Has anyone used a vacuum scraper evaporator?
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We have installed a new scraper evaporator that operates under vacuum; it is mainly used to process materials such as waste salts and polymers. However, the concentration of the waste salts is quite low, around 10%, which makes processing them quite difficult. Do anyone have any good suggestions?
"Dealing with low-concentration waste salts is indeed quite tricky; our workshop has encountered similar situations before. It is recommended to try the following approaches: 1) Slightly increasing the feed temperature to reduce viscosity can improve the performance of the scraper conveyor ； 2) Check the gap between the scraper and the cylinder wall; for a 10% concentration, it may need to be adjusted to 0.5–1 mm ； 3) If polymers are present, consideration should be given to applying an anti-adhesive coating. What is your current evaporation temperature setting? "
Increase the evaporation area, raise the evaporation temperature, and circulate the waste liquid. Have you used drum evaporators made in Changzhou?
We purchased it from Yantai, Shandong; it’s our first time using it.
Now that all conventional methods have been tried, the properties of the material are quite problematic – it tends to polymerize at high temperatures. There isn’t much waste salt produced, but the energy consumption is too high.
The suggestion of using an anti-sticking coating is good, but it might be necessary to go back to the factory for further processing – increasing the temperature; the vacuum pump can’t handle that, and the pump head is prone to clogging with material
Hot water and a small amount of steam are replenished using steam condensate; the evaporation temperature ranges from 90 to 105 degrees, and the energy consumption is virtually negligible compared to that of MVR and triple-effect systems. It just requires calculation, and the efficiency may not be particularly high due to limited evaporation intensity
Can the vacuum level not ensure that the evaporation temperature remains below the polymerization temperature of the material?
In the presence of water, polymerization occurs at temperatures below 50°C; it is not solely triggered by temperature, as certain salt ions or impurities can also initiate polymerization