Deaerating feedwater heater

Claim 1

A feedwater heater adapted to remove non-condensible gases from condensate drain fluid fed thereto, said heater comprising a tubular shell portion; a plurality of tubes forming a tube bundle so disposed in said shell portion that feedwater flows through the tubes when the heater is operating to form a cold leg portion and a hot leg portion; a steam inlet nozzle disposed in said shell; a condensate drain fluid inlet nozzle disposed in said shell; impingement protecting means disposed adjacent said condensate drain fluid inlet nozzle for protecting the tubes against the direct impingement of said influent condensate drain fluid; means for dispersing said influent condensate drain fluid; said dispersing means being so disposed to effectuate admixing of the dispersed condensate drain fluid with influent steam; vent condensing means disposed to encompass a portion of the cold leg and having baffles disposed therein to cause the fluid flowing therethrough to follow a sinuous path over the tubes in order to condense steam from non-condensible gases and means for venting the non-condensible gases therefrom; and a single U-shaped trough generally centrally disposed with respect to the tube bundle and generally extending lengthwise along the entire length of the tube bundle, said trough being in direct fluid communication with the vent condensing means and with the cold leg portion of the tube bundle, said trough having leg portions each of which extend into the cold leg portion of the tube bundle, subtending a portion of the tubes therein, whereby, when the heater is operable influent steam advixes with the dispersed condensate drain fluid driving the non-condensible gases out of solution, and the steam and non-condensible gases must flow over tubes of the cold leg portion to enter the trough and then flow via the trough to the vent condensing means, wherein steam is condensed and non-condensible gases are vented from the feedwater heater.