Desuperheater

a heat exchanger used to lower the temperature of superheated steam in a boiler unit or before a turbine. Changes in a boiler unit’s operation may lead to wide variations in the temperature of the superheated steam; a desuperheater then becomes necessary to prevent excessive superheating of the steam superheater or to maintain the steam turbine’s normal working conditions. A desuperheater is usually installed either in the intermediate header, which receives partially superheated steam, or at the point where the steam leaves the superheater. The steam is cooled by a water feed that removes heat from the steam. The water feed passes through the tubes of the heat exchanger in shell-and-tube-type desuperheaters, whereas in other desuperheaters it is directly injected. Condensate is frequently used in the latter case.