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. Which liquid fuel needs atomization but not preheating?

No.2

No.1

No.4

No.6

#2. 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

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

vertical cylindrical

cabin

arbor

helical

#4. Why are heaters designed for negative pressures?

lighter structure and casing

personnel safety

better combustion in radiant section

higher process fluid exit temperature

#5. 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?

stainless steel

inconel

low alloy

carbon steel

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

90%

15%

30%

75%

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

soft

Mg-C

brick

monolithic

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

eddy formation

agitation

entrainment

cross-flow mixing

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

fuel gas composition

flame interaction with heat absorbing surfaces

dimensions of combustion device

stack height

#10. Which is the radiant tubes manufacturing technology?

centrifugal casting

SAW

hot rolling

electrical fusion

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

breeching

burner levels

radiant section

arch

#12. 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

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

10-20

7-10

7-15

10-15

#14. What is tramp air?

unburned combustion air

unburned air entering breeching

unburned air infiltrated into heater

air burned during combustion

#15. Burning which stream generates fuel NOx?

acrylonitrile

Isopropyl acetate

vinyl alcohol

acetaldehyde

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

urea

cyanuric acid

ammonia

caustic soda

#17. 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

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

2.5

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

using bag filter

using vanadium removal unit

using high excess air

using soot blowers

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

No.4

No.2

No.6

No.1

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

to hold stack insulation in place

to prevent wind induced vibrations on stack

to provide structural stiffening against internal pressure

to help heat transfer from stack

#22. 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

inconel

low alloy

stainless steel

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

NOx

CO2

SOx

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

32 mm

12 mm

25.4 mm

16.3 mm

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

reactor heater

direct fired heater

Thermal incinerator

indirect heater

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

87% - 91%

75% - 91%

85% - 92%

78% - 92%

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

150,000

600,000

300,000

160,000

#28. Which one is a reactor heater?

naphta heater

water tube boiler

steam methane reformer

fired tube boiler

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

high temperature required

price considerations

high heat transfer surface required

foot-print considerations

#30. 21 % excess air equals how much excess O2 in combustion products?

4.41%

15.8%

4.2%

16.59%

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

increasing firebox temperature reduces draft.

increasing mass velocity of flue gas increases draft.

none

closing stack damper & opening burner damper reduces draft.

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

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

molar volume of oxygen

phase of water produced

no difference

existence of flame

#34. What is another name for arch?

bridge wall

transition

ceiling

breeching

#35. 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 draft in the arc 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.

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

15%

20%

10%

25%

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

raw gas

pre-mixed

natural draft

forced draft

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

latent heat of fuel per unit air mass flow rate

latent heat of water per unit fuel mass flow rate

latent heat of air per unit fuel mass flow rate

latent heat of water per unit air mass flow rate

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

low process fluid flow

high process fluid flow

low draft

high draft

#40. Increase in average allowable radiant heat flux:

decreases initial cost

reduces coking rate

decreases peak flux

increases tube life

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

cold end corrosion in preheater

accumulation of combustibles

low draft in firebox

low O2

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

stack wall friction

convection tubes

stack damper

burner airside pressure drop

#43. Why are burners staged?

to control emissions

to increase thermal efficiency

to prevent after burning

to increase flame temperature

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

none

increased radiant heat flux

Cold End Corrosion at APH

reduction in thermal efficiency

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

de-superheater

superheater

evaporator

regenerative

Finish