Successful operation of ceramic rotary valves
at Karsdorf cement plant
M. Dikty, L. N. Lüth, KREISEL Engineering GmbH & Co. KG, Hamburg,
A. Akdag, OPTERRA Zement GmbH, Sötenich,
P. Kühn, OPTERRA Zement GmbH, Karsdorf, Germany
For many decades screw pumps and discontinuous pressure vessel systems were the only means of introducing abrasive bulk materials into pneumatic conveying systems. These two input systems are familiar for their specific power consumption and sensitivity to changes in the properties of the material being conveyed. Also worth mentioning is the high cost of maintenance, especially for the widely used screw pump. Because of the nature of the system it has to be operated at high rotational speeds and is therefore exposed to excessive wear. Thanks to the progress in the field of industrial ceramics Kreisel GmbH & Co. KG from Krauschwitz has succeeded in introducing a rotary valve to the market with gap widths between the rotating cellular rotor and the surface of the housing of less than 0.1 to 0.2 mm. This provides an effective seal and its wear surfaces are protected by a ceramic coating. For reasons of sustainability and energy efficiency Opterra GmbH, a subsidiary of the CRH Group, therefore decided in close cooperation with Kreisel GmbH & Co. KG to use ceramic rotary valves to replace the screw pumps that were previously used in the Karsdorf cement plant in Germany for the pneumatic transport of cement raw meal, bypass dust and electrostatic precipitator dust. After the pneumatic transport of bypass dust to the cement grinding plants had been successfully implemented using ceramic rotary valves in 2015 this was followed in 2016 by the project for pneumatic feeding of each of the two-string preheater towers of two dry-process kiln lines with raw meal. By the end of March 2019 ceramic rotary valves were also in use for pneumatic conveying of electrostatic precipitator dust. Two ceramic rotary valves were used for feeding each of the two preheater towers in the project realized in 2016. The valves are each driven by a motor with an installed rating of 5.5 kW while the screw pumps that had been replaced were each equipped with 160 kW drive motors. After this project had been implemented the Karsdorf cement plant was able to reduce its annual energy and maintenance costs by € 345 000.
Summary CEMENT INTERNATIONAL 03/2019 pp 46-53
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