Confusion over radar level measurement

We have learned not to get too confused over suppliers using buzz-words and clever marketing names, but recently it seems the major level measurement system vendors have been introducing new and higher radar frequency systems as their latest development – and therefore, by implication, maybe the best. We were used to 6 GHz, and then 26 GHz radar frequencies, but why should we suddenly go to 80 GHz? Then, perhaps just to add a little excitement to the mix, Endress+Hauser started talking about 113 GHz!

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The E+H radar line up that offers 113GHz!

This article was first featured in the journal South African Instrumentation & Control in September 2017, a journal published by Technews

Let’s dispel a few myths. Firstly, in the same way that lasers for fibre-optic communications systems made the technology available to create infrared optical systems for process gas analysers, and mobile phone technology possibly provided the hardware for the first radar level measurement systems; the 80 GHz versions are a result of measurement technology made commercially viable on the back of production investment in the distance measurement systems and parking sensors used in modern cars. So the suppliers take the available sensors and chipsets to create a new industrial product, and then have to find the best applications – in this case, the ones that might benefit from the 80 GHz.

Secondly, E+H do not have a 113 GHz system, this is a marketing statement, made to catch attention – ‘with a wink’ is their expression. They claim a ‘complete radar competence of 113 GHz’ because this is the sum of the many different frequencies their different sensors use! These are 1, 6, 26 and 80 GHz.

So why have different frequencies?

Possibly the best explanation for the applications suited to the different frequencies has been provided by the Rosemount measurement division of Emerson, in their “Engineer’s Guides”. The Emerson expertise stretches back many years, having acquired the Saab Tank Radar business. Per Skogberg, from the Gothenburg HQ in Sweden, separates the devices into low, medium and high frequency, to generalise.

Radar signals are attenuated, i.e. they lose signal strength as they pass through the air, or vapour, above the liquid. High frequencies are more severely affected than lower. When the air has moisture, steam or liquid droplets (from spray or filling) present, the attenuation is higher. Equally in solids applications, dust particles have the same effect. So low and medium frequency radar are best when there is dust or moisture present.

At lower frequencies, the wavelength is longer (30-50 mm), so surface ripples in a tank have a small effect. At higher frequencies, surface ripples and foam on the surface can be a problem. But the shorter wavelength of the high frequency units (4 mm) allows accurate operation over short ranges, for example in small tanks. The higher frequency units can use a smaller sensor construction, so the unit is easier to install. The beam angle is narrower, so it can be aimed at a smaller target area and therefore can be positioned more easily to avoid any obstructions in the tank. But even this can be a disadvantage, as the installation needs to be exactly vertical and any turbulence of the surface during filling or stirring can cause the signal to be lost temporarily, in larger tanks.

When reading these suggestions, it is important to remember that Emerson does not offer an 80 GHz unit yet, so their marketing approach would naturally bias users to look at low and medium frequency units. The suppliers of high frequency units (Vega, Krohne and E+H) would point out that in many liquid storage tanks the surface is undisturbed, since any foam, turbulence and significant ripples (>2 mm) caused by filling or liquid transfer will only cause short-term interference. Plus the small antenna size and short range performance make 80 GHz units very useful for smaller process vessels and tanks.

Radar system types

There are two types of radar systems, Guided Wave Radar (GWR) and Free Space Radar. The GWR systems use a conducting rod, or similar, extending down into the liquid, often working in a stilling chamber attached to the main process tank. These operate at low microwave frequencies, and are independent of surface turbulence and foam. They are useful for shorter range measurements and interface measurement between liquids, as well as long ranges.

The Free Space Radar systems are more widely used, since they are top-mounted with nothing in the tank: indeed, some can operate through non-conducting windows in the tank roof. Low and medium frequency radar systems generally transmit a signal pulse and measure the liquid distance by the time delay for the returned pulse. High frequency (80 GHz) systems use an FMCW radar measurement, where the frequency of the transmission is swept, and the frequency difference of the returned signal is measured to assess the distance. The FMCW technique is also used at 26 GHz in some recently launched sensors.

Radar systems can transmit their measurement data using 4-20 mA, fieldbus systems like HART, FF, Profibus PA and Modbus, or indeed via wireless systems like Bluetooth. The low and medium frequency pulsed radar systems generally operate over a two-wire interface: some of the higher frequency FMCW systems require more power and use a separate power connection.

Major applications

Simple low-cost radar level measurement sensors have been specifically designed for water industry use, in sewage sumps and flume flow measurement, by Vega and Endress+Hauser. Vega suggest that 40,000 such sensors are now in use in the water industry, mainly in Europe, and claim their total output of such sensors exceeds 550,000 units over the last 25 years.

Several of these devices use simple Bluetooth interrogation and programming from a handheld PDA: E+H demonstrates this at its facility in Maulberg, working on the stream that runs through the factory complex, as seen below.

Micropilot_FMR10_FMR20_on test stream at Maulberg, with operator using Bluetooth

Both E+H and Vega produce further industrial units for use on process vessels, and storage vessels for solids and liquids. Recently, E+H has extended its capability to add long-range units, such as the 80 GHz FMR62, working at up to 80 m range, with an accuracy of 1 mm. Other units work up to 125 m range, at 3 mm accuracy. These units will eventually be aimed at the large petrochemical industry storage tank markets, and specifically are working towards use for custody transfer duties.

Krohne have similarly announced a new range of its 80 GHz Optiwave sensors. Some of these can even operate at up to 700°C, for example for use on molten salt vessels in solar power plants. Lower specification units rated at up to 150°C can be used through a tank roof made of plastic, or similar materials. Suitable for small or narrow tanks, the unit can measure ranges of up to 100 m. Krohne also offers lower frequency Optiwave systems for use on solids and powders, or to electronically monitor the float position in magnetic level indicator columns attached to process vessels.

Postscript: Krohne is organising a webinar with the title “80 GHz Radar Level – Allrounder or Overrated?” to discuss their recent developments with such systems. This webinar will take place on 18th October 2017 at 3pm London time/10am New York time.

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UV keeps bottled water safe

Hanovia UV has supplied Cott Beverages UK, based in Derby, with a PureLine intelligent UV system to keep its production process water pure.

PureLine range

In an increasingly regulated and safety-conscious market, legislation such as the EU Directive for Bottled Water 98/88/EC (1998) drives the beverage industry to meet ever more stringent standards of quality. Microbial growth due to contaminated water or ingredients can cause discolouration, off flavours and shortened shelf-life. The threat of contamination is further increased as manufacturers respond to demands for less chemical additives and preservatives. Effective microbial disinfection of the whole process is therefore essential.

To meet this requirement, Cott Beverages has been using Hanovia UV disinfection technology to treat process water used in the production process. The company decided to use UV technology to ensure final product security prior to mixing and bottling and has been very satisfied with the performance of the UV systems.

“The Hanovia UV systems have been easy to integrate, maintain and operate,” said Chris Prentice, site service engineer at Cott Beverages. “They provide us with absolute insurance before bottling by making sure that we are producing and maintaining a high-quality product, which is essential for our brand.”

PureLine UV from Hanovia is an intelligent system that is optimised for the beverage industry to simplify the treatment of water, sugar syrup, brine and even reducing chlorine and ozone. Critically, there are no microorganisms known to be resistant to UV – this includes pathogenic bacteria such as listeria, legionella and cryptosporidium (and its spores, which are resistant to chlorination). Unlike chemical treatment, UV does not introduce toxins or residues into process water and does not alter the chemical composition, taste, odour or pH of the fluid being disinfected.

UV is used for both primary disinfection or as a back-up for other purification methods such as carbon filtration, reverse osmosis or pasteurisation. Because UV has no residual effect, the best position for a treatment system is immediately prior to the point of use. This ensures incoming microbiological contaminants are destroyed and there is a minimal chance of post-treatment contamination.

UV disinfection systems are easy to install, with minimum disruption to the plant. They need very little maintenance, the only requirement being the replacement of the UV lamps every 9-12 months, depending on use. This is a simple operation that takes only a few minutes and can be carried out by trained general maintenance staff. The Hanovia UVCare training programme supports businesses like Cott Beverages to make sure servicing is carried out by certified engineers at all UK production sites.

Yokogawa EPMS and SCADA for the UK’s BPAL pipeline system

Yokogawa has received an order from the British Pipeline Agency Limited (BPAL) to supply a management and control system for one of the UK’s major multi-product fuel pipeline systems, to replace the current BPAL pipeline management and SCADA systems.

The BPAL UK pipeline system consists of three integrated multi-product fuel pipelines that link two, refineries, one at Ellesmere port on the Mersey near Liverpool and the other on the Thames in Essex, to inland distribution terminals. These pipelines, operational since 1969, meet over 50% of the jet fuel needs at London’s Heathrow and Gatwick airports, and are altogether some 650 km in length. BPAL, jointly owned by Shell and BP, are the operators of these pipeline systems (known as UKOP and WLWG), which are owned by a consortium of partners.

This order is for Yokogawa’s Enterprise Pipeline Management Solution (EPMS), which will manage functions such as delivery scheduling and oil storage, and their Fast-Tools SCADA software, to monitor and control the oil pipelines and related equipment such as compressors. The EPMS uses specific gas and liquid applications that enable a pipeline operator to manage delivery contracts in a time and energy efficient manner. With the SCADA system covering monitoring and control, the EPMS will integrate the management of the SCADA data. Delivery of these systems will be completed by March 2018.

Further order for UAE Power and Desalination Station

Yokogawa also recently received its first ever DCS order for a power and desalination plant in the UAE. The company is to supply the Sharjah Electricity & Water Authority (SEWA) with control and safety systems, plus field equipment, for Units 7 and 8 at the Layyah Power and Desalination Station.

Each unit comprises a 75 MW oil and gas-fired thermal power plant and a 27,000 m3 per day multi-stage flash (MSF) desalination plant: a technology that involves the heating and evaporation of seawater in multiple vacuum distillation tanks to produce steam, which is then condensed to produce fresh water. Such systems are energy-efficient because they use the heat from the steam that is created in the vacuum distillation tanks.

Yokogawa Middle East & Africa will deliver the CentumVP integrated production control system for the boiler, turbine governor, turbine protection system and the desalination plant at each of these units, as well as the ProSafe-RS safety instrumented system for burner management and boiler protection. The field instruments will include Yokogawa products such as the DPharp EJA series differential pressure and pressure transmitters, continuous emission monitoring systems (CEMS), and steam and water analysis systems (SWAS). In addition to being responsible for engineering, the company will provide support for the installation and commissioning of these systems, with all work scheduled for completion by September 2017.

Demand for electricity and water is soaring throughout the Middle East due to their rapid economic growth. Power and desalination plants that rely on the region’s abundant oil and gas resources make up an important part of this region’s infrastructure.

Alfa Laval sees marine market growth in ballast and SOx

Readers of this blog will recall the Alfa Laval launch on their “PureBallast” water treatment system for marine vessels way back in 2007. The IMO international convention for the ‘control and management of ship’s ballast water and sediments’ was the legislation that would drive the adoption of such systems world-wide: at last this convention became legally binding on shipping and ship-owners worldwide on 8th September 2016. Inevitably there is a 12 month time lag before it will be legally enforced, and then, hopefully, tankers will not be allowed to ply their trade without having an approved ballast water treatment system fitted.

Ballast water treatment market

Peter Leifland, current president of the Marine & Diesel Division of Alfa Laval presented some interesting views of this market in support of the recent Alfa Laval Capital markets Day presentation to analysts and stockbrokers.

Leifland commented that “With the ratification in place, the market for retrofit installations is expected to start to move.”  Alfa Laval expects that 35 000 ships will install a ballast water treatment system between 2017 and 2025. This is split between 15 000 newly built ships and 20 000 retrofit installations. The average order value per ship for the Alfa Laval chemical-free solution is EUR 200,000 – 225,000.

The Alfa Laval system fully complies with IMO standards and requirements, but as ever different countries can impose further approval and performance requirements and testing, effectively policing their own waters so that only ships with their approved systems can trade in their waters. This means more approval testing, fees, and even design changes for suppliers like Alfa Laval. They have their PureBallast system nearing completion of the long testing procedure needed by the US Coast Guard to check that it meets with their USCG criteria.

Shipboard sulphur oxide emissions (SOx)

The IMO convention for the reduction of sulphur oxides (SOx) emissions from ships has been ratified and since 2015 it has been implemented in some Emission Control Areas (ECAs). This IMO regulation will become global by 2020, requiring that that emission levels will be cut to 0.5%.

Leifland commented that Alfa Laval estimates that 5 000 ships, new as well as existing, will install a scrubber solution in the period 2017-2025.” Given the continuing development of new solutions, Alfa Laval’s average order value per ship is expected to be EUR 1 million. Leifland sees these two developing markets as a useful opportunity, during a period where “falling ship contracting is impacting our order intake”.

Postscript 27 December 2016: 

Alfa Laval PureBallast 3 receives U.S. Coast Guard type approval

Peter Leifland, President of the Marine & Diesel division in Alfa Laval, reports that:

“I am very pleased to receive this type approval, as it confirms the reliable performance of our ballast water treatment system. We now have a system approved by both US Coast Guard and the International Maritime Organization”.

Alfa Laval PureBallast 3 has received US Coast Guard type approval for usage in all water salinities, including fresh water. It follows upon two and a half years of compliance testing, according to the strict demands of the Environmental Protection Agency’s “Environmental Technology Verification” (EPA ETV) testing protocol. The tests were performed at DHI’s test facilities in Denmark, supervised by DNV GL as the independent inspection laboratory.

 

2M EM Flowmeters in 40 years

Since 1977, Endress+Hauser has produced over two million electromagnetic flowmeters. The company claim this is more than any other manufacturer, and that E+H is the market leader in electromagnetic flowmeter technology. “This magic number stands for high-quality measuring technology and, above all, satisfied customers in all kinds of industries,” says Bernd-Josef Schäfer, Managing Director of Endress+Hauser Flowtec AG, the center of competence for flow measuring technology.

The Endress+Hauser success story as a manufacturer of electromagnetic flowmeters began in the middle of the 1970s. In order to enter the water and wastewater market which was emerging at that time, E+H purchased the company ‘Flowtec’ in Bern, in 1977, and moved it to a new location in Reinach (Basel-Landschaft, Switzerland). This is where Endress+Hauser started to produce flowmeters with just three employees, in a former military barracks.

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The 1977 production unit at Reinach

Then, work was done on an on-demand basis. “Whereas today,” says Bernd-Josef Schäfer, “our production spans six sites around the globe – in Switzerland, France, the USA, China, India, and Brazil – and boasts state-of-the-art logistics. This infrastructure is what has enabled us to produce two million electromagnetic flowmeters to date in accordance with required quality standards.” These two million electromagnetic flowmeters could measure a volume corresponding to four times the flow rate of the Amazon. Each production site also features precise calibration facilities which are regularly checked by national accreditation bodies and which guarantee consistently high measuring quality for each individual device.

Constant innovation for customer satisfaction

The company’s success, which spans almost 40 years, is due to many factors. In particular, its inventive talent has enabled Endress+Hauser to keep offering its customers new, groundbreaking devices capable of measuring all kinds of fluids, such as water, milk, acids, alkalis, or ore slurry, with the greatest accuracy. With clever innovations such as the precision measurement of difficult fluids (Autozero, 1981), microprocessor control (Variomag, 1984), two-wire technology (Eximag, 1987), or the operating matrix (Tecmag, 1990), Endress+Hauser has always managed to stay one step ahead of the competition.

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In 1985, 800 and 2000mm bore flowmeters were produced for monitoring drinking water supplies delivered around Algiers

In 1993, all of these device variants were brought together to form a single product family under the name of “Proline”. Alongside this family, however, Endress+Hauser also produces flowmeters for very particular applications – for example, filling bottles at one-second intervals.

Looking to the future with Proline

Since 1993, the Proline device family has undergone constant development to ensure that it meets the prevailing requirements in a wide range of industries. Following the second generation launched in 2000, the third and most recent Proline generation (2012) offers a multitude of unique functions and device properties. This means that system operators will not only be able to retrieve measurement and diagnostic data via display, WLAN, web server, or fieldbus, but will also be able to monitor the process comprehensively and, if necessary, check the functioning of a flowmeter during operation.

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One modern production line for Proline electronics units

Bernd-Josef Schäfer sees the future of Endress+Hauser optimistically: “Innovations such as these enable us to align our product portfolio consistently with the needs of every industry. We are looking ahead to our three-millionth electromagnetic flowmeter with great confidence.”

This E+H release was first published by Eoin O’Riain in Read-out.net in Ireland

Water Use Cut 75% at IoT Connected Farm

Avocado trees monitored around the clock by a Spirent Communications system are given water only when needed; the farmer uses soil moisture meters, IoT technology, LoRa WAN communications and cloud computing to control the irrigation, reducing his annual water consumption by 75%.

It takes 74 gallons of water to produce one pound of avocados, and drought-stricken California produces 95 percent of avocados grown in the United States. Nearly all are grown in Southern California, in a five-county region that straddles the coast from San Luis Obispo to San Diego. Like the rest of the state, the southern coastal region is locked in a drought and largely cut off from the flow of surface water from the state’s big irrigation projects. Avocado groves have been hit badly with sky-high water costs and reliance on water pumped from underground aquifers.

Water consumption is regulated in California with the state entering its fourth year of drought resulting in water regulators imposing sweeping and draconian restrictions on the use of water. The State Water Resources Control Board has even urged Californians to let their lawns die.

Some avocado farmers in California feeling the heat have turned to new methods in growing avocados such as higher density planting which enables some to produce twice as much fruit for the same amount of water. But a new initiative from Spirent Communications in bringing about connected avocado farms might just be the perfect solution to make further inroads into lowering spiralling water costs.

Useful day-job expertise

It just so happens that Kurt Bantle is a senior solution manager at Spirent Communications and at home has some 900 young avocado trees planted in his “back garden” in Southern California. Within his work remit, which is to develop Spirent’s IoT offering, he decided to experiment into how avocados could be grown using less water through soil moisture monitoring, by using this as an input to automate the irrigation, using a just-in-time approach.

Bantle divided his farm into 22 irrigation blocks and inserted two soil moisture measurement units into each block. The units contain a LoRa (www.lora-alliance.org) unit for narrow band data communication to a LoRa gateway which has a connection via a broadband cellular uplink.

The gateway also contains an Oasis (a partner company with Spirent) re-programmable SIM which becomes the enabler in remote water provisioning. All soil moisture data from the avocado trees is collected in a cloud and visualised by a presentation layer. When a tree needs to be watered, the solution turns the sprinklers on automatically to get the correct level of soil moisture for each tree. It then turns them off when the correct moisture levels are reached. The connected trees are monitored constantly day and night. In all Bantle spent $8200 for LoRa stations, gateway and cellular backhaul, moisture sensors, and irrigation valve controllers.

“Avocado trees typically take 4 acre feet (1 acre foot = 326000 gallons) of water per acre per year. This is not only to supply the needed water, but also to leach the salts which build up in the soil,” says Bantle: “The soil moisture sensors let me drastically reduce water usage by telling me when to water and how deep to water to push the salts past the bulk of the rooting zone. The majority of the roots are in the top 8 inches of soil so there is a sensor there and one at 24 inches so I can see when I’ve watered deep enough to get the salts out of the rooting zone”.

The previous annual cost of watering his 900 trees was $47,336. By connecting this IoT technology, his annual bill dropped to £11,834, a 75% reduction. The hardware investment was recouped in the first 6 months.

“The case study showed a water usage reduction by 75%, but the usage will climb as the trees get bigger. The goal is to reach a 50% reduction of water usage when the trees are fully grown. By keeping the salts in check along with keeping nutrients supplied, stress on the trees is reduced and they are able to have better crop production,” says Bantle.

Future Consequences: both positive and negative

The downside for Bantle in harnessing the power of IoT to reduce water consumption was that he was placed under state surveillance for suspected meter tampering, when his water consumption reduced so dramatically.

The connectivity solution provided by Spirent together with its IoT ecosystem partners for avocado trees applies to every other type of vegetable and fruit farm, which would include almonds, olives, apples, oranges and tomatoes.

IoT technology pioneer Spirent Communications plc is leading the charge with its open eco-system partners such as Oasis Smart Sim through its connectivity and embedded subscription business and recently showed various such connected solutions at the IoT World exhibition.

Spirent’s Embedded Connectivity solution will be launched during 2016 in a phased manner so that the commercially available solution conforms to the corresponding GSMA specification releases.

Spirent conclude with the message that the Internet of Things (IoT) is destined to touch every aspect of human endeavour making factories smarter, supply chains intelligent ….and now farms such as this first IoT connected avocado farm more water efficient, saving farmers vast amounts of water (and therefore money) in the avocado growing process.

The original story from Spirent was first published by WaterActive.co.uk in their July issue.

Power and water for the developing world

In the Journal ‘South African Instrumentation and Control’ I provide a regular column  giving some commentary on the I&C scene as seen from Europe, wherever possible referring to items that could be of relevance to their South African readers. This was the story published in the May 2016 issue.

Some of the products created for the consumers in the developed world have had perhaps surprising benefits in the less well-developed countries too. One example has been the use of mobile phones throughout Africa, enabling the development of a simple banking and payment system.

But there are other engineering developments that are specifically designed for use by people living far from the normal facilities offered in an urban setting, and many universities, philanthropists and aid organisations are active in supporting these ideas. desolenatorOne such development idea from the UK is known as a ‘Desolenator’. This is a portable, solar-powered water purification system, designed to produce clean drinking water, starting from seawater, or polluted groundwater. The device is the size of a flat-screen TV and is equipped with rugged all-terrain wheels to assist transport: it can produce 15 litres of distilled drinking water per day, enough for one family to use for drinking and cooking.

The device uses a solar panel to produce electricity: a thin layer of the water to be treated flows over the photovoltaic surface, absorbing the heat also produced by the sun, and cooling the panels to improve their efficiency. The heated water passes into a boiler, powered by the electrical output from the panel: the steam is condensed to produce distilled water, giving up its latent heat to the incoming water flow. A small drain from the boiler discharges a concentrated dirty liquid stream.

The Desolenator device is claimed to have a life of 20 years, and requires little maintenance: it has recently won two Innovation Award prizes from the UK’s Institute of Engineering Technology.

Further harnessing solar power

Whilst the Desolenator shows one potential application of solar power, making electric power available from such a widely available source is a major objective in both the developed and under-developed world. This is particularly needed in areas without any other source of power at night, when it is dark, which is a slight problem. How can children do their homework, or study anything, without some light?

In the developed world there is a need to store the power generated by wind farms and solar farms, to make it available in periods of high demand, or when the wind or sun are not there. So there is a lot of research into storing large amounts of power. Hopefully some of this might spin-off and make smaller domestic or small village units available soon.

csm_Photoelektrochemie_219a069346At the Technical University of Vienna (TU Wien), current research is following the principles of photochemical cells, as used in nature, where plants absorb sunlight and store this energy chemically. The main problem was that quoted above, in relation to the Desolenator design, that at high temperatures, the efficiency of any current photovoltaic solar cell decreases. While the electrical energy produced by a solar cell can be used in an electrochemical cell to split water into hydrogen and oxygen, the energy efficiency of this process is limited, because of the high temperatures involved.

At TU Wien researchers have now developed new highly specialised materials, which form a photovoltaic that operates at a high temperature (400°C), so concentrated light beams can be used to produce a large energy output: currently achieving 920 mV. These cells use Perovskite metal oxide materials in the photovoltaic, which creates free charge carriers – electrons – that travel into the electrochemical cell. Here they ionise oxygen into negative ions, which can travel through a membrane, separating hydrogen and oxygen. Work continues to increase the power further and produce an industrial prototype, where a hydrogen cell would be used later to produce on-demand electrical power.

Other techniques

More conventional techniques, such as those having banks of rechargeable batteries, and even mechanical flywheel systems, are being installed in areas where short-term interruptions in supplies are common. But the spin-off from such university research will eventually lead to novel ideas to help the less-developed world as well.