Sawtooth walking beams

Unlike most other conveyorized furnaces, walking beam furnaces accommodate top- and bottom-zone-firing. When used at lower temperatures (e.g., for annealing light sections such as pipe), the beam and supports may be of high-grade alloy without water cooling. 

Zone1 Zone 2 Zone 3 Lower row of Burnere (oppoelte elde) 

2XB RUN POSITIONS Ralls r 1 1 Hearth being iflrad as above 

Furnaces for vertical strip or strand (wire) do not have a conveyor, per se, because the strip or wire can be pulled over a series of rollers after it has been threaded through the furnace. A catenary furnace is a continuous horizontal furnace most often used for annealing stainless-steel strip. A long, thin load is supported by rollers at the entrance and exit, and therefore hangs in the shape of a catenary curve within the furnace. (See box on page 132 and fig. 4.10.) 

If a line stop occurs, the 2200 F (1200 C) zone temperature can cause strip thinning or separation. Therefore, a protective control scheme is needed. (See temperature measurement and control discussions that follow.) 

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