| 摘要 |
PURPOSE:To reduce the abrasion of a rotary blade and the inner surface of an external cylinder, by making it possible to adjust the rotary blade in a centrifugal thin film dryer so as to bring the same to the contact or non-contact state with the inner surface of the cylinder corresponding to the number of rotations. CONSTITUTION:A solution to be treated is introduced into a cylinder 2 from a supply port 6 and the powder in the solution is adhered to the inner surface of the cylinder 2 in a thin film form by centrifugal force due to the rapid rotation of a rotary shaft 4. The thin film is dried by the heat of an outside steam jacket 1 and further fallen in a lower hopper 7 while scraped off by the rotation of rotary blades 3 when said thin film is formed, the leading end of each rotary blade 3 is separated from the inner surface of the cylinder by the centrifugal force due to the rotation of the blades 3 and the resultant moment of the springs 10 provided to one ends of the blades 3 and abrasion caused by the contact of both of them is prevented. When the thin film is scraped off from the inner surface of the cylinder, the number of rotations are adjusted to bring the leading ends of the blades 3 into contact with the inner surface of the cylinder to perfectly scrape off the powder thin film. Because the leading ends of the blades are brought into contact with the inner surface of the cylinder only when the membrane is scraped off, abrasion by the friction between both of them is reduced. |
