Engineering solutions provider BMG’s electromechanical team plays an important role in ensuring the dependable operation of wet and dry cooling towers, through the supply and support of many power generation components.
“Hansen gearboxes, which have been designed by diversified corporation Sumitomo Drive Technologies, in accordance with global industry association Cooling Technology Institute (CTI) specifications, are manufactured especially for wet cooling towers (WCT) and air-cooled condensers (ACC),” says BMG national product manager Rob Green.
Hansen gearboxes are suitable for use in cooling towers in many industrial industries, including power generation, petrochemical and steel, as well as the sugar and mining sectors.
“BMG’s Hansen M4 and P4 series are well-known locally for dependable operation and extended service life in arduous conditions. The company is currently introducing the new M5 series to the local market for use in dry and wet cooling towers throughout Africa,” notes Green.
Hansen P4 right angle vertical shaft up units for WCTs are available in 11 sizes, from Z to H and as two stage units in ratios 3.55/1 to 22.4/1, with ratings up to 100 kNm. The internal mechanical driven pump has been specially adapted for low operating speeds and to withstand wind-milling conditions.
There is increased distance between the propeller and the high-speed input shaft to reduce vibrations and there is extended bearing span on low speed shaft bearings. Bearings have been carefully selected to withstand high axial loads.
These application-specific and designed Hansen gearboxes are coated with corrosion-resistant paint for added protection in wet and humid environments. The housing has suitably machined ports to facilitate external piping that enables effective oil drainage and allows easy maintenance.
Owing to regulations of the cooling tower being important, ACCs are subjected to frequent starts and stops of the system. Precise control of factors like temperature and pressure from the condenser to the boilers is critical for the efficient functioning of this closed system.
During starting sequences, it is crucial that the gearbox can withstand high startup torques, up to more than three times the nominal torque of the motor, or sometimes even higher.
BMG’s ‘dry’ Hansen M4 compact gear units for ACCs, are known for efficient performance and long service life in arduous operating conditions. This series is available from BMG in six size units, from DA to FX, as two stage units in ratios from 9/1 to 25/1. The internal backstop is situated in the International Electrotechnical Commission (IEC) or National Electrical Manufacturers Association (NEMA) motor size lantern housings, for effortless installation and removal.
The addition of an internal cooling fan in the lantern is also possible to assist in ensuring that the compact gearbox remains within an adequate thermal operating limit.
New to the Hansen range of gear units for dry and wet cooling towers, is the recently launched M5CT range, which are right angle vertical gearboxes that have been further developed for cooling technology.
This series, with high resistance in corrosive and extreme humidity environments, has a proven design, maximum load capacity, minimum losses and quiet operation. M5CT units are also compliant with stringent comparative tracking index specifications.
Features of these new units include a rigid housing design that can withstand peak loads, which is enhanced by cooling fins with flexible cooling options. The well-balanced design and advanced micro geometry of the gear results in an optimised pressure distribution that absorbs high shock loads.
This system offers smooth transition of high forces from the centre bore to the mounting feet, which are positioned concentric to the low speed shaft. For increased dynamic stability, there is an extended bearing span with heavy duty roller bearings, specifically selected to handle the high axial thrust loads on the output shaft.
An effective sealing system designed to keep the oil in and dirt out, significantly reduces maintenance requirements. The dedicated lubrication system does not require monitoring.
The new M5 range has been designed for easy replacement of the existing P4 cooling tower range and to match the footprint or shaft height, without excessive installation adaptations.
In addition to general Hansen gearbox reducers for use in cooling towers, BMG also supplies Hansen gearboxes with application-specific designs, including a single reduction range of gearboxes for high speed applications, like pumps and fans. Also in the range are agitators and mixers for use in water treatment and product mixers.
The Hansen Invertible I4 range was developed by Hansen South Africa, especially for local customers and specific requirements in materials handling.
BMG’s Sumitomo gearbox brands also include Paramax large industrial gearboxes and Fenner Shaft Mounted Reducers.
Cycle inline reducers offer alternative features and benefits over conventional inline gearboxes, including a 500% shock load ability.