The Screw Manufacturing and Refurbishing Process

The manufacturing process starts with a cylindrical billet of the base metal that is oversized in diameter, as shown in Fig. 10.24(a). Prior to most steps, including at 

Mixing sections are cut into the biiiet next using the miiiing machine and iathe combination, as shown in Fig. 10.29(a). Depending on the mixer design, cutting these sections tends to be more time consuming. 

It is very difficult and not practical to decrease the depths of the flights by welding metal back into the channels. This level of welding is generally unacceptable due to the large level of bends that will occur in the screw. For this case, it is often less costly and quicker to build a new screw with shallower channels. 

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