The Flow Of Gases In Furnaces

204

APPENDIX VII

result by depressing the roof of the furnace. The serious objec-
tions to this poor construction arose from its tending to strangle
the furnace during the heat and from the extremely short life of
the roof. Later experience showed that the flame might be jetted
into this pocket by the direction of the ports and the velocity of
the gas and air. In European furnaces these velocities range
between 12 and 18 m (40 to 60 ft) per second, while in American
furnaces the velocity is as high as 50 m per second.

TABLE 5

OPEN-HEARTH FURNACES

Reference Number, Ton
Square Feet, Port Areas
Reference Number, Ton
Square Feet, Port Areas

Gas
Air
Gas
Air

10-01-A
2.43
10.12
50-04-A
10.50
18.0

50-05-A
7.66
19.2

15-03-B
1.07
4.68
50-07-A
5.75
13.8

50-09-A
7.50
13.7

20-03-A
2.80
3.50
50-10-A
6.60
13.1

50-11-A
4.92
14.53

25-04-A
3.25
9.00
50-12-A
11.59
17.72

50-13-A
12.50
18.0

30-04-A
4.75
13.75
50-14-A
6.80
15.38

30-05-A
3.70
14.60
50-15-A
9.85
16.14

50-16-A
5.62
17.80

35-01-A
, 3.4
6.40
50-16a-A
7.00
20.00

35-Ola-A
3.75
5.98
50-17-A
10.50
12.33

50-18-A
8.00
16.42

40-05-A
15.70
21.00
50-19-A
7.40
13.30

40-06-A
3.5
7.00

<

40-04-A
8.00
14.25
60-05-A
6.75
29.31

60-06-A
8.00
25.74

60-13-A
7.74
25.37

A number of different arrangements of the ports of the Siemens
furnace have been devised and used with more or less success.
The early Siemens furnaces were designed for the use of producer
gas, which required preheating. Later these furnaces were used
with various manufactured and natural gases and fuel oils, while