Experimental investigation on the characteristics of ash layers in a high-temperature wire-cylinder electrostatic precipitator

•Characteristics of four typical ash deposition forms is analyzed.•Ash belts form at low voltages and will overlap to form ash ribs when T⩽500°C.•Smooth slope type ash layer forms at high voltages when T⩾500°C.•Thickness growth rate of a given point decreases with the increasing time.•Back corona discharge onset voltage decreases with ash layer thickness lineally.