Dear Wayne,

If a system is performing well for a long period of time and suddenly (or gradually) the system performance is changing, then one or more parameters are changed or changing.

Plugged the lines in a pneumatic conveying system is caused by a too high Solids Loading Ratio (SLR)

SLR= material mass flow / gas mass flow

A too high material mass flow causes a high SLR and eventually plugging

A too low gas mass flow causes also a too high SLR and also eventually plugging.

A too low gas flow can also cause a too low velocity in relation to the suspension velocity, leading to sedimentation and plugging.

At a too high vacuum (too low absolute pressure), the gas mass flow decreases so much, that the SLR exceeds the limit of the system.

Normally a system gets plugged at a certain vacuum. If this vacuum is reached, the vacuum

increases suddenly and the SLR increases drastically followed by plugging.

Try to measure the vacuum where plugging occurs and the related SLR.

Then try to calculate the system under the condition when it worked satisfactorally in the past.

The difference between the actual measurements and the recalculated history could indicate the problem area(s)

Also check whether the pipeline ids still open and free of obstructions and/or leaks.

Also check the functioning of the eductor, whether enough mass flow is generated.

The interaction between the two systems (especially when they are running in parallel on the same eductor needs a thorough evaluation)

More data might be helpful to help you further.

success

teus ■