Questions and answers for exam Preparation

MCQs

Total Questions : 757 | Page 74 of 76 pages

Question 731. Which is the most thermally efficient furnace _______________________?

Reheating furnace
Reverberatory furnace
Rotary kilns
Boiler furnace

Discuss Question

Answer: Option D. -> Boiler furnace
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 732. Ingress of cold air in the furnaces through cracks, charging doors, openings etc ________________?

Reduces the flue gas temperature and makes the furnace atmosphere oxidising
Increases the load on the induced draft fan
Reduces the furnace draught
All A., B. and C.

Discuss Question

Answer: Option D. -> All A., B. and C.
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 733. To reduce the stack loss, heat recovery from flue gas can be done by_____________________?

Preheating of cold stock
Preheating of combustion air
Steam generation in waste heat boilers
All A., B. and C.

Discuss Question

Answer: Option D. -> All A., B. and C.
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 734. The advantages of firing pulverised coal in the furnace lies in the fact that, it_____________________?

Permits the use of high ash content coal
Permits the use of low fusion point ash coal
Accelerates the burning rate and economises on fuel consumption
All A., B. and C.

Discuss Question

Answer: Option C. -> Accelerates the burning rate and economises on fuel consumption
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 735. In practical operation of any furnace, zero oxygen percentage or theoretical CO2 percentage in flue gas is rarely achieved, because of__________________?

Use of non-preheated combustion air
Use of pulverised solid fuels
Imperfect mixing of fuel & air and infiltration of air
Use of excessive positive draft in the furnace

Discuss Question

Answer: Option C. -> Imperfect mixing of fuel & air and infiltration of air
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 736. Which of the following is a heat treatment furnace ?

Muffle furnace
Annealing furnace
Reheating furnace
Rotary kiln

Discuss Question

Answer: Option B. -> Annealing furnace
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 737. An electric furnace producing heat by means of an electric arc struck between each of three electrodes and the charge is called ____________ furnace?

Resistance
Arc
Low frequency induction
None of these

Discuss Question

Answer: Option B. -> Arc
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 738. Size of the combustion chamber of a furnace depends upon the ___________________?

Heat release rate of the fuel
Preheat temperature of fuel & air
Method of mixing the fuel & air
All A., B. and C.

Discuss Question

Answer: Option D. -> All A., B. and C.
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 739. Metallic recuperators are not used for waste heat recovery, if the hot flue gas temperature is above _____________ °C, because corrosion prevails at higher temperatures?