The Oslo-type evaporative crystallizer, also known as a Kristall crystallizer, is a mother liquor circulating continuous crystallizer. The feed material is added to the circulating pipe, mixed with the circulating mother liquor inside, and then pumped to the heating chamber. The heated solution evaporates and reaches supersaturation in the evaporation chamber, entering the crystalline fluidized bed below the evaporation chamber through the intermediate pipe (see fluidization).
Within a fluidized bed reactor, supersaturated solutes deposit on the surface of suspended particles, promoting crystal growth. The fluidized bed hydroscopically classifies particles, with larger ones settling at the bottom and smaller ones at the top, resulting in a more uniformly sized crystalline product discharged from the bottom of the bed. Fine particles, along with the mother liquor, are drawn into a recirculation pipe and dissolved when reheated, removing minute crystals. Replacing the heating chamber of an Oslo evaporative crystallizer with a cooling chamber and removing the evaporator, etc., forms an Oslo cooling crystallizer. The main drawback of this equipment is that solutes tend to deposit on the heat transfer surface, making operation cumbersome and thus limiting its widespread application.
Key Features
The Chrysalis Crystallizer, also known as such, boasts the unique feature of having the region of supersaturation and the crystal growth zone separately located within the crystallizer. Crystals are fluidized and suspended in the circulating mother liquor, providing an excellent condition for crystal growth.
Operation Principle:
This continuous crystallizer is of the mother liquor circulating type. The solution enters the crystalline fluidized bed below the evaporation chamber through an intermediate pipe. Within the fluidized bed, supersaturated solutes in the solution deposit on the surface of suspended particles, causing the crystals to grow. The fluidized bed hydroscopically classifies the particles, with larger particles at the bottom and smaller ones at the top, and discharge a granulated crystalline product with relatively uniform particle size from the bottom of the bed. The fine particles in the fluidized bed are carried into the circulating pipe with the mother liquor and dissolved by reheating to remove the minute crystals. If the cooling chamber replaces the heating chamber of the Oslo evaporation crystallizer and the evaporation chamber is removed, it forms an Oslo cooling crystallizer. The main drawback of this equipment is that the solute tends to deposit on the heat transfer surface, making operation cumbersome and thus limiting its widespread application.