Horizontal Rotary Screen

Operation of the Horizontal Rotary Screen

  1. 1.The horizontal rotary screen consists of two components, and functions as a screen for the parchment coffee, sorting it into two categories. 

    1. a.The first category are the beans that pass through the screen, because they are ripe, healthy beans.

    2. b.The second category is that of the beans that do not pass through the screen, being the ripe any un-pulped cherries, dry pods, oversize beans, peaberries, and remaining pulp.

    3. c.Parchment coffee enters the rotary screen from tubes, serving as channels between the screen and the depulpers.

  1. 2. The first component of this machine is the screen.

    1. a.The rotary screen is cylindrical and perforated. 

    2. b.Slanted downward, the screen works as it rotates, churning the coffee parchment, allowing it to pass through the oval shaped holes as it travels slowly down the screen.

      1. i.Beans that pass through the screen are funneled into the base of the rotary screen, feeding a pipe that leads to the mucilage remover.

      2. ii.Beans that do not pass through the screen, continue in forward motion, until they pass through the entire screen, where they are funneled into a separate tube. They are gathered, and distinguished as one of four qualities of parchment coffee to be dried.

  1. 3. The second component of the rotary screen is a cylindrical brush.

    1. a.The brush consists of a series of short, black bristles.

    2. b.It is not automatic, but rather rotates by the motion of the screen.

    3. c.As the main cylinder of the screen rotates, the brush removes any pulp, remaining from the depulpers, from the screen, allowing the healthy bean to pass through the screen, on its way to the mucilage remover.