Vertical steam drum

Claim 1

A vertically disposed steam drum for separating water from moisture laden steam comprising: a shell portion; an upper head portion; a lower head portion; a steam outlet; a water outlet; a level above said lower head portion to which said water will rise when said drum is operating; a feedwater inlet; means for discharging water from said feedwater inlet into said drum, said discharging means being disposed below said level; means for introducing moisture laden steam into said drum; means for directing moisture laden steam in an upwardly spiraling path to cause said steam to form a swirling vortex; said steam directing means comprising: a vertically disposed tubular member having a steam inlet disposed adjacent the lower end thereof, a hub centrally disposed within said tubular member, and a plurality of upwardly spiraling vanes disposed between said hub and said tubular member, said vanes being disposed to define a plurality of generally equal upwardly spiraling flow paths for the steam; means for separating water from said swirling vortex of moisture laden steam, said separating means being disposed above said steam directing means; additional means for separating water from said steam, said additional separating means being disposed above said firstmentioned separating means and adjacent said steam outlet, said first-mentioned moisture separating means comprising: an orifice plate disposed above the steam directing means said orifice plate having an orifice disposed therein, a collar disposed within said orifice, the collar being axially aligned with the steam directing means and disposed to extend above and below the orifice plate, said orifice plate being transversely disposed in the drum and having a diameter smaller than the inner diameter of the drum, a sleeve member extending downwardly from said orifice plate and encircling the steam directing means; and a plurality of tangential ducts extending from the upper end of said sleeve member.