Coffee bean polishing apparatus

A green coffee bean polishing apparatus for removing silver skin from green coffee beans having the silver skin remaining thereon after removal of parchment, said apparatus comprising:

• a tubular member communicated at one end portion thereof with a supply port for green coffee beans to be polished and at the other end portion thereof with a discharge port for the polished green coffee beans, said tubular member defining a polishing chamber therein and having a large number of holes passing through a wall thereof;
• a polishing roll rotatably disposed in said polishing chamber for serving to polish the green coffee beans in said polishing chamber so as to separate the silver skin from the outer surface of each green coffee bean, said polishing roll comprising a brush roll portion for scratching the silver skin and a friction type polishing roll portion for polishing the green coffee beans by friction to thereby substantially remove any of the silver skin still remaining on the outer surface of the green coffee beans, said friction type polishing roll portion being located on the downstream side of said brush roll portion in terms of a flow direction of the green coffee beans from the supply port to the discharge port;
• a moisture supplying device for supplying water into a region of said apparatus which is in fluid communication with said polished chamber so that surfaces of the coffee beans are humidified when the coffee beans are polished in the polishing chamber;
• and
• an air passing means for passing air from said polishing chamber to an outside of said tubular member so as to discharge the silver skin separated from the green coffee beans through said holes in said wall of said tubular member.