3287. Cold crushing strength of fireclay bricks is about __________ kgf/cm2.
50-100
100-150
200-400
500-1000
✅ The correct answer is option C.
3292. Presence of nitrogen in combustion air does not reduce the
Amount of heat liberated
Flame temperature
Flue gas temperature
Any of the above
✅ The correct answer is option A.
3297. Zirconia refractories are not used in
making sheaths for thermocouple.
lining high temperature ceramic kilns.
furnaces subjected to fluctuating temperature.
high frequency induction furnaces in the form of inductors.
✅ The correct answer is option C.
3302. Coal is pulverised before burning in large capacity boiler furnaces mainly to
Ensure its complete combustion
Facilitate easy ash removal
Enhance its calorific value
Provide trouble free operation
✅ The correct answer is option A.
3308. Which one contains minimum percentage of SiO2?
Firebrick
Sillimanite
Semi-silica
Aluminous firebrick
✅ The correct answer is option B.
3313. Commercial production of petrol from coal (as practised in a factory at Sasol in South Africa) is done by the __________ of coal.
Hydrogenation
Gasification
Carbonisation
None of these
✅ The correct answer is option A.
3318. Which of the following is a rich fuel gas?
Producer gas
Coal gas from underground gasification of coal
Refinery gases
None of these
✅ The correct answer is option C.
3322. Which is required in an insulating refractory ?
High thermal conductivity
Low porosity
Both (a) and (b)
Neither (a) nor (b)
✅ The correct answer is option D.
3326. Gross calorific value will be equal to the net calorific value for
H₂
C₂H₂
CO
C₂H₆
✅ The correct answer is option C.
3330. Hot blast main (carrying air at 1000°C) in blast furnace are lined with __________ bricks.
silica
fireclay
magnesite
zirconia
✅ The correct answer is option B.