Bending the sheet with the new deep-drawing device

On January 13th, members from SoWaDi met at the University’s campus to test some changes they have been considering for the past few months. In hopes of supporting the system’s new development, the focus of the day’s assessment was fixed on two important prototypes: the pipe-bender and the deep-drawing device. Additionally, the surface of the plexiglass was evaluated.

Before Christmas break, small groups from SoWaDi had formed to consider what changes could be implemented to improve the efficacy of the system. An initial test in Tanzania the previous year had revealed that bending the pipe and processing the sheets needed for the system’s construction were not consistently precise. To bend the pipe, the group had already filled a copper pipe with sand during the Regional-Group-Weekend. This approach gave favorable results with a short pipe, and was further investigated on whether this principle could be transferred to a pipe of eleven meters in length. After the pipe was filled laboriously-intensive with dried sand, a newly built pipe-bender was used to evenly shape the pipe into the best possible form without any constriction. Despite the group’s success with the sand-filled pipe, they soon had learned that it was much more difficult to get the sand out. Therefore, the group is still considering the efficacy of this approach and is keeping other options in mind.

However, for the deep-drawing device, a completely new approach was taken: the sheet was clamped down with a few screw clamps and then bent manually around a metal tube with the aid of a lever. In order to compare results, the small group conducted another test with the previous deep-drawing device.

A third small group investigated whether Plexiglas could be used instead of glass panes to cover the absorber box. The team tested the scratch- and heat resistance of the new material.

It still remains unclear to which extent these new concepts will be used in the future when the team returns to construct the system next year in Tanzania.