FLUE CONDITION INDEX - A NEW CHALLENGE TO INCREASE FLUE LIFETIME, OPERATIONAL SAFETY AND FUEL EFFICIENCY IN OPEN PIT ANODE BAKING FURNACES

摘要

The condition of the flue walls in open pit anode baking furnaces is an important factor in terms of production efficiency. The flue walls change their physical properties which change the flow resistance, produce air leakages and even affect the mechanical stability due to the periodical heating/cooling cycle. Therefore the flue walls have to be observed regularly by maintenance staff and exchanged in average after a lifetime of 150 fire cycles. With the introduction of a flue condition index, each flue in a furnace is evaluated continuously. An on-line mathematical model detects the actual condition of each flue by correlation of the relevant process data available in the firing system. As a consequence the firing properties like the maximum fuel input or the draft can be adapted or limited to the actual condition of the flue. This prevents critical situations, avoids hot spots and increases operational safety, flue wall lifetime and fuel efficiency.