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Water Treatment
Published in Carl Bozzuto, Boiler Operator's Handbook, 2021
A condensate polisher is almost identical to a water softener. The differences are mainly due to the high temperature of the condensate. The resin beads and mechanical parts of a polisher are designed to take the higher temperatures. The resin also has an affinity for iron (Fe++) in addition to calcium and magnesium to remove iron from the condensate. Products of corrosion, dissolved iron oxides, get removed by condensate polishers. Operation of a polisher is very similar to a softener, using brine to regenerate. High temperature and pressure boilers need extremely pure water. For those units, the condensate polisher is designed to take out nearly everything. Such resin-based systems are called “demineralizers.” They remove both cations and anions and are regenerated with sodium hydroxide and sulfuric acid.
Water Treatment
Published in Kenneth E. Heselton, Boiler Operator’s Handbook, 2020
A condensate polisher is almost identical to a water softener. The differences are mainly due to the high temperature of the condensate. The resin beads and mechanical parts of a polisher are designed to take the higher temperatures. The resin also has an affinity for iron (FE++) in addition to calcium and magnesium to remove iron from the condensate. So, products of corrosion, dissolved iron oxides, get removed by condensate polishers. Operation of a polisher is very similar to a softener, using brine to regenerate.
Application of variable frequency drive on the condensate pump motors of APR1400 nuclear power plants for energy savings
Published in Journal of International Council on Electrical Engineering, 2018
Exavier Zakaria Barie, Choong-koo Chang
The condensate and feedwater systems are designed to deliver the condensate water from the main condenser to the steam generator (SG). The condensate system consist of three 50% capacity motor-driven pumps (two operating and one standby) deliver condensate from the condenser hotwells to the deaerator through the condensate polisher, a steam packing exhauster, and three stages of LP feedwater heaters (Figure 1). Condensate is provided to the SG blowdown regenerative heat exchanger for cooling [1]. Three 50 percent capacity motor driven condensate pumps are vertical, multistage, centrifugal, and operate in parallel. During normal operation, two pumps are running [2]. Each condensate pump (CP) supplies 11,000 gpm with 1100 ft of head (approximately 477psi) [3].The third pump is prepared as a standby and starts automatically on the loss of one of the two operating pumps, allowing the plant to remain at 100 percent power [2].The LCVs receive the control signals from the level transmitters which provide the indication and monitors the level of the condensate inside the two deaerator storage tanks (DSTs), A and B with capacity of 450,000 gal each. When the level is low or high the LCVs will control the flow by full opening or minimum opening. If the monitored level is below the minimum stored volume of 239,000 gal [4], the standby CP will start for maintaining the DST’s capacity at the required level. In case of valve malfunction, the operator has the access to operate the LCVs manually.