By means of selected examples you will recognize how we are handling and solving problems. It is shown, how we co-operate with our customers to achieve optimal results. The following pages explain the practical applications of HALDENWANGER ceramics in furnace construction.
Annealing Boxes and Melting Crucibles
Annealing boxes and melting crucibles made from ceramic material are required in almost every industrial sector. The type of HALDENWANGER material used depends on the chemical or thermal stress the material has to withstand. The various sizes and geometries are determined by our customers. We are able to provide helpful advice influencing product quality and costs through our wide range of design possibilities. Such work requires a joint effort in selecting the materials and determining the product geometry.
Working temperatures are possible up to 1000 °C. The low linear thermal expansion and therefore good thermal shock resistance permits short heatup times.
Alsint porous is the right material for temperatures exceeding 1300°C, even in a reducing atmosphere. The main characteristic of this material is its chemical resistance. Heat-up rates must be adapted to this material. It is also possible to influence the required thermal shock resistance by geometry and wall thickness.
Support tubes are required for the construction of furnaces with exposed heating coils. Our material Sillimantin KS has proved itself over the years and is used by many renowned companies building kilns. All commonly used sizes of support tubes can be delivered ex stock.
If the usual material, Sillimantin KS, does not meet the requirements of your special application, there are the following additional possibilities:
• Alsint 99,7 with its higher supporting capacity, greater supporting distance (without bending), gas-tightness and chemical inertness.
• Pythagoras as an impervious material has a better refractoriness than Sillimantin KS.
• Sillimantin 60 NG combines the good refractory properties of Alsint with good resistance to thermal shock.
In the ceramic and electrical industry firing supports or kiln furniture are required for kiln car structures.
Normally in the ceramic industry tube sections, for example of the size 55 x 45 x 200 up to 300 mm, are used in order to keep the firing setters at the right distance. In the production of ferrites rectangular solid shapes of different sizes are used for the same purpose. These supports also carry the setter plates with the ferrites on them. The high mechanical strength of ceramics enables you to use small firing supports. The result is an improvement of the relation between kiln furniture and products to be fired.
Kiln Furniture Structures
HALSIC is the name of four exceptional high-performance ceramics from the silicon carbide (SiC) material group made by W. HALDENWANGER. They share the following characteristics:
• Absolute dimensional stability despite extreme mechanical strain in high temperature applications
• Very good thermal shock resistance
• Excellent high corrosion resistance
• Low specific weight.
This combination of properties makes HALSIC materials ideal for kiln furniture applications enabling you to maximise the amount of product you can fire in each cycle.