Accuracy and reliability dominate the demands that process companies make on their flowmeter technologies, particularly when it comes to high flow rates and custody transfer. Eugene McCarthy reports.
Medium to high flow applications, including gas and liquid custody transfer, process unit material balances in refineries, and critical chemical feedstock measurements, now have a new measurement tool in the form of the Micro Motion ELITE CMF350 Coriolis flowmeter from Emerson Process Management.
Designed for line sizes from 3.5 to 4.5 inches (DN sizes of 90-125), the meter expands the ELITE family by providing accuracy and reliability for customers who require measurement at higher flow rates.
The Micro Motion ELITE CMF350 flowmeter features an optimum level of scalability and standardisation for the best fit in applications where flow rate accuracy with low pressure drop and high turndown is critical. Specifically, this meter delivers 0.05% optional liquid mass flow accuracy and volume accuracy, ±0.35% gas accuracy and ±0.0002 g/cc liquid density accuracy. Maximum flow rates for this sensor reach 15,000 lb/min (409,000 kg/h).
Emerson says this meter is ideal for applications such as cementing, custody transfer of liquid and gas, production separation, basic and specialty chemicals, ethylene and crude production and manufacturing processes.
“The ELITE CMF350 provides a solution for those customers who desire peak performance and ultimate control for their critical and challenging applications,” said Bill Graber, vice president of marketing for Emerson’s Micro Motion business.
Micro Motion ELITE CMF350 meters are available with Smart Meter Verification (SMV) which provides advanced diagnostics of meter health and performance without removing the sensor from the line or interrupting the manufacturing or measurement processes. The verification is quick, easy and can be executed remotely without a trip to the field, additional instrumentation, or data interpretation. SMV diagnostic reports are also increasingly recognised by third-party regulatory agencies, enabling work practice changes that save money and improve worker and environmental safety.
For its part, Endress+Hauser describes its AptiFlow averaging pitot tube as the cost-effective choice for measuring flow. Now the company is manufacturing a range of AptiFlows with two measuring probes for use in dual redundancy. Suitable for a range of applications, the dual redundancy option offers maximum reliability. These instruments can also be designed to meet users’ unique specifications.
The AptiFlow has integral, three-valve manifold heads that allow the company’s PMD series of low range differential pressure transmitters to be direct mounted. This ensures the system is cost-effective and dependable as no extra parts are needed and potential areas of leakage are considerably reduced. There’s also no restriction on the size of the pipeline. What’s more, says the company, as it doesn’t required periodic recalibration, maintenance is often as simple as carrying out a regular inspection and installing a replacement when needed.
Using differential pressure to measure flow has become more popular in recent years, as AptiFlow designer Kenny McGouran explains: “Modern dp transmitters can accurately measure very low differential pressures and boast a turndown ratio as high as 1000:1 with little or no effect on accuracy. This makes flow measurement using the AptiFlow range a very attractive proposition.”
Endress is also focusing on the transport side of the industry, with a smart fuel management solution that reduces costs when loading fuel into vessels; and fuel costs can account for up to 60% of the operational expenditure of a vessel.
Endress’s solution is Promass, with uses Coriolis flow measurement to improve the measuring accuracy even of highly viscous and aerated fluids.
With the Promass Coriolis mass meter, which is suitable for all fuel types, the fuel is measured and presented with unprecedented accuracy. A reliable fuel consumption metering system means that different fuels can be measured without the need for readjustment. In conjunction with other vessel data such as speed, wind and waves, it is possible to determine the optimum operating state for a vessel and thereby maximise efficiency.
Endress believes that its new solution will remove the uncertainty that is associated with traditional quantity measurement via tank gauging, for example, due to error-prone volume to mass calculation as well as disregarded air content caused by tank stripping. These, say the company, lead to incorrect billing and unwanted bunker disputes between supplier and buyer.
An ultrasonic solution
The Atrato ultrasonic flowmeter is the latest release from Titan Enterprises. A true, inline non-invasive flow meter, the company says it comes without the contorted flow path and disadvantages of alternative designs.
It can handle flows from laminar to turbulent and is therefore largely immune from viscosity. It also offers excellent turndown, linearity and repeatability. Now available in 60°C and 110°C temperature versions and a 30 bar higher pressure model, Atrato flowmeters use patented time-of-flight (TOF) ultrasonic technology that enables operation over very wide flow ranges (250:1) with excellent accuracy (better than ±1.0% of reading).
The Atrato system uses the well proven TOF measuring method which is far more reliable and accurate than Doppler shift measurement where reflected signals are required from irregularities in the liquid. The Atrato crystals are plain disks with a hole in the centre forming a washer, which are excited in such a way that they oscillate radially as opposed to the normal mode of excitement which is across the thickness of the ceramic. This strong radial signal sends symmetrical pulses directly into the tube.
Because of these annular ring crystals the sound travelling down the pipe can be considered as a plain wave. The signal to noise ratio is described by Titan as remarkable, as there is little background noise and high signal strengths. At times the signal to noise ratio is as high as 3000:1. As the system is fully balanced at zero flows the two signals are identical and cancel each other out. This gives a very stable zero flow condition and is the basis of the flowmeters high ratio between minimum and maximum flows. As the flow increases these signals go out of phase and we measure this phase shift to an accuracy equivalent to 250 picoseconds.
In addition, the sound waves travelling down the tube in the Atrato operating system are symmetrical and as a result any changes in the fluid’s velocity profile across the pipe diameter will be averaged out by the signal as it passes from the transmitter to the receiver. It is therefore irrelevant whether the fluid is fully formed with turbulent flow or completely laminar with a classic parabolic profile. “In practice this gives the Atrato an excellent immunity to Reynolds number changes and a good high viscosity performance,” says the company.
Flowrox launches deposition measurement solution
Flowrox Deposition Watch is a predictive device that allows its operators to address deposition issues well before they reach critical levels that can cause downtime or costly damage.
The deposition of paraffin wax and asphaltenes is a common reason for a major decrease in production and revenue in oil wells as it affects valves, pumps and pipelines, along with other pipeline components critical to the fluid control process.
The device was developed specifically for use in the oil and gas industry since it will allow customers to generate real-time images of any depositions affecting a piping system without ever having to open up the pipeline and slow down production.
“This is completely new technology which has very little competition,” said Todd Loudin, president and ceo of North American operations for Flowrox. “The Flowrox Deposition Watch can model mathematically deposition profiles and provide calculations on the free available pipe remaining.”
The instrument utilises electrical capacitance tomography (ECT) to create real time images of the inside of the piping and to detect the differences in permittivity of the various substances found in the piping system. In addition, it makes use of a patented algorithm that creates a 3D image of the process fluid in the piping and generates trend data as well as show free volume inside the pipe and the growth rate of the deposition growth over time.
Ultimately, Flowrox Deposition Watch can show the deposition thickness, deposition profile, growth rates over time, composition, and free flow volume, all of which allow engineers to understand areas where pipes are prone to deposits.