BuildoTech Magazine India | November 6, 2015
The elevator industry is witnessing very fast developments and changes. The major focus of all these developments is towards energy efficiency, riding comfort and increased speed. But the desire for even better performance has kept elevator engineers and researchers to keep continuing their efforts, says Rajnikant Lad, Chartered Engineer & Elevator Consultant at Shree Jee Elevators.
Globally, the elevator transportation segment has already seen technological developments like Synchronous machines, Variable Voltage Variable Frequency (VVVF)drive and door operator, touch buttons, Elevator destination dispatch(destination control) system, hydraulic system, serial communication, Bluetooth system, Machine Room-Lesselevators, vacuum elevators and soon. But,
there are some more pathbreaking technological developments happening in the elevator industry which are going to take the elevator utility to a whole new level.
Carbon Fibre Hoisting Technology– A major restriction to building taller is the technological constraints of elevators. Taller buildings mean longer and heavier steel ropes and more energy consumption in just transporting the ropes themselves. Carbon-fibre technology is an alternative to using steel cables in elevator systems. A single strand of carbon fibre is thinner than a human hair but is five times stronger than steel and weighs two-thirds less. Thus the carbon fibre rope is much lighter than the steel wire rope (just about 19% of the weight of the steel wire rope), is corrosion resistant and has double the life compared to steel cables. This pioneering technology allows lifts to travel up to one kilometre in a single run – double of what is currently possible with a round steel traction cable.
Steel ropes tend to stretch lengthwise, requiring periodic adjustments and complete replacement in approximately seven years. However, carbon fibre is elastic and only stretches when tensioned to a certain point to compensate for a heavier load. Also, as building goes higher, they are more prone to swaying in high winds and storms. Carbon fibre ropes have a resonance frequency different than that of the rest of the building, therefore in big storms and high winds, the elevators can continue to function safely. With the reduction in rope weight, the need for balancing weight in the form of counterweight also reduced. This reduction in weight of rope and counterweight minimizes system loading requirement to a great extent, reducing the capacity and size hoist motor, gear and other parts. Ultimately helping in a reduction in energy consumption of the overall system.
Finnish elevator manufacturer Kone has introduced Ultra Rope made of carbon-fibre-reinforced polymer (CFRP) material core, commonly referred to as carbon fibre or simply carbon. It is a strong, lightweight and flat cable with a high friction polyurethane coating. Multiple strands of Ultra Rope are used to hoist each elevator car, operating in parallel to share the load. Ultra Rope’s weight is real innovation. As it is significantly lighter than traditional steel rope, it means the weight of the elevator system and associated machinery can be downsized as also doing away with the need for a transfer floor in tall buildings. The introduction of carbon fibre hoisting has broken the travel height barriers. The engineers can now work for a travel height of one km which was not possible till now with conventional steel cable hoists. Moreover, with an increase in the height, the cost saving is about 15%for the height of 500 m and 40% for the height of 800 m as compared to steel wire ropes.
Magnetic levitation technology – The elevators that enable skyscraper cities across the globe are now proving a hindrance to ever-taller towers because their basic design – a single cabin suspended by cables in a vertical shaft hasn’t changed. The bigger and taller the building, the more elevator shafts you need. The shafts’ “footprint” can eat up to 40% of a tower’s space. A new elevator system under development has replaced cables with magnetic levitation technology, also known as Maglev.
The technology is used in various railway systems around the world and much like a train, Multi elevators would work by following a mag level track throughout a building. A magnetized coil running along the track repels magnets located in the vehicle’s undercarriage, causing it to levitate a short distance above the tracks. The trains are then pulled forward by a moving magnetic
field, created by coils embedded in walls alongside the track. The embedded “traffic control” system will prevent the elevator cabins from forming vertical traffic jams and smacking into one another.
Germany’s ThyssenKrupp has unveiled the first cable-free elevator, called the Multi, powered by maglevmotors and allow several cabins to zip along a single shaft in a continuous,flowing loop. The system would even allow the cabins to move horizontally, in a zig-zag pattern, or on inclines, giving architects the freedom to design exotic buildings that breakaway from the now-standard tall and skinny format. Since the elevators could also move horizontally, they could be shunted off the continuous loop and into a “garage” for cleaning and maintenance. The mag level elevators will use much less floor space than traditional elevators since multiple cars can operate on the same track. Moreover, building manager scan simply adds more elevator cars to a single multi-track to increase the frequency of elevator pickups.
Nanotechnology – Advances in research into nanotechnology and carbon nanotube materials are now presenting the opportunity to create a cable that would be strong enough to support the immense forces on a space elevator. Diamond nano threads, due to their stiffness and strength, are the material of choice currently being developed by JohnV. Badding and his research team at Penn State University. The strength of a diamond nano-thread means that this nanomaterial could be used to create the cables of a space elevator. The cables need to be both incredibly light and incredibly strong to provide the stability required for a space elevator to operate.
The inventor of the “space elevator” is Brendan Quine, an engineering professor at York University in Toronto and co-founder of Thoth Technology. The elevator can take the payload into space with expenses of about 1/100 of the regular spacecraft lunch. Carbon nano-threads is 100 times stronger than steel and is as flexible as plastic.
The basic principle is like tether ballgame where a ball is attached to one end of the rope and the other end of the rope is attached to a pole. Here the rope is Carbon neon tube composite ribbon, the earth is pole and the ball is the counterweight. This will allow vehicle transport along the planetary surface(Earth) to space /orbit without the use of rockets.The satellite will be lifted to space through the elevator and will be placed in the geostationary orbit at an altitude about 35,800 km. Apart from the obvious benefits of transporting material into space in a more cost-effective manner, a space elevator also has huge applications for space launches.
Written by : Rajnikant Lad
Founder Elevator Auditor | www.elevatorauditor.com
Watch Mr Lad and business leaders around the world talking about Elevator Safety and market trends on his our YouTube Channel : YouTube.
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