Electromagmetic flowmeters and effect of 'sand bed' 1

[BobMaron]

What would be the effect of a solids bed in the bottom of a horizontally mounted electromagmetic flowmeter. The slurry is iron ore concentrate, and the height of the solids bed can be up to 20% of the pipe ID. Some people have said that the mag meter will 'compensate' for the solids bed, and not have an error. Other people have said the mag reading will be high, due to the higher velocity caused by the reduced cross section area where the solids bed is. I'm looking for feedback from people with field experience on this. Thanks in advance

 

[pflow]

Some magmeters can correct for solids content with the signal conditioning software. But this assumes that the solids are "well mixed."

Magmeters are velocity meters and calibrated to a known volume flow. The pipe ID is then used to figure volume flow. If the ID is restricted, there is error in the flow measurement. This is different than a partially full pipe, which some magmeters can correct for.