Air Recirculation Fan

A customer suffered regular bearing failures on an air recirculation fan at an ore preparation plant, and a compressed air cooling system was used to reduce the high operating temperature of the bearing. An application review including a thermal study of the fan and bearings identified serious issues such as incorrect mounting, over-lubrication and inadequate sealing. NSKHPS Spherical Roller Bearings with labyrinth seals inside NSK SNN Plummer Blocks were recommended; no failure occurred for over 12 months and the compressed air cooling system was removed.

• Air recirculation fan — coal dust; 1 machine, operated with external cooling
• Bearing overheating, incorrect mounting, incorrect lubrication quantity and frequency
• NSK solution: NSKHPS Spherical Roller Bearings with labyrinth seals in SNN Plummer Blocks
• No bearing failure for more than 12 months
• 36 hours of annual failure downtime (€302,400) eliminated entirely
• Annual compressed air cost (€88,954) reduced to zero

Technical Features: NSKHPS Spherical Roller Bearing + SNN Plummer Block

• Spherical roller bearings with the highest load carrying capacity
• Optimum raceway design and surface finish
• Brass cage design (CAM) or reinforced steel cage (EA)
• High-cleanliness Z-Steel
• Temperature stability up to 200°C; 40 mm – 260 mm bore
• Up to twice the operating life; up to 20% higher limiting speed
• 25% higher dynamic load rating; enables size reduction