Chapter 9
STEAM GENERATION- BOILERS
OBJECTIVES
• After studying this chapter, the student will be able to:
• Describe the basics of boiler operation.
• Describe a fire-tube boiler.
• Describe the main components of a water-tube boiler and explain how it operates.
• List some boiler operating problems.
REVIEW QUESTIONS
1. What is the name of the section in a water tube boiler that preheats the water? Answer:
2. What is a spud? Answer: A group of gas filled tubes in a natural gas burner.
3. Contrast a water tube boiler and a fire tube boiler. Answer: Water tube boiler- a type of
4. Contrast a downcomer tube with a generating, or riser, tube. Answer: The downcomer
5. Identify the key components of a water tube boiler and describe the water circulation in
the boiler. Answer:
a. furnace f. downcomer
b. water tubes g. riser
6. Contrast superheated steam, desuperheated steam, and saturated steam. Answer:
Superheated steam is steam that is separated from the liquid and heated up without
7. List five operations in which steam is used. Answer:
a. distillation f. extrusion
7. List six types of tubes found in a water tube boiler. Answer:
a. generating d. water make-up
8. Contrast the upper and lower drum in a water tube boiler. Answer:
The upper drum is the primary feed drum. It is never filled all the way. It is connected to
9. List the key components of a natural gas burner. Answer:
a. dampers
10. What are the seven major things an operator does when starting up a boiler? Answer:
1 . Fill the steam drum with water to the normal level.
2. Start the fan.
11. List three operating problems found in a boiler. Answer:
a. tube rupture
13. What is the purpose of a steam trap? Answer: Remove condensate from a steam system.
14. Name two classes of steam traps. Answer: Mechanical and thermostatic.
15. Name and describe two types of mechanical steam traps. Answer: Float-type traps have
a float that rests on the top of the condensate. A rod to the outlet valve attaches the float.
The position of the float determines the position of the valve. As the level in the trap
16. Name and describe a type of thermostatic steam trap. Answer: Thermostatic steam traps
responds to the temperature differences between condensate and steam. A common
17. What term is used for a condition in which slugs of water cause damage to equipment.
18. Describe hazards associated with boiler operation. Answer:
A number of hazards are associated with the operation of a boiler system.
Some of these hazards include:
• Hazards associated with high temperature steam, “burns”
• Hazards associated with using natural gas
19. Define “placed on the line.” Answer: Steam generation causes pressure to rise. When the