A heat-transfer device used for condensing steam to water by removal of the latent heatof steam and its subsequent absorption in a heat-receiving fluid, usually water, but on occasion air or a process fluid. Steam condensers may be classified as contact or surface condensers. In the contact condenser, the condensing takes place in a chamber in which the steam and cooling water mix. The direct contact surface is provided by sprays, baffles, or void- effecting fill. In the surface condenser, the condensing takes place separated from the cooling water or other heat-receiving fluid (or heat sink). A metal wall, or walls, provides the means for separation and forms the condensing surface. Both contact and surface condensers are used for process systems and for powergeneration serving engines and turbines. Modern practice has confined the use of contact condensers almost entirely to such process systems as those involving vacuum pans, evaporators, or dryers, and to condensing and dehumidification processes inherent in vacuum-producing equipment such as steam jet ejectors and vacuum pumps. The steam surface condenseris used chiefly in power generation but is also used in process systems, especially in those in which condensate recovery is important. Air-cooled surface condensers are used in process systems and in power generation when the av ailability ofcooling water is limited. See alsoSteam; Steam turbine; Vapor condenser. Two broad types of condensers are: (i) Direct contact type condensers; where the c ondensate and cooling water directly mix and come out as a single stream. (ii) surface condensers; which are shell and tube type heat exchangers where the two fluids do not come in direct contact and heat released by the condensation of steam is transferred through the walls of the tubes in to the cooling water continuously circulating inside them Surface condenser Surface condenser is the commonly used term for a water-cooled shell and tube heat exchangerinstalled on the exhaust steamfrom a steam turbine in thermal power stations. [1][2][3] These condensersare heat exchangers which convert steam from its gaseous to its liquid state at a pressure below atmospheric pressure. Where cooling water is in short supply, an air-cooled condenser is often used. An air-cooled condenser is however
