In-line bulk density of powders sensor 4

[CARF]

Dear all,

Does anyone of you know manufacturers of in-line measuring systems for density of powders? The powders we produce typically have a density of 30 kg/m3. We want to measure (and control) in-line density.

Many thanks,
CARF

 

[DaveScott]

Do you want to measure the overall density of powder in a pipe, mixed with the transport medium?

 

[CARF]

Dear Dave,

That's a very good question, I realised there is no such thing as in-line density of a powder. I depends on the ratio of the particles to the transport medium.

The off-line measurement gives 30 kg/m3, but that also depends on the bulk stacking. If we transport the powder it may become more compact and dense due to vibrations.

Hmmmm..., any idea's? What else can I typically measure on a powder (particles) to characterize the product?

Thanks for helping,
CARF

 

[JimCasey]

You probably want to look at a precision weight-loss feeder such as one manufactured by Acrison. I suspect that the reason you are interested in the density of the powder is because you are blending it with other components and the mass ratio is the significant result you intend to control.

http://www.acrison.com/pages/pro_wf_00.html

If you are just transporting it, pneumatic conveyors work well for powders. Take a look at Premier Pneumatics

http://www.premierpneumatics.com

And rest assured that the Acrison feeder will work in conjunction with the Premier conveyors.

( I am not affiliated with either company, just have had good rapport with both)

 

[Ashereng]

How about a coriolis meter? It measures density of gases, and in this case, if it is mostly gas with solids, it should work - assuming the erosion is okay.

E&H and Krohne both have staight through mass meters (not the old school U or Z bends). That should help with the erosion.

"Do not worry about your problems with mathematics, I assure you mine are far greater."
Albert Einstein
Have you read FAQ731-376 to make the best use of Eng-Tips Forums?

 

[JimCasey]

Ashereng: I don't think a coriolis meter will work with a light-phase conveyor flow. The vibrations in the coriolis meter would not uniformly affect the suspended particles in the stream, so the meter would measure essentially just the mass flow of the carrier gas. If the powder is being conveyed dense-phase, it might be more accurately measured or the vibrations in the coriolis meter just might make the powder pack down.

 

[DaveScott]

Perhaps this is of interest:

http://www.cidra.com/iss/appnote/powder_massflow_BI0261.html

There are also microwave based instruments, which I think are intrusive.

 

[CARF]

That's a very nice hit, Dave!

Thank you,
CARF