Continuous annealing

Continuous mesh belt furnaces are employed for the sub-critical annealing of steel components, such as pressings and small machined parts, with section thickness of up to 1 inch. The temperature of the components is gradually raised as the batch progresses through the tunnel furnace. The belt speed is variable and is set to provide the necessary time within the high temperature region of the furnace to produce the required softening, based upon the section thickness of the component. Uniform spacing of the components on the belt is vital to ensure uniformity of heating and the spread of the load governs the efficiency of the soak at temperature.

Although somewhat labour intensive as operators are needed at the entry and discharge ends of the furnace when there are a variety of components to be annealed, it is possible to automate the process when large volumes of very similar parts are involved. The energy efficiency of the process is good if sufficient product is available to run the equipment on a 24 hour basis. Endothermic gas generators coupled to the furnace provide an efficient supply of protective atmosphere economically.