FURNACE TECHNOLOGY QUIZ

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

85

99

65

50

TRUE ANSWER : ?
YOUR ANSWER : ?

Very high pressure boilers are usually __________ boilers.

Fire tube

Waste heat

Natural circulation

Water tube

TRUE ANSWER : ?
YOUR ANSWER : ?

Low stack loss indicates the

Use of sub-stoichiometric air for combustion

Oxygen enrichment of combustion air

Efficient use of fuel

Inefficient use of fuel

TRUE ANSWER : ?
YOUR ANSWER : ?

In order to maintain an oxidising atmosphere in a furnace, it should have

More of CO₂ in flue gas

More of CO in flue gas

More of excess air

Less of excess air

TRUE ANSWER : ?
YOUR ANSWER : ?

Regenerators as compared to recuperators for the same duty

Store smaller quantity of waste heat

Are lighter & compact

All of these

Involve higher initial cost

TRUE ANSWER : ?
YOUR ANSWER : ?

Rotary kilns are used in the

Both A and B

Cement manufacture

Neither A nor B

Calcination of limestone & dolomite

TRUE ANSWER : ?
YOUR ANSWER : ?

Thermal efficiency of an open hearth furnace may be about __________ percent.

5

80

20

50

TRUE ANSWER : ?
YOUR ANSWER : ?

Turn down ratio of a burner

Should be as low as possible i.e., 1 : 2

Is the ratio of maximum to minimum permissible heat input rates

Should be 1:1 for a batch type furnace.

Is normally much more for a continuous furnace as compared to a batch furnace

TRUE ANSWER : ?
YOUR ANSWER : ?

The heating capacity of muffle furnace depends on the

Neither A nor B

Properties of the muffle wall (temperature, area, emissivity)

Surface area & emissivity of the stock

Both A & B

TRUE ANSWER : ?
YOUR ANSWER : ?

Fuel economy in furnaces can be achieved by

Preheating the combustion air

All of these

Reducing the heat loss through furnace openings & doors

Using oxygen enriched combustion air

TRUE ANSWER : ?
YOUR ANSWER : ?