ESET-212 Lecture Notes - Lecture 15: Geothermal Power, Surface Tension, Total Dissolved Solids
Document Summary
Location: water wall blowdown valves shall be locked or sealed closed to prevent being opened by mistake when the boiler is firing. When to use: water walls are usually blown down when the boiler is being taken off the line. If the waterwall blowdown valves are opened, the loss of water or circulation will cause the water wall tubes to overheat. Water wall blowdown valves should only be blown down when the furnace has cooled properly. Some boilers are equipped with surface blowdown valves. Surface blowdown valves are located at the normal operating water level (nowl) of the boiler and are used to remove impurities from the surface of boiler water. This reduces surface tension and prevents carryover of water and impurities. The surface blowdown line discharges to the blowdown tank. It is a manual controlled blow down, and it needs to be operated once a while.
