Comparison chart between common halogen heaters and kanthal heaters. Please refer to it in the operation and equipment design of heat sources.
Halogen heater |
Kanthal heater |
|
| Outline | ・A bulb-type sealed heater derived from an incandescent light bulb. The heating element is made of tungsten (W). |
・Derived from an electric heater, this open-type heater contains a heating element inside a quartz tube and uses kanthal, an alloy of Fe, Cr, and Ar. |
| Usage | ・The melting point of tungsten is 3420 degrees. ・Various temperature settings are possible. ・The main application other than heating is in the field of lighting. |
・Melting point of heating element is 1500°C. ・Used for heating liquids such as pure water and chemical solutions. ・The main application of heating elements is industrial electric furnaces. |
| Stracture | ・Coiled tungsten is sealed inside a quartz tube. ・A retaining ring holds the coil in the center of the tube to prevent the heated coil from directly touching the quartz tube. (The softening point of quartz glass is 1600°C) ・The introduction part is made of molybdenum (Mo) foil. (Avoiding breakage due to the difference in thermal expansion coefficient between quartz and metal) |
・The heating element is processed into a coil shape, several entrance examinations are made to inscribe it in the quartz tube, and it is fixed to the end of the quartz tube, the part from which the introduction battle is drawn out, with an insulator such as silicon. ・A thin Teflon tube is used as a function of intake and exhaust with the outside air. |
| Shape | ・Complex shapes such as straight, ring, parallel, and double-tube structures can be manufactured. | ・Shapes similar to halogen lamps can be produced, but there are limitations to the coil shape and it is difficult to produce them with thin quartz tubes. |
| Power | ・The foil sealing structure described above limits the power to 4000W at 200V (20A). | ・Although there is a limitation in the winding shape of the strands, it is possible to produce more than 6000W at 200V. |
| Feature | ・About 1~2 seconds to reach design temperature . ・The low heat capacity of the heating element allows for quick cooling time and excellent temperature controllability. |
・Requires 1-2 minutes to reach design temperature. |
| Lifetime | ・The load on the tungsten coil changes depending on the color temperature at the time of heat generation, and the life of the tungsten coil also changes. Color temperature: K=heat generation temperature + 273 degrees Celsius ■2300-2500K Average life time 5000 hours (for liquid to resin) ■2800K Average life time 3000 hours (for metals and semiconductors) |
・Wear and tear of the heating element causes the thinning of the strands, leading to wire breakage. ・Average life time of normal products is 10,000 hours. |
Current control |
・The temperature characteristic of the heating element causes an inrush current six times the electrical capacity at startup due to low electrical resistance at room temperature. (2-3 cycles) ・Larger electrical capacity of the control circuit or slow-up control is required. ・Current control and slow-up control by SCR is necessary. |
・Since no inrush current is generated, the electrical capacitance of the control circuit is sufficient to control the output value. |
