Sendzimir Mill Management Systems

Introduction

The Mill Management System (MMS) is a set of computer programs which is designed for use by the operator of a reversing type rolling mill, using a computer located at the operator's desk, or nearby. Versions of the software are available for Sendzimir 20-High mills, and also for 6-high, 4-high and 2-high cold rolling mills. Programs are available to work in inch units or metric units.

The main program of the set utilizes a mathematical model of the rolling process to generate optimum pass schedules for the mill, and to set up the mill accordingly.

Any suitable computer using Windows XP or newer can be used, although, for the mill environment we recommend a "ruggedized" machine such as the IBM Industrial PC or rack mounted in a protected cabinet. Almost all new installations are Windows based solutions.

Systems have been supplied which operate on networks - this enables uploading and downloading of data to the MMS computer. The MMS computer can either be located on a PC network, or on a VAX network, using standard hardware and software (Pathworks) supplied by DEC.

Speed of Computation - Multiple pass schedules are optimized and displayed within one second normally.

Sendzimir Mill Management Systems

The MMS is covered by US Patent no. 4,745,556 and corresponding patents in other countries.

The MMS has many features that maximize and optimize production rates, these features include:

  1. To enable maximum reductions and rolling speeds to be utilized at all times, thus maximizing production rates.
  2. To achieve more consistent production rates from shift to shift, by running the same optimized schedules on every shift.
  3. To give new mill operators continuing instruction in setting up the mill - such as determining effective pass reductions, strip tension and speed settings.
  4. To take the guesswork out of the selection of intermediate gauges.
  5. To balance the Roll Separating Force from pass to pass, in order to achieve more consistent flatness, and minimize the requirement for changes in mill profile settings from pass to pass.
  6. To re-schedule the remaining passes to give maximum pass reductions, and balanced Roll Separating Force from pass to pass if the actual schedule deviates from the planned pass schedule for any reason, and at any point.
  7. The program is designed to take the maximum reduction on every pass, consistent with available mill power or Roll Separating Force, and with avoidance of roll skidding and consistent with good flatness and the desired strip surface finish.

The program has three main routines summarized below:

The Optimizing Routine

The optimizing phase establishes the minimum number of passes needed by the mill to achieve the desired final gauge. A complete optimized pass schedule is computed, where maximum reductions are taken on every pass except the last. The last pass is merely a "fill-in" pass which gets the gauge down to the final gauge from the last optimized pass.

  Pass Entry Gauge Exit Gauge % Red

For example, rolling from 0.050" down, supposing optimized reductions in a given case were given as follows:

1st 0.050" 0.037" 26%
2nd 0.037" 0.030" 19%
3rd 0.030" 0.025" 17%
4th 0.025" 0.020" 20%

The Rationalizing Routine

To obtain a balanced rational pass reduction schedule, which is necessary in a practical rolling situation, the program repeats the last four passes of the above optimized phase, but with pass reductions adjusted to equalize (substantially) the Roll Separating Force on these passes. This not only helps to produce a flat product, but will also result in a slight increase in rate of production.

  Pass Entry Gauge Exit Gauge % Red

Using the above example, the rationalized schedule might be something like:

1st 0.050" 0.040" 20%
2nd 0.040" 0.033" 18%
3rd 0.033" 0.028" 15%
4th 0.028" 0.024" 14%

The rationalizing phase thus establishes a new schedule using the same minimum number of passes established in the optimizing phase, but with the last four passes balanced for Roll Separating Force.

The Upgrading Routine (Recalculating Sequence Passes)

After any pass has been taken on the rolling mill, if, for any reason, the operator does not achieve the exit gauge specified by the computer, and achieves either a greater or lesser gauge, the computer generates a new optimized schedule for the remaining passes, by running the optimizing and rationalizing phases again when the pass is advanced.

  Pass Entry Gauge Exit Gauge % Red

In the above example, suppose the operator achieved a gauge of 0.043" after the first pass instead of 0.040". After the value 0.043" is typed into the computer, the program might give a new rationalized schedule:

2nd 0.043" 0.035" 19%
3rd 0.035" 0.029" 17%
4th 0.029" 0.024" 17%

The upgrading routine is of vital importance in any mill management program, since there are valid reasons why the computed schedule cannot be achieved in some instances. Possible reasons are:

Please contact us to learn more about our Mill Management Software and its features.