OFENBAU FRITZ manufactures top-heated galvanizing furnaces with ceramic tank and foundation cooling since 1956, when Karl Fritz realized the great advantages of this design over the conventional galvanizing furnace with steel tank. Since then, OFENBAU FRITZ has supplied nearly 400 galvanizing furnaces of this type. While the direct heating from above (by electricity) was first applied in Norway, we were the first to heat the zinc bath from the top (with a heating cover) also by gas and oil and to include a cooling of the foundations.
The ceramic tank is made of special refractory and insulating bricks and is assembled on site. Its major advantage over a steel tank is that it is not attacked by the liquid zinc (at 460 – 500°C), giving a theoretically infinite lifetime: we have galvanizing furnaces that have been in service for 50 years!
Even in the improbable case the ceramic tank gets a fissure and liquid zinc penetrates, the refractory lining is so thick that the zinc will freeze (at 419°C) well within the ceramic layer. At the bottom of the tank, where temperatures are higher (no air at ambient temperature), our proved foundation cooling keeps the zinc’s freezing point within the ceramic layer as well.
The heating cover (light construction) is lined with special ceramic fibre, resulting in a low weight even for large heating covers. For cleaning of the surface below the heating cover, the heating cover can be lifted by electric motors. To avoid oxidation of the zinc below the heating cover and to improve the heat transmission, the zinc is covered with our FRICO powder (otherwise a frequent cleaning of zinc ashes under the heating cover is necessary). The free bath is covered with vermiculite gravel or floating insulating plates.
For the galvanizing of small pieces (screws, bolts etc.) the furnace can be designed for high temperature (max. 560ºC).
OFENBAU FRITZ galvanizing furnaces are distinguished by:
● very long life expectancy of the ceramic tank (decades in service)
● no danger of tank break and leaking zinc
● easy regulation (only 1 – 3 burners in the heating cover)
● very low energy consumption
● maximum use of the heat: the waste gases heat the drying furnace and flux bath before going into the chimney