Self-purging, pneumatic conveying apparatus

Claim 1

MATERIAL TRANSPORTING APPARATUS COMPRISING A CONTAINER INCLUDING A MATERIAL PLENUM ABOVE, A GAS PLENUM BELOW, AND A GAS PERMEABLE DIAPHRAGM THEREBWTWEEN, A SOLENOID ACTUATED, VALVE OPERATOR MOVED, FILL VALVE CONTROLLED INLET FROM A MATERIAL SOURCE, A SOLENOID ACTUATED, VALVE CONTROLLED, MATERIAL DISCHARGING DUCT FROM SAID MATERIAL PLENUM, A SOLENOID ACTUATED, VALVE CONTROLLED GAS DUCT CONNECTING GAS PLENUM AND A REGULATED COMPRESSED GAS SOURCE, A SOLENOID ACTUATED, VALVE CONTROLLED PURGE BY-PASS CONNECTING MATERIAL PLENUM AND DISCHARGE DUCT DOWNSTREAM FROM SAID DISCHARGE VALVE, AND ELECTRICAL POWER SOURCE TO CIRCUITRY CONNECTING SAID SOLENOID, A VARIABLE AND A FIXED TIME DELAY RELAY, A LATCHING FIRST RELAY, A SECOND RALEY, A NORMALLY OPEN, A NORMALLY CLOSED, AND A CONTROL PRESSURE SENSITIVE SWITCH, SAID CONTROL SWITCH CLOSING CIRCUI, AS CONTAINER PRESSURE FALLS TO A PREDETERMINED INITIAL, SUBSTANTIALLY ATMOSPHERIC, TO OPEN SAID FILL VALVE AND TO START THE INTERVAL OF A PRESELECTED VARIABLE TIME DELAY SWITCH TO LAPSE, THUS TO ACTUATE SAID LATCHING FIRST RELAY TO OPEN THE VARIABLE TIME DELAY SWITCH CIRCUIT, TO CLOSE SAID FILL VALVE, AND TO CLOSE CIRCUIT TO SAID FIXED TIME DELAY SWITCH, WHICH AFTER ITS FIXED TIME, OPENS SAID GAS SUPPLY VALVE AND CLOSES SAID PURGE VALVE, GAS NOW INCREASING CONTAINER PRESSURE TO SUCCESSIVELY HIGHER PREDETERMINED VALUES, AS SUCCESSIVELY, SAID CONTROL SWITCH OPENS, SAID NORMALLY CLOSED SWITCH OPENS, AND SAID NORMALLY OPEN SWITCH CLOSES TO OPEN SAID DISCHARGE VALVE AND TO ACTUATE SAID SECOND RELAY TO CLOSE DISCHARGE VALVE BYPASS CIRCUIT AND TO PARTIALLY CLOSE LATCHING RELAY CIRCUIT, MATERIAL NOW DISCHARGING AND CONTAINER PRESSURE DROPPING TO SUCCESSIVELY LOWER PREDETERMINED VALUES, AS SUCCESSIVELY, SAID NORMALLY OPEN SWITCH OPENS AND SAID NORMALLY CLOSED SWITCH CLOSES TO COMPLETE LATCHING RELAY CIRCUIT CLOSURE TO CLOSE SAID GAS SUPPLY AND DISCHARGE VALVES, TO OPEN SAID PURGE VALVE, AND TO DEENERGIZE SAID SECOND RELAY, SAID MATERIAL PURGING UNTIL CONTAINER PRESSURE FURTHER DROPS TO INITIAL PRESSURE TO START REPETITION OF THE AFORESAID CYCLE.