![background image](http://html1.mh-extra.com/html/intra-automation/digiflow-515/digiflow-515_installation-and-operating-manual_2081780014.webp)
Gas- and Steam Flowcomputer
DigiFlow 515
Operating Manual
14
Scaling Factor (k-
Factor):
9,500 Pulses/m
3
Specific Gravity d: 1.105
Base Temperature: 15°C
Base Pressure:
101.325 kPa
Time Base:
hours
Other parameters can be programmed as required.
The instrument will now display the corrected volume and mass flowrates of the gas.
Example No. 5:
The same vortex meter installation, as detailed in Example 4, has a 4–20mA output. The instrument produce
at 0m
3
/h a current of 4mA and at 1,000m
3
/h a current of 20mA.
Determine the parameters necessary for the Configuration.
If the calculator gets a linear 4–20mA signal, then the following parameters are to program:
Span: 1,000
m
3
/h
Specific Gravity:
1.105
Base Temperature: 15 °C
Base Pressure:
101.325 kPa
Time Base:
hours
6.1.3 Application for General Gases
For general Gases the compressibility is calculated using the Redlich-Kwong-equation. Therefor it is neces-
sary to know the critical temperature and the criticial pressure of the gas. From these parameters, the com-
pressibility factors z
b
and z
f
are calculated for a gas..
Datas of common gases are listen in Appendix B
Properties of Some Gases:
Equations 1 to 9 are used to calculate the corrected volume and mass.
Example No. 6:
A flow of Hydrogen via an orfice plate shall be calculated under consideration of the compressibility. Which
constants are required?
T
k:
-239.9°C
p
k
: 1,296.9kPa
d: 0.0696
Summary of Contents for digiflow 515
Page 2: ......
Page 43: ...Gas and Steam Flowcomputer DigiFlow 515 Operating Manual 43...
Page 44: ...Gas and Steam Flowcomputer DigiFlow 515 Operating Manual 44...
Page 45: ...Gas and Steam Flowcomputer DigiFlow 515 Operating Manual 45...
Page 46: ...Gas and Steam Flowcomputer DigiFlow 515 Operating Manual 46...
Page 47: ...Gas and Steam Flowcomputer DigiFlow 515 Operating Manual 47...