2. Flow meter is an instrument that is used to
gauge the flow of gases or fluid through a
pipe. Flow measurement applications differ
extensively with respect to the conditional
benchmarks, situational limitations, and
engineering requirements.
Flow meter has other names such as fluid
meter, fluid sensor, flow sensor and flow
gauge. They have a wide range of
applications across different industries
based on its basic function, which is to offer
precise monitoring and measurement for
flow of fluids or gases.
Different Types of Flow Meter
3. Differential pressure flow meters measure
the differential pressure across an orifice
where flow is directly related to the square
root of the differential pressure produced.
There are also primary and secondary
elements in differential flow meters. The
primary element produces change in kinetic
energy using either flow nozzle, pitot tube,
orifice plate, or venturi flow meters. The
secondary element measures the differential
pressure and provides the signal.
Differential Pressure Flow Meters
4. Orifice Plates
An orifice plate is a plate with a
circular hole in the middle of it. When
fluid flows through the hole, the
velocity will increase and the pressure
will decrease. Orifice plates are
commonly used when the flow is
continuous and occupies the entire
pipe.
5.
6.
7. Flow Nozzles
A Flow Nozzle is very similar to an
orifice plate, the main difference is that
flow nozzles have a gradual
constriction rather than the abrupt
constriction of an orifice plate. Flow
nozzles are common for high velocity,
low viscosity flows. Flow nozzles also
have a greater flow capacity when
compared to other differential pressure
meters.
8. variable area flow meters 100%
=>
rarity
ervationof Rotameter;
↓ Pleaving
+z =
0 2.
+z =
zu
Pg +
YgY +
(2, -
zz) =
0
10=
= vi[1-():994s
stat
Q-
V
, A, =
V Az zz -
Z, =
hf
(2)=
2(*p-194) entering
Ve
-- also
- * he-height of float
-[ (l] 1. O
1p =
()[1-():994 : e
F=
N,(1 -
9)9
density of water
1p =
()[- ():994 theortical discharge AP=
V
, (3 =
9)9
Af
sp-gus= ()[1-s] a.
[it] An
a =
C12
19e
2(1p-39hs) --
(-) [1 -
(-
)] are
discharge
in
e
-(2)(()=2(sp-/9nx) AP =
Q =
CdAz
Seethe
F=
mg *
m =
VI
9. A
A
venturi meter is used to measure a liquid flow rate of
where? Vs-volume of float
7,500 liters per minute. The difference in Pressure across the 3) = density of float
Venturi meter is equivalent to 8m of the flowing liquid. The As: Area of float
Pipe diameter is 19cm. calculate the throat diameter of the
Venturi meter. Assume the coefficient of discharge for
the venturi meter as 0.98.
converging Diverging
section.
-
section. I -
-
↑
-
Q =
7
,500 in
IA
z =
0.0098m
-
!
I
&
iven.
""
ison
in
Mass----
e
2d =
0.9d
di = 0.19m
-
h =
8m
4x
d=
0.0098
d=
4 x0.0098
a =
edx
(g)
H
dis
de =
0.1115
