Practice Test: Question Set - 01
1. In which of the following furnaces, the gases are sucked through the stock bed from below?
- (A) Soaking pit
- (B) Sintering
machine
- (C) Beehive
oven
- (D) None
of these
2. In order to maintain a reducing atmosphere in a furnace, it should have
- (A) No O2 in
flue gas
- (B) CO
in flue gas
- (C) High excess
air
- (D) None
of these
3. Test specimen for determination of refractoriness under load (RUL) of a refractory is heated in a
- (A) Furnace
employing neutral atmosphere
- (B) Carbon
resistance furnace
- (C) Reducing
atmosphere
- (D) Furnace
employing negative pressure
4. The heating capacity of continuous reheating furnace depends upon the
- (A) Hearth
area and furnace temperature
- (B) Emissivity
of the stock
- (C) Ratio
of wall surface to stock surface
- (D) All (a), (b)
and (c)
5. Which of the following variables affects the furnace capacity?
- (A) Temperature
of flue gas
- (B) Thermal
conductivity of stock
- (C) Thickness
of heating stock
- (D) All (a), (b)
and (c)
6. The purpose of controlling the furnace atmosphere is to prevent surface attack by
- (A) Oxidation/scaling
- (B) Decarburising
- (C) Sulphur
penetration
- (D) Either
of the above
7. Scaling of furnace stock is reduced by __________ in flue gas.
- (A) CO
- (B) H2
- (C) High CO/CO2
- (D) All (a), (b)
& (c)
8. Which is not accomplished in an underfired furnace?
- (A) Increase
in heating capacity/m2 of floor space
- (B) Elimination
of cold spot at the bottom of the charge
- (C) Reduction
in the temperature of furnace gases
- (D) Protection
of the periphery of the charge from excessive radiation
9. An improved and fuel efficient version of the pusher type reheating furnace is the __________ furnace.
- (A) Walking
beam
- (B) Shaft
- (C) Tunnel
- (D) Rotary
hearth
10. Circulation of gases in furnace is caused by the
- (A) Change
in volume during a change of temperature
- (B) Difference
in density between hot and cold gases
- (C) Furnace
pressure in conjunction with draft in flues
- (D) All (a), (b)
and (c)
11. Forced recirculation of furnace gases is practised
- (A) To
increase heat transfer by convection
- (B) To
ensure uniform temperature
- (C) In furnaces,
operating below 750°C
- (D) All (a), (b)
and (c)
12. Which of the following variables does not affect the furnace capacity?
- (A) Size
of the furnace
- (B) Gas
velocity in furnace
- (C) Ratio
of wall surface to surface of stock
- (D) None
of these
13. In a furnace, the heat taken by the charge/stock and the heat lost to the furnace structure & flue gases depends on the
- (A) Rate
of firing and emissivity of flame
- (B) Thermal
conductivity of the charge & structural materials of furnace
- (C) Nature
of process; whether batch, continuous or intermittent
- (D) All (a), (b)
and (c)
14. An example of a periodic furnace is the
- (A) Blast
furnace stoves
- (B) Blast
furnace
- (C) Coke
oven heating chamber
- (D) Rotary
kilns
15. Flue gas outlet temperature from the chimney of any furnace should be ideally about __________ °C.
- (A) 50
- (B) 100
- (C) 150
- (D) 250