Design of gating system for ductile iron castings of low pressure inner cylinder in thermal power plant

In order to reduce the oxidation of molten iron in the pouring process and achieve smooth mold filling, the bottom pouring system scheme is adopted. Through comprehensive analysis of the structure of ductile iron castings, the inner runner is set at the bottom of the middle steam inlet pipe flange and the arc at both ends, and three relatively independent gating systems are formed, and the molten iron is introduced by three vertical runners respectively. The gating system is open, and the flow blocking section is located in the sprue. The ratio of the sections between different components is: Σ S straight: Σ S horizontal: Σ Within S=1 ∶ 1.2~1.5 ∶ 3.0~5.0.

It is worth noting that there is a large height difference between the middle steam inlet pipe flange and the circular arc on both sides of the surface, which is not conducive to the smooth filling of ductile iron castings. After accurate calculation, the liquid iron filling process is controlled and adjusted by using the delayed pouring process, so that the liquid iron level in the cavity at the bottom of the pouring system and at both sides of the cavity can smoothly meet and rise, and it is easy to cause backflow or turbulence when filling the liquid iron.

Scroll to Top