| 摘要 |
A feed water preheater has an integral desuperheater and an integral supercooler through which passes the feed water tube bundle. To prevent the penetration of steam into the supercooler at the point where the feed water tube bundle passes from the supercooler into the condensation space through a support plate, the tubes of the tube bundle are surrounded by sleeves which are fixed to the support plate. Steam flowing through the sleeves condenses and fills the sleeves to prevent the entry of steam into the supercooler. Sleeves are also provided at points where the tubes pass between the desuperheater and condensation space to reduce the velocity of steam traveling from the former to the latter. The latter sleeves can be oriented vertically in the case of a vertical preheater, as long as they are longer than the thickness of condensate disposed on the support plate in the condensation space. |
