Models FN70/A-A1, FN100/A-A1, FN140/A-B have two heating zones. The electrical resistances are made of wire capable of resisting temperatures beyond 1200°C.
The muffle is built in refractory steel. The patented steel cooling chamber is designed to prevent condensate from dripping on to the items to be annealed or soldered. This chamber is cooled by a closed cycle cooling unit consisting of: stainless steel tank for decalcified water, a circulation pump and a water-water heat exchanger that needs to be connected to a water supply. This cooling unit is fitted on all models except the FN50/A-A1-A2.
The furnaces are fitted with time switches to automatically turn them on and off. When the temperature of the furnace goes above 350°C, the belt automatically starts up and the cooling water begins to circulate.
When the temperature falls below 350°C, the belt and the cooling water automatically stop. Static power modules are used in place of traditional remote control switches.
Propane, methane or butane can be used as protective gas for the two burners on the inlet and outlet of the furnaces.
The protective mixture (H2 + N2) can be used from gas tanks or generated by an ammonia cracker.