Fashions in sensor technology

I confess it was 50 years ago when I started looking at new technology for sensors. Back then, colleagues and I updated the old WW2 mine detector, using really low frequency (i.e. 1 kHz) magnetic waves to discriminate between ferrous and non-ferrous items, and assess the size and range of the target by the signal phase measurement. Here the electronics used ‘modern’ operational amplifiers, on a ‘chip’.

The 1980s

Ten years on, in the ’80s, the technology coming into vogue was ultrasonics, replacing float systems to make liquid level switches, and then, still using analog electronics, the first Doppler ultrasonic flowmeter appeared. With the availability of digital microprocessor circuitry, timed pulses transmitted through the air down to the surface of a liquid led to non-contact liquid level measurement, and major success in the automation of sewage sump pumping systems. (The success lasted maybe 30 years, as when the mobile phone business created low cost microwave components, similar systems based on radar began to take over in this market.)

The next leap forwards in the mid-’80s was the time-of-flight ultrasonic flowmeter – actually achieved with discrete digital circuitry, which was faster than the available microprocessors. The technology was originally developed at Harwell, for measuring liquid sodium flows in nuclear reactors, but these flowmeters found major application in monitoring clean water flows, primarily in water distribution mains. Over the next 25 years the technique was picked up by commercial interests, and continually refined, introducing clamp-on sensor systems, and adapting the technique for gas flows as well. Even domestic gas meters were introduced using the same principle. Eventually the microprocessor speed became fast enough to achieve the flow measurement accuracy needed – using multiple sound paths – for the fiscal measurement of oil flows, which is now one of the major applications, along with similar gas flow measurement tasks.

Other sensors where I was not initially involved were in the fields of gas detection – where for flammable gases, Pellistors created a major business area – and fire detectors. It seems that UV and IR fire detection systems are still seeking the best approach. Possibly because of the awareness brought about by the Internet, the pace of change and the commercial opportunities, the large corporations are quick to acquire small spin-off companies from university or other research after any small success, because of what technology they may have discovered: they do this ‘just in case’, to protect their market position.

Current developments

The area I see as most important currently, and a fruitful area to flag up for research projects, is in any style of optical analytical measurement sensor. Specifically, the component that brought this into industrial instrumentation was the tuneable diode laser (TDL), developed prior to 2005 for the telecommunications industry, to transmit telephone conversations and data down fibre-optic cables. Around 2007 Yokogawa acquired a business from Dow Chemicals, which used TDL sensors for near-infrared absorption (NIR) measurements of a gas mixture, which gave the proportions of oxygen, carbon dioxide and monoxide, and water vapour. This allowed the unit to be used as a combustion analyser for industrial furnaces, boilers etc.

Over the last 10 years this area of technology has grown in importance, and in its capabilities. Spin-off companies have emerged from various universities, like Manchester and Glasgow. A significant task in these developments is the application of the solution to an industrial problem: it needs the two factors of solving both the technical design and the industrial application. Cascade Technologies was established in Glasgow in 2003, and their analysers were initially targeted at marine flue gas emissions monitoring. From 2013 they added a focus on pharmaceutical gaseous leak detection, and also the process industry, on ethylene plants. Their technology allows multiple gases to be measured simultaneously. The Cascade business has now been acquired by Emerson.

Another closely market-focused supplier of NIR analytical systems is TopNIR Systems of Aix en Provence, in France, actually a spin-off business from within BP. TopNIR use their systems to analyse hydrocarbons – both crude oil and processed products – to allow a refinery operator to know how to most profitably blend the available components into a final product, as well as to minimise any quality give-away in blending the different grades of gasoline and diesel. TopNIR quote the annual benefit to a typical refinery at $2 to $6 million, with an implied investment spend of up to $2 million!

This article was first published in the May 2017 issue of “South African Instrumentation and Control” published by Technews.co.za

©Processingtalk.info

Emerson to work with Flexim

Emerson Automation Solutions and Flexim, the clamp-on ultrasonic flowmeter specialists, are to collaborate, to help process customers optimise their flow process design, flow meter selection and flow meter installation on capital projects. This will enable them to reduce execution risk and costs.

With customers under severe pressure to reduce schedule and cost targets on capital projects, Emerson project teams, using the Flexim clamp-on, ultrasonic flow metering portfolio in combination with the broader Emerson in-line flow meter products, are able to consult early and throughout the project cycle to reduce engineering, piping and installation costs as well as schedule risk.

Flexim non-intrusive flow meters are the market leaders in clamp-on, ultrasonic technology and provide the best reliability and the most advanced capability when addressing difficult applications with a non-intrusive flow solution. This co-operation will improve delivery of the exact flow solution needed by clients while supporting  ‘Project Certainty’ – the Emerson approach that is said to enable top-quartile performance in capital projects.

By empowering project teams with flow expertise to work with clients early in project phases, Emerson has consistently eliminated cost, accommodated change and reduced complexity on capital projects. The non-intrusive nature of the Flexim ultrasonic flow meters makes this product a powerful contributor to reduced engineering, piping and installation costs as well as schedule risk, given that it can be installed after piping is fabricated. Emerson and Flexim will collaborate to ensure less time is spent on engineering and installation by selecting the optimal flow solution for a given application and applying the most comprehensive flow portfolio available.

“In today’s market, we are seeing that our customers are looking for us to advise them early in their project cycle on technology to ensure streamlined and cost-effective project execution,” said Bret Shanahan, vice president of flow solutions, Emerson Automation Solutions. “We are pleased to be working with Flexim to provide our clients with the most appropriate flow solution that can be applied and support greater capital efficiency.”

“Flexim is excited to partner with Emerson on capital projects; our flexible, world-class, non-invasive meters are a perfect fit with the experienced Emerson project teams,” said Guido Schwanekamp, managing director for sales and marketing at Flexim. “Together we will be able to offer fully customised solutions that are tailor-made for a wide variety of capital projects, reducing capital expenditures while increasing efficiency for our clients and reducing total cost of ownership at the same time.”

The new Process Atrato ultrasonic flowmeter

A new flowmeter for small bore liquid flows has been introduced Titan Enterprises, an enterprising British company, who are a long established manufacturer of liquid flowmeter systems. Their first ultrasonic meter was introduced in around 2010, after a long development programme in co-operation with Prof Mike Sanderson at Cranfield University, and was called the Atrato. This unit was launched for the typical markets served by Titan, of laboratory testing, drinks dispensing, cooling systems, pilot plants, fuel cells, pharmaceutical applications and OEMs – and offered a 200:1 turndown, 1% accurate obstructionless straight through meter with a 4-20mA output. Materials were mainly PEEK and borosilicate glass or stainless steel for the flow tube, but the BSP or NPT male fittings were available in stainless steel. A very clever and high performance flowmeter for flows up to 20 Litres/min.

The Launch in 2010

Regrettably, while having worked with Titan for many years prior to 2010 on their PR and promotion, a high flying expensive agency was brought in to promote the Atrato, so it disappeared off my radar. I should not say much about whether it has been seen by anyone else since then, because I don’t have any info: but why are you reading this?

Now a new launch has been announced by Titan, of the Process Atrato flowmeter: a new version of the basic flowmeter, now ‘packaged for the process and control environment’.

The Titan Atrato for the Process Industry

atrat

This unit is built from 316 stainless steel and PEEK, plus an elastomer seal to suit the application, and has the on-board electronics sealed to IP65. From the photo you can see that the threads into the stainless steel process connection (at the top of the flowmeter) are female. The lower screw thread is for an M12 four pin electrical connector. The unit is suitable for 65 Celcius and 25 bar process conditions: the non-process Atrato can operate up to 110C if the electronics is installed remotely, so presumably this might be a future development. Flow range covered is 2mL/min to 15 Litres/min, using four flowtube sizes.

Each of the four models covering the different flow ranges is configured to offer the same pre-set ‘K-factor’, which is quoted to assist OEM use and interchangeability: but it also highlights that the electronic output available on these “process units” is a PNP and an alternative NPN pulse train, quoted as a ‘frequency’ output. Presumably this relates back to the pulse output style as was provided by the other Titan turbine and positive displacement flowmeter sensors. A separate power supply, from 8-24VDC, is used to power the unit.

A few criticisms

The other surprise for me was that the meter is pictured, and obviously intended for installation, ‘upside down’, with the electrical connections and housing below the flow line. When this Process Atrato is really an equivalent to a thermal mass style gas flowmeter application, but on liquids, you would think it would be sensible to have it looking similar to these other, well-known gas flow devices. The reason for this cannot be that it needs to allow entrained air to escape, as the flow tube is just a straight tube, with no complicated connections which might trap anything.

For the engineers who can see through these confusion factors, the device is a very effective flowmeter, 200:1 turndown, +/-1% accuracy over 2-100% of range, while working with viscous as well as non-viscous fluids – with the standard Atrato features of linearity, no moving parts and fast response time. Plus the PR says it will offer a ‘reduced cost of ownership’, but does not specify what this is compared with…..surely the point is that there is not much else on offer to provide this performance, except maybe a micro-Coriolis meter.

If Only….

The pity is, ever since launching the Bestobell Doppler flowmeter in 1976, and the Platon Kat in 1998, I’ve been looking forward to being involved in the launch a decent ultrasonic flowmeter for clean liquid process applications…..

Maintenance-free Non-contacting Bulk Fuel Tank Monitoring

Pulsar Process Measurement have supplied non-contacting ultrasonic volume measurement equipment with associated remote plant mimic software to help solve an issue for Northern Rail at three sites; their Newton Heath LMD (Light Maintenance Depot) near Manchester, Blackpool LMD and Barrow LMD, allowing them to control the ordering, delivery and usage of fuel more efficiently.

Northern Rail’s contractor Austin-Lenika, who were engaged in a wider project on site, had identified that the existing level indicators were not suitable for the application and were, therefore, not reading the level correctly. Austin-Lenika approached Pulsar for a solution. They specified that new equipment should provide a measurement of the volume of fuel in the bulk tanks with a target of ±1% accuracy, allowing staff on site to monitor fuel usage and transfer and pinpoint the optimum time to re-order fuel. They also wanted to have both local display of level on the storage tanks and to be able to remotely monitor levels across the entire tank farm of eight fuel vessels, plus three additional bulk tanks.

Pulsar supplied Ultra 3 non-contacting ultrasonic level measurement controllers with associated dB series transducers. The transducers were mounted into flanges at the top of the fuel tanks, and operate on a ‘time of flight’ principle, an ultrasonic signal reflecting back to the transducer from the surface of the fuel. The measurement is reliable and accurate, with sophisticated signal processing by Pulsar’s dedicated DATEM software system. In addition, the Pulsar Ultra Controller can calculate volume based on almost any standard tank shape, taking the tank dimensions and making the calculations necessary to convert them into the volume of fuel in the tank.

Pulsar on-tank hardware and remote display screens

Pulsar ‘on-tank’ hardware and UltraScan display screens

Pulsar also supplied UltraScan software, which uses the RS485 Modbus output of the Ultra to provide a screen display of both levels and alarms. UltraScan can operate either on a site basis or can bring together measurements from a variety of sites.

Staff at Northern Rail are using the system very effectively. Austin-Lenika tested the system by comparing delivered fuel from a tanker to measured levels from the Pulsar system, finding a variance from a 6000 litre delivery of ‘within 60 litres’, achieving the ±1% target.

New Krohne ultrasonic flowmeter for superheated steam

With the Optisonic 8300, Krohne presents a dedicated ultrasonic flowmeter for the measurement of superheated steam. The 2-beam flowmeter stands out with a measuring accuracy of 1%, high repeatability, and a large dynamic measuring range. Typical applications include boiler and plant efficiency monitoring in power plants, energy balancing or inter-company steam billing.

As downtime of steam pipes is very costly and must be avoided, Optisonic 8300 was built for long term use: it features a full bore flow sensor without moving parts or obstructions, and an overall sturdy and robust construction with no cables or sensitive parts exposed. Therefore, it can uphold its measuring accuracy without maintenance or subsequent calibration for up to 20 years, while keeping operating costs at a minimum. If verification of the measuring accuracy should become necessary, it can be provided by using the flowmeter diagnostics, without removing the flowmeter.

With nominal sizes ranging from DN 100 to 1000, or 4” to 40″, Optisonic 8300 is particularly suited to high flow rates. Pressure rating up to 200 bar (3625 psi) and temperature rating up to 540°C / 1004°F are available, higher requirements can be considered on request. With temperature and pressure sensors also connected to the device, the integrated flow computer can calculate steam mass flow.

Optisonic 8300 adds to the Krohne portfolio of ultrasonic process and custody transfer meters for liquids and gases, which now cover the range from compressed air to cryogenic liquid natural gas (LNG).

Well flow testing using Expro PassiveSonar

This is a story from the October issue of the Industrial Automation INSIDER, that would not fit onto the small format mobile friendly version of the newsletter, so it is shown here for readers to be able to access it from their mobile devices. Obviously no-one whose company has not paid their subscription to the INSIDER newsletter should read the following text!

Expro specialize in well flow management services and products. A subsidiary, Expro Meters, based in Wallingford, Connecticut, supply clamp-on ultrasonic flow m e a s u r e m e n t techniques that parallel the technology used in the phased passive sonar arrays used by submarines: these are called, simply, PassiveSonar. These meters were first introduced in 2003, following an exclusive deal with the developers of the technology – CiDRA, also of Wallingford (a Teknoinvest of Norway company) – and they are used to enable oil and gas producers to realize increased value from their wells and fields through improved production monitoring, for optimization of well performance, increased efficiency and reduced metering costs.

At Offshore Europe last month, in collaboration with Marathon Oil in the UK, staff from Expro presented a paper describing the use of PassiveSonar on the East Brae platform, where there are currently 12 producing gas wells. Varying water-gas ratios and low gas rates result in liquid loading being a major flow assurance issue. Well testing is carried out every two months using the Expro clamp-on flow meters – because they are clamp-on units there is no interruption to the production flows while the meter is installed. Different methods have been adopted to optimize production and combat liquid loading: wireless wellhead temperature sensors recently installed have been correlated with sonar measured gas rates, providing a real time trend of liquid loading.

How do they measure?

PassiveSonar is well suited for high liquid loading multiphase flows typical of black oil wells and low pressure gas wells. The flow measurement principle relies on the natural turbulence and noise of the flow producing a pattern that is detectable by the passive sensors, which is time shifted as it travels down the pipe. So I would describe it as a cross-correlation technique.

The same units are quoted to measure the entrained gas percentage, or gas void fraction, 0 to 20%, determined by a measurement of the sound speed through the process medium. In the East Brae example the flow is mainly water, with some gas entrainment, so the principle would be valid, but how the speed of sound can be measured passively does not seem immediately obvious!

There are 1500 Expro PassiveSonar meters quoted as installed world-wide.

Another style of clamp-on flowmeter is the ActiveSonar meter, launched in 2009, which is best suited for gas and gas condensate wells flowing in heavy schedule pipes. It uses a clamp-on array of ultrasonic transmitters opposite the receiver array.

Krohne Australia leverage

In Australia, Krohne have been applying the CiDRA Sonar technology to difficult applications outside the oil and gas sector – primarily in the minerals and mining industry – for several years: earlier this year they signed an agreement with CiDRA to sell these products across the whole of Asia and Australasia.

Following this, Krohne have now signed an agreement with Expro, who have the exclusive rights to oil and gas applications, to resell the Expro versions of these systems for upstream and midstream oil and gas applications throughout Asia and Australia, alongside the standard Krohne portfolio of flow metering systems – which includes conventional ultrasonic meters for both gas and liquids, including LNG and oil.

Patrick Matthews, md of Krohne Australia, said: “The sales agreement with Expro is a strategic partnership of high importance for Krohne in Asia and the Pacific. We also believe this relationship will enhance our position to establish a centre of excellence for reservoir management and wet gas metering in Asia”. Craig Watterson, global sales manager at Expro Meters, commented “The Krohne Asia organization has technical knowledge of and years of experience with PassiveSonar metering technology. This combination makes them a uniquely qualified strategic reseller for us in Asia”.

Emerson buys Groveley Detection

Emerson Process Management, a business of Emerson, has acquired Groveley Detection Ltd., a leading innovator and developer of ultrasonic gas leak detection solutions for both offshore and onshore oil and gas installations. UK-based Groveley Detection was the first company to develop a piezo-electric based ultrasonic gas leak detector engineered for extreme industrial applications.

Groveley will join the company’s Rosemount Analytical business unit, expanding Emerson’s safety monitoring portfolio. With the completed acquisition, Emerson significantly strengthens its position in the global safety monitoring market by adding the Groveley ultrasonic gas leak detection technology to the complementary Net Safety fixed gas detection and flame detection product line. Groveley products are used in a broad range of energy exploration and processing applications, in addition to several industrial plant settings.

“The acquisition of Groveley expands our capabilities to offer the most comprehensive solution to our customers for their total safety monitoring requirements,” said Ken Biele, president of the Emerson Analytical Group. “The addition also leverages our companies’ synergies in sales, marketing, engineering and other key operational areas.”

Robert Bennet, Managing Director at Groveley, added: “Joining a global leader like Emerson Process Management represents an incredible opportunity. We expect our customer base to grow exponentially, as well as our ability to help solve customer problems by developing some of the most innovative safety products in the industry.”