Tower Melting Furnaces
Silcarb manufactures Tower Melting Furnaces from 500 kgs up to 10000 kgs capacity with a throughput of up to 3000 kgs/hour. Tower Furnaces are mainly shaft furnaces which are manufactured keeping in mind the simplicity of operation and running costs the in mind. All castable and backup linings used are the best in the industry. Silcarb requests the customer to visit during the casting process of the Furnace. Silcarb uses various burners and burner combinations to get the desired fuel efficiencies. Furnace charging is done either from the top using a skip charger or end using a push charging system. The burners are located at the bottom of the tower.
The primary mode of heat transfer in tower furnaces is through convection by direct impingement of the burner on the metal in the lower section of the tower, and by the combustion gases as they travel out of the tower past the metal charged into the shaft. A variation of the tower furnace uses a grate system that lowers the metal through four grates, gradually heating the charge through each grate until on the fourth and final grate, the charge melts and falls into the hearth. Various types of Tap out Furnaces are made such as a direct bailout, tilting type and tap out cone systems. The advantages of the tower furnaces are high efficiency (40%-77%) and low oxidation losses. The disadvantages of tower furnaces are their high capital costs and the furnace size is restricted by height limitations. The high degree of automation, quality of the materials and simple construction of the equipment guarantees a reliable and efficient production with a high degree of the economy resulting in profitable production of molten metal.
Silcarb manufactures a stationary type of tower furnace as well as a tiltable furnace. The stationary furnace uses silcarbs in house manufactured tap out systems which are completely automated systems with pneumatic cylinders for operating the tap out plugs. The system is very robust and has all safety systems and interlocks provided.
The advantages of stationary systems being no turbulence in the melt and also dross free metal being drawn out from the bottom of the furnace, thereby having an almost dross free liquid available at the holding furnaces.
The tiltable furnace that silcarb manufacturers are run on high capacity hydraulic cylinders within built-in dampers and high-temperature seals. This is systems are simple to use and safe and also has metal tapped from the top of the furnace hence allowing silcarb to manufacture a furnace with a higher “metal depth” and making the furnace far more compact and economical as when compared to the bottom tap system. Higher throughputs can be achieved in a smaller shop floor are.
With a typical metal charge ratio of 50% of fresh ingots and 50% of shop floor returns the silcarb shaft/tower melter today achieve fuel a fuel efficiency of 500 kWh/tonne of aluminum melted.
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