Contact plate structure for use in a rectifying or contacting column

Claim 1

IN A RECTIFYING OR CONTACTING COLUMN WHEREIN A LIQUID AND A GASEOUS MEDIUM ARE BROUGHT INTO CONTACT, A CONTACT PLATE STRUCTURE COMPRISING IN COMBINATION: A COLLECTING TRAY CAPABLE OF HOLDING A LAYER OF SAID LIQUID, DOWNCOMER MEANS CENTRALLY DISPOSED RELATIVE TO SAID TRAY FOR DISCHARGING SAID LIQUID THEREFROM, SAID DOWNCOMER MEANS COMMUNICATING WITH SAID TRAY AT A PREDETERMINED LEVEL ABOUT THE BOTTOM OF SAID TRAY WHEREBY THE HEIGHT OF SAID LAYER IS DETERMINED, A SUBSTANTIALLY HORIZONTAL PERFORATED PLATE HAVING A CENTER ZONE AND A PLURALITY OF SLOTS FOR THE UPWARD PASSAGE OF SAID GASEOUS MEDIUM FROM THE SPACE BELOW SAID PLATE, SAID DOWNCOMER MEANS BEING IN THE SHAPE OF A TUBE LOCATED IN SAID CENTER ZONE, A DEVICE ABOVE THE TRAY AND EXTENDING INTO SAID TRAY FOR GUIDING THE FLOW OF SAID GASEOUS MEDIUM INTO SAID SPACE BELOW THE PLATE, SAID PLATE BEING SPACED FROM THE BOTTOM OF THE TRAY AND ARRANGED AT A PREDETERMINED LEVEL BELOW THE COMMUNICATING LEVEL OF THE DOWNCOMER MEANS WHEREBY SAID PLATE MAY BE SUBMERGED IN A LAYER OF LIQUID IN SAID COLLECTING TRAY, SAID SLOTS BEING SO DIRECTED THAT THE STREAMS OF SAID GASEOUS MEDIUM PASSING THROUGH SAID SLOTS HAVE A SUBSTANTIAL COMPONENT TANGENTIAL WITH RESPECT TO CIRCLES ABOUT SAID CENTER ZONE, MEANS FOR CIRCULATING SAID LIQUUID AROUND SAID PLATE BETWEEN THE SPACES ABOVE AND BELOW