Patent GB-709423-A (GB)
Title: Improvements in or relating to paper making machines
IPC: D21F5/10
Filed: 1951-01-29
Abstract: 709,423. Hollow rollers. WALMSLEYS (BURY), Ltd., and TEMPERLEY, J. Jan. 29, 1952 [Jan. 29, 1951; Feb. 12, 1951]. Nos. 2144/51 and 3325/51. Class 34(1) [Also in Group VIII] In a high speed drying, cylinder or a cooling roller of paper-making machines, condensate or cooling liquid is removed from the cylinder or roller by collection centrifugally into rotary traps and displacement from the traps to the exterior of the roller by gaseous pressure. Each drying cylinder 11 has a stationary outlet tube 12 upon which a steam cover 13 is rotatably journalled, leaving a space between them, this cover carrying the ends 14 of the cylinder. Within the cylinder an extension 15 of the cover 13 carries eight flexible steam inlet trunks 16 extending radially at equiangular intervals and a non-rotatable bush 17 supporting the rotating hub part of extension 15 has a peripheral aperture 17a allowing steam from the annular space between cover 13 and tube 12 to enter at any one instant two or three of the trunks 16 over an area of approximately 90 degrees at the top of the cylinder. Each trunk 16 extends to the internal periphery of the cylinder and connects to four axially directed inlet pipes 18. Eight scoop sections 20 are arranged around the inner periphery of the cylinder, each comprising an arcuate casting having a shallow longitudinal peripheral channel 20a on the face lying against the cylinder communicating with the cylinder interior through transverse slots 20b which in turn communicate with a radial passage 20c. The channel 20a also connects with pipes 18 via radial passages 20d. A stationary arcuate pan 22 extends over approximately 180 degrees in the upper half of the cylinder and concentric with the corresponding portion of the scoop arrangement, the vertical faces of the pan having openings 22a with holes 23 to permit steam to discharge to the inside of the cylinder. The pan is supported by pipes 25, connecting with pipe 12, and by a central dummy pipe 24. The end of cover 13 remote from the cylinder is attached by a ring 28 to a sleeve 29 presenting a sealing surface 29a and shoulder 29b on which can slide an outer sleeve 30 keyed to rotate with sleeve 29. A stationary. sealing box 31 attached to a steam inlet connection 32 encloses packing ring 33 disposed between surface 29a and a flanged end of the box 31. Another ring 34 is. similarlydisposed in relation to sleeve 30, a spring 35 urging the sleeves 29, 30 in opposite directions. In operation steam passes through connection 32, trunks 16 and pipes 18 and if the cylinder is rotating slowly condensate picked up by the scoops will be discharged into pan 22 and drained via pipes 25 and 12. At higher speeds centrifugal force prevents such removal of condensate which will be forced into the slots 20b of the scoops 20 and occupy the volume defined between the channel 20a of the scoop and the internal periphery of the cylinder. Steam fed to the scoop sections through passages 18 will expel the condensate through radial passages 20c into pan 22, the steam entering the cylinder via hooded openings 22a. A similar arrangement is described for the cooling roller of paper making machines, cooling being carried out by spraying water or other liquid into the cylinder and the liquid is removed by low pressure air fed in similar manner to the steam.