In a Hot Strip Mill (HSM), the slab travelling between the roughing mill and the finishing mill is called a 'transfer bar'.
The irregularly shaped head and tail end of each transfer bar must be trimmed in a 'crop shear' in order to avoid cobbles when the transfer bar is rolled into a very long strip and subsequently coiled.
If too little of the head or tail is cropped the excess material may cause problems when rolled, such as cobbling of the entire bar, marked rolls, or a torn off tail that stays in the mill and cobbles the next bar. If too much is cropped the good material that is wasted may be worth several million dollars per year.
The process by which an ideal length of material is trimmed off the head and tail end of each transfer bar is called 'crop optimization'. Today an upgrade to a state-of-the-art crop optimization system is one of the highest payback improvements possible in a Hot Strip Mill.
Many suppliers offer crop optimization systems, using widely differing technologies and with scopes of supply ranging from extremely simple to extremely complicated. The difficulty of testing a crop optimization system on line makes it possible for all suppliers to make very optimistic promises of performance, but real results and actual savings have often been disappointing.
KELK makes it easy for a customer to confirm which competitive system is really best. There are four processes in crop optimization:
- Imaging of the head and tail
- Determination of the optimum cut lines
- Tracking of the cut lines to the shear
- Control of the shear blades in order to hit the cut lines exactly
There are errors associated with each of these processes which add together into an overall cropping accuracy figure. By using the most accurate components in the world for each process KELK engineers can guarantee, in writing, the best overall cropping accuracy for each application.
KELK Crop Optimization performance guarantees have never been equalled by any competitor, and have been met or exceeded 100% of the time.
The greatest savings reported by a KELK Crop Optimization user so far?...USD $18 MILLION PER YEAR!