Mass flow meter

[Karlando]

Hello all!

Has anybody long term experiences with mass flow meters? We are planning to measure slurry amount by using above meter and total counter instead of weighing to whole tank truck. I know that accuracy of such meters are up to 0.10 % which is enough, but how sure can I be with the usability?
Khrone and Endress+Hauser are quite good alternative, can You recommend any other?
Our stuff is kaolin slurry, solids 50-72 %, density 1,5-1,8 kg/l, viscosity 50-400 mPa.
Thanks!

Best slurry in town

http://www.chemec.fi/

 

[TrevorP]

Mass flowmeters are very good and accurate for a wide variety of applications - and have even been used to replace weigh scales. However, they consist of very narrow tubes, usually in a coat hanger type configuration. I suspect that these will be prone to blockage with a slurry. Straight through types are available. I have no direct experience with these, although believe them to be just as accurate, but again, I believe that even these are narrow bore, so could be prone to blockage. I would discuss this with the manufacturer, and if they think it's suitable, try to get some process guarantee out of them, or get it on a sale or return basis.
The manufacturers you suggest are good starting points. There are several manufacturers out there, so a simple internet search will give you names of others.

 

[Karlando]

Thank you TrevorP. We have quite a lot of experiences with these meters, but not in this kind of application. Nowadays throughtput is about 180.000 kg/h with DN80 meter, which is quite good. This info was from manufacturer, so I will ask written quarantee of it, otherwise we will return it.
We install the meter ALWAYS vertical, so it will empty properly and hopefully it is full when loading. Of course, the vibration and turbulence is always a problem but I hope that with good installation, the system will work.

Best slurry in town

http://www.chemec.fi/

 

[ScottyUK]

Karlando,

Foxboro have a range of straight tube Coriolis meters which may be suited to your application. As TrevorP says, they have two relatively narrow tubes within the straight housing, so discuss with the manufacturer for applications involving solids.



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If we learn from our mistakes,
I'm getting a great education!

 

[EdStainless]

MicroMotion is another that I have used in the past.

= = = = = = = = = = = = = = = = = = = =
Corrosion never sleeps, but it can be managed.

http://www.trenttube.com/Trent/tech_form.htm

 

[StoneCold]

Karlando
We have several micromotion units in solvent service but we have a lot of problems with calibration when we blow them dry. They do not seem to like that. Discuss the fact that your flow meter will be empty part of the time. This has been a big issue for us.

Good luck.


StoneCold

 

[btrueblood]

In blowing out a coriolis mass flowmeter, its very easy to create surge flows due to two-phase and pure gas flowing through the restriction orifice. If you "bang" a micro-motion against its "stops" by giving it a flow rate way beyond its normal range, it can get damaged. Shifting calibration is just one of the issues.

 

[kingsss]

try

http://www.rheonik.de

These coriolis meters are of a high quality and very accurate.
regards, Kingsss

 

[khan101]

Coriolis is a good option and if you are not limited by line size (max 6")then I would recommend coriolis either by E&H or Invensys. E&H is very reliable and we have 1st hand experience and any new mass flow application, we would use E&H. We also have a slurry stream but we never tried a coriolis there. Invensys is another option if you have entrained air/gas in your slurry. Entrained gas bogs down coriolis accuracy but invensys claim they have overcome this issue. I have not seen a real application of invensys but we plan to test it in our research facility soon. Micromotion is another long time supplier and Khrone is also in the market. Another issue you should consider is the wetted material and tube thickness. If your slurry is errosive then I am afraid coriolis is not a good option because every manufacturer has this tube thickness issue. Tube has to be thin to vibrate. If that is the case then try to use a volumetric flow meter and use temp. and density measurement to calculate mass flow.

 

[bewdley]

I have used several systems to control flow in slurry lines, including mass flowmeters. They all work reasonably (although my favourite is always the good old mag) as long as they have nothing inside. So, forget the thermal transfer, vortex and similar.
Coriolis normally have the problem of not being self-draining, and this is a must; you have also to consider that you ought to keep a reasonably high velocity (5+ fps) and a turbulent flow to avoid settling in the sensor, whichever the plant rate.

 

[CARF]

thread698-107326

Foxboro has introduced a mass flow transmitter with digital technology that allows standard Coriolis flow meters to continue operating during two-phase flow, which happens when air is introduced into the liquid flow stream.

The traditional problem has been the impact of entrained air, which can interrupt measurement for tens of seconds and stall or shutdown the flow tube.

... CFT50 demonstrations at the ISA conference. The flow tube was started up from empty and then later, flowing with water, compressed air was introduced. The air started from a small amount and was increased to 60%. The tube continued accurately measuring the flow. The speed of response was in 'tens of milliseconds.'

http://www.manufacturing.net/ctl/article/CA259207

Cheers,
CARF