US Patent 7445039 Heat pipe with multiple vapor-passages

A heat pipe includes a metal casing (100) filled with a working fluid therein, a capillary wick (200) provided inside of the metal casing and a tube (300) contacting with a surface of the capillary wick. The capillary wick extends in an axial direction of the casing. A plurality of spaced vapor passages (700) is formed by the capillary wick in the casing and a liquid channel (800) is defined by the capillary wick. The working fluid in vapor state flows along the vapor passages and the working fluid in liquid state flows along the liquid channel. The tube separates the vapor from the liquid at a place where the tube is located.