CEMENT BURNING: FIXED KILNS. 



473 



top of the chambers and one chamber is fired. All of the flues in the 

 kiln leading to the stack are closed except one, i.e., the flue from the 

 chamber behind the one which has been fired. All the inter-chamber 

 flues are open except one, i.e., the flue between the fired chamber and 



FIG. 109. Section of Hoffmann kiln. 



the one immediately behind it in the series. The result of this arrange- 

 ment is that the hot gases from the fired chamber pass in turn through 

 each of the other loaded chambers until they arrive in the chamber 

 immediately behind the fire, when they are passed into the central 

 stack. The waste heat from the fired chamber is therefore utilized 

 to the fullest extent in heating up all the other chambers. 



When the slurry in the fired chamber is converted into clinker this 

 is allowed to cool. The chamber is then temporarily cut off from the 

 rest of the series by closing its flues and the clinker is drawn. In 

 the meantime the chamber next to it has been fired. The empty cham- 



