Coffee roasting apparatus and method

Abstract

A coffee roaster that includes a combustion chamber and a connected roasting oven in which the heating gases for roasting the coffee beans are recirculated to the combustion chamber wherein the coffee bean chaff is separated from the recirculating heating gases prior to venting to atmosphere, and an associated cooling chamber wherein the roasted coffee beans are cooled in a two-stage heating cycle wherein the cooling air is recirculated to the combustion chamber to be reheated to roasting temperatures and vented to atmosphere during the second stage of cooling. The coffee beans being de-stoned as the cooled coffee beans are conveyed from the cooling chamber to the discharge hopper.

What is claimed is:  
     
         1 . A coffee bean roasting apparatus comprising: 
 a combustion chamber for generating heating gases,    a roasting oven connected in communication with said combustion chamber whereby the heating gases are directed to said oven,    means for recirculating the heating gases flowing through said roasting oven back to the combustion chamber free of any coffee bean residue.    
     
     
         2 . A coffee bean roasting apparatus as defined in  claim 1 , and said combustion chamber including spaced apart baffles within said combustion chamber defines a sinuous path for incrementally reheating a recirculating cooling medium to roasting temperature.  
     
     
         3 . A coffee bean roasting apparatus as defined in  claim 1  wherein said heating gas recirculation means includes a suction fan having an inlet and an outlet, 
 said in let being disposed in communication with said roasting oven,  
 a separator,  
 said outlet of said fan being connected in communication with said separator, whereby said fan draws said heating gases and any entrained chaff from said oven and conveys said heating gases and entrained chaff to said separator,  
 said chaff being separated from said heating gases in said separator whereby said heating gases free of chaff is recirculated to said combustion chamber.  
 
     
     
         4 . A coffee bean roasting apparatus as defined in  claim 1  and including a cooling chamber for cooling the coffee beans after being roasted in said oven, 
 means connected to said cooling chamber for effecting a first phase cooling of said roasted coffee beans therein, and  
 means connected to said cooling chamber for effecting a second phase cooling of said roasted coffee beans therein.  
 
     
     
         5 . A coffee roasting apparatus as defined in  claim 4  and including means for de-stoning said cooled coffee beans.  
     
     
         6 . A coffee roasting apparatus comprising: 
 a combustion chamber,    a burner for generating heating gases within said combustion chamber,    spaced apart baffles disposed within said combustion chamber to define a sinuous recirculation gas path,    a gas inlet and a gas outlet connected to said combustion chamber,    a roasting oven,    a duct connecting said combustion chamber in communication with said roasting oven for directing heating gases from said combustion chamber to said roasting oven,    said roasting oven including a perforated rotating drum,    a separator,    means for directing the heating gases in said oven and entrained coffee chaff exiting said oven during the roasting cycle to said separator wherein said chaff is separated from the heating gases,    means for directing said heating gases free of any chaff back to said combustion chamber,    a cooling chamber for receiving the roasted coffee beans when roasting of the coffee beans has ended,    a first phase cooling means connected to said cooling chamber for drawing a cooling gas through said cooling chamber and recirculating said cooling medium to said combustion chamber,    and a second phase cooling means connected to said cooling chamber for venting said cooling medium directly to atmosphere.    
     
     
         7 . A coffee roasting apparatus comprising: 
 a combustion chamber,    a burner for generating combustion gases within said combustion chamber,    said combustion chamber having a recirculating gas inlet and gas outlet exhausting to atmosphere,    baffle means disposed within said combustion chamber to define a sinuous flow path,    a coffee roasting oven,    a connecting conduit connecting said combustion chamber in communication with said coffee roasting oven,    a modulating damper disposed in said connecting conduit,    said roasting oven including a rotating drum and a gas outlet,    a suction fan connected in communication with said oven gas outlet,    said suction fan having an outlet,    a separator,    a conduit connecting said outlet of said suction fan in communication with said separator,    said separator separating any coffee chaff entrained in the heating gases being recirculated,    and means for directing the heating gases exiting said separator back to said combustion chamber for venting to atmosphere free of any coffee chaff.    
     
     
         8 . A coffee roasting apparatus as defined in  claim 7  and including: 
 a cooling chamber for receiving the roasted coffee beans from said oven upon completion of the roasting period,  
 means for connecting said suction fan in communication with said cooling chamber for drawing cooling air into said cooling chamber and closing said suction fan out of communication with said oven, whereby said suction fan effects recirculation of said cooling air to said combustion chamber,  
 said cooling air being reheated to roasting temperature as it flows through said sinuous path.  
 
     
     
         9 . A coffee roasting apparatus as defined in  claim 8  and including: 
 means for aspirating the cooled coffee beans from said cooling chamber,  
 and a discharge hopper connected with said cooling chamber for receiving said aspirated cooled coffee beans, whereby said cooled coffee beans are de-stoned.  
 
     
     
         10 . A method of roasting coffee beans comprising the steps of: 
 generating heating gases in a combustion chamber,    directing said heating gases to a roasting oven containing a predetermined amount of coffee beans to be roasted,    tumbling said coffee beans within said oven as said coffee beans are being roasted and separating the roasting coffee beans from its chaff,    directing said heating gases and entrained coffee bean chaffs to a separator to separate the chaff from said heating gases,    and recirculating the heating gases free of said chaff to said combustion chamber for venting to atmosphere free of chaff.    
     
     
         11 . A method as defined in  claim 10  and including the steps of: 
 removing the roasted coffee beans from the roasting oven and placing said roasted coffee beans in a cooling chamber,  
 effecting the cooling of said roasted coffee beans in two consecutive phases,  
 recirculating the cooling gases during the first of said cooling phases to said combustion chamber,  
 and venting the cooling gases during the second of said cooling phases to atmosphere.  
 
     
     
         12 . The method as defined in  claim 10  and including the step of de-stoning said roasted coffee beans subsequent to said cooling phases.  
     
     
         13 . The method as defined in  claim 10  and including the step of de-stoning said cooled coffee beans as said coffee beans are transferred from said cooling chamber to a discharge hopper.  
     
     
         14 . A method of roasting coffee beans comprising the steps of: 
 generating heating gases in a combustion chamber,    directing said heating gases to a roasting oven containing a predetermined amount of coffee beans whereby said coffee beans are roasted,    removing said heating gases and any coffee bean chaff entrained from said roasting oven, and    separating the coffee bean chaff from said heating gases prior to said heating gases being recirculated to said combustion chamber.    
     
     
         15 . A method of roasting coffee beans as defined in  claim 14  and including the steps of: 
 removing the roasted coffee beans from the roasting oven,  
 effecting the cooling of said roasted coffee first by directing cooling atmospheric air over said roasted coffee beans and recirculating said cooling air to the combustion chamber, and thereafter directing said cooling atmospheric air and venting the same to atmosphere.  
 
     
     
         16 . A method of roasting coffee beans as defined in  claim 15  and including the step of de-stoning said roasted coffee beans subsequent to the cooling thereof.  
     
     
         17 . A method of roasting coffee beans as defined in  claim 10  and including the step of de-stoning the roasted coffee beans by aspirating said coffee beans whereby the heavier stones are separated from said roasted coffee beans by gravity.