PURPOSE: To deaerate condensed water effectively in the condenser by a method wherein an deaerating chamber, deaerating the condensed water, is provided below the tube nest of the condenser in a steam turbine cycle.

CONSTITUTION: Turbine exhaust gas, introduced into the condensing tube nest 4 of the main trunk 1 of the condenser, is condensed by cooling water in the cooling tubes of the tube nest and flows down into a condensed water receiver 15 along an air conducting chamber. On the other hand, non-condensed gas and accompanied steam are induced into the air conducting chamber 9 and cooled by an air cooling tube nest 8, thereafter, is discharged to the outside of the system. The condensed water drops into the deaerating chamber 12 through a perforated plate 17, enters into an aerating tray chamber 13 and is mixed and deaerated by exhaust gas, which ascends and enters into the deaerating chamber 12, while the deaerated condensed water stays in a hot well 10 and is discharged out of the outlet port of the condensed water. On the other hand, the non-condensed gas enters into the air conducting chamber 9 through a bent tube 18. Supplementing water, from a nozzle 22, is deaerated by a rapid heat exchange due to atomization and the deaerating effect in the deaerating chamber 13.