EGO Tubular Heating Elements - Technical Details Table of contents 1) Structure of the Heating Element / types 2) Configuration of Tubular Heating Elements 3) Thermal fuse 4) Connections 5) Shape of the heater tube 6) Dimensioning of Tubular Heating Elements 7) Compliance with standards September 2012 EGO Tubular Heating Elements - Technical Details page 1 of 12
1) Structure of the Heating Element / Types Structure Inside the metal tube, a heater coil is embedded and electrically isolated in highly compressed magnesium oxide. The optimized structure and very high density of the magnesium oxide form the basis for the excellent mechanical and thermal characteristics of the EGO Tubular Heating Elements. They also can be fitted with Thermostats and Temperature Limiters in most applications. Types We produce heater tubes with different diameters and shell materials to suit any applications. Tubular Heating Elements with oxidized surfaces are used to heat air, while bright surfaces are generally used to heat liquids. September 2012 EGO Tubular Heating Elements - Technical Details page 2 of 12
2) Configuration of Tubular Heating Elements Sectional view September 2012 EGO Tubular Heating Elements - Technical Details page 3 of 12
2) Configuration of Tubular Heating Elements Configuration of a Tubular Heating Element Tube diameter (mm) Tube shell material Heating tube length maximum (mm) Surface per cm length of tubes (cm²) Resistance (Ohm/cm) 4,2 6,5 8,5 Steel Stainless steel Steel Stainless steel Steel Stainless steel 300-2.900 1,32 0,1-2,98 300-4.700 2,04 0,04-3,00 300-4.300 2,67 0,04-3,00 September 2012 EGO Tubular Heating Elements - Technical Details page 4 of 12
3) Thermal Fuse Thermal fuse EGO Tubular Heating Elements with a diameter of 8,5 mm can be fitted with an integrated thermal fuse. Optionally, each end of the Tubular Heating Element can be equipped with a thermal fuse. The preferred cut out temperatures are 144 C or 152 C. Other cut out temperatures are available on request. Sectional view September 2012 EGO Tubular Heating Elements - Technical Details page 5 of 12
4) Connections Types of connection We supply a wide range of different connections for our tubular heating elements. Here are a few typical examples. Type of connection September 2012 EGO Tubular Heating Elements - Technical Details page 6 of 12
5. Shape of the Heater Tube Bending radii The initially straight heater tubes are bent into the required shape for the appliance in which the Tubular Heating Element is to be used. Standardized bending radii make the process easier and keep costs down. Tube diameter (mm) Minimum bending radius (mm), referred to tube centre Reference value deviations depending on the material 4,2 9 6,5 12 8,5 13 September 2012 EGO Tubular Heating Elements - Technical Details page 7 of 12
5. Shape of the Heater Tube Design September 2012 EGO Tubular Heating Elements - Technical Details page 8 of 12
6) Dimensioning of Tubular Heating Elements Dimensioning The determining factors when dimensioning Tubular Heating Elements are the specific loads and the temperature limits of the heated material, the tube shell and the heating conductor. If the heating element is accurately dimensioned, it will operate reliable and over a long period. This also requires the element to be installed correctly and have an adequate outflow of the heat. It is important that the temperature limits of the medium and suitable protection against boiling dry are considered if liquids are heated. Regulation DIN 44875 also includes recommended specific surface loads. Tube shell temperature The tube shell temperature depends on the specific surface load and the surrounding medium. A surface load of 5 W/cm² for operation in air, for example, results in a surface temperature of approx. 670 C (steady state). September 2012 EGO Tubular Heating Elements - Technical Details page 9 of 12
6) Dimensioning of Tubular Heating Elements Factors influencing the tube shell temperature Application limits for tube material: stainless steel, steel, copper September 2012 EGO Tubular Heating Elements - Technical Details page 10 of 12
6) Dimensioning of Tubular Heating Elements Specific loads Application Temperature of medium ( C) Air, static 200 5 Air, in motion 250 10 max. Baking oven 250 5 Grill 250 6,5 Radiant application 250 6,5 Water, static 100 15 Water, in motion (flow heaters) 100 40 Chemical baths Depending on media 6 Suds 90 10-15 Permissible specific load (W/cm²) on sheet material stainless steel(*) Remark Depending on air flow rate (m/s) Alternating operation in water/air 6 (*) Values are for guidance. Functional tests in the application must be done under the responsibility of the customer. September 2012 EGO Tubular Heating Elements - Technical Details page 11 of 12
7) Compliance with Standards Precise compliance with standards EGO Tubular Heating Elements are tested for compliance with German Electrical Industry Association standards (VDE) and comply with the following requirements: DIN EN 60335-1 Electric tubular heating elements for use in household appliances EU-guideline 1907/2006/EG REACH EU-guideline 2011/63/EG RoHS EU-guideline 2006/95/EG low voltage supply UL 1030 electric tubular heating elements September 2012 EGO Tubular Heating Elements - Technical Details page 12 of 12