| 摘要 |
992,364. Trimming ships carrying liquefied gas. PHILLIPS PETROLEUM CO. Aug. 20, 1963 [Sept. 4, 1962], No. 32867/63. Headings B7A, B7M and B7S. A ship comprises a plurality of horizontally spaced cargo tanks containing a volatile liquid, means for withdrawing vapour from said tanks and compressing, cooling and condensing at least a portion of said vapour into liquid, and means for selectively returning said liquid to said tanks such that when the ship lists in one direction a major portion of the liquid is returned to one of the tanks that is located in the opposite direction, whereby the ship is partially righted. As shown, vapour 13 is withdrawn from tank 8 and passed through line 14, valve 16, line 17, tank 18 and line 19 by compressor 21, which compresses the vapour and forces it through line 22 into indirect heatexchanger condenser 23. Vapour which is left and condensed liquid pass through valve 26 and lines 28 and 27 respectively into chamber 29 of tank 31. The outlet valve 32 of tank 31 is controlled by float 33 and when the liquid rises above a fixed level valve 32 opens and liquid passes through line 34 into liquid distributing tank 36 extending athwartships. The liquid level 37 depends upon the degree of listing of the ship. The port side of the tank 36 communicates via line 38 with tank 11 and the starboard side via line 39 with tank 8. Thus for a port list as shown, the liquid will flow into starboard tank 11. Each tank 8 and 11 has means to spray the returned liquid through a Venturi 72, or 73. During unloading of tanks 8 and 11, the vapour in tank 18 is pumped by compressor 21 through by-pass valve 48 and line 66 into tank 36 and hence via lines 38 and 39 into tanks 8 and 11 where it forces the liquid in said tanks through valves 49 and 51 and lines 68 and 67, and through valve 53 into tank 18 where it is pumped by pump 63 through to the unloading lines. Valve 53 is operated by liquid control level 61. In a modification, the means to return liquid to the distributing tank includes a flow control valve operated by a motor adapted to open said valve responsive to a drop in pressure downstream of said valve below a predetermined value (Fig. 2, not shown). Fig. 2 (not shown) also illustrates the invention with the functions of the distributing tank and tank 18 combined in one tank. |
