MODUTHAL. Electric Embedded Elements MODUTHAL. Fully interchangeable ceramic modules for temperatures up to 1350 C

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1 MODUTHAL Electric Embedded Elements MODUTHAL Fully interchangeable ceramic modules for temperatures up to 1350 C

2 MODUTHAL Heating Modules Description Kanthal embedded elements are prefabricated radiant heating modules designed to suit a wide range of thermal processing applications at element temperatures up to 1350 C. To optimise performance all element coils are fabricated primarily from Kanthal A-1 and Kanthal AF resistance Alloys depending on the application. The coils of resistance material are held in place in a non electrically conductive, castable, high quality ceramic to form the MODUTHAL panel. The coiled element may be fully embedded, semi embedded or open coil, with the coils being fully or only partially supported by the refractory. The construction method ensures accurate positioning of the coils and eliminates the possibility of the sagging, distortion and coil migration associated with conventional open coil elements in grooves or on tubes. The high thermal conductivity of the embedding refractory ensures improved heat distribution when compared with exposed coils. Multiple zones can be used to provide sophisticated temperature uniformity within a furnace and due to the modular construction of the element system individual units can easily be replaced without altering the furnace characteristics. Kanthal has taken a major step forward with the introduction of MODUTHAL Fully Embedded, Semi Embedded, Open Coil and High Temperature type elements produced using the Kanthal exclusive manufacturing process. The result is an element which possesses the following features; HIGH QUALITY RELIABLE WORKMANSHIP SUPERIOR ELEMENT SUPPORT EXCELLENT TEMPERATURE CAPABILITY GOOD DURABILITY FULLY INTERCHANGEABLE MODULES INDIVIDUAL DESIGN

3 Types and maximum temperatures MODUTHAL cast refractory element modules can be supplied as one of the following individual types of heating module. 1 MODUTHAL Fully Embedded Is capable of operating up to a maximum recommended element temperature of 1100 C. Although being a fully embedded panel, most of the heating element is covered with a relatively thin layer of refractory allowing the element to radiate more efficiently than a standard fully embedded panel. 2 MODUTHAL Semi Embedded A conventionally designed panel which offers a cost effective solution to applications that do not require the higher temperatures which can be achieved by using MODUTHAL Open Coil elements. The Semi embedded panel is capable of operating up to a maximum element temperature of 1150 C. 3 MODUTHAL Open Coil Due to the unique Kanthal design which allows 75% of the heating element to freely radiate this element is capable of operating up to a maximum recommended element temperature of 1300 C. 4 MODUTHAL High Temperature Kanthal s unique design combines MODUTHAL ceramic casting with freely radiating APM material elements and is capable of operating at a maximum element temperature of 1350 C. 5 MUFFLES Please note that all muffles would be of the MODUTHAL Fully Embedded type of construction and capable of operating up to a maximum element temperature of 1100 C. Design MODUTHAL embedded elements can be designed and manufactured in a variety of shapes and sizes and can also include special features such as thermocouple holes, locating lugs and rebates. MODUTHAL elements are designed for use in either small furnaces or in multiples to suit larger industrial furnaces or kilns and would normally be rated between 1kW and 10kW per element. Process Atmospheres MODUTHAL elements are designed to operate in clean air, but may also be used in process atmospheres within the normal limitations of the resistance wire. The effect of furnace atmospheres is tabulated in Figure 4 Control equipment MODUTHAL elements are normally operated directly from the mains electricity supply and therefore do not require any special power supply equipment. All modules are highly resistant to thermal stress and there is no need to limit the power input during start up conditions, except during the initial firing up when a slower heating rate may be required to expel any residual moisture. Fig 2. Results of laboratory tests showing the mechanical strength of MODUTHAL MODUTHAL PANELS Fully embedded Semi embedded Open Coil Fig 1; Diagram of the three main types of MODUTHAL embedded elements

4 40 Wall loading (kw/m 2 ) 30 High Temperature 20 Fully embedded Semi embedded Open Coil Element temperature ( C) Fig 3. Maximum recommended wall loading versus furnace temperature for MODUTHAL. (Diagram for guidance only) Furnace Metallic MODUTHAL MODUTHAL MODUTHAL MODUTHAL Remarks Atmosphere Elements Fully Semi Open Coil High (FeCrAl) Embedded Embedded Temperature and Muffles Air 1400 C 1100 C 1150 C 1300 C 1350 C These figures are for dry air. Moist air temperatures Air (Moist) 1200 C 1000 C 1050 C 1200 C 1200 C as detailed H C 1100 C 1150 C 1300 C 1350 C H 2 has seven times better heat conductivity than air N /1100* C 1100/1050* C 1150/1100* C 1250/1100* C 1250/1100* C *Higher temperature is for pre-oxidised elements Endothermic 1050 C 1000 C 1050 C 1050 C 1050 C Carbon deposits are detrimental. Use a gas tight muffle if necessary Exothermic 1150 C 1050 C 1125 C 1150 C 1150 C As for Endothermic above Sulphate Attacks Use gas tight muffle to Halogen Alkali Kanthal prevent atmosphere Alloys contacting the elements Vacuum C 1100 C 1100 C 1100 C 1100 C Torr Fig 4. Maximum permissible element temperatures for different atmospheres

5 Applications MODUTHAL elements have been successfully used in these well-established applications. Glass toughening furnace Toughening glass for cooker doors and similar products. Operating for an eight-hour day five days per week at 650 C in an air atmosphere. Billet heating furnace for forging or heat treatment of steel, copper, brass and aluminium billets. Crucible furnace Melting or holding aluminium and copper-based alloys. Both MODUTHAL Fully Embedded and MODUTHAL Open Coil panels are suitable. In MODUTHAL Fully Embedded type some protection is given to the element against metal splashes and fluxes. MODUTHAL permits high wall loadings, gives uniform temperature around the crucible and can be easily replaced. Wire annealing furnace For multi-strand annealing. MODUTHAL panels are mounted in the hearth, roof and walls, operating in the range 800 C-1050 C both continuously and intermittently. Tundish pre-heating For casting aluminium. MODUTHAL gives accurate and even temperature control within a compact design. Fluidised bed furnace Interlinked circular muffles (embedded for protection against bed materials) operating typically at 900 C 1000 C. Billet holding furnace Arch-shaped MODUTHAL Fully Embedded Element for billet holding at temperature after induction heating. Intermittent operation at 750 C-800 C. Glass melting Melting of glass for forming into glass billets, and production of glass fibre from rod. Both MODUTHAL Fully Embedded and MODUTHAL Open Coil types are suitable. Crystal growing Low-temperature crystal growing using a MODUTHAL muffle element at 950 C-1000 C in air. Brass melting furnace MODUTHAL High Temperature panels in roof and walls operating at element temperatures up to 1350 C. Crucible furnace Glass toughening furnace The MODUTHAL anchor system, retaining both element and ceramic fibre backing insulation Cylinder heater Billet heating furnace

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