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. Burning which stream generates fuel NOx?

acrylonitrile

Isopropyl acetate

acetaldehyde

vinyl alcohol

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

90%

15%

75%

30%

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

molar volume of oxygen

existence of flame

phase of water produced

no difference

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

burner airside pressure drop

stack wall friction

convection tubes

stack damper

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

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 fuel line for FFC on flue gas.

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

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

helical

vertical cylindrical

cabin

arbor

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

75% - 91%

78% - 92%

85% - 92%

87% - 91%

#8. 21 % excess air equals how much excess O2 in combustion products?

4.41%

16.59%

15.8%

4.2%

#9. 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

inconel

stainless steel

carbon steel

#10. What is another name for arch?

ceiling

bridge wall

breeching

transition

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

NOx

CO2

SOx

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

fuel gas composition

flame interaction with heat absorbing surfaces

dimensions of combustion device

stack height

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

de-superheater

regenerative

evaporator

superheater

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

15%

10%

20%

25%

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

2.5

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

No.4

No.6

No.1

No.2

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

arch

radiant section

breeching

burner levels

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

10-15

7-10

7-15

10-20

#19. 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?

stainless steel

inconel

low alloy

carbon steel

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

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

No.6

No.2

No.4

No.1

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

latent heat of water per unit fuel mass flow rate

latent heat of water per unit air mass flow rate

latent heat of fuel per unit air mass flow rate

latent heat of air per unit fuel mass flow rate

#23. What is tramp air?

unburned combustion air

air burned during combustion

unburned air infiltrated into heater

unburned air entering breeching

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

none

increasing firebox temperature reduces draft.

increasing mass velocity of flue gas increases draft.

closing stack damper & opening burner damper reduces draft.

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

cold end corrosion in preheater

low O2

low draft in firebox

accumulation of combustibles

#26. 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.)

1/EA

C/H (vol.)

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

forced draft

pre-mixed

raw gas

natural draft

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

150,000

600,000

160,000

300,000

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

the lower the carbon content

the longer the flame length

the higher the hydrogen content of fuel

the higher the rate of combustion

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

Thermal incinerator

indirect heater

reactor heater

direct fired heater

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

32 mm

25.4 mm

16.3 mm

12 mm

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

urea

ammonia

cyanuric acid

caustic soda

#33. 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)

100

150

#34. Why are heaters designed for negative pressures?

better combustion in radiant section

personnel safety

higher process fluid exit temperature

lighter structure and casing

#35. Which one is a reactor heater?

fired tube boiler

steam methane reformer

naphta heater

water tube boiler

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

using soot blowers

using vanadium removal unit

using high excess air

using bag filter

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

agitation

cross-flow mixing

entrainment

eddy formation

#38. Increase in average allowable radiant heat flux:

reduces coking rate

decreases initial cost

increases tube life

decreases peak flux

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

high process fluid flow

low process fluid flow

high draft

low draft

#40. Which is the radiant tubes manufacturing technology?

SAW

electrical fusion

centrifugal casting

hot rolling

#41. Why are burners staged?

to increase thermal efficiency

to increase flame temperature

to control emissions

to prevent after burning

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

high heat transfer surface required

foot-print considerations

high temperature required

price considerations

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

to prevent wind induced vibrations on stack

to hold stack insulation in place

to provide structural stiffening against internal pressure

to help heat transfer from stack

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

increased radiant heat flux

reduction in thermal efficiency

none

Cold End Corrosion at APH

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

brick

monolithic

Mg-C

soft

Finish