Results of Investigations on the Current State of Japanese Industrial Furnaces - High Temperature Air Combustion: From Energy Conservation to Pollution Reduction - page 374

TABLE A.11
Energy Consumption of Industrial Furnaces and the Amount of Energy Saving
by Introducing High Performance Industrial Furnaces

Energy
Consumption
(converted
crude oil),
10 9 l/year

Ratio of
Improvement
of Heat
Efficiency,
%

Number of
Application
(Cardinal
number)

Ratio of
Energy
Saving,
%

Amount of
Energy
Saving,
10 9 l/ year

Ratio of
Application,
%

Type of
Facilities

1. Melting

furnace

3,717 4.13

2. Heating

furnace

4,157 3.58

3. Heat

treatment
furnace

11,614 7.03

4. Baking

furnace
(cement)

100 6,512 - 81

= 6,431

17.01 - 9.47
= 7.54

50 34.0 15.24

5. Drying

furnace

4,591 4.20 (Average

35-53)

6. Chemical

industry
furnace
(petroleum)

2,527 - 832
= 1,695

26.14 - 7.74
= 18.40

Subtotal — 32,351 44.88 — — 15.24

7. Petroleum

heating
furnace

50 832/2 = 416 7.74/2 = 3.87 15 (78-90) 13.3 0.52

8. Industrial

boiler

100 32,350 38.02 6 (85-90) 5.6 2.11

Subtotal — 32,776 41.89 — — 2.63

Grand total — 65,117 86.77 — — 17.87

Notes : (1) Heat efficiency = (Sensible heat of heating material /combustion heat of fuel) × 100(%). (2)
Ratio of energy saving = (1 - heat efficiency before improvement/heat efficiency after improvement) ×
100(%).

efficiency of middle- and small-scale petroleum heating furnaces without the air
preheaters (APHs) is 78% on average. Because the efficiency of a furnace with this
development would be better than that of the APH, about 90% heat efficiency could
be achieved by introducing new technologies of high performance industrial furnaces
to middle- and small-scale petroleum heating furnaces.
Because the energy consumption is at the same level for large-, middle-, and
small-scale furnaces, we estimate, under the objective of 50% of the energy con-
sumption, that the heat efficiency could be improved about 15% from the value of
78 to 90%.