Rotary drying drum

Claim 1

A DRYER FOR THE WET PAPER WEB OUTPUT OF A PAPERMAKING MACHINE AND THE LIKE, COMPRISING: (A) A HOLLOW CYLINDER HAVING A MULTIPLICITY OF CLOSELY SPACED OPENINGS IN THE SURFACE THEREOF AFFORDING A FREE PASSAGE OF AIR THERETHROUGH; (B) MEANS TO SUPPORT SAID HOLLOW CYLINDER FOR ROTATION; (C) STATIONARY SUPPORTING MEANS IN SAID CYLINDER; (D) AXIALLY AND RADIALLY EXTENDING SEALING MEANS MOUNTED IN SAID CYLINDER ON SAID SUPPORTING MEANS AND DEFINING AN AXIALLY ENCLOSED PORTION OF THE SPACE WITHIN SAID HOLLOW CYLINDER, SAID AXIALLY ENCLOSED PORTION HAVING A PERIPHERAL EXTENT EQUAL TO A MAJOR PORTION OF THE CIRCUMFERENCE OF SAID HOLLOW CYLINDER; (E) A PAIR OF SEALING ELEMENTS MOUNTED IN SAID CYLINDER ON SAID SUPPORTING MEANS AND ARRANGED TO FORM END CLOSURES AT OPPOSITE ENDS OF SAID AXIALLY ENCLOSED PORTION; (F) MEANS TO ADMIT A SUBSTANTIAL VOLUME OF HEATED AIR AT A SUPERATMOSPHERIC PRESSURE TO SAID AXIALLY ENCLOSED PORTION, SAID SEALING MEANS AND SAID SEALING ELEMENTS BEING ARRANGED EFFECTIVELY TO PREVENT SAID HEATED AIR FROM LEAVING SAID AXIALLY ENCLOSED SPACED EXCEPT THROUGH SAID OPENINGS IN SAID HOLLOW CYLINDER; AND (G) A THIN POROUS SINTERED FIBER METAL CYLINDER OVERLYING AND COVERING THE OUTER SURFACE OF SAID HOLLOW CYLINDER AND BEING RIGIDLY CONNECTED THERETO.