Technical solutions provider BMG’s NORD drives range is designed for optimum efficiency in sewage treatment applications.

“NORD range, which consist of unicase helical shaft-mounted geared motors, have special features to meet the requirements imposed during water treatment procedures,” says BMG electromechanical division NORD product specialist Derrick Louw.

He says these drives consist of gears, motors and brakes that are protected against corrosion. “Special covers for the hollow shaft and motor also ensure that the drive is entirely resistant to spray from tanks and the humid and aggressive conditions to which it is exposed in sewage treatment plants.”

Louw adds that the NORD range is designed by German precision engineers NORD Drivesystems and assembled locally by BMG, according to stringent local and international quality specifications.

This range has earned recognition throughout the world for reliability, efficiency, low noise levels, extended life and reduced maintenance.

Apart from this range, BMG has explosion-proof motors, with electrical and mechanical speed control. These are fitted with anti-condensation heaters for stand-still periods and reinforced bearings for extended life.

Special vent plugs, lubricants and a valve-type oil drainage facility also enhance performance in these demanding applications.

Louw notes that drives with helical flange-mounted geared motors have the flexibility to fit into restricted and awkwardly shaped areas below tank de-sludgers.

The traversing platform of this system is equipped with a four-wheel drive to prevent wheels from slipping, even under load and in unfavourable wind conditions.

“Drives for revolving de-sludgers (helical bevel geared motors) and propeller-type agitators and aerator drives (helical geared motors, flange mounted) can comfortably handle continuous operation 24 hours a day,” he says.

“Foot-mounted helical geared motors are recommended in paddle mixer drives and, despite heavy loads, design life can exceed 100 000 hours.”

A unique feature of these drives is the unicase gearbox that accommodates all bearing seats within a rigid one-piece casting – no bearing seats are located on bolt-on flanges or covers, he adds.

Sealing surfaces are not subjected to torque stress or overhung loads and hardened wheel bodies with specially treated teeth, ensure smooth and quiet operation at maximum load capacity, Louw concludes.