Endress+Hauser Proline Prowirl 72, Руководство по эксплуатации

Страница: 59 / 114

Proline Prowirl 72 10 Technical data
E Hauser 59
10 Technical data
10.1 Technical data at a glance
10.1.1 Application
The measuring system is used to measure the volume flow of saturated steam, overheated steam,
gases and liquids. If the process pressure and process temperature are constant, the measuring
device can also output the flow as the calculated mass flow and corrected volume flow.
10.1.2 Function and system design
Measuring principle Vortex flow measurement on the principle of the Karman vortex street.
Measuring system The measuring system consists of a transmitter and a sensor:
• Transmitter Prowirl 72
• Prowirl F or W sensor
Two versions are available:
• Compact version:
Transmitter and sensor form a single mechanical unit.
• Remote version:
Sensor is mounted separate from the transmitter.
10.1.3 Input
Measured variable Volumetric flow (volume flow) is proportional to the frequency of vortex shedding after the bluff
body.
The output variables are volume flow or, if the process conditions are non-varying, calculated mass
flow or corrected volume flow.
Measuring range The measuring range depends on the fluid and the pipe diameter.
Start of measuring range:
Depends on the density and the Reynolds number (Re
min
= 4,000, Re
linear
= 20,000).
The Reynolds number is dimensionless and indicates the ratio of a fluid's inertial forces to its viscous
forces. It is used to characterize the flow.
The Reynolds number is calculated as follows:
A0003794
Re = Reynolds number
Q = Flow
di = Internal diameter
µ
= Dynamic Viscosity
ρ
= Density
A0003239
Re
=
4 · Q · m³ [m³/s] [kg/ ]
di [m] · µ · [Pa·s]
v DN 15...25
=
min.
6
[kg/m³]
v DN 40...300
=
min.
7
[kg/m³]
[m/s] [m/s]