Patent ID: 7835483

Claim:
A steam separator for separating gas-liquid two-phase flow into liquid and gas, said steam separator comprising: a stand-pipe for introducing said gas-liquid two-phase flow from a lower portion thereof to an upper portion thereof; a diffuser for forming a flow path which connects to an upper end portion of said stand pipe and expands the flow path area toward the upward direction so as to be greater than that at an upper end of said stand-pipe; a first stage inner cylinder for forming a flow path being connected to an upper end portion of said diffuser; a first stage outer cylinder for forming an annular space which encloses said first stage inner cylinder; a first stage annular plate for sealing an inner peripheral edge of an upper end of said first stage outer cylinder and forming a circular hole with a diameter smaller than an inner diameter of said first stage inner cylinder; a first stage pick-off ring which has a cylindrical shape and extends from an inner peripheral edge which forms said circular hole on said first stage annular plate, and forms a flow path which passes through said circular hole; a main swirler including a hub disposed at an axial center thereof, a plurality of main swirl blades mounted radially around said hub; and an auxiliary swirler and having a plurality of auxiliary swirl blades mounted to said hub; wherein an outer edge of said main swirl blades is fixed to an inner wall of said diffuser or to an inner wall of a lower portion of said first stage inner cylinder, a main swirl flow path is formed in the space formed with said inner wall, said hub and said main swirl blades, each lower end of said plurality of auxiliary swirl blades is positioned lower than an upper end of said main swirl blades, an auxiliary swirl flow path is formed in the space along said plurality of auxiliary swirl blades formed of said hub and said plurality of auxiliary swirl blades, and an outer diameter of said auxiliary swirler is smaller than an outer diameter of said main swirler.