| |
 |
(1) |
Other heat losses are due to opening of furnace door for charging and discharging of the products, cooling of water etc. which are included in Hother. It is important to note that at the constant furnace temperature, temperature of products of combustion leaving the furnace and the wall heat loss temperature are also fixed.
Thermal efficiency of the furnace is defined as
 |
(2) |
Efficiency of the furnace can also be measured by the effectiveness of the insulation. 
 |
(3) |
 |
(4) |
 |
(5) |
Furnace efficiency indicates the amount of fuel required during the unsteady state heating period of the furnace. During the unsteady state period a certain quantity of fuel is required to raise the temperature of the furnace to the temperature of the charge Tu. Higher furnace efficiency as attained by better insulating refractory will require less amount of fuel during the unsteady period.
|
