METHOD AND APPARATUS FOR MANUFACTURE OF GRANULATED PERCARBONATE Russian patent published in 2004 - IPC

FIELD: industries inorganic synthesis and household chemical goods.

SUBSTANCE: seal percarbonate particles 0.1-0.4 mcm in size are loaded into double-screw mixer 2 and into dryer 3 provided with gas-distribution grate 4. Fluidized bed is formed in fryer 3 by means of flue gases heated to 200^oC. Hydrogen peroxide and soda ash solutions are fed into reactor 1 and resulting sodium percarbonate solution is then fed into mixer 2 to moisten seed particles, which, when being moistened, are vigorously stirred and displaced. Wet product is passed on grate 4 of dryer 3. Casing of the latter has variable cross section along its height caused by inclination of at last one of the side walls to an angle 10-20^o to vertical. Variable cross section changes velocity of flue gases and provides size separation of the dried particles: fine fraction in upper layer and coarse fraction in lower layer. Coarse fraction is withdrawn from dryer 3 through line 12 and sent to electrifier 5. Commercial fraction is discharged over line 13, whereas coarse fraction is transferred over line 14 to mill 15 wherein it is combined with fine fraction and fed over line 11 into mixer 2 as recycle.

EFFECT: increased proportion of commercial fraction relative to total amount of granules with drown from dryer to be classified.

2 cl, 2 dwg