level measurement, general info

  • Thread starter Thorsten Lamprecht
  • Start date
T

Thread Starter

Thorsten Lamprecht

Dear List,

as a student of mechanical engineering section process engineering in germany I am currently working on project for our measurement and control class. The goal of this project is a global overview about level measurement technologies which are used in bulk solid and powder applications. Maybe one or another of you has experience in this field automation and can give me information of what level measurement principles are mainly used in the branches which deal with those applications. Is there a standard in field busses for i.e. the cement industry?

What are the suppliers for those level sensors?

I appreciate you taking the time to answer those questions! Thanks!

Best regards

Thorsten
 
H

Helmut Meissner

Mostly there are used Ultra-Sonic level messuring instruments. For security we sometimes use piezo-mechanical sensors to check overfilling of cememt or aggregat silos. In older applications where use
"Stillstandsmotoren" that meens moving padels inside the silo that where blocked by the cement. If there is only one aggragat in the silo,
sometime we use weight messuring. The fieldbusses in german cement factories are mostly Interbus and
Profibus DP.

> What are the suppliers for those level sensors?

For Ultrasonic check NIVELCO or Endress und Hauser.

If you have more questions you can contact me at the office at

Schlosser-Pfeiffer GmbH
Aarbergen, Germany

Greetings
Helmut Meissner
Manager Software Department
[email protected]
 
M

MIke Boudreaux

For level measurement of solids, you should use something that doesn't rely on fluid principles such as floats, pressures, etc.. Examples are:

* Weigh Cells
* Nuclear
* Optical
* Radar
* Ultrasonic
* Capacitance
* Laser

For a good overview, see the article, "Sixteen level sensing technologies" from Chemical Processing Magazine at
http://www.chemicalprocessing.com/protected/cp299/63.html.

There is also a good article from I&CS Magazine called "Process and material characteristics are key to level selection" which will give you an idea of which kind of technology you want for different applications.
http://www.icsmagazine.com/1999/pdf/9911-level.pdf (PDF file)

Mike Boudreaux
http://mike.boudreaux.net
 
D

Daniel Moroncini

Hello,

for level measurement in cement I would not recommend ultrasonic: according to my experience, dust is not yet a ressolved problem for the ultrasonic´s leaders Endress+Hauser and Milltronics (however E+H recently released a new sensor called FDU86). Remember cement is sometimes filled in the silos through pneumatic pumps.

An old and very reliable instrument for cement is the Silopilot from E+H (see at endress.com). Big cement group Holderbank is still specifying this electromechanical instrument in new plants.

New promisses for this application: " flexible" radars, for example BM from Krohne or Levelflex form E+H. (up to now I don´t know the practical results).

For limit detection: piezo-actuated forks or rods.

Regards
Daniel Moroncini










> For level measurement of solids, you should use something that doesn't rely on fluid principles such as floats, pressures, etc.. Examples are:

>

> * Weigh Cells

> * Nuclear

> * Optical

> * Radar

> * Ultrasonic

> * Capacitance

> * Laser

>

> For a good overview, see the article, "Sixteen level sensing technologies" from Chemical Processing Magazine at

> http://www.chemicalprocessing.com/protected/cp299/63.html.

>

> There is also a good article from I&CS Magazine called "Process and material characteristics are key to level selection" which will give you an idea of which kind of technology you want for different applications.

> http://www.icsmagazine.com/1999/pdf/9911-level.pdf (PDF file)

>

> Mike Boudreaux

> http://mike.boudreaux.net

>
 
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