Page 578 - Air and Gas Drilling Manual

11-16 Air and Gas Drilling Manual
2
2 635)
0 021
.
.
53 36
b
isp
2
(
10 .
232 2 . )
(.
4 2 () ( . 0 120) 2 5
,
,
b 1 673 000
isp
Equation 6-72 becomes
. 05
2 (. 0 019 ) (. 0 917 )
(,520 ) 2 ( , 1 673 000 ) (604 41 2 e 604 .41 1
29
,
. )
P
isp 2 (. 0 019 ) (. 0 917 )
e 604 .41
2
,
P isp 30 100 lb/ft abs
P isp
p isp
144
p 209 0 psia
.
isp
Air Hammer Bit Piston Passages
The air hammer bit used in this example operation has three passages in the
piston that allow the compressed air to flow to the chamber below the piston, each
with an inside diameter of 0.625 inches and length of 8.0 inches. Thus, the inside
diameter of the passage, D pp, is
d pp 0 625 inches
.
d pp
D pp
12
.
D pp 0 0521 ft
The length of the piston passages, L , is
pp
.
l 80 inches
pp