Process and apparatus for coating a controlled release product in a rotating drum

Abstract

The present invention is directed to a process for coating a substrate in a rotating drum, wherein a pocket is created in a substrate bed into which pocket coating materials are delivered. Also provided is a controlled release product produced according to this process, and an apparatus for carrying out the process.

1 . A process for coating a substrate in a rotating drum, wherein a pocket is created in a substrate bed into which pocket coating materials are delivered.  
   
   
       2 . The process according to  claim 1 , wherein the substrate is fertilizer granules.  
   
   
       3 . The process according to  claim 1 , wherein the pocket is created by a mechanical device or high pressure air.  
   
   
       4 . The process according to  claim 1 , wherein the pocket is created by a plow means.  
   
   
       5 . The process according to  claim 4 , wherein the coating materials are delivered behind the plow means.  
   
   
       6 . The process according to  claim 1 , wherein the coating materials are delivered on the surface of the granule bed.  
   
   
       7 . The process according to  claim 1 , wherein the coating materials are delivered below the surface of the granule bed.  
   
   
       8 . The process according to  claim 1 , wherein the coating materials are substantially simultaneously delivered onto the surface of the substrate bed by spraying or dribbling.  
   
   
       9 . The process according to  claim 1 , wherein a device is used to bury the coating materials in the pocket.  
   
   
       10 . The process according to  claim 9 , wherein the burying device is one or more blades.  
   
   
       11 . The process according to  claim 1 , wherein the drum comprises one or more baffles.  
   
   
       12 . The process according to  claim 11 , in which the baffles are oriented in a direction opposite to the drum's direction of rotation.  
   
   
       13 . A controlled release product produced according to the process of  claim 1 .  
   
   
       14 . A rotatable drum for coating a substrate comprising a mixing zone and a drying zone, wherein the mixing zone comprises (a) one or more means for creating a pocket in a substrate bed, and (b) one or more means for delivering coating materials into the drum.  
   
   
       15 . The drum of  claim 14 , wherein the means for creating the pocket is a plow or high pressure air.  
   
   
       16 . The drum of  claim 14 , wherein the means for delivering the coating materials is a nozzle or pipe, or a combination thereof.  
   
   
       17 . The drum of  claim 14 , wherein means for creating the pocket is a plow, and the means for delivering coating materials into the drum are located behind the plow.  
   
   
       18 . The drum of  claim 14 , further comprising baffles, oriented in a direction opposite the direction of rotation of the drum.