KBS Kokerei betriebs gesellschaft Schwelgern GmbH, Duisburg:

M. Cremer, Eng., machael.cremer@thyssenkrupp.com

The coking plant Schwelgern started production in 2003. It produces high-quality coke for the iron ore production at the blast furnaces of ThyssenKrupp Steel Europe AG in Duisburg. It has been a big challenge to handle the new plant and perform the production schedule. In addition to this we had to set-up the coke oven door maintenance process for the biggest oven doors all over the world. It is necessary to check the doors continuously to ensure the tightness and thefunction of the door cleaning elements. 8.43 m oven doors are weighing more than 8 t. The tightness is on the most important details, which has to observe in asteady ongoing process. The responsible management decides to start a Six Sigma project called “Revise of the cokeoven door maintenance” to check all 280 doors yearly. The project started in November 2009. The Six Sigma technique includes the following stages of solving the problems: definition, mesaurement, analysis, improvement and control. Content and results of each stage are described and illustrated, including reorganization of the process and intensive investigation of the process showing its further potential. This publication showsthe DMAIC-circle to improve the door maintenance process so we are finally able to set-up an optimized maintenance instruction for a yearly check of all the 280 doors.