GB809510A - Improvements in and relating to contact condensers - Google Patents

Abstract

<PICT:0809510/III/1> In apparatus for condensing steam, e.g. from a turbine, by direct contact with water, wherein some of the water withdrawn from the condenser is pumped back to the water inlet of the condenser via the vertical pipes of a heat-exchanger in which the water is cooled by atmospheric air flowing over the outside of the pipes, the heat-exchanger is provided with valves which may be adjusted in such a way that the water flows upwards through all the pipes and drives the air out of the pipe system, or in such a way that the water is quickly discharged from the pipes. The pipes can be readily filled with water or emptied; and the freezing of the water in the apparatus, when the atmospheric air is below zero and the turbine is not running on a large amount of steam (or is not in operation at all) can easily be avoided. The heat-exchanger shown in Fig. 2 comprises two groups of ribbed pipes 28, 30 disposed between lower headers 27, 31 and upper header 29. Water is pumped into the heat-exchanger through pipe 25, while valves 14, 16, 18 are open but valves 13, 15, 17 are closed, so that the water flows up both groups of pipes and displaces air which escapes through valve 18. After removal of the air, the apparatus is made ready for normal operation by opening valve 13 and closing valves 16, 18. The water now flows up pipes 28 and down pipes 30, and it then flows via valve 13 and pipe 34 to the nozzle 10 of condenser 9. Steam from a turbine plant (not shown) flows through pipe 8 into condenser 9, where it is condensed by the water sprayed in through nozzle 10. The water leaves the condenser through pipe 11; some of it is pumped through pipe 24 to the boiler, and the remainder is pumped to header 27. The discharge of water from the heat-exchanger is effected by closing valves 13 and 14, and opening valves 15, 16, 18. If the empty plant has to be set in operation in cold weather, the water that is supplied to the heat-exchanger has to be preheated. This may be achieved by admission of steam to the condenser through line 32 and valve 33, and circulation of the water from the base of the condenser, by means of pump 26, through pipes 25 and 34 (the heat-exchanger is not in circuit) until the water attains a suitable temperature, whereupon the filling of the heat-exchanger is effected as already described. The headers of the heat-exchanger may be connected to the vacuum space of the condenser, so that any air entering the system during operation is expelled through the vacuum pump.