Our silos are 16m with a conical bottom. We are using E&H ultrasonic level sensors. Our problem are that as soon as the material level goes into the cone, the level starts jumping around on the display. Dust are also a problem. Our material are very abbrasive, so any wire sensor won't last.
Any suggestions of how to make the ultrasonics work or a new type of sensor?

 

Hi

Why don't you try RADAR type Level Instrument?

Best Regards

PP Muthu
Rezayat Trading Company Ltd
Kuwait

 

You could use a radar transmitter from Rosemount, it has worked very well for me.

 

the level starts jumping around on the display. Dust are also a problem.

These are the reasons I use Milltronics. Their filtering and adjustibility are top notch.

 

Is the Lower Level set at the bottom end of the cone or the top where your vessel straightens out?
Perhaps consideration should be to set your 0% level at the later point rather than at the vessel exit point (I'm assuming the cone tip is the exit point).

Can the Dust be filtered with sensitivity adjustment?

I worked on a Polyethylene/ Propylene unit once a we good results from the E+H "Wire type" transmitter for the additives, these were also abrasive, but be aware of the electrolytic constant for the material and transmitter if you select this system.

Otherwise, have you considered load cells?

Good Luck
Gray

 

No any chance to measure the weigth of the material ?
Tavazzi

 

Air radar will present more than likely present same problems as sonic. The only possibility is if you can locate a radar with a narrow beam You will have to go with a large horn, 8" would be a suggestion. That would give a beam of approx. 6 degrees. However, even with that beam angle, you couldn't 'see' to the bottom of the cone.

Another option would be laser but they have their problems also. Dust during filling. If you were willing to let dust settle before measuring, laser would have possibilities. Beam angle of laser is approximately .3 degrees. You could point laser into the bottom of the cone. KTek would be a place to look.

L.Kolbert

 

Hi, Hope this helps!

There are many types of level measurement systems for silos depending on the type of materials handle. There is ultrasonic, radar, some also use a servo type mechanism (when the surface is touched the torque reduces) Do not forget load cells. You can make multiple uses I.e. for both level and inventory management! Double Maza (double fun!). Empty silos do give problems as do dusty atm. in ultrasonics. But you should be able to circumvent that by the transducer commands. Sometimes incorrect angle of the untrasound tx can also cause some headaches! Think what happens when the silo is at very low level and your beam is cut by material flowing in or out or some dust that pops up every now and then!!

I would recommend that you first talk with engineers of the transmitter provider in your area and find if the matter can be resolved by making some config changes.

Regards, Anand.

 

plz send mail on [email protected]
We are abrasives manufacturing company and currently undergoing trials for the same purpose.

yogesh m. tapaswi
Grindwell norton ltd
mumbai unit, India.

 

If the material in the silo is always the same they why not use a load cell under the supports of the silo. Weight will then be directly proportional to volume.

 

My company has a complete ultrasonic line that works well in a dusty environment. "Usually", when people call me with operational problems, resolution is in the sensor mounting location and in other setup parameter issues (assuming that an appropriate sensor was specified to meet the challenges of the application). We also have another economical technology that may be of interest to you. Feel free to give me a call at 800-766-6486 and we can discuss your installation and application. You may also visit our website at www.monitortech.com

Greg DeRudder,
Technical Sales Support Manager
Monitor Technologies LLC

 

Why not try a simple rotating paddle switch which incorporates a 'V' shiled over the top. Paddles can be obtained in varying sizes to suit material BD. When material is present the paddle stops rotating, when material moves the paddle begins to rotate again. The paddle is protected by the inverted 'V' cover above so it is shielded from the head of material.
Device can also be removed from outside of the vessel.

 

Suggest you try laser. Laser beam is on order of .3degrees and can get down to base of cone. Dust could be an issue but units can be tried to verified for application.

Optech in Canada has possibilities for you. Unfortunately I don't recall their website address. They are in Toronto area. Their units do coal in 300' silos with success.

L.S. Kolbert
Manning Environmental, Inc.

 

I agree 100%, go with the Milltronics, but in general sense of the word dust should not cause problems. Most likely you are getting false or second echos from the conical bottom because the unit has to wide of a beam pattern at the distance involved. go through your setup parameters very carefully, check for filtering settings, you can usually set the units up to average over a period of time (typically a few seconds will do the trick), Check with the manufacture, typically they can provide very good tech support on their products.

Matt Hyatt
Technical Consultants
[email protected]

 

The web site is:

http://www.optech.on.ca

My contact info is below and would like to discuss further. Silo measurement is something we have done lots of with laser.

Michael Vujicic P. Eng., M.B.A.
Director, Industrial Products Division
Optech Incorporated
tel: 416-661-5904
fax: 416-661-4168
[email protected]

 

Are you suggesting that Milltronics can 'see' into the cone at the bottom of the silo w/o losing signal with filtering etc? I don't recall the Milltronics having a sonic beam tight enough to not be affected by sound scatter off the angled cone of the vessel.