Patent ID: 7549838

Claim:
A turbomachine compressor comprising at least one plurality of moving blades and, spaced apart therefrom in an axial direction relative to a central longitudinal axis of the turbomachine, a plurality of stationary vanes, and a stationary casing surrounding said plurality of moving blades, wherein said stationary casing includes a plurality of bleed holes passing through said stationary casing so that an inside of said stationary casing is in flow communication with the outside of said stationary casing via said bleed holes and, when said moving blades move inside said stationary casing during normal operation of said turbomachine, air is sucked outside of said stationary casing via said bleed holes, wherein said bleed holes are centered in a range of 5% to 50% of a blade chord length of each blade, said blade chord length being defined by a straight line segment connecting a leading edge to a trailing edge of each blade, wherein said range of 5% to 50% define limits for said bleed holes such that no bleed hole is centered outside of the range of 5% to 50%, and wherein said bleed holes are of a cross section largest length less than or equal to 30% of said blade chord length, each of said bleed holes sloping at two angles relative to said longitudinal central axis.