Design of ventilation system to prevent epoxy fume release from vacuum pressure impregnation

In this study, a model for the exhaust of epoxy fumes generated by vacuum pressure impregnation (VPI) was developed using computational fluid dynamics (CFD), and an optimal design for minimizing the fume exhaust time was developed to improve the safety of the working environment. VPI is a process of durability reinforcement by impregnating epoxy varnish insulators to the windings in the stator. In addition, the VPI process can be used for applications such as coating, sealing, and insulating porous parts. The VPI process tanks are composed of a working tank with an inner tank. As the working tank is opened after the vacuum and pressurization to proceed with the final step of the process, the epoxy fumes derived from the resin can leak into the environment. To address these safety and environmental problems, an epoxy fume exhaust process is required. Therefore, a case study was conducted using CFD to validate the exhaust efficiency of epoxy fumes by rearranging different exhaust methods. It was found that the method of using pressurization yielded a higher fume exhaust efficiency (99.46 %) than did the depressurization method (96.42 %).