The first Christian Pfeiffer ultrafine classifier ROC for industrial minerals. Installed at Bernegger GmbH in Austria

Christian Pfeiffer Maschinenfabrik GmbH developed the ultrafine classifiers ROC and U-ROC designed to produce industrial minerals. Christian Pfeiffer specializes in the design of efficient processes in the grinding and classification of bulk materials. The classifiers meet the increasing requirements for reaching higher product fineness and to achieve particle sizes down to d98 < 3 µm. In July 2021, the first two ROCs were commissioned at Bernegger GmbH in Austria for the classification of limestone and zeolite. The products were subject to the highest quality standards and had to be absolutely free of grit at the highest fineness.
Both classifiers, which took only 5 months to build, were installed in an existing building. The mechanical and electrical installation, including programming, took one additional month. The ROCs were designed to produce capacities of up to 25 t/h. The complete plants consist of a piping circuit and filter systems.
The installed ROC-22 are dynamic cross-flow rotary classifiers rotating at up to 2500 rpm. By counteracting centrifugal and air forces, a precise separation cut below 10 µm is achieved. The fine limestone powder obtained, is used for example, for special fine plasters. Due to the material’s special structure with an extremely large grain surface, the zeolite is further processed for a wide variety of applications.

To be able to guarantee the required fineness, a classifier prototype was developed and put into operation at Christian Pfeiffer’s technology centre at its headquarters in Germany. The outstanding performance of the ROC classifiers is based on the results of complex flow simulations and modern calculation methods for dimensioning and designing highly accurate equipment. The company's extensive experience with dynamic classifiers formed an essential starting point for the design of the classifiers. Delivery to Bernegger GmbH was followed by an intensive test phase with trial grinding and classifying as well as iterative product analysis.
The systematic development and precise adjustment of the classifier lead to the production of the required product fineness. For Kurt Bernegger, Managing Partner at Bernegger GmbH, the installation of the ROC classifiers is a great success and the professional cooperation with Christian Pfeiffer Maschinenfabrik GmbH is highly appreciated. "The ROC classifiers from Christian Pfeiffer meet the high demands on our product quality. The ROC classifiers allow us to expand our product range, a real economic advantage for Bernegger GmbH."