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

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```280

APPENDIX VII

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

Valve resistances :

QQ= volume flowing  .
5m3 32
8m3 51
5 m3 19
7 m358

t° = average temperature' .....
500°
50°
750°
550°

1 -\-at = gas factor ...............
2.835
1 . 1835
3.7525
3.0185

Q/ = Q0(l+aO = . .
15 m3 08
10 m3 07
19 m3 48
22 m3 89

Valve size in inches
54 in.
66 in.
54 in.
66 in

w= valve area
1m2 48
2m2 21
1 m248
2 m221

vt — velocity  through  valve =

Qj -T- to = m per sec
10m 19
4m 56
13 m  16
10 m 36

h=vz+2g=.
5 m 291
1 m  06
8 m 83
5 m 47

A0 = specific weight gases .
1.125
1.293
1.32
1 32

Ai = A0-5-(l+aO=kg perm3.. .
0.397
1.093
0.352
0.437

As the gases make a 180° bend in

passing through the valve, the

velocity   must    be    created

twice; therefors, the pressure

required will be:

5=2/iAz = kgper m2 ...........
4 kg 201
2 kg 317
6 kg 216
4 kg 781

Where changes of direction of flow occur, there is a loss of
pressure, or, more exactly, additional pressure is required to
impress the necessary velocity in the new direction of flow. In
addition, where the gases flow from a larger passage into a smaller,
their velocity of flow increases and additional pressure must be
provided to impress this change in velocity upon the gases. The
pressures necessary for this purpose must be approximated in the
following manner:```