Optimal Design of Investment Casting System for a Stuffing Box with Pedestal of Centrifugal Pump: Computer Simulations and Experimental Verification

摘要

The stuffing box with pedestal (SBP) is a major component in centrifugal pumps (CPs). It is responsible for the transfer of load generated in the CP to the baseplate of the pump and finally to the ground. SBPs are usually fabricated using investment casting; however, this process is prone to residual casting defects, which can reduce mechanical strength and increase the likelihood of crack formation following long-term usage. In this study, the AnyCasting numerical simulation software package was used to optimize the investment parameters for the casting of an SBP in SUS304 alloy. Optimization efforts targeted the shrinkage cavity (based on retained melt modulus) and porosity defects (based on Niyama criterion). The results of preliminary simulations and experiments informed the establishment of five casting schemes for subsequent simulation. We used virtual thermodynamic sensors to determine the rate and direction of solidification in the mold cavity, and also investigated variations in the velocity of the molten metal at the inlets of the gating system as a function of time. The optimal casting parameters derived in simulations were assessed by fabricating an SBP via investment casting in a domestic foundry. Nondestructive testing based on X-ray analysis revealed none of the detrimental defects commonly associated with this type of casting.