BCIT 5th class boiler engineer quiz 1 Flashcards
Large pipes which collect or supply fluid from a series of smaller pipes or tubes are called
a) headers.
b) collectors.
c) siphons.
d) boiler tubes.
e) waterlegs.
a) headers.
CH001 Q14
A header is a larger pipe which supplies to or collects from a series of smaller pipes or tubes. Also called a manifold.
Large steam generating units used to produce electricity common consume fuel at rates in excess of 100 tonnes per hour.
True
False
True
CH001 Q31
Large Steam Generating units may burn 100 to 1000 tonnes of coal per hour.
The combustion zone of a straight tube watertube boiler is surrounded by

a) widely spaced horizontal water filled tubes.
b) finned tube heat exchange surface.
c) refractory.
d) closely spaced vertical water filled tubes.
e) layers of loosely wound tubes.
a) widely spaced horizontal water filled tubes.
CH001 Q28
As shown in the figure below, the straight tube longitudinal drum boiler is made up of a steam drum and a large number of straight tubes. The tubes are connected to headers at each end and the header, in turn, are connected to the steam drum. The entire unit is supported on a brick setting which contains the furnace area and flue gas passages. The tubes and bottom half of the drum are filled with water. Hot gases from combustion circulated around the tubes and are directed by baffles through the heating zone and out to the stack. The tubes are sloped and as the water is heated and steam bubbles form, the water and steam rise upward through the tubes and are collected in the upper headers and returned to the steam drum. The heavier water flows down the headers at the back end of the boiler to replace the water rising to the drum and circulation is maintained.
The term “condensate” refers to
a) water supplied to the boiler to make up for losses in the system.
b) the water formed when steam gives up heat and returns to a liquid.
c) water supplied to a boiler from the deaerator.
d) water drained from a boiler to remove sludge.
e) water formed by the combustion of hydrogen in the fuel.
b) the water formed when steam gives up heat and returns to a liquid.
CH001 Q22
In a steam heating system the boiler supplies steam to the heating system. In this system various pieces of equipment are connected by supply and return piping. The steam gives up its heat in the equipment and condenses back into water forming what is commonly called steam condensate. This condensate is returned to the boiler to be converted to steam again.
The brick or concrete like material used in a boiler to withstand high temperatures and erosion is called
a) insulation.
b) cladding.
c) foundation.
d) refractory.
e) cement.
d) refractory.
CH001 Q04
Refractory is the protective layer of material that is applied to various parts of the boiler to withstand high temperature and abrasion. It usually has an appearance similar to concrete or brick. Refractory is also added to keep the combustion zone temperature high enough to ensure complete combustion because it absorbs and stores heat from the flame.
The term “uptake” refers to the
a) opening allowing access to the furnace.
b) top of a straight tube boiler furnace.
c) duct that conveys flue gases to the stack.
d) shield that protects the gauge glass.
e) duct that supplies combustion air to the burners.
c) duct that conveys flue gases to the stack.
CH001 Q13
Uptake, the duct used to convey the spent combustion gases from the boiler to the stack or chimney. Also known as the flue vent or breeching.
The actual level of water in a boiler is called the
a) steam line.
b) water line.
c) interface.
d) steam space.
e) water space.
b) water line.
CH001 Q12
Water line is the actual level of water in a boiler. It is the point at which water and steam separate.
The travel of combustion gases once along the length of a boiler is called
a) a travel.
b) an uptake.
c) a combustion gas pass.
d) a furnace tube.
e) a fire tube.
c) a combustion gas pass.
CH001 Q17
Combustion gas pass, one pass is the travel of the combustion gases once along the length of the boiler. If the gases are reversed and passed through additional tubes of the boiler, this is a second pass. For example, in a two pass boiler, combustion gases make two sweeps or passes through the boiler.
A boiler that is only operated when a qualified operator is present to monitor its operation is called
a) an industrial boiler.
b) an HRT boiler.
c) a supervised boiler.
d) an attended boiler.
e) a controlled boiler.
d) an attended boiler.
CH001 Q01
An attended boiler is a boiler that is only operated when a qualified operator is present to watch over and control the various boiler functions.
The boiler shown below is
a) an “A” Type.
b) a “Q” Type.
c) a “D” Type.
d) a “C” Type.
e) an “O” Type.
e) an “O” Type.
CH001 Q26
The boiler shown in this figure is an “O” Type.
The term “heating surface” refers the parts of the boiler
a) that heat is transferred from the hot gases to water or steam.
b) where combustion of the fuel takes place.
c) that keep the high temperature from escaping the furnace.
d) where steam is superheated.
e) where the flame impinges on the walls.
a) that heat is transferred from the hot gases to water or steam.
CH001 Q08
The heating surface of a boiler consists of all parts of the boiler through which heat from the burning fuel is transferred to the water side of the boiler. It includes all parts of the boiler plates and tubes which have water or steam on one side and are swept by fire or hot combustion gases on the other side.
The purpose of multiple drums in a three drum bent tube boiler was to
a) reduce the cost of manufacture.

b) improve heat transfer from the hot gases to the water.

c) reduce required height for low ceiling installations.
d) improve water circulation.
e) provide two mud drum for sediment to settle out.
c) reduce required height for low ceiling installations.
CH001 Q33
The 3 drum design was created to reduce the height requirement of a water tube boiler to allow for installation in low ceiling facilities.
A machined and slightly tapered short pipe found in sectional cast iron heating boilers is referred to as
a) a push nipple.
b) a tapered bushing.
c) a water leg.
d) a tie rod.
e) a cleanout plug.
a) a push nipple.
CH002 Q11
The short tapered pipe between the sections of a cast iron sectional heating boiler is referred to as a push nipple.
Cast-Iron boiler sections maximize heat transfer by
a) exposing as large a surface as possible to the hot gases.
b) using an external furnace.
c) using four push nipples per section.
d) vertical firing.
e) using as few passes as possible.
a) exposing as large a surface as possible to the hot gases.
CH002 Q15
The heat transfer is maximized by ensure that the flue gases are as low temperature as possible when exiting the stack. This requires extended heat transfer surface to extract the heat from the flue gases and transfer them to the water. This is done by using a number of gas passages.
The water filled component that extends from the main section and surrounds the furnace in some cast iron boilers is referred to as
a) a refractory wall.
b) a water tube furnace.
c) an internal extension.
d) a water leg.
e) a convection bank.
d) a water leg.
CH002 Q01
The term waterleg refers to a water- filled section extending from the shell, which surrounds the firebox of some types of boilers. Most locomotive boilers are equipped with waterlegs around the firebox.
A cast iron boiler disadvantage is
a) they are limited to relatively low pressures.
b) they are difficult to assemble.
c) they are subject to corrosion.
d) they have high ductility.
e) they are extremely high cost.
a) they are limited to relatively low pressures.
CH002 Q17
One disadvantage of cast iron boilers is that the pressure they can withstand is low compared to steel boilers.
The term “condensing boiler” refers to a boiler where
a) some of the steam produced in the boiler is condensed before entering the heating system.
b) the flue gases are cooled to the point where moisture is condensed in the boiler heat exchanger.
c) condensate from a gas processing plant is used as fuel.
d) condensate is used as feedwater for the boiler.
e) condensate from the heating system is not returned to the boiler.
b) the flue gases are cooled to the point where moisture is condensed in the boiler heat exchanger.
CH002 Q21
Most fuels contain some hydrogen which is converted to water when burned. In addition, some boilers have water in the fuel that evaporates during combustion. In order to maximize boiler efficiency the flue gases must be cooled as much as possible by transferring heat to the water. However if the temperature is lowered too much, the water vapor in the flue gas begins to condense. This condensation tends to cause corrosion in the heat exchangers and stack. When building these high efficiency boilers, the materials used must be chosen to ensure that they can withstand this corrosion.
The sections of a cast iron sectional boiler are held together by
a) push nipples.
b) gaskets.
c) flaring of tube ends.
d) gravity.
e) tie rods.
e) tie rods.
CH002 Q03
The sections of a cast iron boiler are held together by long tie rods extending the length of the boiler or short tie rods as shown below.
Smaller firetube boilers are low cost and
a) reach operating pressures very quickly from a cold start.
b) require very critical water treatment.
c) have simple rugged construction.
d) are not suited to ON/OFF operation.
e) do not cause much damage on waterside rupture.
c) have simple rugged construction.
CH003 Q35
Small firetube boiler are made with a simple rugged construction. While they will heat up faster than large boilers, it is important not to heat them too quickly or stress may occur to the metal. Any boiler operating under pressure will cause extensive damage if a rupture occurs because water in the boiler will flash into steam increasing its volume by about 1600 times.
In a vertical firetube boiler, the steam space is located
a) at the top of the shell.
b) this type of boiler does not require a steam space.
c) in a separate chamber.
d) in a compartment on the side.
e) at the lower part of the shell.
a) at the top of the shell.
CH003 Q27
In a vertical boiler, the top of the shell is the steam space.
One improvement to firetube boilers was adding a furnace tube inside the shell. This is referred to as
a) an internally fired boiler.
b) a water tube boiler.
c) an HRT boiler.
d) a furnace tube boiler.
e) a package boiler.
a) an internally fired boiler.
CH003 Q03
A boiler in which the furnace is surrounded by water by inserting a furnace tube through the shell or surrounding the furnace with water tubes is called an internally fired boiler.
A boiler in which combustion of the fuel takes place outside the boiler and the hot gases pass through the boiler to heat the water is called
a) a remote furnace.
b) a haycock boiler.
c) a locomotive boiler.
d) a firebox Boiler.
e) an externally fired boiler.
e) an externally fired boiler.
CH003 Q01
An externally fired boiler is a boiler with the combustion chamber outside the boiler drum. This type of furnace is not surrounded by water but is surrounded by brickwork or refractory called the setting.
One advantage of electrode type electric boilers over immersion type is that they
a) can be operated at much higher temperatures.
b) are more efficient.
c) have lower power requirements.
d) are less expensive.
e) do not require a low water cutoff.
e) do not require a low water cutoff.
CH004 Q02
Advantages of the electrode type only
* no low water cutoff is required with the electrode type since no heating effect is produced if the water level is below the electrodes.
* Since the water temperature is the same as the electrode temperature in the electrode type, little scaling is produced.
The maximum operating voltage for an electrode type electric boiler is
a) 480 volts.
b) 1 200 volts.
c) 5 000 volts.
d) 12 000 volts.
e) 16 000 volts.
e) 16 000 volts.
CH004 Q08
Electrode type electric boilers may operate at voltages as high as 16 000 volts and have capacities as high as 30 000 kW.
