rates in a strict ratio for proper formulation of batch material.
We make separation skids that use supercritical CO2 to separate valuable oils from plant matter, but control of flowrate is critical to ensuring the fluid flow is maintained at the optimal rate for maximum extraction. We need both accuracy and compactness. Is a Coriolis meter suitable for this?
Manufacturing and processing industries worldwide use CO2 (and other gases) when separating raw materials into valuable end products. High-end Coriolis meters are commonly used in separation and extraction systems because they are compact, highly accurate and capable of handling the high pressures often present with supercritical gases.
Industry depends on high quality machinery to be able to produce consistent, high quality products. The consistently reliable performance of Coriolis mass flow meters in manufacturing and processing equipment contributes to the production of high-quality end products by providing measurements compliant with international standards for a wide variety of fluids.
Filling automobile air conditioning systems is a delicate task. Adding too little refrigerant means the performance of the system is unsatisfactory, while too much can lead to premature failure of the compression components, plus result in emissions to the atmosphere. How can Coriolis meters help?
Coriolis meters are ideal for refrigerant filling. With a wide turndown capability, Coriolis meters remain accurate for all flow rates, and are pressure independent, ensuring that the right mass of gas is delivered every time.
Vehicles on a production line have a variety of fluids dispensed to them as they are being built. Robots are frequently used as some of these fluids represent a safety hazard to production line personnel. Accurate filling and avoiding spillage are critical. How can Coriolis meters help?
The most accurate fills are achieved when the point of measurement is close to the dispensing point. High-quality Coriolis meters are compact and can be installed directly onto robotic arms very close to dispensing nozzles. Apart from being highly accurate, built-in advanced diagnostic data can be used to increase confidence in automated dispensing.
Whether used in a test environment measuring fuel consumption, injector performance or coolant flow, in production dispensing fluids such as oil, coolant, transmission fluid, and even wiper fluid, or at the pump delivering fuel, Coriolis meters play a large role throughout the automotive industry. With a wide variety of meter sizes available and industry standard communications options, South Fork Instruments supplies compact, cost effective, accurate and reliable flow solutions to all major automobile manufacturers, their suppliers, and consumer fueling companies.
I fill my H2-powered fuel cell car from gas “pumps” that look similar to gasoline and diesel pumps. But I’m buying kilograms of H2, not gallons. How do I know I’m getting what I paid for?
Coriolis meters have been integral in H2 dispensing for many years, with higher-end manufacturers developing high pressure flow meters specifically for the purpose. At the heart of every hydrogen dispenser is the point of sale flow meter. This meter must be Weights and Measures tested and sealed to ensure end customers receive the amount of hydrogen they are paying for. Sold in mass units (kg), Coriolis meters are ideal as they read primarily in mass and have a large measurement turndown.
Rheonik is the world leader in hydrogen dispensing for fuel cell vehicles. At the heart of the majority of hydrogen dispensers is a Rheonik meter, certified to national standards, built for the purpose, tamper proof, and sealed by Weights and Measures to give the customer peace of mind.
Paint, Adhesives and Coatings
We use mechanical meters to measure the flow of fluid transferred from holding tanks to day tanks on our production line where it is used in a coating process. The fluid can agglomerate and create lumps that sink to the bottom of the tanks. When the tanks get low, we suck these lumps up and have found that they can gum up our meter mechanisms, starving our lines of material. Will using Coriolis meters solve this problem?
Coriolis meters have no moving mechanical parts to get jammed by solids in the flowing stream, making them a good solution for flows with solids, while providing lower maintenance overhead.
We run different products on our machinery, and I need to measure a variety of different fluids in the same meter. It’s important that I can capture an accurate flow rate and the total flow of the fluid when flowing so I can maintain product quality and inventory. Can I do this using a Coriolis meter?
Unlike many other flow meter technologies, Coriolis meter accuracy is not fluid dependent, so it will measure correctly regardless of the fluid type running through it. Using a Coriolis meter can save the cost of installing multiple flow meters when switching between different fluids and reduces the risk of error.
Paint, adhesive and coating applications require metering capable of handling thick, “sticky,” and often abrasive materials. Meters must additionally be able to withstand pump pulsations at often high line pressures due to the viscous nature of the flows, while providing measurement to the highest degree of accuracy. With high pressure thick wall tubes that resist abrasion and no internal splitters to clog or block, high-end meters provide reliable, high accuracy flow measurement for all paints, coatings and adhesives.
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