Process for coating bodies, including tablets

Abstract

Bodies, including tablets, are coated by producing an upward spray of coating fluid by means of a two-fluid nozzle as defined herein; before contacting the bodies with said spray, providing the bodies with a spinning movement by a central impact of gas jets directed upward to intersect the centerline of said spray; guiding the spinning bodies by said gas jets towards a central position over the two-fluid nozzle, thereby increasing the number of suspended bodies contacting the spray; providing atomization gas to the two-fluid nozzle in an amount less than the one which after moderation by means of muffling gas would scatter the bodies in the spray zone; and pneumatically muffling the atomization gas just above the nozzle to reduce the body scattering effect thereof.

1 . A process for coating bodies comprising 
 producing an upward spray of coating fluid by means of a two-fluid nozzle as defined herein;    before contacting the bodies with said spray, providing the bodies with a spinning movement by a central impact of gas jets directed upward to intersect the centerline of said spray;    guiding the spinning bodies by said gas jets towards a central position over the two-fluid nozzle, thereby increasing the number of suspended bodies contacting the spray;    providing atomization gas to the two-fluid nozzle in an amount less than the one which after moderation by means of muffling gas would scatter the bodies in the spray zone;    pneumatically muffling the atomization gas just above the nozzle to reduce the body scattering effect thereof.    
     
     
         2 . A process according to  claim 1 , wherein the muffling of the atomizing gas is accomplished by blowing in muffling gas encircling the nozzle and partially tangential in relation thereto to produce a swirling upward flow encircling the nozzle and influencing the atomizing gas leaving the nozzle, thereby decreasing the upward body lifting and scattering effect thereof.  
     
     
         3 . A process according to  claim 2 , wherein said muffling gas is provided through grooves connected to a source of gas also feeding said gas jets impacting a centrally on the bodies.  
     
     
         4 . A process according to  claim 2 , wherein the muffling gas is provided through a mantel surrounding the two-fluid nozzle thereby forming a three-fluid nozzle.  
     
     
         5 . A process according to  claim 1 , wherein each of the bodies being coated has a maximum dimension of from 2 to 50 mm, preferably from 3 to 25 mm.  
     
     
         6 . A process according to  claim 1 , wherein the number of bodies being coated simultaneously is less than 500 per nozzle.  
     
     
         7 . A process according to  claim 1 , wherein the gas jets have a velocity of 80-180 m/sec.  
     
     
         8 . A process according to  claim 1 , wherein the gas jets have a velocity of 100-150 m/sec.