Optimum Operation and Maintenance of EL Pulverizers - Innovative .76. The Babcock and Wilcox EL pulverizers can provide outstanding pulverizer performance when optimum operational and maintenance practices are adhered to. Optimum operation of the EL pulverizer requires the following: • Coal fineness of 75% passing 200 Mesh and. <0.1% remaining on 50 Mesh. EL pulverizers that.how to maintenance coal mill,DETERMINATION OF PREVENTIVE MAINTENANCE TIME FOR .key words: preventive maintenance, coal mill, decision-random model. Abstract: The paper presents a determination method of the most advantageous time of preventive maintenance for milling assemblies used in the energy industry. In this particular case, we considered bowl-mill pulveriser assemblies used in power.