I need to install the best level measurement technology for the Coal bunker. The total height is 17m and dia of 6m. The measurement technique should have a local display as well as in remote thru mA output.

Is there any body who can help me. It's urgent.

Ramji

 

Ultrasonic is proven. Radar probably does just as well.

I've had the Milltronics AirRanger XPL-10 work very well on multiple coal bunkers at two plants I've been at. Milltronis is now Siemens and LU-10 is the current model name.

The Siemens LU 10 centralizes the electronics in one box for up to10 ultrasonic transducers (which mount up high over the bunker) with a digital display that rotates amongst the points. Analog outputs come from an auxiliary module or Modbus RTu is available directly from the LU10 with a comm card.

The transducer is picked for the range required. If I recall properly, there's 10m range transducer that would work at your 6m range.

I haven't tried radar level on coal yet, because radar units are always one radar transmitter per level point, whereas the ultrasonics provided up to 10 level points by just adding a transducer in the Siemens version. It was very cost effective for multi-point level.

It sounds like you only have one bunker. Siemens has single point ultrasonics (LU-01). Same design - electronics box with display mounts at ground level, remote transducer up high, 4-20mA output.

The ultrasonics use a $100 battery powered hand-held programmer for set up. I don't know if the radars use the hand-held or if they've gone to HART.

David

 

Just realized I read your dimensions wrong - you'll obviously need a transducer that shoots your 17m range, not 6m. David

 

Well, unless you can put a load cell under the coal bunker, you are limited to sensors mounted on the top of the bunker.

That means, effectively, guided wave radar, rf admittance, pulse radar, FMCW radar, and ultrasonic level. I doubt that laser will work in coal-- blackbody problem, eh?

So you have five different (some quite similar) technologies.

Two of them are contacting: guided wave radar and rf admittance require a probe hanging down into the bunker. This is a maintenance weakness, but isn't really a killer of the technology type.

Pulse radar and ultrasonics share similar mounting requirements, and some of the same issues. Pulse radar is somewhat better at 'seeing through' clouds of coal dust or moisture. Ultrasonics, especially very low frequency sensors, have a significantly longer history with measurements like this than radar does. But radar has been out there more than a decade in these applications too.

FMCW radar is likelier to be more accurate than any other methodology, but it is also likelier to be more expensive too.

Here's what I'd do. You have a nice big bunker. I'd contact vendors of each of those technologies, and tell them that you want to do a test of all of them, and you'll buy the one that works the best.

Remember that you will have to deal with error issues, such as ratholing, angle of repose issues, and bridging. It may be that you will need more than one sensor to accurately measure the profile of the coal in the bunker.

I hope this helps.

Best,
Walt

Walt Boyes
Editor in Chief
CONTROL magazine
Putman Media Inc.
555 W. Pierce Rd. Suite 301
Itasca, IL 60143
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[email protected]

 

Laser by Optech from Canada is a good option as well as K-tek in USA located in Louisiana. I have had laser sight 17m in coal silos easily.

L.Kolbert

 

I saw a coal plant once that had coal bins with a level sensor that was a weight hanging on a cable. It would drop from the ceiling and when it hit the top of the coal it stopped dropping and the height was determined from where it stopped. Nearly fool proof, and it is not as if coal bins change level very fast.

 

Check out the following case study for the Siemens LR460.

https://pia.khe.siemens.com/efiles/feldg/files/case_studies/level/en/LR460Coal_en.pdf

 

Go to http://www.bestobell.com

 

Ultrasonic is indeed a proven technology. Siemens has very narrow-beam ultrasonic sensors (Echomax) which have a range up to 40 m. I commissioned much of these XPL Plus/ LU10 ten point level monitors at power plants and coal handling sites. Cost effective and easy to install & setup. Just follow the guidelines how to mount a sensor properly, and use the aiming kit "easy aimer".
https://pia.khe.siemens.com/index.aspx?Nr=5829

If your dealing with extreme dust, and measuring during filling is necessary, then the Sitrans LR460 is an excellent choice. It has a small horn (4", so no big dish antenna), and the horn can be ordered with an air-purge connection, to keep the horn clean. http://www.siemens.com/lr460

 

VEGA Grieshaber have the best bulk solids radar available. Visit http://www.vega.com/vegapuls/en/index.htm for more information

 

Hello Mr.Walt,

I am looking for cola bunker level measurement system with strain gauge type level sensor, bar graph level display. Please write how the system works and also suggest few reputed manufacturers.

Regards,

S.A.Reddy
www.arihantelectricals.com

 

Is this tank in Ex zone ?