Density measurements should be related to the operating conditions of interest for meaningful results. Wall effects on particle structures influences the packing array many particles from the surface so different results will be given with containers of different size and shape. Dynamic, on-line measurement opens a can of worms if comparisons are to be made with static values. However, given a reasonably consistent flow rate, it should be practical to use a small, mass-flow type buffer chamber on load cells between two flexible diaphragm chute connections. Upper and lower flow inserts should be fitted to minimise the transfer of flow pressures and eliminate velocity contours across the flow channel. The weight of the coherent, bed flow column would yield a reliable on-line continuous plot of the product density in a stable density state. To my knowledge there is no commercial device available of this type but it is an interesting concept and, through Ajax Equipment, I would be pleased to co-operate in its design and manufacture if this is of interest. ■

If you currently utilize a flood-fed weighbelt feeder for metering the kibbles, you can simply use the net material weight reading from the loadcell.

The cross-sectional kibble profile will be constant, so the only weight variable will be the bulk density.

Regards, Delmar Schmidt

Melfi Technologies Houston

www.melfitechnologies.com ■