Design Guidelines for High Performance Industrial Furnaces - High Temperature Air Combustion: From Energy Conservation to Pollution Reduction - page 336

The energy-saving ratios of the other furnace groups increased virtually in
proportion to the respective processing temperatures ( Figure 5.86 ) .

Rate of Change of Unit Energy Consumption before and after the Modifica-
tions:

U
U

am

η =− 1

bm

where
η = energy saving ratio

U am = unit fuel consumption after modification

U bm = unit fuel consumption before modification

Because continuous heating furnaces consume a large amount of fuel, the amount
of energy saved was substantial, although the energy saving ratio appeared to be
low numerically. On the contrary, the amount of energy saved in batch-type heat
treatment furnaces was small as both the size of each facility and fuel consumption
were generally small ( Figure 5.87 ) , i.e.,

∆ E = η E bm

where
∆ E

= amount of energy saved

E bm = energy consumption before modification

100.0

80.0

60.0

40.0

20.0

0.0

0 200 400 600 800 1000 1200 1400 1600

Atmospheric Temperature in Furnace, ° C

Continuous heating furnace
Continuous heat treatment furnace
Melting furnace

Batch type heating furnace
Batch type heat treatment furnace

Ladle
Gas treatment furnace

FIGURE 5.86 Relation between atmospheric temperature in furnace and energy-saving ratio.