88 



The Philippine Journ-al of Science 



1914 



A design of a furnace which we have found to be satisfactory 

 is shown in text figures 1, 2, and 3. Fig. 1 represents the 

 empty furnace. Fig. 2 is a cross section of the furnace showing 



small blocks of the raw mixture 

 piled one upon the other. The 

 top is arranged in such a manner 

 that the lower part of the chim- 



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Fig. 2. Cross section of cement furnace, 

 showing small blocks of the raw mixture. 



ney instead of being straight 

 has the form of a staircase. 

 This is accomplished by cutting 

 the bricks which cover the 

 furnace in such a way that they 

 rest on the sides of the furnace 

 and project or hang in the in- 

 terior. Fig. 3 shows the furnace 

 covered and ready for use. The 

 furnace was fired by means of a Gary hydrocarbon burner with 

 gasoline under 40 pounds' air pressure supplied by an electric 

 motor-driven compressor. The equipment was supplied with 

 the necessary valves and pressure gauges so that the exact 

 pressure was always known and was under control. The 

 hydrocarbon burner'^ is placed 

 directly against the furnace 

 opening, in order to throw all 

 the heat generated into it. At 

 the hot end of the kiln, there 

 is no opening for the clinker to 

 emerge as in a laboratory rotary, 

 and consequently practically all 

 the heat generated is thrown 

 directly into the kiln and re- 

 flected back and forth around 

 the pile of cement mixture in 

 the interior. The material is 

 burned uniformly to a hard, black clinker which under a mag- 

 nifying glass shows no white spots indicating free lime. Plate 



Fig. 3. 



The furnace covered and ready 

 for uso. 



" Since a hydrocarbon burner does not work well until a temperature of 

 low redness has been obtained, it is desirable to place a piece of wood 

 about 7 centimeters square inside the furnace at the opening directly in 

 front of the burner. This enables the burner to draw well, and prevents 

 it from striking back. After about thirty minutes the wood is completely 

 burned and the interior of the furnace red hot. A piece of asbestos con- 

 taining a hole exactly the size of the opening of the burner is placed be- 

 tween the furnace and the burner to protect the latter from the heat. 



