FORCED CIRCULATION TYPE EVAPORATIVE CRYSTALLIZER It is a kind of crystal mush circulation type continuous crystallizer. During the operation, the feed liquid is fed from the bottom of the circulating tube. After mixed with crystal mush that has left the bottom of the crystallizing chamber, it is sent to the heating chamber by the pump. When crystal mush is heated (generally 2~6) in the heating chamber, no evaporation occurs. The hot crystal mush will boil after it enters the crystallizing chamber, so that the solution reaches the status of supersaturation. Then some solute will deposit on the surface of suspended crystal grains to make the crystal grow. The crystal mush as a product is discharged from the top of the circulating tube. The forced circulation type evaporative crystallizer has high production capacity, but the granularity distribution of products is wider.

  DTB Continuous Crystallizing Evaporator Also called diversion barrel-baffle evaporative crystallizer, it is also a kind of crystal mush circulation type continuous crystallizer. The crystallizer connects with the elutriating cylinder at its bottom and is provided with the diversion barrel and barrel-shaped baffle. During the operation, the hot saturated liquid is continuously fed to the bottom of the circulating tube. After mixed with stock solution containing small crystals in the circulating tube, it is sent to the heater by the pump. The heated solution flows into the crystallizer near the bottom of diversion barrel, and is sent to the liquid surface along the diversion barrel by the slowly rotated screw propeller. The solution is evaporated and cooled on the liquid surface, reaching the status of supersaturation. Some solute will deposit on the surface of suspended grains to make the crystal grow. There is a sedimentation area outside the annular baffle. Inside the sedimentation area, the big grains settle, and the small grains enter the circulating tube with the stock solution and are heated and dissolved. The crystal enters the elutriating cylinder from the bottom of the crystallizer. To make the granularity of crystallized products as even as possible, some stock solution from the sedimentation area are fed to the bottom of the elutriating cylinder. By using the effect of hydraulic classification, the small grains will return to the crystallizer with the liquid and the crystallized products will be discharged from the bottom of the elutriating cylinder is constituted. 

Advantages of the DTB Crystallizer:

A. Capable of producing large singular crystals.  
B. Longer operating cycles.  
C. Lower operating costs.  
D. Minimum space requirements, single support elevation.  
E. Adaptable to most corrosion resistant materials of construction.  
F. Can be easily instrument-controlled.  
G. Simplicity of operation, start-up and shutdown.  
H. Produces a narrow crystal size distribution for easier drying and less caking.  
I. The product size varies only slightly with large changes in production

Basic Principles of the DTB Crystallizer:

A. Growing crystals are brought to the boiling surface where supersaturation is most intense and growth is most rapid.  
B. The baffle permits separation of unwanted fine crystals from the suspension of growing crystals, thereby affecting control of the product size.  
C. Sufficient seed surface is maintained at the boiling surface to minimize harmful salt deposits on the equipment surfaces.  
D. Low head loss in the internal circulation paths make large flows at low power requirements feasible. 

  OSLO EVAPORATIVE CRYSTALLIZER Also called Krystal crystallizer, it is a kind of stock solution circulation type continuous crystallizer. During the operation, the feed liquid is fed into the circulating tube, mixed with the circulating stock solution in the tube and sent to the heating chamber by the pump. The heated solution is evaporated in the evaporating chamber and reaches supersaturation. It will enter the crystal fluidized bed under the evaporating chamber after passing through the central tube. Inside the crystal fluidized bed, the supersaturated solute in the solution will deposit on the surface of suspended grains to make the crystal grow. The crystal fluidized bed will carry out hydraulic classification of the grains. The big grains are at the bottom and the small grains are at the top. The crystallized products with even granularity are discharged from the bottom of the fluidized bed. The small grains in the fluidized bed will flow into the circulating tube with the stock solution and tiny crystal will be dissolved after reheating. If the heating chamber of the Oslo evaporative crystallizer is replaced by the cooling chamber, and the evaporating chamber is removed, the Oslo cooling crystallizer is constituted.