Slot forge furnaces

Slot furnaces are in general use throughout the steel industry to heat steel for forging and are usually fired with light oil. Because many such furnaces are located in small businesses, it is difficult to obtain an accurate estimate of their total energy use. The best approximation available is that about 0.2 quad is consumed in slot forge furnaces annually. 

Preheating loads with waste gases has been widely practiced in the forging and hardening of tools.. . from the village blacksmith to slot forge furnaces where extra loads were placed in the slot for preheating. Their fuel efficiency may not have been so crude after all. Fuel was often scarce or dear. Necessity was the mother of invention. 

Slot forge furnaces are wasteful of fuel and prone to uneven heating because of the tremendous heat loss through the slot. They must have movable flaps for easy opening to add or withdraw pieces, and operators must be convinced that they must close them promptly after every use. 

If a flue poc carries heavy particulates and has ells (elbows) or horizontal sections where particles may be deposited, flues must be made even larger, and clean out doors must be provided, and used For some forge furnaces and for bolt heading furnaces, all the poc are purposely forced out the slot through which the stock is charged. 

---