METHOD FOR PREVENTING CORROSION OF HIGH OR MEDIUM PRESSURE STEAM CONDENSATE RETURN PIPING

摘要

PURPOSE: To prevent the air and non condensible gas from being left in a condensate return piping after the feeding of steam is stopped by keeping the inside of the condensate return piping whose end is immersed in the water in a hot well tank at the negative pressure in the prescribed range by a vacuum pump when the temperature of the condensate return is below the prescribed value after the feeding of steam is stopped. ;CONSTITUTION: When a boiler 10 is stopped and the feeding of medium pressure steam is stopped, the temperature of the condensate return falls below the prescribed value, and then, the inside of a condensate return piping 14 whose end is immersed in the water in a hot well tank 12 is kept at the negative pressure in the prescribed range by a vacuum pump 18. The inside of the condensate return piping 14 is kept at the negative pressure after the temperature falls below the prescribed value in the condition where the end of the condensate return piping 14 is immersed in the water in the hot well tank 12, and the inside space of the piping can be kept at the negative pressure without causing the flushing of the condensate return at the negative pressure. Thus, the inside space of the piping is sucked to make it difficult for the air and the non condensible gas to be left in the piping, and to suppress the proceeding of corrosion of the condensate return piping 14.;COPYRIGHT: (C)1996,JPO