Calrod® tubular heaters are electric tubular heaters used to produce radiant heat in an application. Calrod® heating elements can be found in incoloy, stainless steel, steel alloys and are used in many applications such as kitchen appliances, flange heaters, screw plug heaters and over the side heaters. Watt density for Calrod® heaters vary as they can be used in air and liquid applications, and are also used in mold designs to help with heat transfer from the Calrod® heater to the steel or aluminium mold. Calrod elements come in a variety of shapes and forms and also come in four specific common diameters: 0.315, 0.375, 0.430 and 0.475 inch diameters. Calrod® heaters can be terminated with common 10-32 screws or have special terminals to assist in electrical connections. Calrod® heaters that are used in air applications should have a watt density of less than 25 Watts per square inch while Calrod elements that will be used in liquids should have densities of 30 WPSI (Glycol applications) or 65 WPSI (Water applications). Please consult with a Wattco representative for assistance on density.
Calrod heaters are normally mounted on the side of a wall using brass bushings and a nut that holds the element in place. It is always suggested depending on the shape and form of the element to use brackets to prevent vibrations and to give the element additional structural support that is needed. Calrod elements might be susceptible to calcium deposits in water applications. This would require maintenance to prevent buildup and, eventual failure of the element from poor heat transfer into your medium. Water softening agents are used as a preventative measure.
Calrod elements have quick heat up times and are used in applications that require durability and various changes in temperatures. The wire inside a Calrod element is called NiCr (Nichrome resistor) and is the main source of heat. It is encased with MgO (Magnesium Dioxide) that offers excellent heat transfer properties.
The various types of products that use Calrod heaters are:
Screw Plug Heaters
Over the Side Heaters
Temperature controllers are used for these applications. Mechanical thermostats are often considered for their low amperage qualities. For more accurate measurements, engineers opt for digital controllers that offer precise measurements.