Glass-fused-to-steel tanks for power station water

The Medupi Power Station is a new dry-cooled coal fired power station being built in the Limpopo province of South Africa. When completed, the power station will have six high pressure boilers each powering an 800 Mega Watts (MW) turbine, producing 4800 MW of power and will be the largest dry-cooled coal fired power station in the world.

The boilers require extremely highly purified water, requiring the removal of all dissolved organics and suspended solids. The water is subject to many purifying processes including ultrafiltration, reverse osmosis, and electrodialysis to achieve the level of purity required by the boilers. During and after the treatment process, the water would be contained in 19 storage tanks which must retain the integrity of the quality of the water, and not allow any impurities from the tank coating to enter the water stream which could affect the operation of the high pressure boilers. The extremely tight parameters for the water quality specified a maximum silica content from the tank shells of < 1 ppb and for operating temperatures between 30 oC and 90oC. For such demanding containment requirements, PERMASTORE® Glass-Fused-to-Steel bolted tanks were chosen ranging in capacity from 85 m3 to 5,000 m3. The tanks were supplied via Permastore's local Distributor in South Africa. www.permastore.com