Granulizer rolls, journals, and bearings are designed for precision grinding in large volumes. With applications requiring tight particle distributions and roll gaps as small as 50 microns, stabilizing tolerances and controlling temperature can make all the difference between a great coffee product and an inferior one.
Heat alters tolerances and contributes to faster mechanical wear. Heat on just a single bearing can throw off the parallelity of the rolls and significantly alter particle distributions and reduce overall precision.
To control the heat of the components, one of MPE’s signature engineering designs is genuine thru-water cooled rolls found on most IMD models. The idea is simple; running water through both sets of bearings and journals—and rolls of course—so that they stay a consistent temperature during operation. This two-sided cooling keeps the rolls in perfect parallel operation and reduces component wear.
Water-cooling designs seen on competitors’ industrial coffee grinders are usually one-sided. And while this may adequately cool the rolls and prevent an undesired 2nd roast of the coffee, non-cooled bearings on the other side are liable to increased heat-related wear and metallurgical expansion leading to a loss of roll parallelity. This loss results in a less precise grind, and consequently, a lower quality ground coffee product.