Part 1
For many tube mills faced with the constant challenge of adjusting or exchanging tooling for making tubes with different dimensions, a frequent question concerns the existing changeover equipment. Should the mill be upgraded with new tooling, i.e. rolls or roll stands, to speed up the “quick-change” process even more in order to save time and money in the long run?
The obvious answer is “yes” and, believe it or not, a brand new mill can be put into service over as short a time as a weekend. A further incentive, given recent technology advances, is that new mill bases can now be designed with extra space in mind for future additions.
So why are many old mills still in use? Quite simply, an upgrade from the conventional design can sometimes turn out to be complicated and the cost not easy to accept. However, mill operators who want to succeed in growing their businesses really have no choice. Moreover, upgrades don’t require a single big leap into the future. They can be carried out one step at a time.
Step one is likely to be an investment in new mill bases and movable subplates called “rafts” on which the roll stands are mounted. The rafts are aptly named because their portability provides the flexibility needed for faster and smoother quick-changes compared to the conventional method.
The next steps for speedier quick-change will likely introduce automation for changeover and tooling settings, including automatic connections for universal joints, coolant lines and other devices. At the same time, plenty of physical work will also be required for changeovers, including the use of overhead cranes or forklift trucks to remove and replace the rafted stands on the mill bases.
In Part 2, we will delve deeper into aspects of the “rafted” mill design.
Vincent Van Gogh
“Great things are done by a series of small things brought together”