Role of Chamber Design, Seal Selection, and Pump Operation on Leakage from End Face Mechanical Seals, 1994 Environmental Conference Proceedings

T. C. Suprise, C. J. Ropp, E. T. Krogel

Many pulp and paper mill centrifugal pumps are not operated at design head and flow. In addition to wasted energy, there are other consequences from such off-design operation. These include dry running, air ingestion, vibration, cavitation, and internal recirculation. These conditions are generally regarded as detrimental to the reliability of end face mechanical seals. However, little direct evidence of the role of these off-design operating conditions on seal performance is reported in literature.

An industrial size pump is equipped with single pusher, single bellows, and double bellows mechanical seals in a stuffing box designed for compression packing and in an enlarged seal chamber. An acrylic pump is also equipped with an enlarged seal chamber to apply High Speed Videography and Laser Doppler Velocimetry techniques. The pumps are used to investigate temperature rise at the seal faces and damage to seal faces, secondary seals, and seal hardware of the various seal designs and arrangements during off-design pump operation. Seal designs, seal arrangements, and seal chamber designs are suggested to reduce downtime and leakage from pumps and agitators.