Patent ID: 6052917
Filing Date: 2000-04-25
Classification: F26B

Abstract:
A vacuum rotary dryer for drying particulate solids, comprising:a rotary drum supported so as to be varied in inclination angle at which a central axis thereof acting as a center of rotation thereof is inclined with respect to a horizontal direction in a vertical plane;a drum inclination angle adjusting structure for adjusting the inclination angle of the central axis of said rotary drum;a drum rotating driver for driving said rotary drum to rotate it;a gas flow pipe arranged so as to airtightly extend through a central portion of one end of said rotary drum in an axial direction thereof into said rotary drum while permitting rotation of said rotary drum;a pressure reducing unit for sucking gas in said rotary drum to reduce a pressure in said rotary drum;a gas flow passage change-over structure for connecting said gas flow pipe to a piping connected to said pressure reducing unit and a gas space at an atmospheric pressure while carrying out change-over thereof;a solids feed and discharge pipe including a straight pipe section having one end inserted into said rotary drum from a side of the other end of said rotary drum in the axial direction thereof while permitting rotation of said rotary drum and a swing section arranged so as to extend from the one end of said straight pipe section positioned in said rotary drum toward a peripheral wall of said rotary drum and communicate with said straight pipe section;a feed and discharge pipe drive structure arranged so as to rotate said straight pipe section of said solids feed and discharge pipe to pivotally move said swing section in said rotary drum;a feed and discharge change-over structure for connecting said straight pipe section of said solids feed and discharge pipe to a piping connected to a feed source of solids to be dried and a piping connected to a solids suction and transport structure for transporting dried solids by suction while carrying out change-over thereof; anda drum heating structure for heating said rotary drum to dry solids in said rotary drum;said drum inclination angle adjusting structure varying the inclination angle of the central axis of said rotary drum;said swing section of said solids feed and discharge pipe being arranged so as to be pivotally movable between a final suction position at which a distal end of said swing section approaches a corner between an end wall of said rotary drum on a side of the other end of said rotary drum in the axial direction thereof and a lower portion of said rotary drum and a retreat position at which said swing section is retreated from said final suction position.