Method for disassembling a spray drying system

Abstract

The present invention relates to a spray drying system provided with a neutralizing system, which system is intended for use in the pharmaceutical industry or in other industries, where the product is e.g. infectious, toxic or highly reactive and constitutes a risk for the surroundings and/or a health risk to people handling the product. The spray drying system comprises a spray drying chamber ( 1 ) comprising a drying chamber ( 1 ) provided with an atomizer device ( 17 ), followed by units ( 2, 3 ) for collecting of product powder and means ( 8 ) for cleaning the exhaust gas, wherein an atomization device ( 16 ) connected to a vessel ( 13 ) containing a neutralizer agent is placed upstream of the drying chamber ( 1 ). The invention also relates to a method which method comprises the following steps: i) sterilizing the spray drying system if the process has to be conducted under aseptic conditions, ii) processing by drying a fluid feed added to a drying chamber ( 1 ) through one or more atomization nozzle(s) ( 16 ), iii) neutralizing comprising adding a neutralizing agent upstream of the drying chamber ( 1 ), iv) cleaning the spray drying system.

1 . Method for processing hazardous substances in a spray drying system, wherein the method comprises the following steps:
 i) sterilizing the spray drying system if the process has to be conducted under aseptic conditions,   ii) processing by drying a fluid feed added to a drying chamber through one or more atomization nozzle(s),   iii) neutralizing comprising adding a neutralizing agent upstream of the drying chamber,   iv) cleaning the spray drying system.   
   
   
       2 . Method according to  claim 1 , wherein the neutralizing step iii) comprises wetting the inner surfaces of the spray drying system with a neutralizing aerosol. 
   
   
       3 . Method according to  claim 1 , wherein the neutralizing step iii) comprises dedusting, disinfecting or chemically neutralizing. 
   
   
       4 . Method according to  claim 2 , wherein the neutralizing aerosol has a mean droplet diameter between 0.1-50 μm. 
   
   
       5 . Method according to  claim 1 , wherein the neutralizing agent in step iii) is added while drying gas flows at normal design rates. 
   
   
       6 . Spray drying system for processing toxic, highly reactive or contaminating substances, wherein said system comprises a spray drying chamber provided with an atomizer device, followed by units for collecting of product powder and means for cleaning the exhaust gas, and wherein an atomization device connected to a vessel containing a neutralizer agent is placed upstream of the drying chamber. 
   
   
       7 . Spray drying system for processing hazardous substances according to  claim 6 , wherein the atomization device is located at the gas inlet for drying gas to the drying chamber after one or more filters filtering the process gas. 
   
   
       8 . Spray drying system for processing hazardous substances according to  claim 6 , wherein the atomization device is one of the following: a two fluid nozzle, a single fluid nozzle or a venture. 
   
   
       9 . Spray drying system for processing hazardous substances according to  claim 6 , wherein the atomizer nozzle is connected to a tank containing neutralizing agent. 
   
   
       10 . Spray drying system for processing hazardous substances, wherein said system comprises a drying chamber, after treatment equipment placed downstream of the drying chamber and a process gas heater placed upstream in relation to the drying chamber, wherein an inlet filter capable of removing microorganisms at a temperature below 140° C., is placed upstream of the process gas heater, and wherein the process gas heater is a non-flaking heater. 
   
   
       11 . Spray drying system for processing hazardous substances according to  claim 10 , wherein the atomizer nozzle is connected to a tank containing neutralizing agent. 
   
   
       12 . Spray drying system for processing hazardous substances according to  claim 10 , wherein an atomization device is located upstream of the drying chamber, which atomization device is connected to a vessel containing a neutralizer agent. 
   
   
       13 . Spray drying system for processing hazardous substances according to  claim 12 , wherein the atomization device is located at the gas inlet for drying gas to the drying chamber. 
   
   
       14 . Spray drying system for processing hazardous substances according to  claim 13 , wherein the atomization device is located downstream of one or more filters filtering the process gas. 
   
   
       15 . Spray drying system for processing hazardous substances according to  claim 12 , wherein the atomization device is one of the following: a two fluid nozzle, a single fluid nozzle or a venture.