# Full text of "The Flow Of Gases In Furnaces"

## See other formats

```268

APPENDIX VII

TABLE IS—Continued

Gas Checker
Air Checker

The heat surface per pass was computed as ..... The corrected value for total heating surface will be : For gas- 3 556X720 =
3 m2 556 2560 m2 00
3 m2 556

For air* 3 556X 1200 =    .............

4267 m2 20

The corrected total area of the passes will be: For gas* 0 0162X 720 =
27,558 sq ft 11 m2 664
45,935 sq ft

For air- 0 0162X1200=       ..........

19 m244

The corrected average velocity per second of the gases will be : For gas: 21 92-r-ll 664= .................
125. 58 sq ft 1 m 879
209.32sq ft

For air* 31 93-f-19 44 =

1 m 642

For waste gases: 28 05 -r- 11 . 664 ............
6.17ft 2 m 405
5.38ft

38 18-^19 44  =

1 m 964

6.71ft
6.44ft

TABLE 19

Gas on Gas
Air on Air
Gas on Waste Gas
Air on Waste Gas

The heat transfer, total per second,

in calories is. .
1484
2,618
1990
3,516

in B.t.u. is   .............
5900
10,400
7900
13,900

Calories per sq m per second .....
0.5797
0.6135
0.7773
0.8239

B.t.u. per sq ft per second .......
0.214
0.226
0.287
0.306

Average temp, differential brick to

gas or gas to brick, C
175°
175°
175°
175°

F. .
315°
315°
315°
315°

Convection factor to still air, ac-
f

cording to curve plotted from

Langmuir's   experiments   (Fig.

164) is calories per m2 per second
0.294

Correction factor for velocity ==

/35+u
2.516
2.384
2.803
9  ^RQ

\   35       ...............

u . O\J*j

v — velocity in cm per second.

Convection corrected for velocity:

in calories per m2 per second . . .
0.7397
0.7009
0.8241
0.7553

in B.t.u. per sq ft per second . . .
0.273
0.258
0.304
0.278

```