Analysis Of The Thermal Behavior In The Sealing Cavity Of An Overhung Api Process Pump

Abstract

In recent years, cooling requirements for mechanical seals have become a subject of controversial opinions. While the maximum limiting temperatures of mechanical seals are known and specified by seal manufacturers, the actual temperatures in the sealing cavity of the pump stuffing box during pump operation are not readily available. A conservative approach has been to provide extra cooling to the stuffing box. However, the availability of clean cooling water is often scarce in many installations, and therefore, knowledge of the thermal behavior of the sealing cavity region becomes important. A developed analytical method, which utilizes the finite element analysis (FEA) technique to determine the thermal behavior of the pump stuffing box in the sealing region is presented. A single-stage overhung hot water (590°F) boiler circulation pump was analyzed. The stuffing box of the pump described herein the paper was equipped with API plan 23. The developed method is not limited to a specific API stuffing box piping plan, but can be used for a variety of cooling/flushing stuffing box configurations, such as API Plan 2, or others. The values of the heat transfer coefficients used in the method were found iteratively, based on published correlations for natural convection (Nusselt number vs Garashof number).