Paper 9: Operational Experience with Steam Evaporators and De-Aerators

Abstract

The authors review the operating experience of evaporators and de-aerators used in power stations of the South of Scotland Electricity Board over the last 45 years.

Water sources used and their effect on evaporators are covered, together with the purity of the water achieved and the requirements for the various generating cycles. The type of evaporators available) their steam heating supply and delivery of the purified water to the system is discussed, together with some of the problems.

A review of the de-aerators, their integration into the various feed cycles and heating supply arrangements is made. The level of de-aeration obtainable is considered. Operating problems, both on base load and on two shifting, are discussed especially in connection with oxygen content and metal pick-up in feed systems related to boiler corrosion.

Future possible operational requirements are outlined.