Overall casting process of mixed flow water turbine runner

Abstract

The invention relates to an overall casting process of a mixed flow water turbine runner. The overall casting process is technically characterized in that an overall sand core of a runner through-flowpart is manufactured through a 3D printing method; an anti-cracking rib is reserved on a blade area of a 3D printing entity, and a side hoisting groove, a top locating groove, a double-base locatingcore head and the like are reserved on a sand mould; and in the hoisting and core setting process, a dedicated annular sling and locating tool are used for guaranteeing the locating precision. After coating soaking and brushing and drying are carried out, the sand core is combined with an upper crown upper box sand mould and a lower ring lower box sand mould, then molten steel is poured, and the overall runner is manufactured. Compared with the process of carrying out casting and installing and welding in sequence, the overall casting process has the characteristics of being short in period, high in precision, high in quality and low in cost.

Description

technical field [0001] The invention belongs to the field of casting technology, and relates to an integral casting process of a Francis turbine runner, in particular to a Francis turbine runner casting produced by a sand mold gravity casting method (or centrifugal casting method). Background technique [0002] In view of the long production cycle of medium and small Francis turbine runners, especially the exposed central shrinkage area of ​​the cast small blades after processing, it is difficult to repair, and the blades wear and cavitation are serious during the operation of the runners. However, the size deviation of the inlet and outlet of the traditional integral casting runner is large, the error of the blade profile is large, and the overall dimensional accuracy of the runner is poor, which cannot meet the design and use requirements. Based on the above considerations, the present invention relies on the development and application of 3D printing technology in the cas...

AI Technical Summary

Problems solved by technology

[0002] In view of the long production cycle of medium and small Francis turbine runners, especially the exposed central shrinkage area of ​​the cast small blades after processing, it is difficult to repair, and the blades wear and cavitation are serious during the operation of the runners

However, the size deviation of the inlet and outlet of the traditional integral casting runner is large, the error of the blade profile is large, and the overall dimensional accuracy of the runner is poor, which cannot meet the design and use requirements.

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