Alumina Ceramic

Wear Resistance by Alumina Ceramic in Coal Mill Pulverizer and Pipe Line
Alumina Ceramic liners offered by us find extensive usage to strengthen resistance of surfaces from wearing as well as are also used for carrying out repairs of surfaces in coal mills. These Alumina Ceramic are designed to provide best performance and help in decreasing erosion possibility that is caused by pressurized air that carries entrained abrasive solid coal particles. Here, when angle of impingement is less than 30 deg, wear produced is closely analogous to abrasion and if the angle of impingement is greater than 30 deg to surface, particles from mill internals are dislodged by impact erosion.

Why Alumina Ceramic Liners:
* Accumulated coal particles have abrasive wear mechanism same as machining, grinding, polishing or lapping processes that are used for shaping materials
* Here, two body abrasive wear (coal dust & mill internals) occur when one surface (coal- harder than metal mill internals) cuts material away from mill body and internal
* This mechanism changes to three body abrasion as generated wear debris also act as abrasive with coal dust on mill internal surfaces
* The abrasion can be greatly reduced by fixing Alumina Ceramic Liners especially on high coal accumulation areas

Coal Flow Concentration Distribution Within The Model Pulverizer
A understanding the issue a study was conducted for seeing erosion pattern of coal mill internals that happened because of coal flow in vertical spindle pulverizers in PC Boilers. As coal & air mixture makes number of turns before reaching Multiple Port Outlets, here the changes in direction of flow cause majority of coal particles to accumulate in "Red marked" portion of the pulverizer as defined in the diagram.

Based on above study, we - BMW have developed the following:
* Alumina Ceramic Lined Mill internals
* Multiple Port Out Let
* Mill Discharge Valves
* Coal flow Orifices
* Coal Pipe and Bends
These are well elaborated under their specific sections.