Computer simulation of mechanical seal leads to design change that improves coolant circulation

Engineers at AW Chesterton Co. used computer simulation to improve the design of a mechanical seal and extend the performance limits established through laboratory testing. Using computational fluid dynamics (CFD) software to simulate the flow of fluid within the seal, it was determined that the barrier fluid, which also functions as a coolant, was not circulating to areas of the seal where heat is generated. A number of design changes were evaluated using CFD as a guide toward improving the axial circulation. Results showed that by tapering the bounding surfaces of the stationary seal rings and the shaft sleeve, axial movement of barrier fluid could be improved and heat removal increased by almost 50% compared to the earlier design. This change is now being implemented in some of Chestertonʹs product line, providing customers with a cooler-running, longer-lasting mechanical seal for centrifugal pumps and mixers. Chesterton is comprised of three business units: fluids sealing systems; which includes mechanical seals, mechanical packing and gasketing, and process pumps; hydraulic/pneumatic sealing devices; and technical products, which includes maintenance chemicals and ARC component materials. Many of the commonly accepted technologies in fluid sealing systems have originated in the companyʹs research and development labs, including such industry-changing developments as the original cartridge seals and the first commercial split seal.