Page 622 - Air and Gas Drilling Manual

11-60 Air and Gas Drilling Manual
t
L
0 0113 ft
L t t l 12
.
The nozzle depth along the periphery of the stator, L , is
d
.
l d 0 280 inches
l d
L
d
12
.
L d 0 0233 ft
Assuming that 16 of the nozzles are plugged, then the total nozzle flow area,
A , is
tn
0
A tn (23 16 ) ( .0113 ) ( .0233 )
0
A tn 0 00185 ft 2
.
Assuming sonic gas flow conditions at the throats of each of the remaining 7
nozzles in the stator, Equation 6-62 can be used to determine the pressure above the
turbine stator. Equation 6-62 becomes

2
41
(.635 ) (604 . ) . 05
P ias
. 24 . 05
(32 . ) ( . ) ( . ) 2 . 04
2
1
0
1
4
0
(.00185 )
53 .36 . 24
2
P ias 65 790 lb/ft abs
,
P ias
p ias
144
.
p ias 456 9 psia
The ratio of the pressure below the turbine to the pressure above the turbine
(stator) is