The stirring shaft of a frame-type mixer has broken – how to repair it?

Any metal or anti-corrosion coating that is damaged should be replaced; it is necessary to contact the equipment manufacturer to obtain spare parts for replacement.

Do it yourself – use butt welds of seamless steel pipes to restore it to its original length

The key is to determine how it broke – whether it was due to corrosion or insufficient design strength, etc. Only by accurately analyzing the cause can appropriate measures be taken to resolve the issue; otherwise, it will break again after repairs

1. Bevel groove, low-current surfacing, followed by correction; 2. Machining of the entire shaft

This post was last edited by qwl on 2018-1-19 08:44. Butt welding is feasible, but stress-relief heat treatment is required. Post-weld heat treatment, also known as heat treatment after welding, is primarily intended to prevent cold cracks that may occur due to internal stresses as the weld cools down. If nothing is done, it will still break.

This post was last edited by jmdc on 2018-1-19 09:11. The mixing shaft is likely a seamless steel tube with dimensions of φ108×10. The breakage occurred at the lower end of the reinforcement plate under the connection flange, as shown in the schematic diagram

This post was last edited by CHANGBAISHI on 2018-1-19 09:33. Usually, this component needs to have a certain level of torsional strength, mainly due to the resistance encountered during mixing. It can be used as a temporary solution, but it’s better to replace it with the original manufacturer’s version. There is also the issue of the service life; if it gets damaged frequently, it will inevitably affect production, which would be counterproductive. It is also necessary to consider whether the corrosion products have an impact on the production materials. The most important thing is to address the issues related to mixing resistance, such as material caking, crystallization, scaling, foreign particles, as well as the viscosity and humidity of the material, to ensure that they meet the design requirements for using the equipment. This is the most crucial one.

How to straighten it? During butt welding, it’s not always possible to ensure precise alignment; using a solid shaft is too heavy

Judging from the cross-sectional shape, it’s due to excessive torque~~

+1 upstairs; the torque is not sufficient. How long is the shaft? Solid shafts aren’t heavy either, and carbon steel isn’t expensive. These days, I make some of the larger blades solid. Customers don’t provide information on the viscosity of the materials, which leads to various issues and blame-shifting when problems arise. . .