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  SEALING OF ROTARY DRUMS FOR OPERATION

  UNDER PRESSURIZED CONDITIONS

  M. Shirvani, M. H. Khanof, M. R. Yousefi, S. Sadighi

  ABSTRACT

  In practice, rotary drums are always designed for operation under vacuum conditions. In this paper, a novel technique is proposed for sealing the rotary drums under pressurized operation condition. The proposed system is based on applying a secondary pressurized volume around the leaking gap of the drum. By controlling the pressure of this volume, a little bit above the pressure of the drum, it will be possible to prevent from any leakage of gases to the ambient. The objective of controller in this system is that the pressure of secondary volume be kept above the pressure of the drum in spite of the disturbances which may exerted on the system by the wind outside the drum. The control system is also required to trace the variations in the drum pressure with the least fluctuations in the pressure difference between the drum and the volume.