Endress+Hauser prowirl 70 - Measuring Ranges Liquids; Pressure Drop; Example for Liquids; Example for Saturated Steam

Measuring Ranges
Liquids
Example for Liquids
To determine:
Nominal diameter (DN) for measuring a
flow of 50 m
3
/h of liquid with a density of
0.8 kg/dm
3
and a kinematic viscosity of
2 cSt.
Note: This diagram serves as a guideline
for a quick estimation of Prowirl measur-
ing ranges. Your E+H sales organisation
will be pleased to help select and
dimension a flowmeter for your applica-
tion.
Calculation:
Select the nominal diameter from the
measuring range diagram for liquids
V = 50 m
3
/h ⇒ DN 50.
For ρ = 0.8 kg/dm
3
and a kinematic
viscosity of 2 cSt, the initial value of the
measuring range is 1.8 m
3
/h.
This results in a measuring range of
1.8...75.6 m
3
/h or 1440...60480 kg/h.
Pressure Drop
Example for Saturated Steam
To determine:
Pressure loss for a saturated steam flow
of 8 t/h (12 bar abs.) with a nominal
diameter DN 80.
Calculation:
Convert kg/h ⇒ m
3
/h using steam den-
sity (6.13 kg/m
3
) from page 11.
V [m
3
/h] =
m
ρ
=
8000
kg
⁄
h
6.13
kg
⁄
m
3
= 1305 m
3
/h
Pressure drop:
∆p [mbar] = coefficient C ⋅ density ρ [kg/m
3
]
Determine the C coefficient from the
following table:
For V = 1305 m
3
/h and DN = 80 ⇒ C = 55
∆p= C ⋅ ρ = 55 ⋅ 6.13 kg/m
3
⇒ 337 mbar
Note: This diagram serves as a guideline
for a quick estimation of Prowirl measur-
ing ranges. Your E+H sales organisation
will be pleased to help you select and
dimension a flowmeter for your applica-
tion.
•
ti031e51
V in m
3
/h
ti031e53
Coefficient C
V in m
3
/h
Density dependent
start of measurement
0.75% o.f.s.
Kin. viscosity indicates
begin of 0.75% o.r. li-
nearity
* Limit 1 Hz
ρ
= 0.6 kg/dm
3
12