370
K. R. Arun
Fig. 1 Line diagram of injector
Table 1 Geometric specification of gas-centered coaxial injector
S. No.
Parameter
Value
1
Liquid injection orifice diameter
d j
1 mm
2
Number of liquid injection orifices
6
3
Number of row of orifices
2
4
Radial angular distance between the two
injectors in single row
R d
120°
5
Axial distance between the two row
d row 8.06 mm
6
Ratio of Length of liquid orifice to
diameter of orifice
l/d j
2 mm
7
Distance from last row to the exit of
injector
L exit Varying depend upon the MFR
change because when MFR increases then the velocity of cross-flow decreases and
the transverse breakup of liquid jet gradually increases. Therefore, the center post
diameter (d g) designed on the basis of maximum MFR. When the MFR Z point of
liquid jet increases. Therefore, the distance from the last row of liquid injection to
injector exit (L exit ) designed on the basis of minimum MFR. At low, MFR L exit will be
maximum value. From this designed value, ensure that the primary breakup of liquid
jet within the injector. The distance between the two rows of liquid injection orifice
is fixed as 8.06 mm for all hardware because the axial breakup length for single jet
is equal to 8.06 times of liquid jet diameter [4]. In order to avoid the hydraulic flip
and cavitation, the ratio of length of liquid injection orifice to diameter of orifice is
fixed as 2 [10]. Six number of liquid injection orifices are arranged in two rows. The
radial angular distance between two orifices in single row is 120°. In the next rows,
three orifices are drilled 60° offset at angular distance 120°. Thus two rows of the
orifices are arranged in zigzag manner to avoid the striking of the liquid jets when it
emerges out.
K. R. Arun
Fig. 1 Line diagram of injector
Table 1 Geometric specification of gas-centered coaxial injector
S. No.
Parameter
Value
1
Liquid injection orifice diameter
d j
1 mm
2
Number of liquid injection orifices
6
3
Number of row of orifices
2
4
Radial angular distance between the two
injectors in single row
R d
120°
5
Axial distance between the two row
d row 8.06 mm
6
Ratio of Length of liquid orifice to
diameter of orifice
l/d j
2 mm
7
Distance from last row to the exit of
injector
L exit Varying depend upon the MFR
change because when MFR increases then the velocity of cross-flow decreases and
the transverse breakup of liquid jet gradually increases. Therefore, the center post
diameter (d g) designed on the basis of maximum MFR. When the MFR Z point of
liquid jet increases. Therefore, the distance from the last row of liquid injection to
injector exit (L exit ) designed on the basis of minimum MFR. At low, MFR L exit will be
maximum value. From this designed value, ensure that the primary breakup of liquid
jet within the injector. The distance between the two rows of liquid injection orifice
is fixed as 8.06 mm for all hardware because the axial breakup length for single jet
is equal to 8.06 times of liquid jet diameter [4]. In order to avoid the hydraulic flip
and cavitation, the ratio of length of liquid injection orifice to diameter of orifice is
fixed as 2 [10]. Six number of liquid injection orifices are arranged in two rows. The
radial angular distance between two orifices in single row is 120°. In the next rows,
three orifices are drilled 60° offset at angular distance 120°. Thus two rows of the
orifices are arranged in zigzag manner to avoid the striking of the liquid jets when it
emerges out.