CHAPTER FIFTEEN
FLOW MEASUREMENT
Chapter 15
270
15.6 Find
p across Venturi, Q = 600 gal/min(1 ft
3
/s)(449 gal/min) = 1.336 ft
3
/s
15.7 Find Q through an orifice meter. D1 = 97.2 mm; A1 = 7.419 103 m2; d = 50 mm = 0.050 m
15.8 Orifice meter. Propyl alcohol at 25 C;
= 7.87 kN/m3; = 2.39 106 m2/s
2 2
1 2 1
[( / ) 1]
A A
15.9 Flow nozzle Design: Install in 5 1/2 inch Type K copper tube; D1 = 4.805 in; A1 = 0.1259 ft
2
Specify the throat diameter d. NOTE: Multiple solutions possible.
FLOW MEASUREMENT
271
a
)
Use
Eq.
(
1
5
–
6)
and
s
o
l
v
e
f
o
r
A
2
f
r
o
m
which
we
can
ob
t
ain
the
thr
o
at
dia
m
et
e
r
d
b) Use Eq. (15-6) and solve for h to determine the manometer reading when Q = Qmin.
15.10 Orifice Meter Design: Install in 12 inch ductile iron pipe; D1 = 12.51 in = 1.043 ft;
A1 = 0.8536 ft2
Specify the orifice diameter d. NOTE: Multiple solutions possible.
a) Use Eq.(15-6) and solve for A2 from which we can obtain the throat diameter d.
