Screen cylinder

Abstract

A pulp screen cylinder that includes screen media releasably engaged with a frame at spaced locations opposing movement of the media away from the frame during screening. A preferred frame includes a plurality of spaced engaging structures that releasably engage screen media. A preferred frame includes an arrangement of flow windows that are triangular or rhomboid. A preferred method includes producing a frame cylinder by centrifugal casting and machining flow windows using a jet cutting process. A preferred screen media has a plurality of spaced apart engaging structures that each releasably engages the frame at spaced apart locations. A preferred screen media is of wedgewire construction having engaging structure carried by a plurality of spaced wire retaining clips. A preferred clip has vee-shaped rounded slots and an arm thicker than an end wall. A preferred engaging structure includes a projection that has a lip or hook for releasable interlocking engagement.

1 - 48 . (canceled).  
   
   
       49 . A pulp screen cylinder comprising: 
 a generally cylindrical perforate frame;    a removable perforate screen media that is receivable in the frame, the perforate screen media comprised of a plurality of pairs of screening slots and removably attachable to the frame at a plurality of axially spaced apart and discrete locations such that movement of the perforate screen media relative to the frame in a direction away from the frame is opposed when the perforate screen media is received in the frame.    
   
   
       50 . The pulp screen cylinder of  claim 49  further comprising a plurality of axially spaced apart engagement structures that each effects removable attachment of the perforate screen media to the frame at one of the plurality of the axially spaced apart and discrete locations.  
   
   
       51 . The pulp screen cylinder of  claim 50  wherein each engagement structure effects removable attachment of the perforate screen media to the frame along a circumferentially extending region thereof.  
   
   
       52 . The pulp screen cylinder of  claim 50  wherein each engagement structure is carried by one of the frame and the perforate screen media.  
   
   
       53 . The pulp screen cylinder of  claim 50  wherein the frame has a pair of axial ends and each engagement structure is disposed between the axial ends of the frame.  
   
   
       54 . The pulp screen cylinder of  claim 50  wherein each engagement structure extends in a radial direction.  
   
   
       55 . The pulp screen cylinder of  claim 50  wherein the perforate screen media is comprised of wedgewire.  
   
   
       56 . The pulp screen cylinder of  claim 49  further comprising a plurality of axially spaced apart engagement structures that each is used in removably attaching the perforate screen media to the frame at one of the plurality of the axially spaced apart and discrete locations without welding.  
   
   
       57 . The pulp screen cylinder of  claim 56  wherein each engagement structure effects removable attachment of the perforate screen media to the frame along a circumferentially extending region thereof.  
   
   
       58 . The pulp screen cylinder of  claim 56  wherein each engagement structure is carried by one of the frame and the perforate screen media.  
   
   
       59 . The pulp screen cylinder of  claim 56  wherein the frame has a pair of axial ends and each engagement structure is disposed between the axial, ends of the frame.  
   
   
       60 . The pulp screen cylinder of  claim 56  wherein each engagement structure extends in a radial direction.  
   
   
       61 . The pulp screen cylinder of  claim 56  wherein the perforate screen media is comprised of wedgewire.  
   
   
       62 . A pulp screen cylinder comprising: 
 a frame;    a removable perforate screen media supportable by the frame, the perforate screen media comprised of a plurality of pairs of screening slots; and    a plurality of engagement structures extending from one of the frame and the perforate screen media to the other one of the frame and the perforate screen media and effecting removable attachment of the perforate screen media to the frame at a plurality of axially spaced apart locations such that movement of the perforate screen media in a direction away from the frame is opposed when the perforate screen media is removably attached to the frame.    
   
   
       63 . The pulp screen cylinder of  claim 62  wherein each one of the plurality of engagement structures is carried by one of the frame and the perforate screen media and disposed in contact with the other one of the frame and the perforate screen media.  
   
   
       64 . The pulp screen cylinder of  claim 62  wherein each one of the plurality of engagement structures effects removable attachment along a region between the perforate screen media and the frame in a direction generally transverse to axial.  
   
   
       65 . The pulp screen cylinder of  claim 62  wherein the perforate screen media is comprised of wedgewire.  
   
   
       66 . A pulp screen cylinder comprising: 
 a generally cylindrical perforate frame having a pair of axial ends;    a removable perforate screen media that is supportable by the frame, the perforate screen media comprised of a plurality of pairs of screening slots and removably attachable to the frame without welding at a plurality of axially spaced apart locations disposed between the axial ends of the frame.    
   
   
       67 . The pulp screen cylinder of  claim 66  further comprising a plurality of engagement structures extending interjacent the perforate screen media and the frame with each one of the engagement structures effecting removable attachment of the perforate screen media to the frame at one of the plurality of axially spaced apart locations such that movement of the perforate screen media relative to the frame in a radial direction away from the frame is opposed when the perforate screen media is removably attached to the frame.  
   
   
       68 . The pulp screen cylinder of  claim 67  wherein each one of the plurality of engagement structures effects removable attachment of the perforate screen media to the frame along a circumferentially extending region therebetween.  
   
   
       69 . The pulp screen cylinder of  claim 67  wherein each one of the plurality of engagement structures is carried by one of the frame and the perforate screen media and disposed in contact with the other one of the frame and the perforate screen media.  
   
   
       70 . A pulp screen cylinder comprising: 
 a generally cylindrical perforate frame;    a removable perforate screen media receivable in the frame, the perforate screen media comprised of a plurality of pairs of screening slots;    a plurality of axially spaced apart engagement structures that removably attach the perforate screen media to the frame; and    wherein movement of the perforate screen media relative to the frame away from the frame is restrained when the perforate screen media is received in the frame.    
   
   
       71 . A pulp screen cylinder comprising: 
 a generally cylindrical perforate frame;    a removable perforate screen media disposed in the frame, the perforate screen media comprised of a plurality of pairs of screening slots; and    a plurality of axially spaced apart engagement structures extending from one of the frame and the perforate screen media to the other one of the frame and the perforate screen media that each effect removable attachment of the perforate screen media to the frame without welding such that movement of the perforate screen media relative to the frame in a radial direction away from the frame is opposed when the perforate screen media is removably attached to the frame.    
   
   
       72 . A pulp screen cylinder comprising: 
 a generally cylindrical perforate frame;    a removable perforate screen media receivable in the frame, the perforate screen media comprised of a plurality of pairs of screening slots; and    a plurality of axially spaced apart engagement structures that each releasably attach the perforate screen media to the frame along a circumferentially extending region thereof such that movement of the perforate screen media relative to the frame away from the frame is opposed when the perforate screen media is received in the frame.    
   
   
       73 . A pulp screen cylinder comprising: 
 a generally cylindrical perforate frame;    a perforate wedgewire screen media disposed in the frame, the perforate wedgewire screen media comprised of a plurality of pairs of screening slots; and    a plurality of axially spaced apart engagement structures disposed interjacent the frame and the perforate wedgewire screen media removably attaching the perforate wedgewire screen media to the frame at a plurality of discrete and axially spaced apart locations.    
   
   
       74 . A pulp screen cylinder comprising: 
 a generally cylindrical perforate frame having a pair of axial ends;    a perforate wedgewire screen media disposed in the frame, the perforate wedgewire screen media comprised of a plurality of pairs of screening slots; and    a plurality of axially spaced apart engagement structures disposed between the axial ends of the frame that removably attach the perforate wedgewire screen media to the frame such that movement of the perforate screen media away from the frame is restrained.    
   
   
       75 . A pulp screen cylinder comprising: 
 a generally cylindrical perforate frame having a pair of axial ends;    a perforate wedgewire screen media disposed in the frame, the perforate wedgewire screen media comprised of a plurality of pairs of screening slots; and    a plurality of axially spaced apart engagement structures disposed between the axial ends of the frame that removably attach the perforate wedgewire screen media to the frame without welding.    
   
   
       76 . A pulp screen cylinder comprising: 
 a generally cylindrical perforate frame;    a perforate wedgewire screen media disposed in the frame, the perforate wedgewire screen media comprised of a plurality of pairs of screening slots; and    a plurality of axially spaced apart engagement structures that each extend outwardly from the perforate wedgewire screen media removably attaching the perforate screen media to the frame at a plurality of axially spaced part and discrete locations.    
   
   
       77 . A pulp screen cylinder comprising: 
 a generally cylindrical perforate frame;    a perforate wedgewire screen media disposed in the frame, the perforate wedgewire screen media comprised of a plurality of pairs of screening slots; and    a plurality of axially spaced apart engagement structures that each extend outwardly from the frame removably attaching the perforate screen media to the frame at a plurality of axially spaced part and discrete locations.    
   
   
       78 . A pulp screen cylinder comprising: 
 a generally cylindrical perforate frame of one-piece and unitary construction, the frame having a pair of axial ends;    a perforate wedgewire screen media the is receivable in the frame, the perforate wedgewire screen media comprised of a plurality of pairs of elongate and axially extending screening slots; and    a plurality of axially spaced apart and radially extending engagement structures disposed between the axial ends of the frame that each effect removable attachment of the perforate wedgewire screen media to the frame along a circumferentially extending region without welding such that movement of the perforate wedgewire screen relative to the frame in a radial direction away from the frame is restrained thereby.