The multi-effect evaporator has a low processing capacity
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This post was last edited by B0SS on 2017-9-30 at 12:21. The factory has a three-effect evaporation system, but its processing capacity has always been below the designed level. Later, the process was modified by equipping each effect with a vacuum pump; yet the evaporation rate (less than 1.2 t/h) was only 50% of the designed value. The liquid being evaporated is a dilute brine with a concentration of around 5%, and the increase in boiling point is not significant. 1. Steam flow direction: First effect — Second effect — Third effect ； 2. Material flow direction: three-effect — one-effect — two-effect — discharge; it is counter-current ； 3. The absolute pressure of the generated steam is 140 kPa, while that of the last effect is 15 kPa; 4. The total heat exchange area of the evaporator is 170 square meters. In conventional multi-effect evaporation units, a vacuum pump is used only in the last effect to create a vacuum. In this particular unit, however, a vacuum pump is installed in each effect, supposedly to control the negative pressure in each of them. But doesn’t this result in the secondary steam being drawn away as well? I’d like to ask everyone for advice~
I think the steam flow is: first-effect heater – second-effect heater – third-effect heater – condenser, with vacuum being drawn off. In a vacuum flow configuration, with stage 1 – stage 2 – stage 3 – condenser, there is no need to install a separate vacuum pump. If production cannot be increased and the equipment is in good condition, it is recommended to check the steam extraction volume of the vacuum pump, the vacuum pipes, and the flow rate of the cooling water in the condenser.
Our company can help diagnose the cause
If you want me to, I can change it directly to an MVR evaporation system for you. . . Haha, it uses at least 50% less energy than what you use now. The structure is also simple.