Comparison of MVR and multi-effect counter-current flash evaporation processes for potassium chloride recovery
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As the title suggests, I would like to ask everyone: considering factors such as investment and operating costs, which is better – the MVR process or the multi-effect counter-current flash evaporation process for the recovery of potassium chloride? Or what are the advantages and disadvantages of each? Thank you! :handshake
This post was last edited by Tianhei Wumu Rao on 2015-10-8 at 07:41. I’ll calculate it based on one ton of evaporation per hour for you as a comparison. For the MVR system, centrifugal compressors with a temperature rise of 16 degrees are used; the material chosen for these devices is TA2. The total investment for such a setup is around 1 million yuan or so (excluding infrastructure costs). These devices can last for 5–10 years. If carbon steel is used as the material, the total investment is approximately 800,000 yuan (excluding infrastructure costs), and the devices can last for 1 year; the operating cost per hour is around 45 yuan. For three-effect systems, the material used is TA2, and the total investment is around 300,000 yuan (excluding infrastructure costs); these devices can also last for 5–10 years. When carbon steel is used, the total investment is around 200,000 yuan (excluding infrastructure costs), and the devices can last for 1 year, with an operating cost of around 110 yuan per hour. In the case of potassium chloride, with a temperature rise of 8 degrees, both MVR and multi-effect systems can achieve concentration effects. The difference lies in the comparison of initial investment and operating costs.
May I ask, in PH3-4 where chlorine is present and the concentration is near saturation at a temperature of 70°C, how long can TA2 be used?
It can last over 20 years without any problem
You can look up corrosion manuals; they are written in great detail
1. The corrosion problem caused by chloride ions is related to temperature; the higher the temperature, the greater the corrosiveness. 2. In terms of initial investment costs, multi-effect counterflow systems have lower costs, while MVR systems have higher costs. 3. Regarding operating costs, MVR systems are much cheaper than multi-effect counterflow systems. Compared to the three-effect system, the energy consumption per ton of water is 40 kWh ； And with a three-efficiency ratio of 0.43, the steam consumption per ton of water is around 80 yuan
Generally, MVR requires a large initial investment, but its operating costs are low; the cost can generally be recovered within 4-5 years. The investment amount needs to be compared based on the amount of water evaporated. If the amount of water that needs to be evaporated is too large, owners may hesitate to spend so much money at once. This is also why MVR technology is used more in wastewater evaporation, pesticides, traditional Chinese medicine, and milk powder industries than in the chemical industry.