Tunis not Left High and Dry: Robust Nord Gear Units Ensure Smooth Operation in Waste Water Treatment Facility
- 21 February 2012
- Company & Industry News
In water works and waste water treatment facilities, pumps often have to process great amount of liquid. High-performance drives are therefore necessary for smooth operation. In such applications, drive units are often subject to extreme environmental conditions, and must be designed accordingly. But in addition to climatic conditions, other factors also play a great role in the choice of the drive technology supplier. The following article explains how the total cost of ownership needs to be taken into account in this case, and how savings in the wrong place can result in considerable additional efforts and expenses.
The waster water treatment plant in
Avoiding false economies
The original drive technology equipment in the
Getting a grip on heat
NORD uses a high-quality synthetic long-life lubricant for the helical shaft gear units. It withstands the ambient temperatures considerably better than mineral oil – with the latter, the oil film would break down at high temperatures, resulting in increased wear and tear. Each gear unit requires 210 l of oil which have to be changed after approx. 20,000 hours of operation. Other manufacturers often stipulate shorter maintenance intervals, which makes a considerable difference at a price of 10-18 € per liter. An oil cooling system additionally increases operational safety in the NORD gear units: a temperature sensor constantly monitors the temperature of the lubricant and activates the cooling system as soon as a configurable limit is exceeded. In this application, the limit is 60 °C. Heated oil is then pumped out, cooled by an oil cooler and returned to the gear unit. When the temperature falls below 40 °C, the cooling system switches off automatically.
Drive technology in detail
Currently, two helical shaft gear units with a 132 kW performance from NORD's SK 12382VZ series are installed at the waste water treatment plant. They are combined with Siemens motors via IEC adapters. NORD's helical shaft gear units are available as two- or three-stage basic types with hollow or solid shafts, in foot mounted, flange mounted, or face mounted versions – each with the same housing. Suitable for integration into limited installation spaces, they can be combined with many components from the modular NORD system. ATEX models and models with IP55 or IP66 protection are available on request for all types. All gear units are manufactured according to the UNICASE concept, originally developed by NORD in 1981, which enables maximum performance for small gear dimensions and ensures operational safety, high efficiency, high output torques, high resistance to axial and radial loads, low-noise operation, low maintenance and a long lifetime.