A. Should be as low as possible i.e., 1 : 2
B. Should be 1:1 for a batch type furnace
C. Is the ratio of maximum to minimum permissible heat input rates
D. Is normally much more for a continuous furnace as compared to a batch furnace
Related Mcqs:
- Turndown ratio of a burner gives an idea of the ______________ in the furnace?
A. Range of fuel firing rates
B. Volume of the combustion chamber
C. Maximum heat input rate only
D. Minimum heat input rate only - An example of shaft furnace is the__________________?
A. L.D. converter
B. Glass melting tank
C. Blast furnace
D. Soaking pit - Regenerators are used for waste heat recovery in____________________?
A. By-product coke ovens
B. Beehive coke oven
C. Blast furnace stoves
D. Soaking pits - Presence of SO2 in furnace gases attacks the ferrous metal by way of_________________?
A. Accelerating the rate of scaling
B. Causing metal embrittlement
C. Attacking the grain boundaries; particularly severe on low carbon and nickel bearing steels at
high temperature
D. All A., B. and C. - Waste heat from the outgoing flue gases in a thermal power plant is recovered by a/an_________________?
A. Economiser
B. Steam superheater
C. Air preheater
D. All A., B. and C. - 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 - In a furnace operation, which is not preheated ?
A. Solid fuels
B. Hydrocarbon containing fuel gases (e.g. coke oven gas, refinery gas etc.)
C. Both A. and B.
D. Neither A. nor B. - Reducing atmosphere is maintained in a__________________?
A. Calcination kiln
B. Blast furnace
C. Soaking pit
D. L.D. converter - If the flame is produced under the hearth and then sweeps up into the heating chamber, this is called a/an ______________ furnace?
A. Sidefired
B. Underfired
C. Covered
D. Recirculating - Which of the following furnaces will have maximum thermal efficiency ?
A. Soaking pits
B. Walking beam reheating furnace
C. Boiler furnace
D. Rotary kilns
