Neutral atmosphere is maintained in a/an ____________ furnace?
(A) Cold rolled steel coil annealing
(B) Open hearth
(C) Soaking pit
(D) Walking beam reheating
The thermal efficiency of a steel slab reheating furnace (walking beam type) may be about ____________ percent?
(A) 15
(B) 40
(C) 70
(D) 85
Use of pulverised coal in boilers provides____________________?
(A) Higher calorific value
(B) Better combustion
(C) Smokeless burning
(D) Less erosion on furnace wall
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
Which of the following is not a continuous waste heat recovery equipment from the flue gases going out of furnace ?
(A) Economiser
(B) Regenerator
(C) Ceramic recuperator
(D) Waste heat boiler
Pick out the wrong statement?
(A) The vacuum pressure is always the negative gauge pressure
(B) The pressure of the liquid measured by a piezometer tube is the gauge pressure
(C) Manometric liquid should have high surface tension
(D) The point at which the resultant pressure on an immersed surface acts, is known as the centre of gravity
Which of the following advantages is not associated with the use of preheated air for combustion of a fuel in the furnace ?
(A) Increase in calorific value of the fuel
(B) Increase in flame temperature
(C) Reduction in scale losses
(D) Saving in fuel consumption
An example of a periodic furnace is the__________________?
(A) Blast furnace stoves
(B) Blast furnace
(C) Coke oven heating chamber
(D) Rotary kilns
Pick out the correct statement?
(A) Fanning friction factor is inversely proportional to Reynolds number always
(B) The property of a randomly packed bed (with raschig rings) is given by the ratio of the total volume to the volume of voids in the bed
(C) Mach number in an incompressible fluid is always unity
(D) Mach number is given by the ratio of the speed of the fluid to that of sound in the fluid under conditions of flow
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