The vacuum crystallizer equipment is a modern crystallization apparatus in which the processes carried out are vacuum cooling and crystallization. Due to the high degree of vacuum, the operating temperature is generally low or near room temperature, and the raw material liquid is mostly preheated by the external heater of the device, and the flashing and cooling is started in the device (ie, evaporation and cooling are completed instantaneously). Therefore, the crystallization apparatus has both an evaporation effect and a cooling effect.
In a vacuum crystallizer apparatus, concentration and cooling of the solution are carried out simultaneously, and the metastable zone is quickly reached. The vacuum crystallizer generally does not have a heater or a cooler, which avoids the corrosion of the heat exchanger by the precipitation of crystals on the surface of the complicated heat exchanger. Due to its simple structure, the utility model has the advantages of low cost and high production capacity.
In fact, the vacuum crystallizer equipment is developed from a closed vacuum crystallizer. The internal agitating propeller replaces the circulating pump, reducing the resistance loss of the external gripping tube system and saving the driving power. The crystal slurry is completely circulated, and the supersaturation is low. The rate of occurrence of nucleation is low and the yield is high; the fine-grained sedimentation zone is separated from the crystal slurry circulation zone by a shielding cover; the liquid-conducting pipe is large and small, and the supersaturation formed on the boiling flashing surface can be diluted; Before the pulp is taken out, it is subjected to graded leg washing and grading, so that the crystals taken out are large and uniform.https://www.wxhtshen.com/