Fuel economy in furnaces can be achieved by_________________?
(A) Using oxygen enriched combustion air
(B) Preheating the combustion air
(C) Reducing the heat loss through furnace openings & doors
(D) All
______________ is an indirectly heated furnace?
(A) Open hearth furnace
(B) Muffle furnace
(C) Soaking pit
(D) Reheating furnace
Furnace pressure is normally controlled by regulating the__________________?
(A) Air pressure
(B) Fuel gas pressure
(C) Speed of I.
(D) fan
Which one is not an induced draught furnace ?
(A) Blast furnace stove
(B) Sintering furnace
(C) High pressure boiler
(D) None of these
Ceramic coating material for furnace refractory, which increases its emissivity and thus the radiation heat transfer rate in the furnace, comprises of_________________?
(A) Graphite powder
(B) Thoria
(C) Zircon powder
(D) Beryllium
Heat transfer takes place through a liquid medium surrounding the submerged material under heating, in case of a/an__________________?
(A) Blast furnace
(B) Steam boiler
(C) Salt bath furnace
(D) Annealing furnace
Reducing atmosphere is maintained in a__________________?
(A) Calcination kiln
(B) Blast furnace
(C) Soaking pit
(D) L.
The amount of combustible escaping unconsumed from the furnace, depends upon the________________?
(A) Air supplied and furnace temperature
(B) Burner design (thoroughness of mixing versus stratification)
(C) Air preheat and the flow of gases in the furnace (mixing by induction, by acceleration or by change of direction)
(D) All
Metallic recuperators are not used for waste heat recovery, if the hot flue gas temperature is above _____________ °C, because corrosion prevails at higher temperatures?
(A) 350
(B) 750
(C) 1050
(D) 1250
In practical operation of any furnace, zero oxygen percentage or theoretical CO2 percentage in flue gas is rarely achieved, because of__________________?
(A) Use of non-preheated combustion air
(B) Use of pulverised solid fuels
(C) Imperfect mixing of fuel & air and infiltration of air
(D) Use of excessive positive draft in the furnace