Common Base Frame
COVENT has extensive experience designing very large fans with its exclusive common base frame know as arrangement no. 7B. This approach will provide the fan installer with several advantages.
A series of gas treatment centre exhaust fans for a an aluminium smelter. The maintenance accessibility advantage is evident.
- The complete fan has been pre-assembled at the TLT manufacturing facility. This ensures that all components fit well together. Traditional arr. 3 fans will not be fully assembled in the shop.
- Site installation is simplified as the channel frame is installed, shimmed and leveled on the concrete foundation. The fan casing, rotor and motor are then installed on the pre-drilled mounting locations. Alignment is then a minor issue. With traditional arr. 3 fans, the fan bearings, motor and fan housings are all installed on separate concrete pads and thus are much more difficult to align.
- Maintenance and inspections are easily performed on arrangement 7B fans since the equipment is fully accessible from the concrete level.
Key design features
The base frame design results in a centerline supported fan. This ensures that the relative differential expansion between the casing center height and the shaft center height is minimized.
The shaft seals and fan inlets can thus operate at closer tolerances and higher efficiency.