Patent GB-544342-A (GB)
Title: Improvements in heat insulated vessels
IPC: F17C13/08
Filed: 1940-08-15
Abstract: 544,342. Tank wagons. LINDE AIR PRODUCTS, CO. Aug. 15, 1940, Nos. 13018, 13019, 13020 13021,13022 and 13023. Convention dates, Aug. 19, 1939 and Dec. 7, 1939. [Class 103 (iv)] [Also in Groups XXIX and XXVIII] A double-walled insulated container for the storage of liquefied gases &c. comprises an inner vessel for the liquid, a spaced outer vessel, and a supporting frame including a base externally associated with the outer vessel, and supports extending between said frame and the inner vessel and passing through hermetically sealed openings in the outer vessel: In Fig. 1, frames 9, 10, are provided, the outer vessel 12 being secured to members 9, directly or by webs 29, and the inner vessel 11 being suspended from members 10 by girths. 23 with lugs 23<SP>1</SP> attached to rods 24 of material of low heat conductivity such as stainless steel, rods 24 being passed through collars 25 and held by nuts 26, while caps 28 and a sleeves 27 with expansion joints 30 provide hermetic seals. Filling and withdrawal pipes 13, 14, and an evaporation pipe 17 with safety valve 18 and a burstable diaphragm 19 for pressure relief, are provided, the pipes preferably passing through cones 16 of material of low thermal conductivity. A pipe 20, with burstable diaphragm 22 leads to a pump for evacuating the space between vessels 11, 12, which space may also contain finely divided heat insulating material such as asbestos fibre, magnesium carbonate, a magnesia cement consisting of a major portion of magnesium carbonate and a minor portion of asbestos fibre, flocculent blown silica, fiberized fused silica and limestone or mixtures thereof. Manholes 31, 32, may have brazed &c. covers. In another form, particularly for vessels with spherical ends, the vessels extend laterally beyond the frames 9, 10, and adjacent frames are connected by pairs of spaced channel members between which pass the rods 24. In Fig. 2, the outer vessel is supported on short lugs 33 and is stiffened by pairs of spaced rings 34 between which the rods 24 pass. In a tank wagon, Figs. 5 and 6, the outer vessel is further supported from the wagon frame by webs 62 formed of bent I-beams. The inner vessel 11b is braced against end and side away by rods 66, 69, anchored to the ends of the outer vessel, which ends are strengthened by rings 71, 73, and radial members 72. Dished baffles 74<SP>1</SP>, with openings 75, 76, prevent surging of liquid. Gas-withdrawal connections 46, protected by anti-splash baffles 47 and liquid supply and withdrawal connections 48, are provided on each side of the tank connections 48 lead to a header 50 connected to the bottom of the vessel 11b, and an emergency outlet 53, leading through the top of the vessel, is also connected to header 50. Header 50 is controlled by a threaded valve 49 protected by gauge 95 and actuated through a sliding connection 97 by a rod 77 passing through a bellows 82 to a handwheel 78. Pipes 52, 52a, with cocks 102, indicate depth of liquid. In Fig. 10, the end walls of the outer vessel 12b, are inwardly dished and provided with a builtup cruciform structure 111 connecting sleeves 108 containing springs 116 acting on rods 107 to limit end sway of the inner vessel 11b. The space between the vessels is preferably evacuated to an absolute pressure equal to or less than that at the bend of a curve obtained by plotting thermal conductivity of the powdered insulating material relative to the loarithm of the absolute pressure in said space. The space may be initially filled with a gas, such as argon or CO 2 , of lower thermal conductivity than air.