FinFan Optimisation

ASL PowerStream provide a range of services to enhance the performance of Air Cooled Heat Exchangers (ACHE) (FinFans).

Fan Testing

Fan efficiency is most important when considering airside performance. To establish the optimum blade angle setting for maximum airflow it is necessary to complete a fan test. By this process we characterise actual fan performance. Airflow measurements over a series of blade angle settings establish the optimum blade angle for maximum airflow within the capability of the fan and motor. The fan characterisation graph clearly illustrates the impact on power demand, which continues to rise with increase in blade angle.

However air volume reaches a peak then drops off dramatically commonly known as ‘stall point. The often made assumption that optimum fan performance is archived by maximising available motor is not necessarily the case it is therefore most important when considering optimisation a fan test is undertaken. ASL PowerStream recognises this other issue relating to fan efficiency and provides an inspection and performance testing service.

We can provide the following CCTC Pipeline Inspection Systems:

  • Tractor
  • Flexi Probe
  • Mini Probe
  • Video Endoscope
  • Borehole

Tip Clearance

Tip clearance between the blade and inside of the fan ring is critical to proper axial flow fan performance. If close tip clearances are not maintained, performance loss in both, pressure capability and airflow will result. The primary reason for close tip clearance is to minimise air loss or leakage around the tip. Air down steam from the fan will be at a higher pressure than that of the incoming air due to the work expended by the fan. If a leakage path (or clearance) exists, the air will seek the path of least resistance and bypass at the tip, causing loss of performance.

The maximum effect in deterioration of performance is felt towards conditions of maximum pressure development typically as the tube fins become fouled. It is most easily recognised in on forced draught coolers as airflow positively exits the fan periphery in opposite direction to the intended flow. Air then re-circulates around the fan blade resulting in reduced efficiency. In practice the limitations of this clearance are those imposed by mechanical design and production tolerances.

However operating conditions may be improved by fitting of tip seals, ASL PowerStream offer supply and installation as part of our fan maintenance service programme.

Effect of Tip Clearance on Fan Performance

Contact Us

If you have an enquiry about any of our services please contact us.


+44 (0)1642 453283