Gating system capable of effectively controlling air entrainment and slag entrainment and design method thereof

The invention relates to a gating system capable of effectively controlling air entrainment and slag entrainment and a design method thereof. The gating system comprises a sprue, a runner and a plurality of ingates; the sprue is of a big-end-up conical structure, and the maximum cross-sectional area of the upper end is 1.5 to 3 times larger than the minimum cross-sectional area of the lower end; the runner is connected with the lower end of the sprue through a smooth curve, the radius of the curve is 1 to 5 times larger than the equivalent diameter of the runner, the cross-sectional radius ofthe curve is reduced, and the radius-reducing change is between 1 and 5 times larger than the cross-sectional equivalent radius of the runner; the ingates are connected with the runner, and the sum of the cross-sectional areas of the ingates is 2 to 10 times larger than the cross-sectional area of the runner. The invention solves the problem that the conventional gating system is not reasonable and can hardly guarantee the smooth filling and purity of molten metal, the phenomena of secondary oxidation, air entrainment and slag entrainment are prevented in the process of pouring molten metal, so that the quality of castings can be guaranteed, and the invention is suitable for the design of gating systems for the sand mold casting, metal mold casting, casting blank casting and precision casting of non-ferrous metal, ferrous metal, high-temperature alloy and the like.