MechChem Africa July-August 2022

⎪ Automation, process control, instrumentation and CAE ⎪

us i ng p i ezo - e l ec t r i c valves, so there are no implementation compli cations,” he says. Further to this, the VTEM has an ECO Drive App that automatically manages the for ward and return pressures to achieve energy savings of around 70%. “Our VTEM is the world's first digitised pneumatic valve to be controlled by apps, which enables functional changes to be made on the fly by the PLC or controller. This makes for a highly flexible system from a standardised product range, offering flexibility, simplicity and energy efficiency,” Prato adds. Turning attention back to managing air losses and quickly detecting leaks in pneu matic systems, he cites another innovation: theMSE6 family of pneumatic service units. These are electronic energy-efficient mod ules for conditioning, regulating, switching and measuring the compressed air supply into the pneumatic systems of a machine. The MSE6 module is an intelligent service unit with built-in sensors and Fieldbus com munication. “The unit is able to continuously monitor compressed air consumption and shut off the supply when it detects that the machine is not in use,” he explains, adding that this minimises the natural air losses that would arise while the machine is not being used. “More importantly, the MSE6 transmits status data to the PLC, on air and energy consumption for tracking, bench marking and comparing the efficiency of each machine in use. This is a powerful tool for energy efficiency optimisation,” he says. This saves money, reduces compressed air consumption and energy costs, enabling the manufacturer to reduce its carbon footprint and improve sustainability. “It is also a simple way for a facility to start its

Industry 4.0 journey, adding transparency, data analysis, trending, artificial intelligence and machine learning capabilities to better manage and improve operational perfor mance,” notes Prato. “Our MSE6 can actually pick up that one cylinder out of 20 is leaking in a system, which can be used to generate an immediate notification of energy losses. This enables rapid problem diagnosis and repair times.” Electric actuators Describing the key advantages of electri cal actuators, Prato notes that they offer much better speed and positioning and can be accurately controlled. “While generally more expensive in terms of initial costs, switching to electrical actuation can be far less expensive in the long termbecause of its better efficiency for short cycle and holding times,” Prato continues. “Festo has been developing and supply ing an electrical actuator range for over 16 years. We now have third and fourth generation electrical actuators, so this is not a new field for us. In recent years, it has become more of a significant and transfor mational focus for us,” he says. He further adds that with the energy-efficient products Festo has developed over time, there is now a wide range of excellent equipment available. He cites an implementation example for a large machine builder in South Africa. “The company was making ‘bag-in-a-box’ dispensing containers for liquids: such as the 5ℓ boxes of wine and juice with a bag and tap inside. “A machine 20 or 30 metres long is used to make the bags, which have multiple lay ers of plastic/foil welded together. Layers of plastic/foil are rolled off, a tap is inserted, and the shape is formed by melting the layers together to create a square bag – all

at high speed,” he explains. “Two-metre heated sealing bars, traditionally controlled with pneumatic cylinders, were being used to clamp down onto the plastic and fuse the layers. The three variables needed to successfully weld and seal these seams are pressure, heat and duration. Besides the heat, it was the pneumatic cylinders continually pumping up and down at high speed to seal the bags that were consuming big energy – and there were a lot of them. “So we did some theoretical calculations based on replacing most of the pneumatic actuators with electrical ones from Festo. We found that an electrical solution would require only 10%of the energy that the fully pneumatic system consumes. “Another benefit is that the machines are pretty silent. There is no longer any noisy exhaust air coming from the 60 to 70 actuators cycling at high speed,” he adds. “Yes , we love pneumat ics . Yes , i t 's simple. Nonetheless, we have to consider other technologies as well, and sometimes a combination may be the better choice. This ‘bag-in-a-box’ machine still uses some pneu matic actuators, but the bulk of the sealing and cutting bars have been converted,” he tells MechChem Africa. “To achieve energy efficiency for any au tomation system, it is essential to get expert advice on each of the technologies used in the design,” he advises. “Festo develops and sells both pneumatic and electric automa tion technology andwe give unbiased advice on the most cost-effective, energy-efficient and sustainable combination of technolo gies to use for any application,” Skye Prato concludes. www.festo.co.za

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Left: An application example of a gantry system that uses the Festo MSE6 Energy Efficiency Module. Right: The pathway showing how the Festo ECO Drive App and other innovations can reduce pneumatic energy consumption by 70%.

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