Casted heaters (aka cast-in heaters) are normally custom made. Quite often it is a formed tubular heater or coil casted into aluminum or bronze. For food products, cast-in heater can be sheathed in quartz, Incoloy or Inconel. The difference between aluminum and bronze is the process operating temperature and watt density. Aluminum is used up to 400 deg F and 100 watts per square inch, while bronze is used from 400 – 750 deg F and 60 watts per square inch. Air-cooled cast-in heaters operate with less maintenance and longer life than liquid-cooled cast-in heaters.
Cast heaters have usually a longer heater life than other heaters, but the investment costs are typically higher. For testing purposes, a cost efficient sand mold can be used to produce the first couple heaters.
Cast In Heater Application
Very common applications are food industry, plastic processing and medical equipment. 99.5% pure aluminum cast heaters are used in the semi conductor industry.