NZ Steel needed to replace the motor driveshaft gearbox assembly (drivetrain) of their cooling tower fan – an essential piece of equipment for cooling the water used in the steel smelters process at their Glenbrook Steel Mill, just outside of Auckland.
Industrial cooling direct drive motor and variable speed drive (VSD) package brings cost savings
ABB introduced the Baldor direct drive cooling tower permanent magnet motor and drive combination as a cost effective solution, which would have a return on investment of around one year. The specialised motor is designed specifically to eliminate the gearboxes, drive shafts, couplings and bearings, with a direct-drive permanent magnet motor controlled by ABB’s ACS880 drive.
With the use of the ACS880 drive, the new motor speed can be controlled at the fan speed required of 200 rpm. This means the cooling tower fan can be mounted directly onto the motor, allowing the removal
of the existing reduction gearbox from the assembly.
The motor and drive combination provides the high torque required, without additional drive train components. The removal of the standard speed motor, the driveshaft and couplings and the gearbox removes mechanical complexity, emits less noise and less vibration and increases reliability by eliminating major drive train maintenance issues.
This, in turn, puts an end to the associated annual maintenance of approximately $50,000 for around 10 years – an estimated saving of $500,000.
Nathen Phillips, Utilities High Voltage Technician for NZ Steel, comments: “New Zealand Steel has six large cooling towers on its site at Glenbrook. We were looking for opportunities to reduce maintenance costs and downtime associated with these assets. ABB’s direct drive motor offered the opportunity to do this by replacing the high maintenance and costly gearbox driveshaft arrangement with a motor capable of being directly coupled to the fan and surviving in a wet environment. We believe this will reduce the need for a bi-annual shut on the cooling towers to an expected lifetime of 10 years. This will be a significant cost saving for New Zealand steel.”
Cost saving specialised ABB motors at NZ Steel's Glenbrook site.
The installation of this specialised motor and drives package is the first for New Zealand and has a range of applications, including wet or dry cooling towers, air cooled condensers (ACC) and air cooled heat exchangers (ACHE).
About New Zealand Steel
New Zealand Steel is the leading manufacturer of quality steel in New Zealand. New Zealand Steel supplies world class brands and products such as Colorsteel and AXXIS, and is the owner of the Glenbrook Steel Mill, located 40 kilometres south east of Auckland.
The mill was constructed in 1968 and began producing steel products in 1969.