BLRS 6009 - Firetube Boilers (Chp 3)

Question 1

Steam is the cooling medium for the “upper part” of the tubes and the tubesheet in what type of boiler?

A) Circular watertube
B) Horizontal firetube
C) Immersion resistance
D) Vertical firetube
E) Vertical tubeless

Answer 1

D) Vertical firetube

Note: Steam is the cooling medium Upper Part

Question 2

A wetback Scotch marine boiler:

A) Has heating surface surrounding the end section
B) Uses cast iron sections
C) Has a refractory covered end section
D) Has a brick setting
E) Is externally fired

Answer 2

A) Has “heating surface” surrounding the “end section”

Question 3

The number of combustion gas passes in a Scotch Boiler seldom exceeds four due to:

A) Breeching leak
B) Combustion air pressure
C) Stack diameter
D) Chimney height
E) Condensation problem

Answer 3

E) Condensation problem

Question 4

The products of combustion leaving the furnace are referred to as combustion gases or:

A) Noxious gases
B) Natural gases
C) Stack gases
D) Excess gases
E) Flue gases

Answer 4

E) Flue gases
Flue gas (sometimes called exhaust gas or stack gas)

Question 5

A boiler which is built ready for installation is the:

A) HRT boiler
B) Packaged boiler
C) Firebox boiler
D) Scotch marine boiler
E) Locomotive boiler

Answer 5

B) Packaged boiler

Question 6

A horizontal return tubular boiler is:

1. A two pass boiler
2. A watertube boiler
3. Externally fired
4. Constructed entirely of mild steel

Question 6 options:
A) 1, 3
B) 1, 2, 3
C) 2, 3, 4
D) 1, 3, 4
E) 2, 4

Answer 6

A) 1, 3

1. A two pass boiler
2. Externally fired

FOR: HRT HORIZONTAL TUBULAR BOILER

Question 7

A steel plate vertical firetube unit is divided into two sections and the upper part is often called the:

Question 7 options:
A) Heat exchanger
B) Combustion chamber
C) Flue gas collector section
D) Reversing section
E) Expansion tank

Answer 7

A) Heat exchanger

Note;’‘steel plate vertical firetube unit is divided into two sections’’

Question 8

When comparing vertical and horizontal firetube boilers, a horizontal firetube boiler:

Question 8 options:
A) Requires more space for a given capacity
B) Requires more feedwater for a given size
C) Needs more air
D) Is less reliable
E) Requires less overhead space for a given capacity

Answer 8

E) Requires “less overhead” space for a given capacity

Note: comparing vertical and horizontal firetube boilers

Question 9

Firetube boilers have their tubes fixed into flat steel plates, otherwise known as:

Question 9 options:
A) Drums
B) Headers
C) Shells
D) Tubesheets
E) Flues

Answer 9

D) Tubesheets

Question 10

On older boilers, the masonry work that tended to surround the furnace was termed the:

A) Boiler masonry
B) Wind box
C) Setting of the boiler
D) Boiler firebox
E) Boiler casing

Answer 10

C) Setting of the boiler

Question 11

A firetube boiler is a boiler in which:

A) Combustion gases pass around the tubes
B) Air passes around the tubes
C) Water passes through the tubes
D) Combustion gases pass through the tubes
E) Air passes through the tubes

Answer 11

D) ‘‘Combustion gases’’ pass through the tubes

Question 12

A _____ is a water filled section which surrounds the firebox in locomotive boilers.

A) Boiler drum
B) Steam dome
C) Buckstay
D) Water leg
E) Crown sheet

Answer 12

D) Water leg

Note: Water Filled Sections

Question 13

The maximum operating temperature of a hot water heating boiler is:

A) 100ºC
B) 200ºC
C) 120ºC
D) 160ºC
E) 121ºC

Answer 13

E) 121ºC

Question 14

A Scotch marine boiler:

A) Is not used in marine applications
B) Is externally fired
C) Cannot be fired on coal
D) Is single pass
E) Has an internal furnace

Answer 14

E) Has an “internal furnace”

Question 15

Firetube boilers:

A) Are not very rugged relative to portability
B) Have maintenance access difficulties
C) Require relatively small floor space
D) Require special foundations or footings
E) Have very specific design pressures to meet customer needs

Answer 15

C) Require relatively “small floor space”

Question 16

A hot water boiler is “not considered a heating boiler” UNLESS it exceeds:

1. A capacity of 454 L (120gal)
2. 5.1 cm (2 in) inlet
3. A temperature of 99°C (210°F)
4. An energy input of 58.6 kW
5. A pressure of 15 psi

A) 1, 2, 3
B) 1, 3, 5
C) 2, 3, 4
D) 3, 4, 5
E) 1, 3, 4

Answer 16

E) 1, 3, 4

454 L / 120 gal
99°C (210°F)
58.6 kW

Question 17

An internally fired boiler:

A) Requires a setting
B) Must be a watertube type
C) Is less efficient than an externally fired unit
D) Has the furnace surrounded by water
E) Utilizes a high amount of refractory and/or firebrick

Answer 17

D) Has the furnace surrounded by water

Question 18

The first boiler to have an internal furnace was the:

A) Longitudinal drum firetube boiler
B) Scotch Boiler
C) Packaged boiler
D) Watertube boiler
E) HRT boiler

Answer 18

B) Scotch Boiler

A “Scotch” marine boiler (or simply Scotch boiler) is a design of steam boiler best known for its use on ships.

Question 19

The locomotive boiler type is a:

A) Three pass external furnace
B) Single pass external furnace
C) Wetback boiler
D) Three pass internal furnace
E) Single pass internal furnace

Answer 19

E) Single pass internal furnace

Keyword: INTERNAL FURNACE

Question 20

When comparing a watertube and firetube boiler, a firetube boiler:

A) Has a quicker load response
B) Is slower to respond to load changes
C) Has less reserve steaming capacity
D) Is more difficult to maintain water level in when the load changes
E) Requires more fuel to respond to load changes

Answer 20

A) Has a quicker load response

Note: Firetube Boiler quicker load response