Page 599 - Air and Gas Drilling Manual

P
144
p
am
am
2
,
P
am 107 899 lb/ft abs Chapter 11: Specialized Drilling Equipment 11-37
The average pressure in the motor, p mav , is approximately
p bm p am
p mav
2
.
529 3 729 3
.
p mav
2
.
p 639 3 psia
mav
P mav p mav 144
2
P 92 060 lb/ft abs
,
mav
Using Equation 4-11 the average specific weight of the air in the motor cavity,
, is approximately
mav
(92 060 ) ( . )
1
,
0
mav
41
(53 .36 ) (604 . )
.
2 854 lb/ft 3
mav
The average volumetric flow rate of the air through the motor cavity, Q mav , is
approximately
w ˙ g
Q mav
mav
.
2 635
Q
mav
.
2 854
3
Q 0 923 ft /sec
.
mav
3
0
( .923 )(12 )(60 )
q mav
231 .016
.
q mav 414 3 gal/min