节能型硫酸锰连续加热结晶工艺试验研究

Experiment study on energy saving type continuous heating crystallization process for manganese sulphate

针对传统硫酸锰高温蒸发浓缩结晶工艺存在结垢严重、耗能大等问题,提出一种节能型硫酸锰连续加热结晶工艺,并对该工艺进行试验研究。结果表明,当管内平均流速为0.8 m/s,近壁面溶液的名义过饱和度Δcsur<3.09%,试验运行140 min时,空管传热系数下降45%,而插入振动螺旋的换热管传热系数基本稳定不变。当Δcsur<3.09%时,管内固体粒子体积分数对振动螺旋的传热、防垢性能有显著影响。粒子体积分数为1.0%的传热系数比仅加入振动螺旋时高15%。从可行的绝对过饱和度角度,对新型硫酸锰连续加热结晶工艺与传统的蒸发浓缩工艺进行了能耗对比分析,新工艺节能约53%。

To solve the problem of serious scaling and large energy consumption in the traditional high temperature evaporation and concentration process of manganese sulfate, an energy saving type continuous heating crystallization process for manganese sulphate is put forward. Its experiment investigation is carried out in this study. The result shows the heat transfer coefficient of hollow tubes can be reduced by 45% and that for oscillatory spiral-insert heat exchange tube almost does not change under the following conditions ：0. 8 m/s of the mean velocity in the tube,less than 3.09% of the absolute supersaturation △Csur near the tube surface and 140 minutes of the continuous operation. When △Csur is more than3.09%, the volume fraction of the solid-particles have a significant effect on the heat transfer and fouling prevention performance. Compared with the condition of tubes only with oscillatory spiral-insert, the heat transfer coefficient does increase by 15% under the condition of tubes with spiral-insert and 1% volume fraction of particles. Based on the above experiment,the energy consumption comparison analysis is carried out between the continuous heating crystallization technology for manganese sulphate and the traditional high temperature evaporation and concentration technology from the perspective of feasible absolute supersaturation. It is found that the former one has the obvious advantage of energy saving.