A method of direct thermal conditioning of mechanical seal faces: CFD, empirical analysis and testing

Existing API flush plans provide indirect cooling conditions for mechanical seals not only to enhance the durability of the seal but also contribute to the overall efficiency and performance of the machinery. This concept thermally conditions the mechanical seal faces by circulating cooling or heating fluid directly through a process isolated flow channel formed by a specially designed stationary seal ring and a modified seal gland. Test results under both wet and dry running conditions at low rates of coolant flow exhibited significant performance improvement. An exponential increase in dry running PV limit was experienced throughout extensive testing. In addition, significantly lower wear measurements were consistently recorded. Results obtained from CFD modeling agreed well with both wet (water) and dry (nitrogen gas) process fluid data. An optimized direct thermal conditioning design of the stationary seal ring can be a key factor to: o Eliminate the need to maintain circulating fluid pressure above that of the process. o Increase sustainability with reduced environmental leakage. o Increase efficiency in thermal conditioning of the seal, thereby reducing energy requirements. o Avoid compatibility requirement between the circulating and process fluids. o Reduce life cycle operating costs.