Reverse Circulation Crystalline Evaporation Technology Research,

For the evaporation of liquid with crystal precipitated such as salt, inorganic salt, sodium hydrate produced with membrane, phosphoric acid, phosphor. External heated circulation-forced evaporator is widely used all over the world. Among variety of industries, the salt industry is the greatest user of the technology. It is also the first user who adopts the technology of reverse circulation to extend the operating rate of evaporator. Now, in China, the technology is not yet used in alumina plants in the process of evaporation and crystallization.in the alumina industry of China, must equipments of evaporation are standard and external heated circulation- forced evaporator. The energy consumption is high and the operating rate is low. Especially when it is used as the main equipments for the concentration and crystallization evaporation, the operating rate is the key factor for the equilibrium of liquid equilibrium in the production of alumina.With the reverse circulation technology of crystallization evaporation, the operating period can be increased, and the amount of water m slurry reduced to save energy. The innovation of this technology meets the requirements of sustainable development, and has high economic returns and high social effects.In this paper, the mechanics of reverse circulation evaporator was studied. Concerning with the practical production process, the production condition in the operation the reverse circulation evaporator, which should be controlled carefully, were pointed. The influence of the way of circulation on the scaling rate was studied. By changing the way of installation and the feeding approach from tangent feeding to axial feeding, the flow direction of fluid was changed and the reverse circulation operation was achieved. As a result of that, scaling rate was decreased, the leaning frequency was shortened, and the cost of production was reduced. In this way, high concentration evaporation was realized.