air starters? 1

[mectarek]

can someone explain in details the air/gas turbo-starters that are used to start gas turbines..what are their main components? how does

they work?..any links or documents that talk about them theoricaly because I've only found Industrial and commercial links

 

[mohr]

Hi mectarek:

The turbines of medium to large-sized turbofan usually are moved from starter driven by a bleed air from an APU (auxiliary power unit). The bleed air is extracted from the APU compressor stage and injecting it into the the pneumatic starter . Then the air is exhausted to the outside. This action permits rotate the engine high stage compressor shaft reaching the correct RPM to opening the fuel injection system commanded by the start lever until that regime when the starter is no more necessary. Is possible to replace the APU by an external air power unit.The pneumatic starter is simple and consist in a centrifugal turbine such as car turbo charger. Of course is a little bit more complex.

Cheers