Aluminum Ingots Melt Efficiently with Watlow Circulation Heater


The customer wants to preheat the fuel oil that melts the aluminum.


The customer producs aluminum ingots. They are burning fuel oil that is used to melt aluminum in a large furnace. During cold weather the customer preheats the oil which is burned in the furnace to improve the combustibility and consequently, the efficiency of the oil. In the past, the customer was not preheating the oil and have now decided to preheat it to improve its burn efficiency by 10-20%.


A 5 in. circulation heater was chosen. This heater was chosen so that only the oil being used would be heated. The circulation heater has integral temperature controllers built in, therefore allowing the customer to vary the temperature of the incoming oil to maximize fuel efficiency. A stock circulation heater, all steel construction, 8 W/in² was selected. The customer had experimented by using 23 W/in², but severe cooking resulted.

Key features of Watlow heaters:

Advantages of the Watlow stock circulation heater: 

  • -Rapid delivery 

  • -Immediate spare parts availability 

  • -Integral thermostat control to allow varying the temperature of the fuel oil to fit the load of the burner 

  • -Efficiency, since only the fuel oil being used would be heated