Eductor control in sewage treatment plant

Claim 1

AN AEROBIC SEWAGE TREATMENT INSTALLATION COMPRISING: SEWAGE TREATING MEANS FOR AERATING SEWAGE; SEWAGE COLLECTION MEANS FOR COLLECTING SEWAGE PRIOR TO ITS TREATMENT IN SAID TREATING MEANS; AIR LIFT MEANS INCLUDING AN EDUCTOR PIPE HAVING ONE END DIPPING INTO SEWAGE IN SAID COLLECTION MEANS AND ITS OTHER END CONNECTED TO DELIVER SEWAGE TO SAID TREATING MEANS, SAID AIR LIFT MEANS FURTHER INCLUDING AN AIR SUPPLY PIPE CONNECTED TO DELIVER AIR INTO SAID EDUCTOR PIPE BELOW THE LEVEL OF SEWAGE IN SAID COLLECTION MEANS; FIRST AND SECOND BLOWERS FOR SUPPLYING COMPRESSED AIR THROUGH SEPARATE OUTLETS; VALVE AND CONDUIT MEANS CONNECTING THE OUTLET OF SAID FIRST BLOWER WITH SAID TREATING MEANS AND WITH SAID AIR SUPPLY PIPE, SAID CONNECTING MEANS INCLUDING A NORMALLY CLOSED FIRST VALVE AND A CONDUIT EXTENDING THEREFROM TO SAID AIR SUPPLY PIPE, SAID CONNECTING MEANS FURTHER INCLUDING A NORMALLY OPEN SECOND VALVE AND A CONDUIT EXTENDING THEREFROM TO SAID TREATMENT MEANS; CONDUIT MEANS CONNECTING THE OUTLET OF SAID SECOND BLOWER WITH SAID TREATING MEANS, SAID LASTNAMED CONDUIT MEANS BEING SEPARATE FROM THE CONDUITS ASSOCIATED WITH SAID FIRST AND SECOND VALVES WHEREBY WHEN ONLY ONE BLOWER IS OPERATED AIR THEREFROM IS PASSED TO SAID TREATING MEANS AND WHEREBY WHEN BOTH BLOWERS ARE OPERATED AND WHEN THE POSITIONS OF SAID FIRST AND SECOND VALVES ARE REVERSED, AIR FROM SAID FIRST BLOWER PASSES TO SAID AIR SUPPLY PIPE AND AIR FROM SAID SECOND BLOWER PASSES TO SAID TREATING MEANS.