Modern Level-Measurement Technologies for CPI Applications

Advanced level measurement devices enhanced with intelligence solve CPI challenges

Chemical processes often require handling media that is corrosive, flammable, explosive or toxic with wide ranges in temperature and pressure and characteristics that include steam, dust, foam, turbulence and condensation. All these factors, often in combination, can make it challenging for level instrumentation to provide accurate and reliable measurements. However, today’s non-contact and radar-based level measurement technologies enhanced with intelligence solve the industry’s biggest level measurement challenges.

“The primary obstacles for chemical processors in level measurement and control stem from the nature of the materials being processed,” explains Brittany Cost, level product manager with SOR Controls Group (Lenexa, Kan.; sorinc.com). Some of the greatest challenges include the following:

• Corrosive media: Many chemical processes involve handling highly corrosive substances like acids, bases or solvents, which can damage traditional sensors.

• Harsh environments: High pressures, extreme temperatures and abrasive materials can damage measurement devices, leading to inaccurate readings and equipment failure.

• Tank configurations: The geometry of tanks, presence of agitators and interference from internal structures can cause measurement errors.

• Foaming or turbulence: In some processes, foaming or turbulence can create false readings for certain types of level sensors.

• Viscous or sticky materials: Thick, sticky or viscous materials can interfere with sensor surfaces, leading to inaccurate readings.

• Safety and compliance: Ensuring level measurement meets strict safety standards and regulatory requirements is essential to avoid risks in chemical processing.

“When attempting to measure and control level in diverse and challenging applications, the greatest needs for level measurement and control equipment in chemical plants revolve around ensuring precision, reliability and safety,” says Jenny Leion, industry manager for chemicals, with Emerson (Shakopee, Minn.; emerson.com).

“Beyond accuracy, ease of installation and maintenance are key considerations,” Leion continues. “Modern chemical plants require instruments that integrate seamlessly with digital control systems, while providing self-diagnostics to minimize downtime. Instruments should be capable of handling harsh environments while still providing consistent performance.

“Furthermore, advanced level measurement devices should support enhanced connectivity and data analytics,” says Leion. “The ability to gather, transmit and analyze reliable process data is crucial for optimizing production, reducing operational costs and enabling predictive maintenance strategies. This data-driven approach helps improve overall process efficiency, enhances safety and supports sustainable operations in this increasingly complex and regulated industry.”

To that end, providers of instrumentation are leveling up their game when it comes to level measurement devices with the introduction of advanced instrumentation that is enhanced with intelligence to provide solutions to many level measurement issues.

Digitalization is key

“How can today’s smart instruments help chemical processors produce more products with fewer resources? This is one of the major challenges most facilities are facing,” says Keith Riley, national product manager for Endress+Hauser USA (Greenwood, Ind.; us.endress.com). “The need for added value beyond the primary measurement can be categorized into one of three areas: simplicity, safety and increased productivity.”

He says these are achieved using a variety of improvements, including:

• Human-machine interfaces (HMI)that are more intuitive and informative

• Instrument-led commissioning to reduce human error and time

• Tools that allow plant personnel to diagnose instruments in situ, reducing the need for technicians to enter hazardous environments

• Preventive diagnostics to reduce unscheduled downtime due to instrument issues

• Predictive diagnostics through condition-based monitoring of the process

“These technologies eliminate the need for multiple interface tools, improve installation and commissioning time by more than 30%, reduce unplanned and reactive shutdowns, detect process anomalies using predictive maintenance and reduce systematic failure and on-site accidents,” says Riley.

Emerson’s Leion adds: “When modern level instruments are equipped with advanced diagnostic tools that can monitor their own health and performance, they allow operators to identify potential issues before they lead to equipment failure or process disruption, thus minimizing unplanned downtime and reducing the need for reactive maintenance.”

Leion continues: “The industry is really on a digitalization journey with intelligent field instruments providing more process data. New connectivity options, such as Bluetooth, Ethernet-APL and 5G and wireless solutions like WirelessHART are transforming how data are transported throughout facilities and to and from remote locations.

Endress+Hauser’s Riley agrees: “Industrial Ethernet-APL is experiencing increasing application in chemical level-measurement processes, opening the door to numerous critical process and diagnostic datapoints becoming available to an overarching plant control system at a much higher communication speed.

“Some of this data has been available via HART for a long time, but it was often ‘trapped’ in instruments due to a lack of a HART communication gateway for the host controller to use. Ethernet standardization is making this data much more usable in control systems, adding significant value beyond a single process variable,” Riley continues. “This is empowering operations and engineering personnel with the right information at the right times, minimizing the need to mine data manually from a process historian.”

The availability of modern architectures is paving the way to wider adoption of intelligent field devices connected to higher level systems, enabling more robust, flexible and faster data access, which addresses yet another key challenge faced by chemical processors — the pressure to meet strict sustainability targets.

“This includes reducing emissions, minimizing waste and optimizing energy use. Advanced digitalization and smart instrumentation play a pivotal role here because they provide the precise, real-time data needed for more efficient resource management,” says Emerson’s Leion. “By offering greater process insight, these technologies help optimize production processes, minimize material usage and ensure that equipment operates within optimal parameters, thereby reducing environmental impact.”

At the same time, safety remains a critical concern, particularly when handling hazardous chemicals. “Technologies like Smart Meter Verification and remote proof testing of level instrumentation are making significant strides in enhancing safety and reliability,” says Leion. “When operators can verify the health of their level instruments without needing to stop the process or physically access hazardous areas, it ensures that the instruments are functioning properly and reduces the risk of human error and accidents associated with manual intervention. And, remote proof testing allows safety instrumented systems to be tested and validated from a safe, remote location, further improving plant safety, while reducing the need for costly shutdowns.”

Technology for every challenge

In addition to intelligence and connectivity enhancements, recent developments have advanced level measurement technologies to come down in price and complexity, which has led to a shift away from traditional technologies to non-contact and radar-based solutions that offer accuracy and reliability, even in harsh conditions, solving some of the industry’s biggest level measurement challenges, according to the experts.

Sreekanth Madhavasherry Sreenivasan, global product line market manager and global product manager for the level product line with ABB (Zurich, Switzerland; www.abb.com), says, “Numerous applications within the chemical industry impose significant challenges on measuring instruments. Specifically, factors such as steam, dust, foam, turbulence and condensation complicate the functionality of level measuring devices, impacting their precision and dependability.

“In addition to these media characteristics, chemical processes entail handling toxic, corrosive, flammable or explosive materials with wide variations in temperature and pressure,” Sreenivasan continues. “Yet, processors are expected to overcome these industry challenges while still increasing performance targets.”

“For this reason, level measurement solutions in the chemical industry must be tailored to diverse applications, each with unique challenges, depending on the process conditions. Today’s advanced technologies address a variety of issues related to accuracy, safety, maintenance and process optimization,” suggests Emerson’s Leion.

Corrosive environments

For example, non-contacting level measurement technologies, such as radar, are ideal for use in mixing tanks and reactors where corrosive, viscous or agitated media are present. “These environments pose significant challenges for traditional contact-based sensors, which can be affected by build-up, corrosion or fouling. Rosemount non-contacting radar with Smart Echo Supervision is beneficial in these applications because it tracks all signal echoes, including those caused by internal obstructions, such as nozzles, baffles or agitators,” explains Leion. “The Rosemount 3408 non-contacting radar level transmitter (Figure 1) is a frequency modulated continuous wave radar instrument suitable for level measurement and overfill prevention.”

The smart features save time and maximize efficiency for trouble-free operations, simplifying commissioning, operation and testing. Diagnostics help users proactively plan maintenance and optional Bluetooth provides wireless connectivity for convenient configuration and maintenance. Verification at scheduled intervals can be conducted from the control room without process interruptions and proof-testing can be done remotely and in-situ with onboard functionality.

SOR’s Brittany Cost agrees: “Non-contact sensors, such as radar and ultrasonic sensors have gained popularity because they do not encounter process material, making them ideal for corrosive or hazardous substances and can avoid issues related to build up or fouling that affect traditional sensors. In addition, modern guided wave radar can withstand extreme conditions and still provide accurate measurements.”

To that end, SOR’s 1100 Series MLI (Figure 2) was designed to help processors overcome issues with corrosive media and harsh environments even in challenging tank configurations. It can incorporate external point level switches or continuous level transmitters, such as guided wave radar or magnetostrictive level transmitters, without breaking the pressure boundary or disturbing any existing piping, says Cost.

“The 1100 Series MLI features specialty materials, ensuring resistance to corrosive chemicals and operation in extreme environments, such as cryogenic applications, with its special chamber design, which is particularly suited for demanding applications like liquid propane gas,” she explains. “The device serves as an alternative to traditional sight glasses since the vessel contents are totally contained within the float chamber, making it ideal for high-pressure systems. These features ensure that the 1100 Series offers reliability and ease of use while helping chemical processors maintain compliance and optimize safety in demanding conditions.”

Tres Thurston, sales manager with Hawk Measurement (Medina, Ohio; hawkmeasurement.com), adds that radar-based technologies, particularly guided wave radar, provide a lot of opportunities in demanding level measurement applications. “With guided wave radar, the part of the instrument that is coming into contact with the media and exposed to high temperatures or pressures is constructed of very robust, rugged industrial materials that aren’t impacted by extreme temperatures, high pressures or caustic environments,” says Thurston. “And, guided wave radar has a tendency to be more accurate that other technologies such as ultrasonic or free air radar, despite harsh environments.”

He says Hawk’s Centurion Guided Radar (CGR) level transmitter (Figure 3) is ideal for measuring liquids, sludge, powders and granules for level and interface measurement. This technology is not affected by pressure, temperature, viscosity, vacuum, foam, dust, changes in dielectric constant or coating of the probe. “In addition, CGR features Power over Ethernet (PoE) communication. The advantages to PoE connectivity include secure in-plant and remote monitoring, remote sensor setup, diagnostics and troubleshooting abilities.”

 

Challenging process conditions

ABB’s Sreenivasan adds that newer guided wave radar technologies with advanced software algorithms and semiconductor technology, such as is found in ABB’s LWT Series guided wave radar (Figure 4), accurately detect level even in demanding applications that previously did not respond well to guided wave radar, including those with fast moving levels and emulsion. “For example, due to emulsion having its own dielectric, the time of flight will change through this layer like the change experienced through the lower dielectric layer, so applications with changing dielectric constants are a challenge for traditional guided wave radar.

“However, with the advanced software algorithms and semiconductor technology, ABB’s guided wave radar meets the challenges of these applications thanks to our Level Expert algorithm. This firmware enables accurate readings, even in changing dielectric constant environments.”

And, for issues related to dust, vapor and condensation, which are “without a doubt the biggest challenges” when it comes to level measurement in the chemical industry, non-contact radar is a good solution, says Jason Kuzmiak, chemical industry sales specialist with VEGA Americas (Mason, Ohio; vega.com). “For example, in the petrochemical field of plastic pellets, dust can be difficult to measure through when trying to obtain accurate pellet level indication. Historically guided wave radar and other mechanical devices were used to take these measurements, but now non-contact radar technologies can be used.”

VEGA’s VEGAPlus series (80 GHz) non-contact radar (Figure 5) can take measurements, even in dusty applications, and has the ability to measure through plastic, glass or fiberglass tanks without the need for a process connection. The instrument also comes with Ethernet-APL, offering fast, secure data transmission, even in challenging chemical environments, to provide faster, more secure connections for field-located instruments.

“This allows data transmission, high-speed delivery of process updates, easy access to diagnostics, settings and protocols using a standard web browser and secure data transmission, even in hazardous areas,” he explains. “And available Bluetooth and remote displays allow end users to commission, monitor and adjust parameters as needed from any location.”

Foaming, another common level measurement obstacle, is also being managed with newer technologies, says Endress+Hauser’s Riley. “Many processes produce foam and keeping it from entering discharge pipes, where it can clog filters and produce other issues, can pose a challenge,” says Riley. “A free-space radar level sensor, such as the Micropilot FMR60B (Figure 6), can detect foam formation in the process and communicate its presence to a host controller via HART communication. This can trigger the application of a foam retardant through the plant control system, as well as continuous feedback to facilitate precise dosing, delivering the required amount to keep foam at bay while eliminating overshoot of expensive agents and the need to scrub it from finished product.”

Micropilot FMR60B is an 80-GHz radar developed according to the international functional safety directive International Electrotechnical Comission (IEC; Geneva, Switzerland; www.iec.ch) IEC 61508 standard. The free-space radar offers maximum reliability due to the drip-off antenna, improved algorithms and small beam angle. The drip-off antenna is suited for free-space applications and offers high beam focusing for vessels with many internal fittings.

The instrument is used for continuous non-contact level measurement of liquids, pastes and slurries and measurements are not affected by changing media, temperature changes, gas blankets or vapors. It also possesses the smart sensor functionality, Heartbeat Technology.

“The latest level measurement technologies are highly adaptable to the chemical process industries’ diverse applications,” notes Leion, adding, “These level technologies provide reliable solutions to challenges related to process efficiency, safety and maintenance, ensuring that operations run smoothly and sustainably, while also reducing downtime and improving overall plant performance.”

– Joy LePree