THE EVAPORATION OF THE JUICE TO SYRUP. 



The concentrated liquor falls to the bottom of separator h and passes along 

 pipe i to the next shell for further concentration, and so on until, sufficiently 

 concentrated, it has reached the last effect, when it has then to be pumped 

 out owing to its being treated in a vacuum. 



The Lillie. The Lillie horizontal tube film evaporator offers a system 

 of evaporation radically distinct in mechanical details from any of the above. 

 A vertical longitudinal section is given in Fig. 169, and in Fig. 170 is shown 

 an end elevation. The evaporating tubes are 5 to 6 feet long and 3 inches in 



FIG. 169. 



diameter"; they are expanded into a tube plate at one end only to allow free 

 expansion and are set at a slight incline to afford easy escape of condensed 

 water ; each tube has its own air vent at the end opposite to the tube plate. The 

 juice is circulated by means of centrifugal pumps c all worked off one shaft; 

 these pumps are of sufficient power to force the syrup out against atmospheric 

 pressure. The supply of juice enters through the balanced valve operated by 

 the float resting on the surface of the liquor in the float box /, and which 

 permits the thin liquor to enter the effect and be added to the circulating 



299 



