Val av teknik för hastighetsmätning i kallvalsverk
An often encountered problem when implementing a mass flow regulator in a rolling mill is the one with measurement of speed. The most widely used solution is to fit a pulse counter to a wheel that is in contact with the strip. Common problems with this design are for instance scratch marks on the strip and problems with the flatness measuring system. One way of circumventing the aforementioned problems would be a non-contact measuring system. The market of today only offers systems based on the Doppler principle.This report evaluates three different systems for non-contact speed measurement. Important areas in the evaluation have been the ability to operate under normal rolling conditions, integration in existing control system and how well the sensor can be fitted to the rolling mill. The potential gains and possibilities for improvements have also been evaluated. To be able to calculate the possible earning potential of the implementation of a mass flow regulator it?s very important to know how much scrap the rolling mill in question generates. The approximation showed that the average loss is 250 kg per coil which equals 2,5 % of the weight of a full size coil. It?s possible to improve this number with a perfectly tuned mass flow regulator. Focus for the near future ought to be on designing a solution for measuring speed with existing components with a Laser-Doppler system as a backup plan.