Owing to the sluggish local and global economy, South African fan manufacturer CFW Fans is homing in on research and development (R&D), particularly in terms of developing large fans for heavy industry and mining, says CFW Fans Gauteng branch manager Bart Ziemski.

He tells Engineering News that the company is specifically aiming to capture a bigger market with large fans for the mining industry.

Ziemski states that significant increases in efficiency should be expected from the current R&D being undertaken by CFW, but insists that a specific timeframe for such increases cannot be provided, as R&D is a lengthy and unpredictable process.

He adds that, when designing a fan to be more efficient, the company focuses particularly on fan geometry in terms of the shape and angle of the blades.

In addition, air must enter and leave in the optimal direction. This is calculated and achieved using computational fluid dynamics, which is constantly employed by CFW, says Ziemski, adding that reducing the noise produced by a fan is another way of avoiding unnecessary power consumption.

He tells Engineering News that, once a particular model is developed, a prototype of the fan is manufactured, which is tested for further improvement opportunities at CFW’s laboratory, in Cape Town, using computerised test rigs.

Efficiency gains often necessitate the production of a new set of prototypes and, once there are no further improvements to be made, the fan is added to CFW’s product range.

Operations at CFW’s laboratory include volumetric tests, during which a fan is tested within its speed range and power consumption is compared with volume flow and pressure.

Ziemski highlights that the laboratory provides CFW with the advantage of being able to fully demonstrate and test the performance of fans according to the particular needs of a client, rather than producing only theoretical proofs. Even when an extremely large fan needs to be tested and power requirements – sometimes as big as a few megawatts – might seem to prohibit testing, the nature of the fan designs allow for a scale model to be tested and demonstrated.

Ziemski notes that, as fans are governed by geometry and speed, a smaller model can be used to prove their performance parameters, bearing in mind that there is a proportional reduction in power consumption.

The company has been accumulating its legacy data since its conception in 1966, providing CFW with significant depth in its knowledge base.

In addition to mining, CFW is active in other heavy industries, including food processing, oil and gas, chemicals processing, iron and steel smelting and cement, with its range of centrifugal and axial fans.

It also supplies fans for light industries – such as heating, ventilation and air conditioning, or HVAC, systems – and provides a portfolio of box products such as localised, portable ventilation units, wall-mounted light and medium duty fans, dehumidifiers and greenhouse fans.

As CFW is producing an in-house range of fans at its 20 000 m2 manufacturing plant, in Cape Town, instead of sourcing products from overseas, the company is provided with a significant advantage, as it is more flexible in meeting the needs of the local market, says Ziemski.

He notes that, as technology changes, industrial plants grow and processing methods evolve, clients require modifications and improvements to their existing ventilation solutions.

He adds that CFW provides aftermarket services to clients using company equipment, which poses an interesting challenge to CFW engineers, who must gain insight into the thought processes of the original designers of the fans to repair and sometimes re-engineer the equipment.

Ziemski concludes that CFW is constantly researching and developing solutions to meet customer demands by designing new fan ranges and improving on existing in-house and external fan ranges.