Jan 01, 1970 · Another problem that sometimes causes severe boiler fouling is the introduction of ion exchange resin into the boiler feedwater system. This situation is frequently caused by the failure of the ion exchange vessel internal piping or lateral screens.
The primary problems are corrosion, due to oxygen and improper pH, and erosion from the tube side or the shell side. Due to the temperature increase across the heater, incoming metal oxides are deposited in the heater and then released during changes in steam load and chemical balances. Stress cracking of welded components can also be a problem.
Calculate stress in in steam boiler shells caused by steam pressure. Sponsored Links. The stress in a steam boiler shell can be calculated as. σ = P D / 2 t (1) where. σ = hoop stress (Pa, N/m2) P = boiler pressure (Pa, N/m2) D = diameter of boiler shell (m) t = thickness of boiler shell (m)
The Temperature in Your Boiler and the Dangers of
It will be seen that the stress level on a water leg stay increases if the burner is firing, or conversely approaches zero if the burner is shut off. Obviously the cooler the
When heat is added to water, its temperature rises at a rate of 0.56°C (1°F) for each heat input of 2.095 kJ/kg (1 Btu/lb) If we take water at 0°C (32°F) and we add 419 kJ/kg (180 Btu/lb) then we will increase the temperature of the water by 100°C (180°F) This rise in temperature can be detected and is called Sensible Heat (Specific Enthalpy - Water)
As the water removes heat from the tubes, the water temperature increases and it rises to the boiler steam drum. Eventually, sufficient heat is transferred and steam is generated. Colder feedwater replaces the water that rises, which creates the natural circulation. A typical boiler circulation (as
Stress in Steam Boiler Shells from Boiler Pressure
Water Handbook - Preboiler & Industrial Boiler Corrosion