Exam - FurnicoHeat Engineering Co.

Fired heater design multiple choice test.
Conditions:
1. 45 questions, 1-hour time
2. No negative point
3. Once “FINISH” button is pressed the answers cannot be changed.

Fired heater design project.
Conditions:
1. A VC fired heater shall be designed for EOR case based on below datasheet.
2. Solution shall be submitted to:
E-Mail: f.naghsh@gmail.com
Subject format: Gastesh – Engineer name
3. The project shall be submitted no later than Saturday 23rd of Tir 1403

2001-82-ED-PR-DS-H8201-A1-50-ppm-EOR-test Download

QUIZ START

Results

#1. What is the difference between combustion and oxidation?

existence of flame

no difference

phase of water produced

molar volume of oxygen

#2. What is the range of overall thermal efficiency of a mechanical draft direct fired heater?

85% - 92%

87% - 91%

75% - 91%

78% - 92%

#3. Which one is a more acceptable reason to choose a fired heater over a heat exchanger in a process?

high heat transfer surface required

price considerations

foot-print considerations

high temperature required

#4. Which one is not considered a pollutant in heater design?

SOx

CO2

NOx

#5. What is another name for arch?

ceiling

transition

breeching

bridge wall

#6. Assume a natural draft heater. Which cause & effect is necessarily correct?

increasing mass velocity of flue gas increases draft.

increasing firebox temperature reduces draft.

none

closing stack damper & opening burner damper reduces draft.

#7. Which one causes hot spot in a properly designed heater?

low process fluid flow

high process fluid flow

low draft

high draft

#8. Increase in average allowable radiant heat flux:

decreases initial cost

decreases peak flux

reduces coking rate

increases tube life

#9. Why are heaters designed for negative pressures?

better combustion in radiant section

higher process fluid exit temperature

personnel safety

lighter structure and casing

#10. Which liquid fuel needs atomization but not preheating?

No.1

No.4

No.6

No.2

#11. What is the allowable travel time range from damper fully open to damper fully closed? (seconds)

10-15

7-10

7-15

10-20

#12. Which one is a reactor heater?

fired tube boiler

water tube boiler

naphta heater

steam methane reformer

#13. Which pressure drops does NOT induced fan make up in a well-designed vertical cylindrical heater?

burner airside pressure drop

stack damper

stack wall friction

convection tubes

#14. We intend to burn a waste gas stream. What is the suitable equipment for this purpose?

Thermal incinerator

reactor heater

indirect heater

direct fired heater

#15. Which is the radiant tubes manufacturing technology?

SAW

centrifugal casting

electrical fusion

hot rolling

#16. What is tramp air?

air burned during combustion

unburned air entering breeching

unburned combustion air

unburned air infiltrated into heater

#17. What is main usage of strakes on stacks?

to hold stack insulation in place

to prevent wind induced vibrations on stack

to help heat transfer from stack

to provide structural stiffening against internal pressure

#18. What is the result of (HHV-LHV)?

latent heat of air per unit fuel mass flow rate

latent heat of fuel per unit air mass flow rate

latent heat of water per unit fuel mass flow rate

latent heat of water per unit air mass flow rate

#19. For single-fired, box-type, floor-fired heaters with sidewall tubes only, what is the maximum height to width ratio?

2.5

#20. How much pressure of the total airside pressure drop should be used at the throat of burner as per API-560?

30%

90%

15%

75%

#21. How can we mitigate effects of vanadium ashes generation in fuel gas?

using vanadium removal unit

using bag filter

using soot blowers

using high excess air

#22. Which one is not a safety concern in direct fired heaters?

accumulation of combustibles

low O2

low draft in firebox

cold end corrosion in preheater

#23. Which liquid fuel vaporizes when it comes into contact with a hot surface?

No.6

No.2

No.4

No.1

#24. 21 % excess air equals how much excess O2 in combustion products?

15.8%

4.2%

16.59%

4.41%

#25. Why are burners staged?

to prevent after burning

to increase thermal efficiency

to increase flame temperature

to control emissions

#26. Assume we have 900 deg.C as the exit temperature of process fluid from radiant section. The fluid in preheated in convection section up to 350 deg.C. If nickel alloy is selected as the radiant tube material, what is a good choice for shield tubes?

low alloy

stainless steel

carbon steel

inconel

#27. Which one does NOT the flame speed depend on?

stack height

fuel gas composition

dimensions of combustion device

flame interaction with heat absorbing surfaces

#28. Which one is caused by the excessive heat recovery in mechanical draft heaters?

none

reduction in thermal efficiency

increased radiant heat flux

Cold End Corrosion at APH

#29. What the maximum apex angle of transitions in cylindrica stack diameters? (degrees)

#30. What is the minimum thickness of end tube sheets required by API-560?

25.4 mm

32 mm

12 mm

16.3 mm

#31. We intend to post-treat a flue gas using SCR system. Which reagent is NOT used for this purpose?

caustic soda

urea

ammonia

cyanuric acid

#32. Burning which stream generates fuel NOx?

acrylonitrile

vinyl alcohol

Isopropyl acetate

acetaldehyde

#33. How much excess air is needed for natural draft heaters with oil as the primary fuel?

10%

20%

25%

15%

#34. Where is a heater draft controlled as a minimum?

burner levels

radiant section

breeching

arch

#35. How much is the limitation of radiant floor firing density? (Btu/h/ft2)

150,000

300,000

600,000

160,000

#36. Which one is better defined as an air preheater type?

de-superheater

superheater

regenerative

evaporator

#37. Which heater type is normally economical to be used for lowest duties (up to 5 MW)?

cabin

vertical cylindrical

helical

arbor

#38. Which one is not an architecture to control combustion air on natural draft direct fired heaters?

RSP set by fuel line for FFC on flue gas.

RSP set by excess O2 in flue gas for FFC on combustion air

RSP set by fuel line for FFC on combustion air.

RSP set by draft in the arc for FFC on combustion air.

#39. Which one is not a mechanism for air and fuel mixing in a burner?

agitation

cross-flow mixing

entrainment

eddy formation

#40. Which burner type has a danger of flash back?

forced draft

pre-mixed

natural draft

raw gas

#41. Assume we have 250 deg.C process fluid with the fuel having high degrees of sulphur. Which choice of material is better for radiant tubes?

carbon steel

stainless steel

low alloy

inconel

#42. Which one is not correct? The higher the API degree gravity, ….

the higher the hydrogen content of fuel

the higher the rate of combustion

the longer the flame length

the lower the carbon content

#43. If not previously completely dried out to operating temperature, what is the maximum heating rate of castable refractory as per API-560? (deg.C/h)

150

100

#44. Which one is the flame color wave length color in direct relation with? (Note: yellow has a higher wave length than blue in visible spectrum)

H/C (vol.)

C/H (vol.)

1/EA

#45. Chemically bonded plastics are from which group of refractories?

Mg-C

soft

monolithic

brick

Finish