Molton Steel Level Measurement

[Chinook82]

Our present practice to achieve the bath height is to attach a metal bar to the blowing lance. This bar is dipped into the bath and the remaining bar length is measured considering the lance position. The duration of this measurement is rather long and the measurement itself is relatively inaccurate. the bath height is only measured periodically.

We like to try a radar system to improve measurement accuracy, or maybe go to a nuclear level systems.

Here are a few parameters, I have for my application

Diameter of the opening: 36 inches
Measuring distance: 50 feet
Inside diameter of the vessel: 16.5 feet
Pressure: atmosphere pressure
Material: liquid steel
Ambient temperature: ~20 Deg. C
Radiant temperature: ~63 Deg. C

During the blowing process, the gas temperature and steam flow are highest. Bath height measurements are taken after the blowing process.

We would like to keep the transmitter away from the opening, maybe some waveguides required.

Anyone have some experence?

Thanks!

 

[JLSeagull]

I think that a nuclear source can be aimed about 45 degrees. Nuclear can handle high temperatuers by standing the sources and detectors off the vessel. Radar is limited to about 750 degrees. I lack molten metal experience.

The suppliers may know of special installation practices to accommodate molten metal. I would contact some of the suppliers. Ohmart-Vega is in both the nuclear and radar market. Berthold, Thermo Electron and Ronan are other nuclear suppliers. Endress-Hauser, Krohne and Rosemount are other radar suppliers.

 

[itsmoked]

JLSeagull; No laser rangefinders? I would think a modulated laser would work.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[JLSeagull]

K-TEK does radar level. I was looking at that for plastic pellets. The decision between laser and radar in plastic pellets was based upon whether you could watch the pellets with a flashlight. Too much dust then laser is out. I suspect that steam, etc. would eleminate laser.

 

[waross]

I serviced an instrument that measured the level of molten glass years ago.
There was a pinion and rack that lowered a probe. When the tungsten tip on the end of the probe touched the glass surface, the completed circuit halted the downward motion. (Molten glass conducts electricity).
The position of the mechanism was read and the probe was lifted clear. The process repeated continously.
The PID controller would "Sample and Hold" the input signal.
respectfully

 

[Chinook82]

Sounds like radar worth a shot. I can use a bent waveguide at 90 degrees to keep the transmitter distant from the process temperatures. The dielectric is high enough and that's the variable radar need for a good microwave reflection I'm told.
Thanks!