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 fiber isthinner than human hair but is fivetimes stronger than steel and weighstwo-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 length wise, requiring periodic adjustments and complete replacement in approximately seven years. However, carbon fiber is elastic and only stretches when tensioned to a certain point to compensate for a heavier load. Also, as building go 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, there fore in big storms and high winds, the elevators can continue to function safely. With the reduction in rope weight the need of balancing weight in form of counter weight also reduced. This reduction in weight of rope and counter weight minimizes system loading requirement to a great extent, reducing the capacity and size hoist motor, gear and other parts. Ultimately helping in reduction in energy consumption of the over all system.
Finnish elevator manufacturer Kone has introduced Ultra Rope made of carbon-fiber-reinforced polymer (CFRP) material core,commonly referred to as carbon fiber or simply carbon. It is 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. The Ultra Rope’s weight is the 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 increase in the height, the cost saving is about 15%for height of 500 m and 40% for the height of 800 m as compare 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, hasunveiled 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 evators will use much less floor space than traditional elevators, since multiple cars can operate on the same track. Moreover, building manager scan simply add 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 nanothreads,due to their stiffness andstrength, are the material of choicecurrently being developed by JohnV. Badding and his research team atPenn State University. The strength ofa diamond nano-thread means thatthis nanomaterial could be used tocreate the cables of a space elevator.The cables need to be both incredibly light and incredibly strong in order to provide the stability required for a space elevator to operate.
The inventor of the “spaceelevator” is Brendan Quine, an engineering professor at York University in Toronto and co-founder of Thoth Technology. The elevator can take the payload into the space with expenses of about 1/100 of the regular space craft lunch. Carbonnano-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 counter weight. This will allow vehicle transport along the planetary surface(Earth) to the space /orbit without the use of rockets.
The satellite will be lifted to the space through 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.