Southern Cross Industries manufactures a range of water pumping windmills varying in size from 2,5 to 7,5 meters in diameter with a range of windmill towers to suit most terrain types. Southern Cross and Climax windmills have been used all over the world and have earned a reputation for reliability and sound engineering design. Southern Cross, South Africa, has extensive experience with windmill design for potable water as well as stock watering applications.
The two types of Windmills Southern Cross manufacture are:
- Climax Windmill (Works with roller bearings)
- IZ Southern Cross Windmill (Works with white metal bearings)
- Southern Cross adopts a holistic approach to windmill water supply systems embracing wind speed domains as well as the necessary hydraulic aspects of large as well as small systems.
Whether you are a farmer interested in purchasing one small mill for a stock watering point or a potential purchaser of a large scale rural village supply scheme Southern Cross can assist you with advice and a quality product.
- Simple to maintain technology
- Low running costs
- Ease of installation
- Predictable pumping performance
- Designing wind pump systems
Complex analyses are possible however Southern Cross considers windmills to be economically viable in areas where the wind speed exceeds 3 metres per second (approx. 11 km/hr) for eight or more hours per day. Southern Cross windmill performance tables are based on this criteria.
The water source should be a well-tested source to ensure over pumping does not occur. The rule applied is not to draw off more than seventy percent of the available water. This is arrived at by assuming that the entire amount of water pumped daily is pumped in five hours. This will ensure that even in the strongest winds the water source will not be pumped dry and damaged.
The design of water pumping windmills has been improved over the years with the result that many reliable products are available today. Southern Cross windmills follow the geared type design philosophy with mills of sizes up to 4,3 metres in diameter, this resulting in more than one rotation of the windmill wheel being required to produce one pump stroke. This reduces the stresses on the system as the pumps will never exceed a stroke rate of more than forty strokes per minute. Further all Southern Cross windmills are fitted with a reefing device so that at wind speeds of in excess of eleven meters per second (40 km/hr) the windmill head turns out of the wind so that the wheel is parallel with the wind direction and the pump stops pumping. Other design features include replaceable roller bearings (Climax Windmill), babbit metal bearings (IZ Southern Cross Windmill), self-oiling (once a year) system, hot dip galvanising of all steel components and sturdy towers.
Windmills operate a reciprocating pump and as such are subject to transient hydraulic effects. These will be aggravated by the results of the windmill pump sucking in air if the water source is pumped dry. These effects can easily be overcome with sound system design, surge tanks and correct component sizing. As such however they are the greatest cause of system failure and an integrated design approach must be used.
Windmill Selection Chart