Hi,

can someone please assist me. we have a problem with our coriolis meter. it keeps plugging just after a few minutes of operation and we have not been able to get it running. can people please advice on some things we could consider?

thanks,
FT

 

Hello FT

may be You need to be filter in front of the meters or strainers or upgrade the size of the meter?. how big is the flow meter?

 

FT, What is your process fluid and what make and model of Coriolis sensor do you have? How is the sensor mounted, tubes down, up or flag position?

Is your process fluid homogeneous or contain larger slugs of solid material?

The correct solution depends on the answers to the questions above.

Regards,
Rob S

 

Hi Bahawi,

Thanks for your reply. we cannot filter the process stream because it is not homogeneous and consists of a mixture of various constituents, all of which we are interested in. We might not be able to upgrade the size either because the flow rate is low and we might have a problem of insufficient feed pressure into the flow meter.

 

What is the viscosity of your liquid? Try to heat it.

 

Try an Endress meter they have a full bore Promass I that would have no pres. drop

 

Hi FT,

Please provide detail information on the service & operating conditions to better understand the problem. Application is key to meter selection & it could be that the Coriolis was not the correct choice of product on the application.

 

What type of coriolis meter do you have?

For some high viscosity fluids/slurries conventional twin tube meters with complex flow paths (the only ones available in the early days of coriolis metering) have suffered problems where one tube can block causing all the flow to pass through the second tube.
As the flow slows in one tube the problem rapidly gets worse because the flow in that tube may tend to cool more or to deposit solids.

Whatever the mechanism, the solution may be to choose a different type of coriolis meter.

Single tube meters are far less prone to blockage because as a blockage starts to form the pressure drop increases.
If you are using a centrifugal pump then flow will reduce and stop entirely but if you are using a positive displacement pump the flow will be maintained and as the bore size reduces due to blocking by the fluid, the flow velocity will increase which would then tend to help to clear the blockage.

The Exac meter was a single tube mass meter for which this was far less of a problem even though the flow path was complex (actually a double loop so that sequential loops were vibrated relative to each other).

Of course, single straight tube mass meters are better at this and the first such meter, the Solartron MassMaster (10, 40 and 200s - Khrone were not the first with a single straight tube mass meter) were fitted successfully in a number of applications where conventional twin tube mass meters showed a tendency to block.

Straight tube meters also have the advantage of being less vulnerable to erosion with abrasive slurries, a particular problem because of the thin walled tubes which make up mass meter tubes and the relative high velocities needed to generate a good signal to noise ratio.

Today, though the Solartron is no longer available, there are a variety of single tube tube and single straight tube mass meters to choose from.

It is interesting that you should have this problem, however, because I would have expected that the meter selection should have addressed these issues at the quotation stage - it is, after all, a recognised and manageable problem and most questionnaires inquire about the process fluid in sufficient detail to identify such problems.

Is it possible that the fluid properties were not properly disclosed during the quotation process or that this meter has been transferred from another duty?