A. Preheating the combustion air
B. Oxygen enrichment of combustion air
C. Preheating the fuel gas
D. All A., B. & C.
Correct Answer: D. All A., B. & C. ✔
Last Updated: March 11, 2019
Related MCQs
- Which of the following is a directly fired intermittent furnace ?
- In case of pulverised coal fired steam boiler, the secondary air serves the main purpose of__________?
- Example of an indirectly heated furnace is__________?
- Use of pulverised coal in boilers provides__________?
- Waste heat from the outgoing flue gases in a thermal power plant is recovered by a/an__________?
- Which of the following is not a continuous waste heat recovery equipment from the flue gases going out of furnace ?
- Which of the following advantages is not associated with the use of preheated air for combustion of a fuel in the furnace ?
- An example of a periodic furnace is the__________?
- Which of the following variables does not affect the furnace capacity ?
- Circulation of gases in furnace is caused by the__________?
- Which is not accomplished in an underfired furnace ?
- The purpose of controlling the furnace atmosphere is to prevent surface attack by__________?
- Regenerators as compared to recuperators for the same duty__________?
- Dampers are located__________?
- The resistance furnace produces heat by the__________?
- Thickness of stock does not affect the fuel economy of furnaces, if the material to be heated is of__________?
- An example of indirectly heated furnace is the__________?
- Neutral atmosphere is maintained in a/an __________ furnace?
- The thermal efficiency of a steel slab reheating furnace (walking beam type) may be about __________ percent?
- In low or standard frequency induction furnace, heat is produced by the__________?
- The rate of scaling of furnace stock depends upon the__________?
- The reason for excessive clinker formation in gas producers is the__________?
- In furnaces operating at very high temperature (say) 1250°C, e.g. soaking pit), the maximum heat transfer takes place by__________?
- Amount of coal lost in ash particle, which is carried through the boiler system, depends upon the__________?
- Coke ovens in steel plant are heated by__________?
- Specific heating capacity of a furnace is expressed as__________?
- Unit of furnace loading is__________?
- Thermal efficiency of a limestone calcination rotary kiln may be around __________ percent?
- Maximum thermal efficiency of boiler may be about __________ percent?
- Advantages of use of preheated combustion air are__________?
- Thermal efficiency of blast furnace stoves used for heating blast (air) may be about __________ percent?
- Very high pressure boilers are usually __________ boilers?
- Pot furnace which is either regenerative or recuperative, is used in the manufacture of__________?
- Soaking pits are meant for heating steel__________?
- Rotary kilns are used in the__________?
- While the fuel fired furnace can be used upto a maximum temperature of about 1700°C, the electric furnace can be used upto a temperature of about __________ °C?
- Power required in case of forced draught as compared to induced draught (for the same draught produced) is__________?
- Thermal efficiency of furnaces can be improved by__________?
- In producer gas making furnace, steam is added along with air to mainly control the__________?
- In a heating process, a heat flow diagram in which the quantities of heat in the various items of a heat balance are represented by the width of a band is called the__________?
- Presence of SO2 in furnace gases attacks the ferrous metal by way of__________?
- Regenerators are installed in__________?
- Shaft furnaces are used for__________?
- Reheating furnace (pusher type) is used for heating__________?
- Acid dew point temperature (ADT) of a flue gas produced by the combustion of a fuel containing 1% sulphur may be about __________ °C?
- Protective gas used in the annealing furnace for steel coil comprises of__________?
- Artificial draught produced by a fan in the furnace can be controlled by the__________?
- Which of the following is the most suitable for preheating combustion air above 650°C ?
- The electric furnace in which heat is produced by a combination of induced current and skin effect is called __________ furnace?
- Thermal efficiency of an open hearth furnace may be about __________ percent?
- Which of the following is not a directly fired furnace ?