Six strategies for combating abrasion in your low-speed blender — Part II
Abrasion problems aren't confined to high-speed mixing equipment: They also affect low-speed blenders — namely, ribbon blenders and vertical cone screw blenders — with equally serious results. This two-part article outlines six strategies for fighting abrasion in your low-speed blender. Part I [June 2000] covered the first two strategies as well as low-speed blender basics and tips for assessing the wear potential of your abrasive materials. Part II covers the final four abrasion-fighting strategies.
Strategy 3: Protecting the shaft. To prevent particles from penetrating a ribbon blender's stuffing box and wearing the shaft, you can add a lantern ring inside the stuffing box, as shown in Figure 1. The lantern ring fits around the shaft and is packed with compressible [often Teflon] packing material to form a tight seal against the shaft. An air connection in the lantern ring is linked to a supply of 10- to 15-psi compressed air. During blending, air passes through the connection, out of the stuffing box, and toward the blender trough to entrain particles that have entered the stuffing box and direct them back into the trough, thus protecting the shaft from abrasive wear.