PURPOSE: To increase a condensate removing rate at a low differential pressure by mixing steam jetted out from a steam port with condensate in a center plenum to form a condensate mass, and providing a siphon shoe with a condensate removing means communicated with the center plenum.

CONSTITUTION: Steam is introduced from a recess 50 through an annular outlet 40 to a center plenum area 42, the flow of the steam is directed to a siphon shoe condensate flow opening adjacent to a drum inner surface 60 to define a fluid boundary face, and also directed to a siphon shoe radial axis. In the fluid boundary face adjacent to the drum inner surface 60, condensate flowing into the siphon shoe is mixed with the injected steam to form a mixture having a density lower than that of only the condensate. Thus, by the direct action of the steam on the condensate and its lowered density, a condensate removing rate at a low differential pressure is increased.