Engine Bleed Air Systems

Engine Bleed Air is supplied from the compressor section of the engines which is compressed and pressurized air at high temperature. Bleed air is a ready source of energy and is available as long as the engine is running.

Engine bleed air can be used for

-    Air conditioning
-    Ice/Rain protection
-    Airborne auxilliary power
-    Pneumatic power supply

The high energy in bleed systems requires special design and installation features. Ducts bursting, effects of external leakage must be considered, as well as internal failure effects. Bleed shutoff provisions have to be provided, bleed temperatures and pressures need to be regulated and instrumentation must be provided to indicate failures if present. Reverse flow has to be prevented and sufficient insulation of components needs to be provided.

Bleed Air systems generally require the installation of high temperature pneumatic ducts which need to take the following factors into account

 -   Structural Deflections
 -   Thermal Expansion
 -   Thermal Shock
 -   Space Allocation
 -   Duct Mounted Equipment
 -   External Pressures

Bleed air extraction from the engines must be limited using venturi orifices.