116
4 Mine Ventilation Networks
Since the resistances 2, 4 and 5 are in series, we have:
Hence:
R 245 = R 2 + R 4 + R 5 = (15 + 30 + 18)
N s
2
m 8 = 63
N s
2
m 8
R 245 are in parallel with R 3 :
Thus:
1
√
R 2453
=
1
63
N s 2
m 8
+
1
35
N s 2
m 8
Therefore:
R 2453 = 11.49
N s
2
m 8
4 Mine Ventilation Networks
Since the resistances 2, 4 and 5 are in series, we have:
Hence:
R 245 = R 2 + R 4 + R 5 = (15 + 30 + 18)
N s
2
m 8 = 63
N s
2
m 8
R 245 are in parallel with R 3 :
Thus:
1
√
R 2453
=
1
63
N s 2
m 8
+
1
35
N s 2
m 8
Therefore:
R 2453 = 11.49
N s
2
m 8