Product category:
Industrial Drives/Controls
News Release from: Control Techniques | Subject: Unidrive SPM drives
Edited by the Engineeringtalk Editorial
Team on 05 February 2008
Drives save power on massive presses
Alcoa's aluminium extrusion presses were upgraded in 1998, a big project requiring the installation of 12 132kW Unidrives.
Three of Alcoa's massive aluminium extrusion presses in Hannover now depend on variable speed drives from Control Techniques The drives have dramatically increased production time availability, increasing throughput by 10% and decreasing maintenance costs
This article was originally published on Engineeringtalk on 30 Jan 2001 at 8.00am (UK)
Related stories
Plan how to offset the Climate Change Levy now
The Climate Change Levy is viewed by industry as an imposition, but it is also a stimulus to action, to be more energy efficient ...and with good reason
Unidrive with DeviceNet simplifies cable winder
A despatch-winding machine, recently installed at BICC General UK Cables in Wrexham, features a new approach to the design of the drive control system.
The installations have cut energy consumption by a 40%, saving thousands of kWh of energy every year.
The two biggest extrusion line accept billets of aluminium alloy at around 265 and 412mm diameter and lengths between 400 and 1350mm, pre-heated to between 300 and 550C.
These billets are then extruded through two high-pressure extruding presses at 56 and 33 MN respectively.
Both extruders are hydraulically-powered, with the oil pressure being generated by pumps controlled by Control Techniques AC drives.
The big press line was upgraded in 1998, a big project requiring the installation of 12 132kW Unidrives (for 12 pumps), to produce the required maximum pressure of 315bar.
Further reading
Modern drive updates yarn winding machine
A retrofit drive package, comprising Control Techniques' Unidrive, UD70 soft logic module and a flux vector motor, is achieving 20% more output from a 25 year old yarn winding machine.
Big savings on fan running costs with zero outlay!
Owens Corning is achieving annual energy savings of over £150,000 on the operation of three large fans, with zero capital outlay, thanks to Control Techniques and Hyder Energy Services
Ski innovation helped by versatile digital drives
Mantec in Italy has developed a form-grinder which uses Control Techniques Unidrives and Unimotors to drive 4 servo axes that combine to grind tiny profiles into skis.
In January this year, the 33MN line was similarly upgraded with variable speed drives.
This time the drives chosen were six 160kW Unidrive SPM modular drives, producing an oil pressure of 250bar.
The operation runs around the clock, 365 days a year and so the latest installation was carried out with the line in full operation.
"In both cases, the savings are considerable", explains Stefan Heine, who has responsibility for technical operations and purchasing at the Alcoa plant.
"The original hydraulic plant was designed to give the required thrust with additional oil being sent through a bypass, so effectively the pumps were running at full speed all the time".
"Now Control Techniques variable speed drives integrate with the hydraulic controller using Profibus and give exactly the required power at every stage of the operation".
"Not only does this save some 40% of the power, but also gives better control, giving improved quality of extrusions".
"But this is just part of the story".
"Because the plant (the valves, pumps, pipes and seals) is less stressed, equipment is less susceptible to breakdown and I believe that our throughout has increased by around 10% because of reduced downtime".
"The oil lasts longer too - a not inconsiderable saving when you consider that the machine incorporates some 15,000 litres of oil and 6000 litres passes through the system during each extrusion (this is then cleaned and returned)".
The savings run to thousands of euros per year and have given Alcoa a payback of less than 18 months.
The Unidrive SPM range spans 90kW to 1.9MW range and includes very compact input and output modules that enable flexible power configurations to be achieved.
Multiple systems are mounted on an interconnected DC bus that allows circulation of energy between drives that are motoring and regenerating and also allows regenerated energy to be returned to the mains.
Drives can share braking duty and the whole installation requires a single AC power supply, simplifying installation.
The 38MN extrusion press produces some 800-900 tonnes of aluminium extrusions per month, in a wide range of profiles including stars and tube down to less than 10mm with wall thicknesses down to 2mm.
Single extrusions can be as long as 45m in length and the fastest extrusion rate is 15m/min.
Each billet is ultrasonic-tested and carefully heated to a point just below its 'plastic' state so that during the high-pressure extrusion process the pressure takes the material up to the required plastic state, but no further, in order to maintain the structural integrity of the material.
Every extrusion is stretched, cut-to-size, 'aged' in an aging furness, then tested for hardness, tensile strength and conductivity as well as passing through three-co-ordinate measurement testing before being passed for delivery.
"We particularly like the new modular Unidrive SPM drives" Heine said .
"They are extremely compact and easily fitted into our plant room".
"Most of the drives in our plant are connected by Profibus to the factory management system". Request a free brochure from Control Techniques ...
• Control Techniques: contact details and other news
• Email this article to a colleague
• Register for the free Engineeringtalk email newsletter
• Engineeringtalk Home Page
