High accuracy mill load data in real time can increase the utilization of installed power without risk of overfilling the mill. By using trunnion roller bearings with integrated load sensors, actual mill load can replace motor power for control of the milling process. This means the useable milling capacity can increase whilst, at the same time, limiting the risk of downtime. The result? Increased output, improved process reliability and simplified process control with additional operational insights hitherto unachievable.

What our customers think

“SKF has developed a technology called SKF Insight sensor-bearing for live measurement of bearing load.

An SKF Insight sensor-bearing application to measure the fill rate of a horizontal grinding mill (HGM) has been field tested in collaboration with LKAB. This innovation has been used to control an HGM during operations and, from the point of view of reliability and accuracy, the technology has exceeded expectations. LKAB has demonstrated that SKF Insight sensor-bearing improves milling capacity and will continue exploring the potential increase in plant production capacity in dialogue with SKF.

The SKF Insight sensor-bearing has proven to be a robust technology for controlling HGMs with high accuracy. We see this as a powerful tool in our effort to continue developing a world-leading minerals processing operation.”

Carina Lejon, Manager Minerals Processing, LKAB Svappavaara

How does it work?

One output from the system is a control signal representing the mill load. Usable for controlling i.e. ore or grinding media feed rate. Additionally, the large number of sensor positions allows for measurement of load angle.

SKF uses the fiber Bragg grating (FBG) method utilizing the precise reflective effect of a grating written in the core of an optical fiber. This makes it possible to monitor the strain seen in the specific location caused by a local temperature or stress field.

The FBG technology is a well-established sensing technology that basically acts as an optical strain gauge.

With FBG technology, it is possible to simultaneously measure a large number of FBGs in a fiber. Using a fibre optic cable the strain data can be transferred at very long distances up to or above 10 km and is insensitive to electro magnetic disturbance.

SKF rolling bearing and bearing housing allows for a robust integration of the sensorized bearing. The bearing and housing unit is designed to allow simple connection to the optical sensor unit and onwards to the SKF data process unit, DCS or similar systems.