Boilers

Question 1

ideal gas law

Answer 1

also called the general gas equation. every gas has a constant that can be calculated under ideal conditions and the behavior of gasses can be predicted under ideal conditions

Question 2

work

Answer 2

the product of force acting through a distance

Question 3

3 modes of heat transfer

Answer 3

conduction, convection, and radiation

Question 4

latent heat

Answer 4

heat to create phase change, no change in temperature, ie vaporization - water to steam

Question 5

sensible heat

Answer 5

change in temperature, ie water getting hotter

Question 6

Steam cycle

Answer 6

Generation - expansion - condensation - feed - Generation - expansion - condensation - feed

Question 7

safety valves

Answer 7

• prevent overpressure
• open completely when set pressure is reached and stay open until pressure drops
• 2 common types: huddling chamber type and nozzle reaction type
• typically 3 on a propulsion boiler: 2 on steam drum, 1 on superheater

Question 8

the removal of water from a boiler. Its purpose is to control boiler water parameters within prescribed limits to minimize scale, corrosion, carryover, and to remove suspended solids present in the system.

Answer 8

blowdown

Question 9

excess air

Answer 9

more air than theoretically needed to achieve complete combustion (15% optimal). 17 pounds of Air to burn 1 pound of fuel

Question 10

plate in the end of the straight mechanical atomizer that the oil sprays through, before the burner tip

Answer 10

sprayer plate

Question 11

burner barrel with a burner tip attached with a cap nut. the quantity of oil is controlled by varying the oil pressure.

Answer 11

straight mechanical burner

Question 12

similar to, but has higher turndown ratio than straight mechanical burner, due to an oil return path.

Answer 12

return-flow atomizer burner

Question 13

auxiliary steam provides the energy to atomize the oil. 2 passages, one for oil, one for steam

Answer 13

racer steam atomizer

Question 14

atomizes oil by throwing it off the edge of a tapered cup

Answer 14

rotary-cup atomizer

Question 15

increases surface area of oil for rapid combustion

Answer 15

atomization

Question 16

too little air in combustion

Answer 16

black smoke

Question 17

too much air in combustion

Answer 17

white or clear smoke

Question 18

light brown smoke

Answer 18

efficiency haze

Question 19

boiler loss

Answer 19

heat loss to the surroundings

Question 20

the ratio between full boiler output and the boiler output when operating at low fire. maximum oil flow divided by minimum oil flow

Answer 20

turndown ration

Question 21

a series of steel doors that open when the burner is one, to allow air from the forced draft fan in and close when the burner is off. air volume is controlled by the forced draft fan, not the register.

Answer 21

register (air register)

Question 22

continuously bleeds off a low volume of water from within the boiler as a means of ridding the boiler of dissolved impurities

Answer 22

Surface blowdown

Question 23

The lowest temperature at which fuel gives off vapor which when combined with air will ignite. Will not continue to burn if source of ignition is removed

Answer 23

Flash Point

Question 24

The temperature at which oil gives off sufficient vapor to continue to burn after ignition.

Answer 24

Fire Point

Question 25

The temperature at which oil begins to flow

Answer 25

Pour Point

Question 26

The ratio of the weight of a defined volume of a substance to a corresponding defined volume of another substance (usually water). Degrees API is common unit

Answer 26

Specific Gravity

Question 27

flame appearance

Answer 27

Dark Red – Incomplete combustion – unburned fuel Orange – Incomplete combustion – high Carbon Monoxide Yellow Gold – Proper combustion (115% O2)– high Carbon Dioxide Bright Yellow - Too much excess air (125-200% O2 Dull White to Brilliant White - Too much excess air (200-300% O2)

Question 28

soot blower types

Answer 28

rotary and retractable

Question 29

soot blower operation

Answer 29

jets of auxiliary steam blow soot and other deposits off the outside of generating tubes, superheater tubes, and economizer and air heater surfaces

Question 30

rotary soot blower operation

Answer 30

the element is rotated manually or remotely by air motor. a cam opens and closes a valve admitting steam to the element. the steam blows around 270 or 360 degrees of operation. there are a series of steam nozzle exits.

Question 31

retractable soot blower operation

Answer 31

the element is inserted when in use and retracted when not. there are 2 steam nozzle exits on the tip. high volume and high velocity. a "mass action" blower