Extraction of Na2SO4 crystals using a double-effect evaporator
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A double-effect evaporator from Hebei University of Technology is being used to extract salts from sodium sulfate, with a processing capacity of about 3 tons per hour. I have two questions: 1. In the two-stage evaporation process, the original 5% concentration of Na2SO4 is evaporated to 13% and 25% concentrations respectively – what is the reason for choosing these specific concentrations? 2. Is it also related to the fact that the temperature for evaporation using saturated steam is 118 degrees for the first stage and 103 degrees for the second stage?
Both the first and second stages involve issues related to the efficiency distribution of the evaporator. For ease of design and manufacturing, the separators and heat exchangers for these two stages are usually designed to be identical; that is, initial design calculations are carried out using methods such as equal pressure difference or equal area, followed by fine-tuning
Do you mean that if it’s a two-stage process, the best way is to evaporate 50% of the water in the first stage and then another 50% in the second stage?
No, the standard approach is to adjust the parameters so that the separation units in stage 1 and stage 2 have the same heat exchange area (this facilitates design and manufacturing and reduces costs). Please refer to the chapter on evaporation in the first volume of \"Principles of Chemical Engineering\"
Are double-effect ones still in use? All has been evaporated by MVR,,,
I have the product now; I’ll help you sell it:lol
This depends on the saturated solubility of sodium sulfate at different temperatures. At an evaporation temperature of around 100 degrees, the saturated solubility of sodium sulfate is 30% by concentration. A processing capacity of 3 T/H can certainly be handled using an MVR evaporator for sodium sulfate solutions. The operational energy consumption of an MVR is at least twice lower than that of a double-effect evaporator; therefore, an MVR evaporator is a viable option. For any inquiries or further details, please contact Lu at 18562717155