Black Ice Deflectors on IMD Granulizers for Improved Flow of Coffee

BY Cyberoptik | July 25, 2017 | Case Study , Coffee

MPE’s Black Ice Deflectors (pictured above) are another design innovation found inside IMD Series granulizers. Their function is to make sure oily and static-charged ground coffee falls consistently into lower sections


After coffee is ground by the top section, it takes on a static charge, which, along with the help of the coffee oils, causes it to stick on the inside surfaces of the roll chamber. Gravity makes the coffee fall into the subsequent rolls, however not consistently—at least not without the help of the Black Ice Deflectors.

Without these deflectors, coffee accumulates like snowpacks on the internal surfaces and then falls like an avalanche. These avalanches are hard spikes of resistance detrimental to rolls, components, and motors. The sheering function of the rolls suffers when the rush of coffee forces its way between the rolls leading to crushing, which is not good for achieving accurate particle size distributions. Some manufacturers answer the problem by having chains inside each chamber that slide across angled deflectors. But this is a purely mechanical approach not favored by MPE because while chains manage the problem, they do not solve it. Coffee particles still accumulate like snowpacks waiting for the next chain sweep, merely dividing up the avalanche into many smaller ones.


The approach favored by MPE is a two-fold solution. First, a vibration device behind each panel renders the entire surface unstable and virtually impossible to stick to. Secondly, application of the food-grade non-stick Black Ice coating on the deflectors helps transient particles in their downward slide into lower chambers. This two-prong approach achieves a consistent rate of coffee always falling into subsequent rolls, which completely eliminates torque spikes and achieves the most accurate particle size distributions.

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