CHEMICAL ENGINEERING

FLOW AND PRESSURE MEASUREMENT 83

P< 192 .2kN/m^2 P> 192 .2kN/m^2

PGPG

(MN/m^2 ) (kg/s) (MN/m^2 ) (kg/s)

0.1013 0 0.2 0.0083

0.110 0.0024 0.5 0.0208

0.125 0.0039 1.0 0.0416

0.150 0.0053 2.0 0.0830

0.175 0.0062 6.0 0.249

These data are plotted in Fig. 6b, from which discharge rate is seen to be linear until
the cylinder pressure falls to 0.125 MN/m^2.

01234

P 1 (MN/m^2 )

P 1 (MN/m^2 )

56

0 0.1 0.2

0.010

Low pressure

range

0.005

0.3 0.4 0.5

0.25

0.20

0.15

0.10

0.05

G

(kg /s)

G

(kg /s)

Figure 6b.

Ifmis the mass of air in the cylinder at any pressureP 1 over the linear part of the
curve,GDdm/dtD 0. 0415 P 1.

∴ dtDdm/ 0. 0415 P 1

mD 29 / 22. 4 P 1 / 0. 1013 ð 30 D 383. 4 P 1 kg

∴ dtD 383 .4dm/ 0. 0415 mD9240d m/m

and tD9240 lnm 1 /m 2