Cast sleeve handling and filter system set new standards
Around 10,000 anodes are supplied monthly at the Essen aluminum smelter. Machining the iron cast sleeves is the most complex step in the process. They are used to fix the pins of the anode rods in the carbon anodes. The cast sleeves of used anodes need to be removed from the anode rods, freed of slag and then melted down before they are recast as new anodes.
TRIMET has taken advantage of the upcoming modernization of the cast sleeve handling equipment to implement a concept that takes into account a full range of processes, from the dismounting press to the shot blast machine to charging the two melting furnaces with the corresponding feed and discharge systems. The new blast machine cleans 300 kilograms of cast sleeves in just a few minutes. In contrast to the old system, it is much more productive, delivers better quality, requires considerably less energy and is several times more efficient. The cleaned sleeves are transported by a conveyor system to a round magazine mounted on a turntable, where they are deposited in charging containers for filling the furnaces. The new charging system has a larger volume than its predecessor and operates fully automatically. Manual refilling and the repeated transfer of material by crane and forklift are no longer necessary. Because all the equipment is now on a single level, workers no longer need to climb stairs. This eliminates the risk of accidents occurring.
Virtually dust-free and very quiet
In addition to improved quality, productivity, energy efficiency and increased work safety, the newly equipped anode rodding shop is also a big plus for the environment. The existing extraction and filtration equipment was completely replaced by a system with variable suction power that regulates itself and only goes into action when needed. This works like a modern radiator, where the thermostat regulates the room temperature in an energy-saving way, eliminating the need to turn a control knob. This system is efficient and saves energy, and the new sintered membrane filter elements achieve higher filtration values. In addition, the exhaust devices are precisely aligned with those operating points where emissions occur. This also includes reserves that can capture higher short-term emissions, such as those occurring at the melting furnace sprues.
The values that have been measured since commissioning provide impressive evidence of the progress that has been made. The dust concentration has dropped to 0.5 milligrams per cubic meter, well below the more stringent limit of 10 milligrams, which is currently in force. At 77 decibels, the noise level also remains below the permissible value. This achievement is the result of careful planning and a comprehensive concept that sets new standards.