Study on Predrying by Spin Flash Dryer for Granulation

Spin flash dryer has the advantages of both fluidized bed dryer and pneumatic dryer. It has predominance in dealing with thermal sensitive materials. In this paper, the distribution of the air velocity in the spin flash dryer is discussed,which indicates that the rotating air in the dryer chamber can be divided into two areas,potential flow area and plane swirl area. Experiments show that air tangent velocity effects the process of granulation most remarkably. The radial distribution and moisture content of the particles have their intrinsic rules along either the diameter or height of the drying chamber. Besides, the operating parameters of predrying on bleaching powder are optimized. To meet the strict standard of the wet-pressing granulator on the moisture content of the feeder,a narrow lap is made at proper height in the wall of the drying chamber,where a chute and a rotating valve are installed in order to predry the filter cake and remove a part of water. Then the material is fed into the wet-pressing granulator.

Study on Predrying by Spin Flash Dryer for Granulation

Spin flash dryer has the advantages of both fluidized bed dryer and pneumatic dryer.It has predominance in dealing with thermal sensitive materials.In this paper,the distribution of the air velocity in the spin flash dryer is discussed,which indicates that the rotating air in the dryer chamber can be divided into two areas,potential flow area and plane swirl area.Experiments show that air tangent velocity effects the process of granulation most remarkably.The radial distribution and moisture content of the particles have their intrinsic rules along either the diameter or height of the drying chamber.Besides,the operating parameters of predrying on bleaching powder are optimized.To meet the strict standard of the wet pressing granulator on the moisture content of the feeder,a narrow lap is made at proper height in the wall of the drying chamber,where a chute and a rotating valve are installed in order to predry the filter cake and remove a part of water.Then the material is fed into the wet pressing granulator.