How to design a manganese sulfate MVR evaporator without plugging the tube? Xiaobian believes that it is designed according to the solubility characteristics, evaporation characteristics, material characteristics, etc. of manganese sulfate, the specific content is as follows:
First, the use of manganese sulfate
Manganese sulfate is one of the important trace element fertilizers, which can be used as a base fertilizer, soaking seeds, seed mixing, topdressing and foliar spraying, which can promote crop growth and increase yield.
In the animal husbandry and feed industry, it is used as a feed additive, which can make the livestock and poultry method develop well and have a fertilizing effect.
In the manganese deep processing industry, it is a basic raw material product, with a large amount and wide use, mainly used for the production of electrolytic manganese dioxide, electrolytic metal manganese and chemical manganese dioxide in the metallurgical industry.
Manganese sulfate can also be used to process paints, ink drying agents, catalysts for the synthesis of fatty acids, can also be used for batteries, smelting catalysts, analytical reagents, additives, etc.
High-purity manganese sulfate is mainly used in the synthesis of nickel-cobalt-manganese ternary cathode materials and lithium manganate cathode materials.
Second, the evaporation characteristics of manganese sulfate
Most sulfates have an unconventional solubility curve trend, that is, the characteristics that decrease with increasing temperature at high temperatures (such as zinc sulfate, magnesium sulfate, manganese sulfate, sodium sulfate, sodium sulfite, cobalt sulfate, calcium sulfate, lithium sulfate).
Especially such materials as manganese sulfate, its characteristics are the higher the temperature, the lower its solubility, and most materials are the opposite, the evaporation concentration of manganese sulfate is often due to a large number of precipitation of manganese sulfate crystals during the evaporation process, scaling on the evaporator tube heat exchange surface, significantly reducing the heat exchange efficiency of the evaporator, resulting in a sharp rise in the energy consumption cost of evaporation, and reducing production efficiency.
Third, the cause of manganese sulfate evaporator plugging pipe analysis
For many years, the efficiency of evaporative crystallization equipment for manganese sulfate and zinc sulfate products has been at an extremely low level, and coil evaporation tanks are used.
In the low concentration concentration concentration stage, the column tube evaporator can still be used, but in the high concentration crystallization stage, the column tube evaporator is severely and frequently blocked. The reason for this is the special solubility properties of manganese sulfate.
In the evaporation temperature range, manganese sulfate increases with temperature and the solubility decreases. Based on this characteristic, during the circulation of the material in the heat exchanger tube, a certain degree of temperature increase is generated due to being heated, so that the solubility in the heat exchange tube begins to decrease, resulting in a tendency to precipitate solids. Therefore, even if the solution is not boiled and concentrated in the heat exchanger tube, it may precipitate solids and thus adhere to the heating surface. This situation is very likely to occur when the flow rate between the tubes is too low and the circulation of the axial pump is insufficient.
Fourth, how to design an MVR evaporator that does not block the tube
When designing the evaporator, it is necessary to take into account the phenomenon of fouling, design anti-fouling measures in advance, on-line cleaning measures, and consider the delay of fouling and the selection of the right evaporation process.
Combined with the reasons for the pipe blockage of the manganese sulfate evaporator and the evaporation characteristics of manganese sulfate, the company developed the manganese sulfate MVR evaporator to solve the manganese sulfate material pipe plugging accident, and at the same time solve the problem that the coil evaporation tank is subject to the heat exchange area and is not convenient to use MVR evaporation, greatly improving the evaporation crystallization efficiency of the manganese sulfate industry, and creating a new benefit growth point by means of energy saving and consumption reduction.