A novel mechanical seal design with superior thermal characteristics

Abstract

A mechanical face seal is an important component of variety of pumps used in chemical, petrochemical and process industry. The primary function of a mechanical seal is to prevent leakage of the process fluid from the pump housing and shaft to the environment. The factors that affect the performance of a mechanical seal to leak are friction, wear and its thermal characteristics. Improving upon the thermal characteristics of a mating ring in a mechanical seal would enhance its performance. Implanting a heat exchanger in the mating ring hold great promise for improving the performance of mechanical seals from the viewpoint of reducing heat at the interface and hence enhance the performance of the mechanical seal. To reveal what affect the implanted heat exchangers can have on the thermal characteristics of different seals, in this thesis, three different designs of mating rings were tested in a test rig and the results were compared to a conventional seal in this thesis. A new design of a mechanical seal with an implanted heat exchanger in its mating ring is reported. The mating ring incorporates an internal channel in which a coolant (either a gas or a liquid) flows to remove heat from the seal face. Prototypes were built and tested in a pump. Results are indicative of effective cooling and improved performance when compared to a conventional seal. A Coating on the mating ring was successfully implemented. A simplified heat transfer analysis using the results of the finite element method is also presented for all the seal designs.