氧化铝厂精液降温工序板式换热器换相阀的应用

The phase changing valve of plate heat exchanger for green liquor cooling in alumina refineries

晶种分解的原理是指在过饱和的铝酸钠溶液(精液)中添加晶种、降温并不断搅拌分解析出Al(OH)3的过程。通过板式换热器充分换热后,降低精液温度提高种分母液温度。板式换热器精液相在降温的过程中水解产生结疤,板式换热器需频繁碱洗才能保证其正常换热。本文通过对板式换热器换相阀的应用实践研究其可行性,提高板式换热器换热效率,稳定分解条件。

The principle of seed precipitation is that the seed is added into the supersaturation sodium aluminate solution （green liquor） , Al（OH）3 is constantly precipitated by cooling and stirring, during this process, the temperature of green liquor is reduced and the temperature of spent liquor after pre- cipitation is increased by the plate heat exchanger. As the scale occurs by the hydrolysis during temperature decreasing on the green liquor phase of plate heat exchanger, the alkaline washing should be often carried out for the plate heat exchanger. In this paper application feasibility of phase changing valve is introduced which the heat transfer efficiency of plate heat exchanger is increased and precipitation conditions are steadied by application of the phase changing valve.