CHAPTER 12
BOILER MODEL
OBJECTIVES
• Describe the basics of boiler operation
• Describe the scientific principles associated with steam generation.
• Draw a simple block flow diagram of the boiler system.
• Describe the main components of a water tube boiler.
• Operate the boiler system.
• Identify common problems encountered when operating a boiler.
• Solve various troubleshooting scenarios associated with boiler system operations.
• List the safety aspects associated with operating the boiler system.
• List the operational specifications of the pump system; pressures, flow rates,
temperatures, etc.
REVIEW QUESTIONS
2. Explain the purpose of FIC 402B.
3. Explain the purpose of FIC 402C.
4. Describe the purpose and operation of the deaerator.
5. Draw a process flow drawing for the primary parts of a boiler system.
See Figure 12-1 Steam Generator
6. List the various components of a steam generation system.
7. Explain how water circulation occurs between the upper and lower drum.
Circulation occurs due to density differences inside the tubes. Boiler water
circulation operates under the principle of differential density. When fluid is
heated, it expands and becomes less dense. Cooler water flows from the upper,
8. Describe how pressure builds inside the system.
Pressure builds through the natural expansion of water to steam. Steam can be
raised to higher temperatures as it comes into contact with higher temperatures
9. Compare and contrast superheated steam and desuperheated steam.
10. List three operating problems associated with operating a boiler.
11. Compare and contrast the various tubes described in boiler operation.
The tubes found in a boiler include:
• water make-up tubes and distributer
12. Identify what the function of the economizer section is.
The economizer section is used to increase boiler efficiency by preheating the
water as it enters the system. This section is a series of headers and tubes
13. Draw and explain the purpose of LIC-402 and any associated equipment.
PIC-402A is designed to control the pressure on the steam header.
15. List the important aspects associated with Ai and AA-402.
16. List the three variables monitored in the stack.
17. Describe the purpose of BA-402.
BA-402 is designed to let the technician know if the burner is on or off.
18. Identify the temperature and pressure of the primary steam header.
19. Identify the temperature and pressure of the desuperheated steam header.
20. Write a paragraph or two about how to start up the boiler system.
While a number of variations are possible when looking at an operational
2. Set FIC-402C to 150 gpm and place controller in CASC.
4. Set PIC-402A to 120 psig and place in AUTO.
6. Start pump 402 and monitor system pressures. Establish proper level in upper
and lower drum.
8. Open FCV-402A to 100% leave in MAN.
10. Monitor process pressures and level in TK-402.
12. Set FIC 402A to 50% and place controller in AUTO.
14. Set FIC 402B to 50% and place in AUTO.
16. Light burner and allow boiler to come up to pressure and temperature.
18. Monitor TR-402 video trends.
20. Cross-Check process variables with SPEC sheet.
NAME:____________________________ TEST A
DATE:____________________________
CHAPTER TWELVE
TEST BOILER MODEL
1. As steam flows from the boiler to the plant it begins to cool. When steam cools it
forms _______________ .
2. A boiler is most closely defined as a:
a. device used to convert steam energy into mechanical energy
b. device used by industry to boil water and produce steam
c. fire tube filled container submerged in water
d. furnace with water filled drums and tubes passing through it
3. Boiler load is most closely defined as a:
a. plants demand for steam
b. boilers steam capacity
c. boilers total energy demand
d. water load in boiler tubes
4. Boilers produce a variety of steam temperatures and pressures.
a. True
b. False
5. The steam generating drum is typically operated:
a. 1/4 full
b. 1/2 full
c. 3/4 full
d. Liquid full
6. The downcomer is connected to:
a. mud drum and steam generating tubes
b. steam generating drum and mud drum
c. deaerator and economizer tubes
d. superheated and desuperheated tubes
7. The water make-up system takes its level measurement from the:
a. deaerator and steam generating drum
b. economizer and deaerator
c. mud drum
d. superheated tubes
8. Identify the following components:
Boiler
8-1 8-11
8-3 8-13
8-5 8-15
8-7 8-17
8-9 8-19
9. The deaerator has the following flows in and out except:
a. safety valve (out)
b. pump (out)
c. chemical additives (in)
d. oxygen vent (out)
e. water make-up (in)
f. steam generating drum (out)
10. Fans are used in a water tube boiler system to:
a. cool the burners
b. control oxygen flow rate
c. distribute heat
d. blow hot gases out the stack
11. The burners in a water tube boiler are surrounded by which tubes:
a. riser and downcomer
b. superheated and desuperheated
c. steam generating tubes
d. economizer tubes
12. Flow moves in the opposite direction in these tubes.
a. downcomer and steam generating
b. riser and downcomer
c. riser and steam generating
d. a & b
13. The steam generating tubes are connected to the:
a. riser and downcomer
b. economizer and water make–up
c. superheated and desuperheated
d. mud drum and steam generating drum
14. Used to evenly distribute air and fuel vapors over an ignition source and into a
boiler firebox.
a. flame distributor
b. igniter
c. burner
d. flare tip
15. A section of the boiler utilized to preheat feed water before it enters the main
boiler system.
a. convection section
b. economizer section
c. radiant tube section
d. shockbank
16. Slugs of water can damage equipment and lead to a condition known as: a.
thermal expansion
b. water hammer
c. thermal shock
d. warping
17. The principle reason water circulation occurs in a water tube boiler is because of:
a. natural buoyancy forces
b. equipment design
c. tapered design of steam generating tubes
d. length of riser tube
18. Some processes can not take superheated steam so a process known as
desuperheating is applied to remove this additional heat. This process routes the
superheated steam through the liquid level in the upper drum.
a. boiler load
b. superheated steam
c. desuperheated steam
d. cut in the line
19. Steam that is removed from the steam generating drum and heated up to a
higher temperature.
a. boiler load
b. superheated steam
c. desuperheated steam
d. cut in the line
20. A device used to separate liquids from gases and return them to a condensate
header.
a. strainer
b. steam bucket
c. steam trap
d. check valve
21. There is a direct correlation between steam temperature and:
a. analytical variables
b. flow rates
c. level in steam generating drum
d. pressure
22. The primary purpose of a condensate recovery system is: Circle all that apply!
a. Save money
b. Remove oxygen
c. Return water to boiler.
d. Remove slugs of water from steam.
23. List five operating problems associated with steam generation.
a.
b.
c.
d.
e.
24. The steam pressure on Boiler-402 is set at:
a. 60 psig
b. 100 psig
c. 120 psig
d. 180 psig
25. The steam temperature on Boiler-402 is set t:
a. 305ºF
b. 215ºF
c. 480ºF
d. 350ºF
26. The steam generating drum level is controlled at:
a. 50%
b. 35%
c. 75%
d. 15%
27. The draft in the furnace is controlled at:
a. 5 psig
b. -.5
c. -.05
d. -.02
28. Pump-402 feed water pump ‘s discharge pressure is:
a. 35 psig
b. 155 psig
c. 120 psig
d. 60 psig
29. Boiler.TS#1
1
30. Boiler. TS#2
1
8. Boiler.TS#3
1
2
3
4
5
6
Answer Key CHAPTER 12 TEST A
BOILERS MODEL
