A stoker-fired firetube boiler has 100 m2 of heating surface. How much steam must its safety valve be capable of discharging per hour?

The correct answer is based on the relationship between the heating surface area of a boiler and its steam-generating capacity, which is commonly represented through established formulas. In the context of a stoker-fired firetube boiler, a standard formula used to estimate the required safety valve discharge capacity is approximately 34 kg of steam per square meter of heating surface per hour.

By applying this concept to the information provided, we take the total heating surface area of 100 m² and multiply it by the discharge capacity per square meter:

100 m² x 34 kg/m²/h = 3400 kg/h.

This calculation reveals that the safety valve must be capable of discharging 3400 kg of steam per hour to ensure safe operation of the boiler under maximum expected load conditions. The safety valve is a critical component in maintaining the boiler's pressure within safe limits, so it is crucial that it is adequately sized based on the heating surface area.

Other answers suggest different values for the steam discharge capacity, but in accordance with the standard method of flow calculation for safety valves in stoker-fired firetube boilers, 3400 kg/hr is the correct and appropriate figure.