16 Department Circular 263, U. S. Dept. of Agriculture. 



emulsion mixture is boiled by steam in one of the galvanized tanks, 

 from Trhich it runs by gravity to the pump. It is pumped to the 

 second galvanized tank, from which it again flows by gravity to the 

 pump for the second pumping into barrels for storage. 



Figure 5 shows a very convenient oil-enmlsion plant. In this 

 outfit the emulsion mixture is boiled by live steam from a boiler 

 which also runs a steam pump to emulsify the mixture. 



The most satisfactory method of preparing the emulsion on a large 

 scale is to employ live steam for the cooking. In case steam is used, 

 a 1-inch steam pipe can be run down into th6 boiling tank in the 

 form of a double coil, placed a few inches above the lx)ttom of the 

 tank. Several holes should be bored in the lower side of the coil to 

 allow the steam to escape into the mixture. The steam boiler should 



Fig. 6. — A plant capable ot pruUiKUig uii emui&ioii uu a large seak'. 



furnish a head of steam large enough to boil the mixture quicldy. 

 so that the condensation of steam into water will be overcome by the 

 evaporation that takes place. Where it is found that some water 

 through condensation is added to the mixture during boiling, allow- 

 ance can be made by deducting the amount of the increase from the 

 original amount of water used. Plants which use steam for cooking 

 in northwestern Arkansas plan to bring the mixture to a boil in 

 from 5 to 10 minutes. A steam pump is best for operation on a largt^ 

 scale. 



Figure 6 shows a plant which can manufacture oil emulsion on a 

 large scale. Steam is supplied from a boiler in a factory near by 

 into the 1,500-gallon tank at the right. After boiling, the mixture 

 floAvs by gravity from the cooking tank to a steam pressure pump in 

 the factory, where the mixture is pumped under pressure through a 

 pipe overhead into the central tank. The o])ei'ation is then re- 

 peated, the emulsion being discharged by gravity and jjumped by 



