The Surface Electric Radiant Tube (ERT)® system and the Prolectric® is a versatile heating system for heat processing equipment that uses radiant heat. This system is capable of using the radiant tube’s electrical resistance property of the alloy as the heating source to replace your current gas fired burner within the tube. This electric conversion allows you to choose the most sustainable energy mode for your furnaces that use radiant tubes as their heat source.
For the ERT, thealloy radiant tube used with gas firing becomes an electrical resistor when powered by a low voltage, high current step-down transformer; in our case, a Variable Reactance Transformer (VRT). For the Prolectric, a stainless steel tube is energized and provides uniformity and long-life in carburizing applications. For both cases, the tube ends are connected to the transformer supplying a tunable current for the particular electrical input.
ERT® (Electric Radiant Tube)
Prolectric® Heating Elements
Heating Element Alternatives
| Small Diameter Prolectric® | Electrified Radiant Tube (ERT®) | Canned Bayonette Element | Silicon Carbide “Globar” or “Starbar” Type Element | |
|---|---|---|---|---|
| Use in Endothermic Atmosphere | Self decarburizing design relates to low maintenance |
Self decarburizing design relates to low maintenance | Element protected by external radiant tube | Element susceptible to shorting if carbon build up is present |
| Element Removal | From inside of furnace | From outside of furnace through bungs (Requires additional floor space) | Through top of furnace through flange connection | Through top of furnace through packing gland |
| Risk of Breakage | Extremely low | Extremely low | Smaller wires and ceramic spacers susceptible to breakage when maintenance is performed | Elements get brittle with temperature and will break if stressed |
| Typical Maintenance | Annual visual inspection | Annual visual inspection | Annual removal of elements and cleaning of radiant tube | Annual visual inspection and adjustment of transformer to adjust for resistance change in elements |
| Element Control | Hunterdon transformer | Hunterdon transformer | Line voltage SCR | Line voltage SCR |
| Element Voltage | Low voltage to reduce arcing risk | Low voltage to reduce arcing risk | High voltage (element can short inside radiant tube if scale is present) | High voltage |
| Element Life Expectancy | 3 – 5 Years | 3 – 5 Years | 2 – 3 Years | 2 – 3 Years |
| Radiant Tube Life Expectancy | N/A | N/A | 3 Years | N/A |
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