| 摘要 |
959,493. Pumping systems for liquefied gases. CONCH INTERNATIONAL METHANE Ltd. Dec. 1, 1961 [Jan. 16, 1961], No. 43101/61. Headings F1C, F1G, F1R and F1T. [Also in Division B8] A pumping system for liquids such as liquefied natural gases comprises a turbine 16 driving a pump 10 near the bottom of the liquid container and the working fluid has a solidification temperature below the temperature of the liquid 18 in the container 14. The turbine 16 may be driven by a combination of liquid and gas in which case the turbine exhaust fluid passes through a condenser 40 below the liquid level. After passing through the pump, the pressurised liquid is vaporised in a heat exchanger 50 and led to the turbine in an insulated pipe. If the turbine working fluid has a liquefaction temperature below the temperature of the liquid 18 then the pressurised working fluid passes through a pressure regulator fitted externally of the tank. The working fluid may be the vapour from the liquid in which case it is drawn off from the interior of the container (Fig. 4). Vapour from the container may pass into a separator (Fig. 3 not shown) or directly to the turbine 16 via a compressor 68. The exhaust from the turbine may pass into the line 22 and assist the flow of the effluent from the pump 10 in which case the vapour and liquid pass into the separator, the vapour passing to the compressor or back to the container and the liquid passing to a delivery line. In the event of a pump failure, or to assist the pump, compressed vapour may be passed through the delivery line. This pumping system ensures that vapour is returned to the container to counteract any pressure drop as the liquid level falls. In a modified form of this embodiment, (Fig. 4), the turbine exhaust is led directly to an accumulator 82, which also serves as a separator, and the line 70 has a by-pass 82 leading directly to the delivery line 22 the liquid being pumped direct to a separator 102. When the turbine 16 and pump 10 are inoperative the valve 78 and valves 84, 88 may be opened and liquid is pumped by vapour pressure into the accumulator 82, which has a relief valve 98. The liquid drains through lines 90, 92, 106 to a delivery reservoir. |
