热系统 -美国Ogden热系统
TUBULAR HEATERS
The most versatile of all electric heating elements， the tubular heater is capable of being formed into virtually any configuration. The basic design consists of a helical coil of nickel-chromium resistance wire precisely centered in a metal sheath. This coil is surrounded by magnesium oxide powder which is vibration loaded to insure even density throughout the length of the heater. This entire assembly is then reduced to the finished diameter， compacting the MgO and "freezing" the coil in the center of the heater. The range of ratings， sizes， materials and terminations available makes the tubular heater adaptable to many industrial， commercial and scientific applications.
Copper Sheath: Water heating， water solutions non-corrosive to copper.
Steel Sheath: Immersion in oils， molten salt baths， alkaline cleaning solutions， tars and asphalt. Also suitable for clamping to metal surfaces and casting into aluminum.
Stainless Steel Sheath: Corrosive liquids， food processing equipment.
Incoloy Sheath: Air heating， radiant heating， cleaning and degreasing solutions， plating and pickling solutions， corrosive liquids.
Other sheath materials are also available for application considerations. Commonly specified are 316 stainless steel and Carpenter 20 stainless steel for corrosive immersion heating， copper clad steel for metal casting， Inconel for high temperature applications， and titanium for severely corrosive solution heating. Porcelain and ceramic coatings can also be provided for corrosive atmospheres in process air applications， immersion heating， or for other application considerations.