Skewed particle distributions with pour/dev

Hi,

We're using LIGGGHTS to study a problem in materials handling for the minerals processing industry. Particles enter into a rectangular containment vessel from several defined feedport regions near its roof - this is to simulate material flowing into the vessel through feedports from storage hoppers above (for various reasons we don't want to model the particles inside the hoppers themselves). The idea is that the vessel slowly fills up with particles until they physically block the feedports, at which point the feed rate into the vessel slows down or stops ("choke-fed" condition).

We are using "fix pour/dev" commands to feed various types of material into the feedport regions with specified flowrates and mass %. The problem (as noted in the LIGGGHTS warning messages) is that as the pour/dev regions become blocked with the particles filling the vessel, the specified flowrate cannot be achieved - the particle distribution (both size and composition) of the inserted particles becomes highly skewed and not at all indicative of a "constant and uniform feed material".

Is there any way to get around this limitation of pour/dev and force it to attempt to always add particles at a constant size distribution and composition, even if the flowrate is below what is specified?

-QR