Robust, reliable drives for water and sewage sector
24 July 2020 | Web Article Number: ME202019721
THE selection of robust equipment which can endure continuous operation under severe conditions is critical when it comes to drive solutions for the water, wastewater and sewage sectors.
That’s according to Kelly Mac Iver, Gears Business Unit Manager for BMG’s ElectroMechanical Division, who said company specialists with extensive experience in water engineering play an important role in upgrading ageing water and wastewater facilities and designing new drive systems.
“Every drive package selected must match the application perfectly, to ensure energy-efficiency, low running costs, minimum downtime and extended service life of the system. Care for the environment is also a priority at BMG and for this reason, we select environmentally friendly drive solutions that help minimise CO₂ emissions.”
Mac Iver said reliability was another key focus when designing the drive systems for new and upgraded facilities.
“All BMG components are precisely matched to each other and to application requirements, to ensure high productivity, smooth operation and long service-life. Apart from the supply of new drive systems, the company’s broad branch network offers original spares and advanced workshop resources that ensure all repairs to drive components meet pristine OEM standards.”
The company supplies an extensive range of drive packages from Nord Drive Systems and Sumitomo Drive Technologies which have been designed especially for optimum efficiency in harsh applications, including water, wastewater and sewage treatment plants.
Sumitomo’s Hansen product range include gear units that drive aerators, water screws and brush aerators.
Notable features of BMG’s locally-assembled Hansen agitator/aerator gearboxes include the flexibility for application-specific product design to meet exact requirements, carburised and ground bevel and helical gearing for added strength, as well as high torque capacity, surface durability and low noise performance. Robust weatherproof housings raise the gearbox and drive motor above the service platform, to prevent contact with water.
Hansen gearboxes are available from BMG with standard or heavy-duty output bearings and have the additional option of extended output bearing distance housings which allow for greater output shaft support.
There is a large overhung load capacity of the gear units and the housing design to help ensure smooth transition of forces from the centre bore to the mounting feet. A rigid lantern housing seamlessly connects the gear unit with the motor. Continuous oil circulation is facilitated via a mechanical oil pump and internal oil channels, through to the bearings, to ensure extended service life of the gear unit.
BMG’s Sumitomo Paramax gear reducers, used in the conveyor and materials handling industry, also offer the water treatment sector a range of gearboxes that the company says is well-positioned with regards to product capabilities and advanced features, at competitive pricing.
This range is available as right angle or parallel vertical units, with a 25-degree pressure angle tooth form, that produces stronger gearing. The mechanical oil pump requires no electricity, gears are carburised, heat-treated and finished to the highest standards of accuracy. Paramax units are painted with anti-corrosion paint for extended service life in harsh working conditions.
Nord drives, which include a Unicase helical shaft mount geared motor in its range, have special features to meet the requirements imposed during water treatment procedures.
“Nord 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,” said Deon Crous, National Product Manager, Nord Drive Systems at BMG.
Explosion-proof motors, with electrical and mechanical speed controls, are fitted with anti-condensation heaters for stand-still periods and reinforced bearings for extended life are standard. Special vent plugs, lubricants and a valve-type oil drainage facility also enhance performance in these demanding applications.
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 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. 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. 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.
Also in BMG’s Nord range is the compact combination of Maxxdrive industrial gear units and the Sealless Adapter For Mixers (SAFOMI) which offer operating reliability and reduced maintenance requirements. Important features of these gear units for mixers include fewer wearing parts – no shaft sealing is required between the gear unit and the IEC adapter. There are also fewer attached components and no additional oil tank is necessary. This reduces installation space.