2Nd Class Fireman, High Pressure Boilers, Chapter 10, Exam

Front 1

_____ draft is produced by the natural action from temperature differences between air and the gases of combustion

Back 1

Natural

Front 2

Mechanical draft is controlled by the speed of the draft fans and/or by the use of _____

Back 2

Dampers

Front 3

Balanced draft combines _____

Back 3

Forced and induced draft

Front 4

The draft system for smaller package boilers that burn natural gas and fuel oil typically consists of _____

Back 4

A forced draft fan and a windbox

Front 5

A damper control system adjusts the dampers to maintain constant _____ in the furnace

Back 5

Pressure

Front 6

A continuous emissions monitoring system is used for measurement of pollutants in _____ from the combustion process

Back 6

Exhaust gases

Front 7

Scrubbing is the method of choice for removing _____ from emissions from coal-fired plants

Back 7

Sulfur oxides

Front 8

Two basic types of air heaters are _____ and regenerative air heaters

Back 8

Convection

Front 9

The _____ are environmental standards for ambient pollution emissions from new sources of emissions

Back 9

New Source Performance Standards (NSPS)

Front 10

A(n) _____ source facility emits 10 or more tons per year of any single air toxic or 25 tons or more per year of any combination of air toxics

Back 10

Major

Front 11

Draft is measured in _____

Back 11

Inches of water column

Front 12

_____ draft is created by a draft fan that pulls the gases of combustion through the furnace

Back 12

Induced

Front 13

Pressure at the discharge side of a forced draft fan is _____ atmospheric pressure

Back 13

Greater than

Front 14

_____ compounds are classified as a pollutant because they react with water vapor to form sulfuric acid

Back 14

Sulfur

Front 15

An air heater employs a counterflow principle in which the gases of combustion _____

Back 15

And air move in opposite directions

Front 16

If the temperature of air entering the heater gets too low, it will cause _____

Back 16

Condensation on the gas side of the air heater

Front 17

Air heaters can be cleaned by ____ to ensure good heat transfer

Back 17

Using soot blowers

Front 18

Air heaters can most successfully be used in plants that _____

Back 18

Have a fairly constant steam load

Front 19

If air supplied for combustion mixes with the gases of combustion, it could lead to _____

Back 19

A loss of air for combustion and incomplete combustion

Front 20

Mechanical draft is produced by _____

Back 20

Power-driven fans

Front 21

Mechanical draft can be classified as _____

Back 21

Forced or induced

Front 22

The _____ is a law that was passed to allow for monitoring and controlling environmental air pollution

Back 22

Clean Air Act (CAA)

Front 23

The gases of combustion leaving a boiler that has natural draft are controlled by _____

Back 23

Dampers

Front 24

The induced draft fan is located _____

Back 24

Between the burner and the chimney

Front 25

Mechanical draft is used when burning _____

Back 25

Fuel oil, coal, gas

Front 26

Larger steam boilers that are equipped with air heaters and/or economizers typically use _____ to overcome the associated flow resistance

Back 26

Balanced draft

Front 27

When using forced draft, the amount of draft is controlled by ____

Back 27

Inlet dampers, outlet dampers, variable-speed fans

Front 28

A _____ draft system is used to overcome air and gas-flow resistance

Back 28

Balanced

Front 29

The oldest form of draft used in a boiler is _____ draft

Back 29

Natural

Front 30

Solid particles created in the combustion process are called _____

Back 30

Flyash

Front 31

A ____ can be used as part of a damper control system to adjust the speed of a fan

Back 31

Variable-speed drive

Front 32

_____ is the method of choice for removing sulfur oxides from emissions from coal-fired plants

Back 32

Scrubbing

Front 33

The amount of draft produced in a natural draft system depends on the ____

Back 33

Height of the chimney

Front 34

Boilers can be equipped with ____ to reduce the heat loss from the gases of combustion going to the chimney

Back 34

Economizers and air heaters

Front 35

_____ is produced from incomplete combustion due to poor burner design or firing conditions

Back 35

Carbon monoxide

Front 36

To convert measurements in inches of mercury to inches of water column, ___.

Back 36

Multiply inches of Mercury by 13.6.

Front 37

Natural draft is produced without the use of ___.

Back 37

Fans.

Front 38

Balanced draft is when ___ are used.

Back 38

Both induced and forced draft fans.

Front 39

A ___ is a chamber surrounding a burner assembly or coal stoker that allows the pressurized air from the forced draft fan to enter the burner.

Back 39

Windbox.

Front 40

The pressure in induced draft furnaces is kept at ___ pressure so the air and gases of combustion can be pulled though the furnace.

Back 40

Slightly less than atmospheric.

Front 41

Cold air entering the furnace can cause ___ in the brickwork.

Back 41

Spalling.

Front 42

___ is a type of heat transfer that occurs due to the circulation of a fluid or gas.

Back 42

Convection.

Front 43

Air heaters in a breeching should be examined about once every ___ for signs of corrosion.

Back 43

1 year.

Front 44

The ___ zone is a barrier area in a regenerative air heater that prevents the gases of combustion from mixing with the air for combustion.

Back 44

Sealing.

Front 45

The air from a forced draft fan in a pulverized coal system that flows to the air-tempering damper blends with ambient air to maintain an air temperature of about ___°F.

Back 45

200.

Front 46

Dampers work by changing the ___.

Back 46

Amount of resistance to the flow of air and gases of combustion.

Front 47

If a boiler room is airtight, the furnace is ___.

Back 47

Starved for air.

Front 48

The primary air and pulverized coal are removed from a pulverizing mill by the ___.

Back 48

Exhauster.

Front 49

The ___ Act requires that the EPA prioritize six pollutants that are responsible for much of the concern over air emissions.

Back 49

Clean air.

Front 50

___ forms from the products of combustion as a result of a reaction between NOx and volatile organic compounds (VOCs) in sunlight.

Back 50

Ozone.

Front 51

A(n) ___ source is a facility that emits less than 10 tons per year of any single HAP and less than 25 tons per year of any combination of air toxics.

Back 51

Area.

Front 52

A hazardous air pollutant is any material from a list of approximately ___ pollutants that has significant health effects when it is emitted into the air.

Back 52

200.

Front 53

___ control technology is technology that meets the environmental requirement for emissions from an existing source in a nonattainment area.

Back 53

Reasonably available.

Front 54

Scrubbing can have removal efficiencies of ___% or higher.

Back 54

90.

Front 55

A(n) ___ is a device that removes finer PM from the gases of combustion using electric charge.

Back 55

Electrostatic precipitator.

Front 56

A burner that premixes fuel and air and has FGR rates of approximately 25% to 30% can achieve NOx levels of less than ___ ppm.

Back 56

10.

Front 57

A high stack results in what?

Back 57

Better draft.

Front 58

* How much does an air heater increase overall efficiency?

Back 58

2%-10%. The amount of efficiency increase depends on the unit location, steam capacity, and whether an economizer is installed.