Thermal efficiency of furnaces can be improved by____________________?

Related Mcqs:

1. Which of the following furnaces will have maximum thermal efficiency ?

   A. Soaking pits
   B. Walking beam reheating furnace
   C. Boiler furnace
   D. Rotary kilns

2. Maximum heat transfer in high temperature furnaces is by____________________?

   A. Conduction
   B. Convection
   C. Radiation
   D. Either A., B. or C.; depends on the type of furnace

3. The thermal efficiency of an air/fuel gas preheating recuperator may be as high as _____________ percent?

   A. 50
   B. 65
   C. 85
   D. 99

4. Thermal efficiency of an open hearth furnace may be about _____________ percent?

   A. 5
   B. 20
   C. 50
   D. 80

5. Thermal efficiency of blast furnace stoves used for heating blast (air) may be about _____________ percent?

   A. 20
   B. 40
   C. 60
   D. 80

6. Maximum thermal efficiency of boiler may be about _____________ percent?

   A. 10
   B. 25
   C. 65
   D. 90

7. Thermal efficiency of a limestone calcination rotary kiln may be around ______________ percent?

   A. 20
   B. 40
   C. 65
   D. 80

8. The thermal efficiency of a steel slab reheating furnace (walking beam type) may be about ____________ percent?

   A. 15
   B. 40
   C. 70
   D. 85

9. Overall thermal efficiency of a lumpy coal fired suitably designed heating furnace, if operated & maintained properly may be about ____________ percent?

   A. 10-15
   B. 25-30
   C. 45-50
   D. 65-70

10. Hearth furnaces are not used for____________________?

    A. Roasting
    B. Melting
    C. Reheating
    D. None of these