98.6% water evaporation 4-effect falling film evaporator system Designed by Fritz Voltz sohn feed rate 3.4m3/hr, product 1.3 m3/hr Feed to 1st evaporator is 3.4 m3/hr @ 34.8% concentration and @ 104 deg C vacuum @ 4th evaporator 130 mbar Evaporator concentrations are: 1st = 42.1% @ 116 deg C 2nd = 55.8% @ 107 deg C, 3rd = 91.3% @ 81 deg C, 4th = 98.6% @ 98 deg C System consists of: (3) 46 square meter 316 stainless steel tube, head and shell falling film evaporator (1st , 2nd, 3rd effects), manufactured by APV, design pressure tubeside 0.69 bar + full vacuum @ 130 degrees C, shell 3.10 bar + full vacuum @ 140 degrees C, working pressure tubeside 0.207 bar @ 120 degrees C, shell 2.07 bar @ 130 degrees C, (44) 50mm diameter x 18 SWG X 7m long 316 stainless steel tubes, 316 stainless steel tube sheets, 560mm diameter 316 stainless steel shell with expansion joint, (1) 316 stainless steel bonnet head, (1) bolt dished bottom head, mounted on a carbon steel skirt (1) 6 square meter 316 stainless steel tube, head and shell falling film evaporator (4th effect), manufactured by APV, design pressure tubeside 2.5 bar + full vacuum @ 150 degrees C, shell 2.5 bar + full vacuum @ 150 degrees C, (14) 44mm diameter x 16G x 3.5m long 316 stainless steel tubes, 323.9mm diameter 316 stainless steel shell with expansion joint, 4295mm overall height, (1) 316 stainless steel flat bonnet head, (1) weld coned bottom, effect attached on top of a 720 liter 316 stainless steel vertical pressure separator/tank, manufactured by APV, design pressure 2.5 bar + full vacuum @ 250 degrees C, 792mm diameter x 1.5m straight side, weld dished top and bottom, mounted on legs (3) approx 600 liter 316 stainless steel vertical separators, manufactured by APV, design pressure 10 psig + full vacuum @ 130 degrees C, 775mm diameter x 1219mm straight side, weld slight coned top, weld coned bottom, (1) 10.6 square meter 316 stainless steel tube and shell horizontal condenser (1st stage), manufactured by APV, design pressure tubeside 2.5 bar + full vacuum @ 150 degrees C, shell 2.5 bar + full vacuum @ 150 degrees C, (34) 25mm diameter x 16G x 4m long 316 stainless steel tubes, (2) 316 stainless steel flat heads, 406mm diameter 316 stainless steel shell, 4.5m overall length, mounted on saddles (1) 11 square meter 316 stainless steel tube and shell horizontal condenser (2nd stage), manufactured by APV, working pressure tubeside 2.07 bar @ 35 degrees C, shell -0.9 bar + full vacuum @ 50 degrees C, (76) ¾” x 18 swg x 4145mm long 316 stainless steel tubes, (2) 316 stainless steel flat heads, 300mm diameter 316 stainless steel shell, overall length 4523mm, mounted on saddles, (3) approx 132 liter 316 stainless steel vertical pressure tanks (flash vessel), manufactured by APV, design pressure 2.5 bar + full vacuum @ 150 degrees C, 400mm diameter x 750mm straight side, bolt dished bonnet head, weld dished bottom, mounted on legs Process operation The first 3 evaporators are falling film and tube (shell & tube) evaporators, where the product flows up and down through a series of tubes which are surrounded by a heating medium, steam @ 1.8 bar is used as the heating medium The hot liquid from each evaporator is fed to its associated “separator” in which the vapour separates from the liquid and is drawn off, The 4th evaporator uses a “once-through” falling film concentrator, the unit is similar to that of a shell & tube heat exchanger except that the product falls down the unit through a number of pipes which are surrounded by a heating medium, steam @ 1.8 bar is used as the heating medium, Vacuum @ 130mbar is applied to the 4th evaporator, which draws the vapour through the first 4 evaporators. After the 4th evaporator the product is fed through a heat exchanger, where it cools the product to between 50 deg C and 70 deg C, water is used as a cooling medium, from there the product goes to storage tanks (not available)