Practical Combustion Methods Used in Industries - High Temperature Air Combustion: From Energy Conservation to Pollution Reduction - page 227

250

high performance
type

conventional
type

200

high performance
type

high performance type, furnace length = 25mm
high performance type, furnace length = 30mm
high performance type, furnace length = 45mm
conventional type, furnace length = 25mm
conventional type, furnace length = 30mm
conventional type, furnace length = 45mm

conventional
type

150

100

50

0

Heat loss to the water plus heat
radiation from the fumace body

Amount of waste heat
to the waste gas

FIGURE 4.8 Comparison of heat losses.

average-total-heat flux-length

1.20

1.15

Pitch 2m

1.10

Pitch 2.5m

1.05

Pitch 3m

1.00

0.95

M-W=S-H=1300-P=2000-Cap=500
M-W=S-H=2000-P=2000-Cap=500
M-W=S-H=2200-P=2000-Cap=500
M-W=S-H=2500-P=2000-Cap=500
M-W=S-H=3000-P=2000-Cap=500
M-W=S-H=2000-P=2500-Cap=650
M-W=S-H=2500-P=2500-Cap=650
M-W=S-H=2000-P=3000-Cap=750
M-W=S-H=1300-P=2500-Cap=650
M-W=S-H=1300-P=3000-Cap=750

0.90

0.85

0.80 0123 45678910

11 12 13

length, m

FIGURE 4.9 Furnace height against the furnace width, effect of the burner pitch.

height and the results of analyses through the overall in-furnace model (taking such
reactions as heat flow, combustion reaction, and heat transfer into consideration).
It is clear that, even if the furnace height is lowered to 1.2 m, there is no difference
in the heating efficiency, although the nonsymmetrical heat may be increased slightly.
Therefore, a value for the height of about 2 m is proposed, taking the maintenance
of inner parts of the furnace into consideration. However, if maintenance work is
performed entirely by a robot for gunning and repairing, and carried out only
from the outside of the heating furnace, a heating furnace with a superlow height
of less than 1.5 m would be feasible. From the discussion of furnace height, it can
be seen that the outer shape of the heating furnace leans toward the shape of the