Patent GB-966208-A (GB)
Title: Improvements in or relating to concentrating fruit juices by evaporation
Inventor: MOJONNIER JULIUS JOHN
IPC: A23L2/10
Filed: 1962-10-29
Abstract: 966,208. Concentrating fruit juices. MOJONNIER BROS. CO. Oct. 29, 1962, No. 40844/62. Heading A2D. [Also in Division B1] Fruit juice is partially evaporated in evaporator 23 to obtain an intermediate liquid concentrate and a vapour containing the flavour and aroma components of the juice, the vapour is submitted to fractionation in distillation column 13 and a vapour enriched in flavour and aroma components is withdrawn from the head of the column, this essence vapour is condensed by heatexchange with the intermediate liquid concentrate in evaporator 77 where the intermediate concentrate is maintained under vacuum so that further evaporation takes place yielding the concentrated liquid product. A portion of the essence condensate is returned to the distillation column at reflux through line 102; and the remainder is cooled, and then blended with the concentrated liquid product. In the plant shown, evaporator 23 and preheater 21 are both of the shell and tube type, and heating steam is introduced into the two shells. The column 13 is heated by injecting live steam into it through ring 65. Evaporator 77 is also of the shell and tube type and the concentrate in the tubes is maintained under vacuum by a two-stage steam ejector system 16 connected to contact condenser 81. The process is particularly suitable for concentrating grape juice and for obtaining an essence condensate in which the flavour and aroma components are from 100 to 150 times more concentrated than in fresh grape juice. The clarified fresh juice is pumped through the tubes of preheater 21 where it is heated to about 225‹ F., the pressure being adjusted by valve 35 so that there is sufficient vaporization of the juice to provide turbulent flow within the tubes. The preheated mixture passes through valve 35 into a horn 39 in the top of evaporator 23, where flash vaporization occurs. The mixture of vapour and liquid flows down the central tubes and then up the outer tubes of evaporator 23. About 30% of the juice is vaporized at this stage. The mixture of vapour and liquid is conducted into separation chamber 25, from which the separated vapour is passed through line 57 into column 13, while the intermediate liquid concentrate flows via line 93 to the tubes of evaporator 77. The overhead vapour from coloumn 13 is conducted through line 83 into the shell of evaporator 77, where it condenses and gives up heat to the intermediate liquid concentrate which partially vaporizes at 115‹ F. The mixture of vapour and liquid is conducted into separator 79. The vapour leaving the separator is condensed in condenser 81 by contact with water introduced through metering unit 125. The concentrated liquid is withdrawn from separator 79 by pump 111; part of it is recycled to evaporator 77 via connection 91, and the remainder is withdrawn from the system as product through line 117. System 17, comprising cooler 149 and scrubber 151, is provided for cooling that portion of the essence condensate which is not refluxed to column 13, and also for recovering the small amounts of flavour and aroma components present in the non-condensable gases withdrawn from the shell of evaporator 77 via connection 104. The essence product is discharged from the scrubber through seal loop 199. The first stage steam ejector 131 of the vacuum system 16 discharges into interstage condenser 135 which is supplied with cooling water through line 141.