“It"s a bit over - is that OK?”
While the butcher of your choice might ask you for a little latitude, this is
certainly “not OK” when it comes to loading trucks!
Up to the max. payload - quickly and precisely!
To lighten after loading is extremely time-consuming and to load less
than the allowed amount is inefficient.
RWE- Germany"s second largest electricity supplier had to increase the
capacity of the fly-ash truck loading station under the silos in their power
plant “Gersteinwerk” near Dortmund in Germany. An additional truck
loading station with an online mass flow rate measurement was
necessary.
Facts
Product:
Coal fly-ash
Location:
Coal fired power plant, truck loading station,
vertical pipeline, free fall, DN200 (~8”), in front of
a FLUIDCON conveying system
Mass flow rate:
Max. 150 t/h
Velocity (solid Material):
5-7 m/s (1000-1500 ft/min.)
Solution
The well-known plant engineering company Claudius Peters Projects
was appointed by RWE as the general contractor. For the online mass
flow rate measurement Claudius Peters Projects implemented the
DYNArad system of DYNAInstruments and Berthold Technologies. The
system is a combination of an electrostatic velocity-measurement and a
radiometric density-measurement.
The System
Velocity-measurement:
The measurement principle is based on the detection of natural electrical
charges on the solid particles to be measured.
To measure the running time, signals are recorded at two sensors which
are installed in a given distance. And the two signals are used in a correlation
calculation.
Density measurement:
The radiometric density measurement is based on the Gamma
transmission principle. When irradiating the pipeline, the radiation is
attenuated. And this attenuation is evaluated by a scintillation detector.
An evaluation unit calculates the mass flow rate by using the velocity
and the density: The value is output as an analogue signal.
Benefits
Truck loading is automatically stopped when the entered
payload is reached. A coarse / fine control was implemented to
slowly reduce the mass flow rate at the end of the loading.
The comparison of the target value and the actual value shows an
accuracy of 1.4%.
- Automatic stop when payload / target value is reached
- Accuracy 1.4%
- Independent from changing product properties
and silo filling level (changing velocity)
- Contactless measurement
- Wear-free
- Minimum operating cost
- Maintena
