Hello,

I need to measure the weight of two existing flat bottom cylinder-shaped tanks, each is 10 feet in diameter and 16 feet tall. Load cells would be the easy way, but the tanks sit flat on the ground (concrete slab) without any support
structures under them. I do not think the tank bottoms could support the weight of the contents if they were not flat on the ground. I have seen bolt-on load cells, but these only seem to work on tank legs, not on part of the tank itself.
The tanks will be heated to around 300 deg. F and they will be insulated. Weight measurement is preferred over level measurement for the process.

Any suggestions other than replacing the tanks or building a support framework under them?

Thanks for any help you can provide,

Ed Mulligan
Armstrong World Industries, Inc.
Lancaster, PA
[email protected]

 

Ed, can you tell if the concrete pad itself could be lifted? Why do you prefer weight?
Are these glue/adhesive tanks for the vinyl tile backing or something? Do you expect that the viscosity of the fluid will preclude the use of
pressure gauges or RF/capacitance?
I'd recommend you look at radar...either pulse radar (E+H, OhmartVega, Siemens (Milltronics))
or phase-tracking radar such as Bindicator (Celtek) http://www.bindicator.com.

Give us some more data, and we can give you some more free advice.

Remember, though that the advice we give is worth what you're paying for it <very big grin>

Walt Boyes


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Ed:
Bolt on cells can be used to measure transverse forces. Anyway it doesn't seem to me like a good alternative for this application. Why don't you try measuring via level and density? Smar manufactures a device that can help. You can check the website www.smar.com. Or you can check specs for the density meter at
http://www.smar.com/Products/Pdf/FBook00/Dt302.pdf.
Equipped with the density, you can measure level and you can calculate the weight. And you don't have to change the shape of your tank or build new
support.
I hope this helps.
Jimmy Saldivias
TECSIM
[email protected]

 

What is in it? if it is some kind of liquid a simple pressure sensor located at the bottom will give you the answer.


/Johan Bengtsson

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Maybe this could help.

You can install a a level transmitter (ultrasonic or pressure type) from the top of the tank AND a diff. pressure transmitter with high and low pressure tap one foot apart also installed from the top of the tank.

This would give you height AND density, hence total weight.

If the tank is not streight and the volume not linear then you could apply a linearization curve to the output signal of your level transmitter directly in the transmitter OR in a PLC...

Many manufacturers will supply this kind of instrument and the precision of this principle is very good (...but what precision would you need).

For example the serie # DBA52A-SP12FC13GE20 from Endress+Hauser ... it can be program with a linearization curve (11 points). and its other versions.


Pierre Desrochers
Integral Instrumentation Inc.