×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

mass flow meter drifting from actual reading

mass flow meter drifting from actual reading

mass flow meter drifting from actual reading

(OP)
Have you all met this problem of a coriolis mass flow meter shows that there is a flow of 300 liters per hour while there actually has no flow in the flow meter. Futhermore, the reading keeps increasing over the time and the trend of the flow increment is pretty steady.What reasons could possibly contribute to this? Is it because of external vibration? or air bubble inside the flow meter? Thanks.

RE: mass flow meter drifting from actual reading

Well, is it a flow meter with a  max scale of 100000000 litre per hour, or 1?

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

RE: mass flow meter drifting from actual reading

(OP)
Hi,

The scale is 0 ~ 16000 liter per hour, with an accuracy of plus minus 0.15%.

Or is this a transmitter problem?

Thanks.

teoaj.

RE: mass flow meter drifting from actual reading

Sounds like a bunged-up meter to me.  Do you have a process fluid that can cake onto the walls of the meter, or corrode them?  

RE: mass flow meter drifting from actual reading

(OP)
Thanks btrueblood.
My process fluid is just a normal solvent, ethanol.
However, after we repack the line, the meter became to be ok.

RE: mass flow meter drifting from actual reading

Talking about this. My site do have this problem. Its like after issuing the product to a truck. All the valves are shut. But from the control room, it shows that there is flow in the meter. Its really weird. The worst thing is that the meter can go reverse without any flow.

Not sure if it is valve passing or is due to the coriolis meter.

 

RE: mass flow meter drifting from actual reading

Oh.  Or is it residual ethanol boiling in the line, and bubbles causing flow/reversed flow?

RE: mass flow meter drifting from actual reading

I already had the same problem. In my case was:
We had several lines (tubing) supplied by only one general(mother) line (tube), and each (daugther) line was connected to the mother by TEEs. So, when we were measuring in one line, the liquid was coming up from the mother and, each daugther line which were not measuring in the same time had the liquid movement reverse by "venture force" (decreasing the pressure) , and after the stop off all, the liquid move positive again (reincreasing the pressure), with no end line valvs opened.
The solution were separate the lines or exchange the TEEs for small vessels.
Hope could be clear.

RE: mass flow meter drifting from actual reading

Check the meter mode - Is it in 'integration' or 'measure':)

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources