Page 48 - Advanced Mine Ventilation

Air Flow in Mine Airways 31

Figure 2.3A Three airways in series.

Figure 2.3B Three airways in parallel.

individual resistance of these roadways is R 1 ,R 2 , and R 3 , we have total head
2
2
2
loss ¼ H ¼ R 1 Q þ R 2 Q þ R 3 Q or
2
H ¼ðR 1 þ R 2 þ R 3 ÞQ (2.20)
2.8.2 Airways in Parallel
Fig. 2.3B shows that the total quantity of air is now divided into three branches or
splits.
Here Q ¼ Q 1 þ Q 2 þ Q 3
Where Q 1 ,Q 2 , and Q 3 are air quantities in splits 1, 2, and 3, respectively.
The head loss, however, for each split is the same.
Modifying Eq. (2.18)

1

2
H 1
2
H 1 ¼ R 1 Q 1 or Q ¼
1
R 1
1

2
H 2
2
H 2 ¼ R 2 Q 2 or Q ¼
2
R 2