| 摘要 |
<p>938,847. Forcing liquids by gaseous pressure. UNION TANK CAR CO. Feb. 6, 1962 [Oct. 16, 1961], No. 4585/62. Class 102(2). Apparatus for handling liquid material comprises a pair of vessels 10, 12 having vents 26 to atmosphere and conduits 28 supplying pressurised fluid for emptying the tanks, and valve means 24, 25 for the vessels 10, 12 respectively disposed in the respective conduits and vents. Material flows into the tanks, through inlets 14, until the level reaches either of the sensing elements 30, 32, whereupon a first electric circuit energizing coil 42 is completed should the liquid level reach element 30. The first circuit comprises contact 78, pole 106, rectifier 80, coil 42, element 30 and earth point 38. When coil 42 is energized a timer 48 is energized through switches 44, 46 which energizes a solenoid 56 shifting the valve 24 to allow pressure fluid to enter the vessel 10. As the material clears the element 30, the circuit which initially energized the coil 42 is broken, but a holding circuit maintains the coil energized. The holding circuit comprises contact 78, pole 106, rectifier 80, coil 42, contact 92, pole 102, line 168 and contact 76. When the vessel 10 is empty the timer 48 operates the switches 52, 54 to break the holding circuit. Under normal conditions, since the circuit for coil 42 or 60 of one vessel passes through a coil operated switch of the other vessel only one coil can be energized at a time to prevent both vessels being emptied simultaneously. In the event of vessel 10 becoming fouled and contact between the element 30 and earth being maintained after the timer has broken the holding circuit, when the vessel 12 is filled, coil 60 is energized and coil 42 de-energized. Should the element 32 also become fouled and remain earthed, an energizing circuit for coil 42 is established on closing the switch 70 at the end of ejection of the vessel 12. This process continues, one vessel ejecting immediately after the other, until the fouling is removed.</p> |
