1 / 22

Information required to optimise a fan selection

Information required to optimise a fan selection. Howard Brooke, Chief Engineer. Woodcock & Wilson Ltd. Objectives. To have a basic understanding of the information required by a fan engineering company to enable the selection of a suitable fan. K ey Areas of Coverage.

lethia
Download Presentation

Information required to optimise a fan selection

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Information required to optimise a fan selection Howard Brooke, Chief Engineer. Woodcock & Wilson Ltd.

  2. Objectives To have a basic understanding of the information required by a fan engineering company to enable the selection of a suitable fan.

  3. Key Areas of Coverage • A - Information relevant to basic fan selections. • B - Ancillary Equipment. • C - Information required to avoid system effects. • D - Information required for an ATEX-Certified fan.

  4. A - Basic Fan Selection • Flow Rate – Actual, Standard and Normal • Units (m³/s, m³/s, m³/min, cfm, l/s) • Fan Pressure • Units – Pa, kPa, mbar mmWg, insWg Static Pressure orTotal Pressure - Temperature related to the specified pressure - Pressure split between fan inlet and discharge

  5. Climatic Conditions • Temperature • Humidity • Altitude

  6. Operating Conditions • Maximum operating temperature • Requirement for cold start would also need to be known. • Minimum fan efficiency ? • Is the fan handling corrosive or erosive gases? • Material Handling • Type and Size of Material • Concentration

  7. Operating Conditions • Power supply (Voltage/Phase and Frequency) • Is the fan to be driven by inverter? • Is fan subject to cyclic operation? • Thermal or Speed? • Any noise limitations • Fan Finish and Colour

  8. B - Ancillary Equipment • Inlet and Discharge Flexible connectors • Anti-Vibration Mounts • Inlet/Discharge Dampers • Instrumentation(Vibration/Temp/Speed) • Sealing Arrangements

  9. C - Information required to ensure that fan is free from system effects • Select a fan type most appropriate to your installation.

  10. Fan Types • Axial Fans • Air Enters and exits axially • Long case, Short case or Plate mounted • Tubular Case- can be as with a portable man cooler, ducted on either inlet, outlet or both inlet and outlet. • Bifurcated axial – internal tunnel or pod for mounting the motor out of the airstream – Used for hot or corrosive gases

  11. Fan Types • Centrifugal Fans • Air enters axially & exits at 90° • Single Inlet. All airis drawn through one inlet (SISW) • Fan case is an expandingvolute shape, which assistsstatic pressure regain & directs the airflow in one direction

  12. Fan Types • Centrifugal Fans • Double Inlet Double Width (DIDW) • Air is drawn from both sides

  13. Fan Arrangements & Handings • Select the most appropriate handing to suit the site conditions

  14. System problems • Fans will only meet the duty point shown on the performance curve under “ideal” installation conditions. • Ideal conditions are seldom obtainable in practice consequently there will always be some “SYSTEM EFFECT”.

  15. SystemProblems Factors that influence system effect: • Elbow or bend too close to fan inlet or outlet • Abrupt duct transition • Pre swirl of the incoming air due to duct design. (Swirl in same direction as rotation). • Dampers not fully open. • Damper location • Poorly designed fan drives – large drive pulley - solid rather than spoked. • Fan inlet or outlet too close to wall or bulkhead. • Fan inlet box design • Bend orientations at discharge • Free discharge – abrupt expansion. • Weather cowls and hoods

  16. SOME DO’S & DONT’S FOR FAN INSTALLATIONS

  17. SOME DO’S & DONT’S FOR FAN INSTALLATIONS

  18. Fan Discharge Orientation Good Bad Good

  19. Fan Inlet Swirl COUNTER-ROTATION AIR SWIRL IN OPPOSITE DIRECTION TO IMPELLER ROTATION

  20. Section D Information required to select ATEX-Certified Fans

  21. ATEX ZONE • Fan Category • Temperature class (Gas Only) • Gas or Dust Group • Max Allowable surface temperature • Ignition Temperature of Dust • How fan is installed • Description of Operation • Details of extreme environmental conditions

  22. Thank you very much for listening. Any Questions?

More Related