Apparatus for heat-treating cast iron pipes

In a system for manufacturing cast iron pipes comprising a rotary mold of the stationary type included in a centrifugal casting machine and a heat-treating furnace, the improvement wherein:

• the heat-treating furnace is disposed close to the rotary mold for receiving red-hot cast iron pipes directly therefrom;
• the furnace has a plurality of furnace chambers arranged side by side in parallel to the axis of the mold and partitioned by partition members provided between the chambers, each furnace chamber being adapted to accomodate and separately treat one cast iron pipe;
• rotating means is provided in each of the furnace chambers for supporting and positively rotating the pipe in a fixed position;
• and
• means is provided for adjusting the temperature of the pipe accomodated in each of the furnace chambers, the temperature adjusting means comprising burners, disposed at least in the chamber for receiving a cast iron pipe from the mold, for emitting heat directly toward the top of the pipe.