The Efficiency Of Industrial Fans
One of the best examples of how important it is to have an efficient method of power transmission is within industrial fans.
They contain an electric motor, which upon its introduction, revolutionised many industries, as power transmission processes were no longer limited to line shafts, belts, compressed air or hydraulic pressure.
There are two general types of industrial fan: centrifugal, and axial Centrifugal uses the force generated by a rotating disk, imparting movement to the air or gas and increase its pressure.
Axial fans use an axial force to achieve the movement of the air or gas, with a spinning central bladed hub extending radially from its outer diameter.
Industrial fans are used in many different types of machinery, across a wide range of different industries including electrical power production, pollution control, metal manufacturing and processing, mining, food processing and cryogenics.
However, if one does not take precautionary measures, the efficiency of industrial fans can be reduced.
Firstly, one should always ensure the size of the fan in your system is appropriate. Including correctly sized fans are very important to efficiency. If the system resistance curve is not accurately predicted, fan performance and efficiency will be likely to suffer. If a fan produces a flow rate that is too small, it will be unable to cope with peak loads. If a fan is too big, it will be unstable during operation.
If your fan is suffering from inefficiency, it may be an idea to tip or de-tip the impellers of the fan. For example if a fan is producing too much power, it may be an ideal candidate for de-tipping. Conversely, if your fan is not producing enough power, you may want to tip it, as this will increase the fan's capacity to generate pressure.
If you can, it's always an idea to keep an eye on new designs of fan blades. Changing the design can dramatically improve efficiency and capacity. One facility saved over $200,000 worth of energy within the first year of installing a new backward curved impeller into the existing radial blade housing.
It's a good idea to make sure that the fans in your system are as adjustable as possible. For varying speed operations, inverter duty electric motors with an adjustable frequency drive, will minimise losses with four to one turndowns.
Finally you should ask for a draft system assessment. Draft system assessments, including field flow testing along with computational fluid dynamics can identify the performance issues related to your fan. They serve as a guide for implementing changes and maximise efficiency while reducing energy costs.