Following items are key technologies to implement the successful endless rolling.
- Dynamic APFC (Automatic Profile & Flatness Control)
- Shear to split long strip before coiling
- Dynamic switching over of coilers during high- speed rolling and coiling
Primetals Technologies is the only supplier in the world that can supply a complete endless rolling system, and five hot strip mills are under operation with our endless rolling technology, with remarkable accomplishments. Primetals Technologies offers, in connection with the above, the following proven technologies for the customer.
- Dynamic Pair Cross Mill
- High-speed shear
- Advanced down coilers with switch-over function (Option: Carrousel coiler)
Fig.1- Dynamic APFC | Fig.2- High-speed shear | Fig.3- Coilers with switch-over function
Dynamic Pair Cross Mill
Dynamic Pair Cross Mill is a Pair Cross Mill which is able to change cross angle of the rolls during the rolling process. The feature allows the control of strip crown and strip shape during rolling (Dynamic APFC) in order to deal with flying strip thickness changes and growing of roll thermal crowns which occur at the continuous rolling.
Application and number of Dynamic Pair Cross Mill stands are customized in accordance with product range and other requirements.
Dynamic Pair Cross Mill can also be effective for normal batch rolling for compensation of thermal expansion of work rolls and changes in other rolling conditions in one bar.
High Speed Shear
High Speed Shear splits long strip before coiling at endless rolling. It is a rotary-type shear equipped with eccentric mechanism. Before shearing, drums are rotating with a gap in order to let strip go through. And at shearing the eccentric mechanism narrows the gap and has knives approach to shearing position. The speed of drum is set synchronized with the speed of strip at shearing.
High-Speed Down Coiler with Threading Direction Change Function
Endless rolling requires coiling facility special features. Threading starts immediately after the preceding strip had passed. And the threading speed is higher than normal batch rolling. In order to continue coiling without gap time, coiler is equipped with switch-over function which can change threading direction in high speed. Pinch roll with offset adjustment system is the core technology for the function. To ensure stable threading at carry-over table between No. 1 and No. 2 coilers, Pneumatic strip feeding system is introduced. Also, the down coiler it's self has a special configuration of 4 wrapper rolls which enables the smooth and quality coiling under the demanding condition.
Primetals Technologies were the first in the world to develop a hot rolling carrousel coiler. This is an alternative option to down coiler.
Fig.4- Carrousel Coiler | Fig.5- Carrousel Coiler Operation