Why perform a test on the straightener?
SWT had noticed changes in the noises associated with the straightener. The noise coming from the area of the drive units and gear stages was accompanied by noticeable vibrations, the cause of which could not be localized. This immediately gave rise to questions such as "How long will my equipment unit last?" and "Can I safeguard my production?" In particular, the large number of bearing points inside the drive trains of the straightener were suitable for analysis, as this puts a condition monitoring system to the test and enables the extension of a system of condition-based maintenance.
The strategy of conducting scheduled maintenance at defined intervals, which was used up to now, did not offer reliable protection against the kinds of failures experienced with the straightener in the past. With this type of maintenance, the reliability of the plant is increased by the targeted replacement of critical components, but a visual inspection and the sensors already installed do not provide a reliable indication of how long these parts will last. In addition, there was also the possibility that components were replaced before the end of their service life, which unnecessarily leads to higher operating costs.
The testing procedure
As the straightener was not equipped with the necessary sensors to supply the requisite data for reliable condition monitoring, SMS group proposed starting with a mobile measuring service. To this end, SMS group presented a solution that was put to use at Stahlwerk Thüringen GmbH: Genius CM® Mobile Service. The condition monitoring experts from SMS utilize a mobile Genius CM® system for temporarily recording and assessing vibrations. It can be used on a variety of different equipment units, especially drive trains.
Genius CM® Mobile comes with all cables, software, and licenses and can be kept in measuring mode close to the gear units for hours, days, or weeks at a time. Genius CM® Mobile can record up to seven vibration signals and one speed signal. Incipient or growing signs of damage to the antifriction bearings and toothing can be detected in this way.
At Stahlwerk Thüringen, six vibration sensors and a speed sensor were fitted to drive train 3 of the straightener. The vibrations on the motor, the distribution gear unit, and the drive and operator sides of the straightening machine were recorded in the process. Furthermore, the speed was measured on the drive motor. It took only three hours to install the pre-configured mobile measuring system.
This absorbed the vibrations on the motor, the transfer case and on the drive and operating side of the straightening machine. The speed of the drive motor was recorded also. The installation of the preconfigured mobile measuring system only took three hours.
The results
The measured data were recorded overnight within an eleven hour period. The next morning, they were evaluated by the SMS vibration experts and presented to the customer based on live data. The intuitive user interface and the analysis options of the Genius CM® software were also described in detail. The possibilities of AI (artificial intelligence) evaluations were also demonstrated.
Permanent installation of Genius CM®
The experience and findings gained from the test phase, the seamless connection of a permanently installed Genius CM® to the existing automation system, and the easy integration of additional signals from the section mill impressed Stahlwerk Thüringen GmbH. As a result, an order was placed for the permanent installation of Genius CM® on the straightener; the system was successfully installed in August 2021. Stahlwerk Thüringen GmbH has thus laid the foundation for an extended system of condition-based maintenance of their equipment.
Genius CM® is flexible and can be used for all metallurgical plant components along the entire process chain, from the steelworks to the finishing line, or from the monitoring of individual components to the condition monitoring of entire production facilities. SMS has its own in-house vibration experts who continuously develop the Genius CM® based on market requirements or customer feedback. What's more, SMS offers flexible service agreements on an hourly basis.