Screen apparatus

Abstract

This invention provides a screen apparatus having an enhanced capacity for separating foreign matter from fibers of an acceptable quality in paper-making material. The screen apparatus S comprises: a sealed casing 1 having a paper-making material supply port 1 a, a refined paper-making material discharge port 1 b positioned above the paper-making material supply port 1 a and a foreign matter discharge port 1 c positioned above the refined paper-making material discharge port 1 b ; a screen 2 for dividing the interior of the sealed casing 1 into a first chamber 1 A and a second chamber 1 B and for separating foreign matter in the paper-making material, the screen being of cylindrical shape with end portions both open, the screen having circular holes or slit-like openings on a side face thereof and which screen is stood within the sealed casing 1 in such a way that a direction of height thereof faces a vertical direction; a rotor 7 disposed inside the screen 2 within the first chamber 1 A and having an agitating member 7 a for agitating the paper-making material within the sealed casing 1; and a water supply passage 10 mounted onto the sealed casing 1 so that a water spouting port 10 a opposes the top end face 7 T of the rotor 7.

1 . A screen apparatus comprising:
 a sealed casing having a paper-making material supply port, a refined paper-making material discharge port positioned above the paper-making material supply port and a foreign matter discharge port positioned above the refined paper-making material discharge port;   a screen for dividing the interior of the sealed casing into a first chamber and a second chamber and for separating foreign matter existing in the paper-making material, the screen being of a cylindrical shape and with end portions that are both open, the screen having circular holes or slit-like openings on a side face thereof and stood within the sealed casing in such a way that a direction of height thereof faces a vertical direction, both open end portions of the screen having an upper opening portion and a lower opening portion with the upper opening portion positioned below the foreign matter discharge port and the lower opening portion positioned above the paper-making material supply port;   a paper-making material supply passage connected to the paper-making material supply port in order to supply paper-making material to a first chamber from a downward direction;   a rotor disposed inside the screen within the first chamber and having an agitating member for agitating the paper-making material within the sealed casing;   a refined paper-making material discharge passage connected to the refined paper-making material discharge port and also connected to the second chamber so as to guide paper-making material that has been refined out of the sealed casing via the screen;   a foreign matter discharge passage connected to the foreign matter discharge port and also connected to the first chamber so as to guide out of the sealed casing foreign matter existing in the paper-making material and which does not pass through the screen; and   a water supply passage mounted onto the sealed casing so that a water spouting port opposes the top end face of the rotor.   
   
   
       2 . The screen apparatus according to  claim 1  further comprising: a ring portion provided at a midway position on the screen, the screen being divided by the ring portion into an upstream screen portion and a downstream screen portion, the ring portion being provided with a diluted water introduction port for introducing diluted water into the first chamber; a diluted water passage provided via the sealed casing and connected to the diluted water introduction port; and an uneven portion provided on a side opposing a rotor of the ring portion,
 wherein a convex portion of the uneven portion is provided so as to project from an inside wall face of the screen, and the uneven portion has a front end portion of the convex portion and a rear end portion of the convex portion that relative to a vertical direction of the casing is positioned lower than the front end portion of the convex portion, and which front end portion is tilted in such a way that relative to a rotational direction of the rotor the front end portion of the convex portion is nearer the rear end portion of the convex portion.   
   
   
       3 . The screen apparatus according to  claim 1  further comprising: a ring portion provided at a midway position on the screen, the screen being divided by the ring portion into an upstream screen portion and a downstream side screen portion, the ring portion being provided with a diluted water introduction port for introducing diluted water into the first chamber; a diluted water passage provided via the sealed casing and connected to a diluted water introduction port; and an uneven portion provided on a side opposing a rotor of the ring portion,
 wherein a convex portion of the uneven portion is provided not to project from an inside wall face of the screen and the uneven portion has a front end portion of the convex portion and a rear end portion of the convex portion that relative to a vertical direction of the casing is positioned lower than the front end portion of the convex portion, and which front end portion is tilted in such a way that relative to a rotational direction of the rotor the front end portion of the convex portion is located nearer than the rear end portion of the convex portion.