The situation

In the end of 2006, HENFEL's technical team was invited to assess the situation of the iron ore pellet screens of three pelletizing plants of an important customer. The customer was facing an excess of non-scheduled maintenance shutdowns due to the premature contamination of the bearing housings of a competitor's make.

Iron ore pellet roller screen

In that ocasion, the technical team was informed that between 2005 and 2006, 65 maintenance interventions were required in order to solve problems, mainly due to premature bearing failures.

The solution

Based on the information gathered during the visit, HENFEL's engineering department developed a new model of bearing housing with special seal which is more suitable for the abbrasive / aggressive work environment due to the presence of taconite powder. Besides, the team made recommendations in order to solve other problems not directly related to the bearing housings, such as the positioning of the gearboxes, the connection coupling, and the type of lubricant that was being used.

Special HENFEL roller screen bearing housing

The result

After the replacement of the problematic bearing housings,the MTBF(meantime between failures) of the bearings increase and throughout 2007 and 2008 there was an impressive reduction in the amount of necessary maintenance interventions. 

Altogether, the maintenance operations of the roller screens lasted 4 hours and 33 minutes in 2007 / 2008. As a comparation, during 2005 and 2006, these equipment were stopped for over 69 hours.

Overall, the solution reduced the amount of interventions (- 48 required) and increased the equipment availability in 65 hours.