Vertical Coal Mill Seal Air Fan Solution For Ore Mining. Jan 18, 2021 Annual Rate Contract For Mechanical Maintenance Including Upkeepment And Equipment Cleaning Of Coal Mill And Auxilliaries Including Pa Fan, Seal Air Fan, Coal Feeder, Associated Ducts, Gates, Dampers, Pulverized Fuel Piping Etc Of Mejia Tps Unit 5, 6 - 15-02-2021.Cleaned air enters the mill fan.