4Th Class Power Engineering Chapter 56

Front 1

How many types of air are used in the combustion process and what are they called?

Back 1

Primary air and secondary air

Front 2

When using a forced draft system the furnace is under _________ pressure. This type of furnace construction is called a _________ furnace.

Back 2

Positive pressure

Pressurized furnace

Front 3

What simple device can be used to measure pressure in the combustion air system?

Back 3

"U" tube manometer

Front 4

Standards with respect to the required openings in buildings for supply of adequate combustion air for oil burning appliances can be found.

A. CSA 139.1

B. CSA 146.2

C. CSA 148.1

D. CSA 149.1

Back 4

A. CSA 139.1

Front 5

Standards with respect to the required openings in buildings for supply of adequate combustion air for gas burning appliances can be found.

A. CSA 139.1

B. CSA 146.2

C. CSA 148.1

D. CSA 149.1

Back 5

D. CSA 149.1

Front 6

The code that specifies the size of openings required for a boiler room when using multiple heating units

Back 6

CSA code B-51

Front 7

In a balanced draft system, the forced draft fan is:

1) Smaller than the induced draft fan

2) Designed to handle hot combustion gases

3) Larger than the induced draft fan

4) Subjected to the products of combustion and high temperatures

5) The same size as the induced draft fan

Back 7

1) Smaller than the induced draft fan

Front 8

Balanced draft:

1) Means furnace pressure is maintained slightly below atmospheric pressure

2) Requires an FD and ID fan, never just an FD fan

3) Means air flow is always constant

4) Means air and fuel quantities are the same per unit time

5) Can be accomplished with just a chimney

Back 8

1) Means furnace pressure is maintained slightly below atmospheric pressure

Front 9

A draft gauge on a furnace indicates the draft in:

1) Inches of water per square metre

2) mm of mercury column

3) mm of water column

4) Kilograms per square centimetre

5) psi

Back 9

3) mm of water column

Front 10

What are the advantages of mechanical draft?

1. Dependence on atmospheric air temperatures

2. Independence of chimney temperatures

3. Better draft regulation

4. Can be accurately regulated

A) 1, 2, 3, 4

B) 1, 2, 3

C) 2, 3, 4

D) 1, 3, 4

E) 3, 4

Back 10

C) 2, 3, 4

Front 11

Variable speed couplings:

1) Rave a low initial cost

2) Use a variable speed driver

3) Are usually found in small boilers

4) Require the least amount of energy when a variable speed motor drives the fan

5) Require a remote speed controller

Back 11

4) Require the least amount of energy when a variable speed motor drives the fan

Front 12

In a balanced draft system, the air heater is placed:

1. Between ID fan and stack

2. Between ID fan and boiler

3. Between forced draft fan and boiler

4. On inlet ducting to forced draft fan

A) 1, 4

B) 2, 3

C) 2, 3, 4

D) 2

E) 1, 2, 3

Back 12

B) 2, 3

Front 13

Relative to draft, a steam jet is very popular:

1) As a forced draft unit

2) For increasing furnace pressure

3) As a fuel atomizer

4) On railway steam locomotives

5) For decreasing draft during cold weather

Back 13

4) On railway steam locomotives

Front 14

A diaphragm draft gauge on a furnace indicates the draft in:

1) mm water per square metre

2) MPa

3) mm of water column

4) kPa

5) mm of mercury column

Back 14

3) mm of water column

Front 15

Primary air:

1) Enters the furnace before the fuel

2) Is premixed with fuel before being admitted to the furnace

3) Is supplied in the combustion zone

4) Is the same as excess air

5) Is supplied with all types of burners

Back 15

2) Is premixed with fuel before being admitted to the furnace

Front 16

Inlet damper control on a fan:

1) Is used on forced draft fans only

2) Can only be used when the fan is driven by a steam turbine

3) Requires more power to drive the fan when the vanes are closed

4) Is less complicated than outlet damper control

5) Requires less power to drive the fan at reduced loads

Back 16

5) Requires less power to drive the fan at reduced loads

Front 17

With fan output damper control:

1) The fan air pressure decreases with a decrease in air flow

2) Flue gas velocity will rise

3) The fan air pressure increases with a decrease in air flow

4) It is placed in the inlet side of the fan

5) Fan output is difficult to control

Back 17

3) The fan air pressure increases with a decrease in air flow

Front 18

Chimneys are commonly lined with:

1) Insulation

2) Concrete

3) Mortar

4) Common brick

5) Clay lining

Back 18

5) Clay lining

Front 19

A more durable chimney for a power plant application is the _____ chimney.

1) Steel

2) Insulated

3) Brick

4) Guy wire supported

5) Reinforced concrete

Back 19

5) Reinforced concrete

Front 20

The most efficient operation of a fan demands that:

1) Inlet damper controls are used

2) Gaseous fuels are fired

3) Outlet damper controls are used

4) The speed be only sufficient enough to supply the required amount of air

5) Constant speed electric motors are used

Back 20

4) The speed be only sufficient enough to supply the required amount of air

Front 21

A diaphragm type pressure gauge:

1) Cannot be used for pressures greater than atmospheric

2) Operates on a mercury column

3) Is used for very small pressures

4) Is used for high pressures

5) Is only found on large steam generators

Back 21

3) Is used for very small pressures

Front 22

With fan output damper control:

1) Fan output is difficult to control

2) The fan air pressure increases with a decrease in air flow

3) Flue gas velocity will rise

4) The fan air pressure decreases with a decrease in air flow

5) It is placed in the inlet side of the fan

Back 22

2) The fan air pressure increases with a decrease in air flow

Front 23

When a diaphragm draft gauge is used to measure furnace draft:

1) It can only be used on a forced draft system

2) It can only be used for positive pressures

3) It can only be used on a balanced draft system

4) The furnace draft connection is on one side of the diaphragm

5) Furnace draft connections are on both sides of the diaphragm

Back 23

4) The furnace draft connection is on one side of the diaphragm

Front 24

When the least amount of energy is desired to drive a fan with variable output control, the type of control used would most likely be:

1) A variable speed coupling

2) A variable speed driver

3) Outlet damper control

4) Inlet damper control

5) Register control

Back 24

1) A variable speed coupling

Front 25

The most efficient operation of a fan occurs when:

1) Speed is just enough to meet the demand

2) Draft is FD only

3) Draft is ID only

4) Speed is at maximum

5) Draft is balanced

Back 25

1) Speed is just enough to meet the demand

Front 26

The purpose of the uptake damper is to:

1) Control the furnace pressure

2) Supply combustion air to the furnace

3) Decrease flue gas velocity

4) Control fan output

5) Prevent a back flow of gasses from the chimney

Back 26

3) Decrease flue gas velocity