Inkjet & Digital Printing

New turbine wheel for electricity generation

Wednesday 12. June 2013 - A defective turbine wheel meant that a small hospital in Ethiopia was no longer able to warrant the supply of its electricity. The purchase of new wheel did not appear feasible due to the cost. However, the problem was solved quickly and without bureaucracy due to the social commitment of several technology companies and the use of innovative production methods.

The project for the production of a new wheel was led by Swiss-based Turbal AG, a medium-sized family-owned company with 50 years of experience in turbine and equipment construction. Other participants in the direct-help project included voxeljet technology and steel foundry Wolfensberger.
The problem: The conventional production of wheels is an extremely cumbersome and expensive process because it requires the manual production of several sand core segments and complicated undercuts. voxeljet’s innovative 3D print technology offers an elegant, rapid and cost-effective solution for this problem.
voxeljet produced the Francis wheel for the flow-carrying interior area that was required for Ethiopia with a monoblock sand core. In this context, one single sand core, which is created on a fully automated basis using 3D printing, replaces many manually product core segments that are strung together. 3D print technology offers enormous production-related advantages that affect quality, production targets and profitability equally. In this case, the 3D print resulted in higher component accuracy, fewer cleaning requirements and an excellent surface quality and contour precision.
It also does away with conventional model construction, since the sand core for the wheel is produced on the basis of 3D CAD data without the use of tools and on a fully automated basis using the layer building method. This reduces the time required to produce the wheel by several weeks. In addition, the process also resulted in cost savings.
The Wolfensberger steel foundry, which is increasingly relying on voxeljet sand moulds for the production of complex cast part prototypes, was again very impressed by the quality of the 3D prints for this project. The cast also impressed Turbal AG. This ‘help for self-help’ project by the participating companies has restored the production of electricity at the clinic in Ethiopia.