Numerical Simulation and Evaluation of Campbell Running and Gating Systems

Abstract

The most common problems encountered in sand casting foundries are related to sand inclusions, air, and oxide films entrainment. These issues can be addressed to a good extent or eliminated by designing proper running systems. The design of a good running system should be based on John Campbell’s “10 casting rules”; it should hinder laminar and turbulent entrainment of the surface film on the liquid, as well as bubble entrainment. These rules have led to the establishment of a group of components such as high and low placed filters (HPF/LPF) and standard gate designs such as the trident gate (TG) and vortex gate (VG) which are incorporated in well-performing running system designs. In this study, the potential of the aforementioned running system designs to eliminate air entrainment and surface defects has been investigated via means of computational fluid dynamics (CFD) simulations. The obtained results suggest that the use of filters significantly enhances the quality of the final cast product; moreover, all of the gating system designs appear to perform better than the basic running system (BRS). Finally, the five in total running and gating system designs have been evaluated with respect to their ability to produce good quality cast products (reduced air entrainment and surface defects) and their sustainability component (runner scrap mass).

Energy Resilient Foundries: The “Small is Beautiful” Projects

“…considerable improvements with regards the use of material, an optimised casting system design can result in less material being recycled, thus reducing the embodied energy of the material and the associated emissions; reducing the critical superheat temperature that the material needs to be maintained at for assuring that the moulds are filled before it starts solidifying; As part of the SiB projects, various elements of the casting systems have been thoroughly investigated and correlated to the energy and resource savings. Indicatively, Papanikolaou et al [10] used computational fluid dynamics (CFD) to investigate and validate the potential of running and gating systems proposed by Campbell [11] to deliver enhanced quality castings. Salonitis et al [12] used CFD as well for designing the casting system and simulating the filling process, and integrated this model to a discrete event simulation model for optimizing the productivity of the whole foundry.…”

Influence of Gating System Parameters of Die-Cast Molds on Properties of Al-Si Castings

“…The melt loses pressure and speed, resulting in premature cooling and thus solidifying the ingate. Resistance pressure loses its effect and can be observed as shrinks due to material shrinkage when transiting from the liquid to the solid state [27]. Diminishing the areas of sections of the gating channels with the preservation of technological parameters shall increase the speed of melt flow and mold shaping cavity loading within a shorter period.…”

Archives of Metallurgy and Materials

“…Many fragments of the oxide layer, which covered most of the pore surface may be evidence that the porosity was formed by expanse of the double oxide layer. By Papanikolau work [9], it's assumed that the presence of a relatively strong oxide layer inside a pore, could be evidence of an old bifilm from the batch material rather than a new oxide layer entrained during the filling process. The thickness of the bifilm may perhaps be an indication that the oxide had a relatively long time to absorb Mg by diffusion.…”