Improvements relating to heaters for boiler feedwater

摘要

884,221. Feedwater heating systems. PERMUTIT CO. Ltd. July 19, 1960 [Aug. 6, 1959], No. 26932/59. Class 64(1) In a boiler feedwater heater and vacuum deaerator in which water to be heated is introduced as a spray 5 into a vacuum vessel 1 into which steam is introduced through a pipe 7 so that condensation of the steam heats the water, the vessel 1 has an overflow pipe 9 having an inlet 10 at the overflow water level and extending downwardly below the vessel to an overflow tank 11 which has a water supply connection 14 with a ball valve 15 or other device, for controlling the filling of the tank to a set level, the outlet from the overflow pipe 9 being below this level and the tank having an overflow 13 above this level. In the preferred arrangement as shown, the vacuum in the vessel 1 is maintained by an ejector 3 which also removes air or other gases and uncondensed steam. Pressure changes in the vessel 1 are accommodated by corresponding changes in the water level in overflow pipe 9 (see e.g. level L2 in the Figure) this water being drawn from the tank 11. Heated and deaerated water flows from the vessel 1 to a container 2 through a pipe 8.