Pneumatic conveying system

Claim 1

IN A SYSTEM FOR PNEUMATICALLY CONVEYING FINELY DIVIDED MATERIALS, THE COMBINATION OF A PNEUMATIC CONVEYING PASSAGEWAY, A CLOSED FEED HOPPER HAVING A GENERALLY FUNNEL-SHAPED BOTTOM WITH AN OPENING AT ITS VERTEX FOR DISCHARGING THE CONTENTS OF THE HOPPER INTO SAID PASSAGEWAY, MEANS FOR SUPPLYING A STREAM OF AIR INTO SAID PASSAGEWAY TO MOVE THE FINELY DIVIDED MATERIAL THEREALONG, A FLEXIBLE FUNNEL-SHAPED POROUS LINER MEMBER FOR THE INNER SURFACE OF SAID FUNNEL-SHAPED BOTTOM, SAID LINER BEING IN ABUTMENT WITH THE INNER SURFACE OF SAID BOTTOM WHEN AIR IS NOT FORCED INTO THE HOPPER THROUGH THE POROUS LINER, A SOURCE OF AIR UNDER PRESSURE, FIRST CONDUIT MEANS FOR CONNECTING SAID SOURCE OF AIR UNDER PRESSURE TO THE INTERIOR OF SAID HOPPER ABOVE THE MATERIAL THEREIN, A PORT IN THE BOTTOM OF SAID HOPPER BENEATH SAID POROUS LINER, A SECOND CONDUIT MEANS FOR CONNECTING SAID PORT TO SAID SOURCE OF AIR UNDER PRESSURE, FIRST VALVE MEANS IN THE FIRST CONDUIT MEANS FOR CONTROLLING THE FLOW OF AIR UNDER PRESSURE INTO THE HOPPER ABOVE THE MATERIAL STORED THEREIN, SECOND VALVE MEANS IN THE SECOND CONDUIT MEANS FOR CONTROLLING THE FLOW OF AIR INTO THE HOPPER THROUGH SAID PORT AND BENEATH SAID POROUS LINER, AND CONTROL MEANS OPERABLE WHEN A STREAM OF AIR IS INITIALLY SUPPLIED INTO SAID CONVEYING PASSAGEWAY FOR OPENING THE FIRST VALVE MEANS WHILE MAINTAINING THE SECOND VALVE MEANS CLOSED FOR A PREDETERMINED PERIOD OF TIME, SAID CONTROL MEANS SERVING TO CLOSE THE FIRST VALVE MEANS AND OPEN THE SECOND VALVE MEANS AT THE EXPIRATION OF SAID PREDETERMINED PERIOD OF TIME.