Originally Posted by Rahulrom

Hi,

We have recently installed a coffee packaging machine. But the coffee powder is not settling due to lower bulk density. I would like to know how to increase the bulk density of pure coffee powder and also every coffee batch has a different bulk density, I would like to know how to maintain a single bulk density.

Current bulk density of coffee is ranging 0.28 to 0.32 . Packaging machine can perform well in terms of powder settling, if the bulk density is above 0.35.

Variations in the coffee density will arise more from the difference in voidage than from the solid mass of the particle. Finer particles tend to embrace a higher proportion of ambient gas during unconfined flow and are slower to deaerate, thereby having a wider range of density that is generally lower than coarser members.

Settling is time and scale related so the feeder supply route and equipment geometry should be examined to minimise flow agitation and maximise residence time in feed hoppers, plus providing local escape routes for excess air.

Get a specialist to review your system for best results and he may consider special de-aerating techniquies. ■

Einstein is credited with saying that insanity is doing the same thing over and over but expecting differing results. The same may be said of those that subject fine powders to differing feed and storage conditions and expect it to have the same density. Therein lies the way to secure bulk consistency. ■