Fluid Power IIoT
Published on : Thursday 04-03-2021
Experts debate the relevance of Fluid Power in general, and automation industry in particular, in the IIoT era.
The potential of Fluid Power has been exploited by mankind from times immemorial. Blaise Pascal’s discovery of the principles of the physics of fluid during the 17th century paved the way for systematic exploitation of fluid power, and the harnessing continues till date, in various applications. There was a time, not too long ago, when the extent a plant’s automation was measured by the compressed air consumed. But with several technological advances, electrical actuation has gained considerable ground over fluid power in many applications in automation. So what exactly is the situation on the ground?
“Fluid power systems started becoming a major driving force in the industry in the early 20th century. Rapid growth occurred post World War II, when the need was felt to increase the productive efficiency of various industrial processes. Further technological advancements took place in the last 3 decades which continue even today,” says Shashank Gune, CEO, Techtonic Engineering, and an industry veteran in pneumatics, with more than 25 years of rich experience in the fluid power domain. According to him, the integration of electronics has spearheaded much of this growth into components and systems, moving from analog to digital electronics to network and wireless communication. These advancements in fluid power technology have made it more energy efficient, compact, sleek, user friendly and cost effective. “Many people were expecting electrical drives to take over completely from fluid power. However, this has not happened in practice, thanks to these technological advancements. In fact, the global market trends predict a decent growth at 5.3% CAGR for pneumatic actuators and 3.6% CAGR for hydraulic actuators over the next 3 years,” he explains.
“Fundamentally, fluid power actuation can always be backed up by electrical actuation in cases wherever fail-safe mode is more prominent. Otherwise, actuation achieved by fluid power is always a first choice of machine/equipment manufacturers as the existing system mechanism can be leveraged and even maintenance, reliability and availability can be much assured,” says Tansen Chaudhari, Chief Operating Officer, Fluid Controls Pvt Ltd, a leading provider of instrumentation products and services.
“Not at all,” says Chandrashekhar S Joshi, R&D Head and Embedded Systems Specialist, when asked if electrical automation is taking over the role of fluid power. “Whereas electrical actuation is being used increasingly, fluid power continues to play an important role as it is the one finally driving the device,” he adds. Joshi has extensive experience of working in the field of process control and industrial automation.
“Well, it depends. There is no easy answer. It all depends on the system design and evaluation of performance, cost of the components, system costs, and performance. Precision, speed and safety are the primary considerations,” explains Sureshbabu Chigurupalli, Unit Head – Plant Operations at Balasore Alloys Limited, taking a more nuanced view. According to him, a fluid-powered actuator's functionality has an advantage over the electric actuator in its capacity to provide a simple fail to safe position function. The diaphragm and cylinder of a fluid-power actuator opposed by spring can move the valve to an open or closed position on the loss of fluid power. “For a process shutdown, the fluid-power actuator is the traditional choice. In contrast to fluid power actuators, electric actuators provide precise control and positioning. Low operation cost helps versatile machines to flexible processes. They are most economical when deployed on a moderate scale. In an era of digitalisation, electrical actuators' application focuses more on intelligent devices, Smart processes. Fluid power actuators are significant in sturdy applications,” elaborates Sureshbabu.
K A Venkataraman, General Manager, Plant Operations, is of the opinion that though all types of automation is operated and controlled electrically, the real work is still done by fluid power actuation, which means pneumatic or hydraulic actuators. “Electrical systems have still not replaced the final output or working element of an automation system. Pneumatic actuation/actuator is economically cheaper and reliable to handle low to moderate workloads and hydro-pneumatic or complete hydraulic actuators are cheaper to handle moderate to heavy workloads. Hence still electrical actuation has not taken over the others, at least in India and Asian countries,” says Venkataraman, who is a seasoned Pneumatic Expert with product development and techno-commercial competencies. He has developed over a hundred types of valves, actuators, FRLs, etc., and 1000+ variants/models from those types.
“Fluid power will continue to play an important role in automation for decades to come. The application determines whether hydraulic or pneumatic or electrical actuator or combination of these is the right choice. For example, electrical actuators are more suited for low load, low noise medical applications like dental chairs whereas hydraulic actuators are preferred in heavy-duty work like large construction machinery, marine propulsion and cargo handling, military weapons and transportation systems,” says Shrikant Bairagi, Managing Director, Argo-Hytos Pvt Ltd. A veteran of over 30 years, Shrikant has served on various industry bodies such as the Confederation of Indian Industries and Fluid Power Society of India, etc.
What are the advantages fluid power still offers vis-à-vis electromechanical drives? “There are a vast number of applications where pneumatics and hydraulics are preferred over electric drives,” says Shashank Gune. “Hydraulic technology is particularly used in heavy-duty applications, where brute force is required whilst pneumatic technology is chosen for lightweight, high-speed and comparatively low-cost applications. Generally speaking fluid power can offer better force-to-weight ratio than electrical drives. In almost all industrial sectors, today’s fluid power components offer specific benefits to ensure efficient operation and lower cost of ownership.”
Tansen Chaudhari, points out the safety aspect. “Definitely, fluid power is safer in hazardous environments. Also, fluid power automation, if one compares weight over high horse-power, is more beneficial. High torque at low speeds can be easily achieved by fluid power. In fact, force or torque can be held constant for a long time. Indeed, long distance pressurised fluid power transmissions through complicated systems is quite possible with a minimal pressure loss. Reversing motion in fluid power is possible instantaneously. In fluid power transmission, elimination of complicated mechanical trains of gears, etc., is possible,” he elaborates.
“For heavy-duty applications, hydraulic drives offer many advantages like high power density (i.e., power-to-weight ratio), proven safety and security and mobility, etc. For quick and light work, electromechanical drives offer superior speed, power savings, precision, and leakage free operation,” says Shrikant Bairagi, emphasising the prominent advantages.
What about the use of fluid power in the automotive sector, especially the heavy vehicles, which have accounted for much interest in hydraulics? Will the upsurge of electrical vehicles sound a death knell for hydraulics? “Large vehicles obviously need higher power and need to run for very long distances for critical and regular supplies distribution. Hydraulic systems will continue to be an option while working along with electrification as Hybrid vehicles for these ones. Whereas electric vehicles will offer most reliability, running range and charging stations availability is going to be a challenge. The cost of an EV is not going to come down in next 5-7 years unless disruptive inventions are done immediately. Hence hydraulic systems will continue to play an important role in future too,” opines Chandrashekhar S Joshi.
Market research valued the electric truck market at USD 19.80 billion in 2020 and expected to register a CAGR of 14-15% during the forecast period (2021-2026). “Global demand for a cleaner environment and low-emission zones drive fleets to replace diesel trucks with EV options. India is among the fastest-growing economies and the third largest emitting country in the world. Petrol and diesel trucks are highly polluting. Stricter emission and fuel efficiency norms to deal with alarming pollution levels in most cities, vehicles with diesel engines may become a relic of the past by as early as the next decade. The advantage of electrical actuators is that they are simple and low cost compared to the hydraulic system, which needs many more components. With increasing emphasis on reduced weight, electric actuators offer integrated designs where traditionally hydraulics or pneumatics have ruled the roost. Weak spots in the application, such as hoses and pumps, are eliminated by installing electric actuators. Easy installations, flexibility and energy efficiency, and compact design reduce trucks' overall weight, improving trucks' fuel efficiency. It will be difficult to conclude at this moment that electrical actuators can replace hydraulics in totality, as efficiency is the prime factor. Design of pump capacities, battery uptime, sturdy applications where more improvements expected, says Sureshbabu Chigurupalli, taking a holistic view.
But there are other, practical considerations. “Normally electronic or electric actuation cannot handle moderate to heavy workloads. For example, though a garbage handling truck can be an electrically operated vehicle itself in the near future, the tipper which can handle a huge weight of the garbage in the behind portion of the vehicle cannot be actuated electrically. It will continue as hydraulic actuation only for at least one to two decades from now. Even attaining the notable population of passenger EVs on roads that can replace the existing petrol/diesel-operated vehicles will take one decade,” says K A Venkataraman.
Along with rest of the industry, even fluid power devices have benefitted from the advances emerging technologies have brought in. So what are the new trends that hold promise for hydraulics and pneumatics in the digital era? “There have been rapid advancements in fluid power technology over the past two decades on account of many factors, viz., Safety Standards & Compliance, Manufacturing Efficiency, Operational Efficiency and the Concept of Industry 4.0 and Industrial Internet of Things (IIoT). As a result, manufacturers of fluid power equipment have worked on all of these factors to make their equipment in tune with these requirements, using advancements in the material technology and manufacturing – metal cutting technology, including 3D printing, and integration with electronics to make them smart and sleek,” says Shashank Gune.
Tansen Chaudhari, concurs with these observations. “Industry 4.0 focuses on making the machines working smoothly and seemingly fine by communicating with other machines and giving signals to humans. The same data can be leveraged and analysed globally using IoT. Undoubtedly this would reduce the efforts spent on gathering, filtering and improving the efficiencies across the industry. Added to it Big-data analysis could be clubbed in the same revolution. The PLC can be used to increase the system level performance of hydraulics and pneumatics systems. With these combinations of systems with hydraulics and pneumatics systems, the products would pass on the health/performance data using the IoT which can predict the system reliability, safety, and maintenance,” he points out.
“New trends are more focusing on Miniaturisation, compact and straightforward designs. For instance, hydraulic pumps with electric drives are extremely precise and highly efficient, valves with embedded intelligence provide unprecedented accuracy and performance, and hydraulic hoses predict when they will fail. Hybrid systems that mix hydraulics and electronics are becoming more common. More research and innovations are happening on high performance, compact envelope, and customisation, says Sureshbabu Chigurupalli.
Process industry is a major user of fluid power. How relevant is fluid power today in process industries? “Highly relevant,” says Shrikant Bairagi, “as most of the main and sub-systems use hydraulics extensively. For example, turbine control systems, paper mill hydraulic systems, conveyor systems, apron feeders, wagon tipplers, side arm chargers, stacker reclaimers, etc.
Chandrashekhar S Joshi feels hydraulic systems find a niche place probably used jointly along with electrical power in process industries due to two distinct reasons: 1. Space and power density, and 2. Safety requirements like ATEX ones.
“Almost all the process industries are operated by fluid power automation systems only. For example, in oil & gas, mining, chemicals and power/energy sectors, they are transmitting operating or processing materials or operating fluids through different types of huge size hydraulic valves, say butterfly, globe, and knife-gate valves, which are operated either by pneumatic actuators only to provide and control the automation mechanism,” says K A Venkataraman.
Are hydraulic and pneumatic devices compatible and in step with digital technologies and integrate with IIoT seamlessly? “Indeed, hydraulic and pneumatic devices have been in place for a long time, and seamless integration with IoT, AI and other digital technologies has already begun. For any business segment, return-on-investment for this combination would be greatly achieved,” says Tansen Chaudhari. “Aviation, Oil & Gas, Nuclear Power, Health-care, entertainment, logistics, etc., are few among many industries where blessings of the combined technologies have already begun with full throttle. Low aim would be a crime here in extracting the benefits!”
“With the emergence of the IIoT and Industry 4.0 started the extensive use of sensors throughout automation systems, including pneumatic and hydraulic components. Sensors have become smaller, more lightweight, and easier to use in various fluid power components, allowing measurement of temperatures, pressures, flow rates, cycle times, and valve response rates and so on. Even the simplest devices can provide crucial information at some point,” observes Shashank Gune. “With all these developments and newer applications of fluid power in almost all the industry segments, we can safely say that fluid power systems are here to stay at least for a decade, if not more,” he sums up.
“Nowadays hydraulic systems are controlled by electrical systems, which include various sensors too. The controllers as well as intelligent sensors can easily be compatible and integrated for IIoT environments. It is not a big deal at all,” points out Chandrashekhar S Joshi.
“Predictive diagnostics software is a key player in IIoT-integration. Smart sensors and intelligence built-in diagnostic capabilities help monitor temperature, voltage, current, and even cycle counts. The massive amount of data these sensors produce creates an equally tremendous opportunity to transform how one operates and maintains industrial equipment. Predictive and preventive maintenance programs are essential to efficiently manage equipment life cycles and maximise the overall equipment effectiveness (OEE) and increase return on investment,” explains Sureshbabu Chigurupalli. “Using data from IIoT sensors, technicians can predict accurate information on deteriorating components and take corrective steps such as modulating stroke speed to enhance life. The value of any IIoT solution is directly proportional to its interoperability,” he elaborates.
“Actually, this implementation/integration of hydro/pneumatic devices with IIoT has been started already in bigger industries already and now step down to MSME sector also wherever applicable/possible. In every automation, either hydraulic or pneumatic actuator is operated through electrical/solenoid valves only along with PLC/timer logic circuits. So for better control or sequencing of solenoid valves thus actuators are possible by communication systems used in IIoT devices,” concurs K A Venkataraman.
“Yes. ECU and telematics-controlled hydraulics systems are already working with IIoT seamlessly,” agrees Shrikant Bairagi. “Real-time machine status information, through remote monitoring and data expertise allowing for smart, just in time, Predictive Maintenance. Argo-Hytos has developed ground-breaking solutions for the online monitoring of fluids. These intelligent measurement systems use smart algorithms to monitor the aging of lubricants and the wear of hydraulic components. Argo-Hytos measurement systems detect problems at an early stage before they cause further damage or downtime,” he concludes.
(Note: The responses of various experts featured in this story are their personal views and not necessarily of the companies or organisations they represent. The full interviews are hosted online at https://www.iedcommunications.com/interviews)