Massachusetts 2nd Class Fireman's Practice Exam

A boiler has a steaming capacity of 34,500 lb of steam per hour. The evaporation rate is 10 lb/ft² of heating surface per hour. What is the boiler heating surface?

1. 100

2. 1,000

3. 3,450

4. 6,900

The correct answer is: 3,450

To determine the boiler heating surface based on the steaming capacity and evaporation rate, we need to understand the relationship between these values. The steaming capacity of the boiler is 34,500 lb of steam per hour. The evaporation rate indicates how much steam can be generated per square foot of heating surface per hour, which is given as 10 lb/ft²/h. To find the total heating surface required for the boiler, we can use the formula: Heating Surface (ft²) = Steaming Capacity (lb/h) / Evaporation Rate (lb/ft²/h). Substituting the given values into this formula: Heating Surface = 34,500 lb/h / 10 lb/ft²/h = 3,450 ft². This calculation shows that for the boiler to have a steaming capacity of 34,500 lb per hour with an evaporation rate of 10 lb per square foot, it requires 3,450 square feet of heating surface. This is why the correct answer is 3,450.