THE EVAPORATION OF THE JUICE TO SYRUP. 



The Kestner Evaporator. This type of evaporator is radically 

 distinct from all the forms previously described, and is the last development of 

 the principle of l ruisellement' or ' grimpage? It is a vertical tube externally 

 heated film evaporator, and consists of a vertical tubular calandria, Fig. 171, 

 with tubes about 23 feet long; the juice under evaporation is contained in the 

 tank #, and passes by the pipe T to the interior of the tubes, which are from 

 1-5 to 3 inches in diameter; the heating steam enters the shell at A, and 

 the formation of vapour within the tubes causes the liquid undergoing the 

 treatment to climb upwards in the tubes ; at D is shown a centrifugal separator 

 designed to prevent entrainment. 



It is claimed for this apparatus that the 

 coefficient of transmission of heat is very 

 great and that owing to the juices being but 

 a short time under treatment it is especially 

 adapted to be used as the pre-evaporator in 

 the Pauly-Greiner scheme of heat utilization 

 described below. 



Van Trooyen 4 gives the following 

 particulars of a Kestner quadruple at 

 ' Pasto-Viejo,' Porto Rico. Each body 

 is a vertical cylinder 24 feet high and 

 3 feet 6 inches in diameter, made in two 

 pieces with an expansion joint ; the separ- 

 ating chamber is 7 feet in diameter and 

 6 feet high, except in the last body where 

 it is seven feet high. The heating surface 

 in the first three vessels consists of 250 

 tubes, 23 feet long and 1^ inches outside 

 diameter; in the fourth vessel there are 130 

 tubes, also 23 feet long and 2f inches 

 diameter. The heating surface in the whole 

 apparatus is 8141 square feet. The pumps 

 are of the following dimensions : 



FIG. 171 



Stroke .. .. 

 Steam cylinder 

 Pump cylinder 

 Revolutions 



Air. 

 Inches. 



20f 



23 

 46 



Juice. 

 Inches. 



Water. 

 Inches. 



10f 

 12J 



The syrup is removed from the last body by means of a barometric 

 fall pipe. 



301 



