Tanks for Transporting Liquids

The present invention relates to an insulating cover for tanks used for transporting liquids.

According to the present invention there is provided a tank structure for transporting liquid, comprising an elongate tank with closed ends, a framework for supporting the tank and an insulating cover formed in panel-line sections and arranged to be secured in position around the tank to cover substantially the whole surface area of the tank. Such an arrangement enables the operator of a fleet of such tank structures to insulate only those tank structures which specifically require insulation. The insulation can also be readily easily removed for inspection of the tank. The risk of concealed corrosion of the tank walls under the insulation is reduced. In the event of collision damage, the tank walls are readily accessible for repair, after which the insulation can be re-fitted. If some panels of the insulation are damaged, they can readily be replaced without the need to re-build the entire insulation.

Advantageously, the panels constituting the insulation are held in place by elastic lacing which is itself preferably protected from direct sunlight and other damage by suitable flaps.

An embodiment of the invention will now be described by way of example with reference to the accompanying drawings, in which:

FIG. 1 is a plan view of a tank structure in accordance with the invention;

FIG. 2 is a side elevational view of the tank structure shown in FIG. 1;

FIG. 3 is an end elevational view of the tank structure;

FIG. 4 is an enlarged cross-sectional view taken substantially along line IV--IV in FIG. 2 and showing the junction of two adjacent panels or of the junction between the two ends of one panel;

FIG. 5 is a section on the line V--V of FIG. 2;

FIG. 6 is a section on the line VI--VI of FIG. 1; and

FIG. 7 is a section on the line VII--VII of FIG. 1.

The tank structure shown in FIGS. 1 to 3 is of basically standard construction in that it comprises a stainless steel tank 1 having a cylindrical side wall 2 and a domed end walls 3. Tubular bearers 4 of slightly smaller diameter than the side wall 2 are welded to the end walls 3 at one end and at their other end to a supporting framework 5 which includes upper and lower corner castings 6 and 7 and in general conforms to ISO standards for containers.

Stiffening hoops 8 are welded to the wall 2 at intervals along its length and can also be attached to adjacent members of the framework 5.

In accordance with the present invention, the side wall 2 and end walls 3 are insulated by means of a jacket consisting of side wall panels 9 and circular end panels 10. Each section or panel 9, 10 consists of an inner skin 11 (FIG. 4) formed for example of TYGLAS (Trade Mark) which is a woven glass fiber fabric faced with aluminum foil (Y182/387), an outer skin 12 for example of 2.times.2 panamar PVC-coated polyester fabric preferably coloured white, the skins 11 and 12 being sealingly connected around their peripheries to define a moisture-impervious sealed envelope, and an insulating filling 13 preferably kapok, for example type Ceibatex (Trade Mark) K20/30, disposed between the skins. The panels are hence flexible so as to conform to the tank.

Preferably, at least one of each pair of opposite edges of each panel is resiliently anchored to an adjacent portion of the tank or its frame and/or to an adjacent panel edge. This is conveniently achieved by means of an elasticated shock-cord 14 laced through eyelets 15 in tapes 16 secured to the outer skin 12. The elasticated cord 14 may also be laced through staples or rings 17 or 18 welded to appropriate elements of the tank or frame, such as to the tubular elements 4 in FIG. 4.

Each run of elasticated cord 14 is protected by a cover flap 19 of the same material as the outer skin 12, the cover flap 19 being welded or stitched at 20 along one edge to the outer skin 12 adjacent one of the panel edges. The opposite edge of each cover strip 19 is provided with a line or row of openings as defined by eyelets 21 which are engaged over staples 18 and secured in position by a standard TIR rope 22 (hemp or sisal encased in a transparent plastic sheath) which extends tautly through the staples and can be secured and sealed in the normal manner.

In FIG. 4, the two ends of the same circumferential panel 9 are connected together elastically, the rings or staples 18 being secured to the outer skin 12.

In FIG. 5, the outer edge of the outermost panel 9 is resiliently anchored to the outer row of staples 17 on the element 4, the staples 17 being elongated to accommodate also the eyelets 21 and rope 22 securing the cover flap 19. Also, the outer periphery of the end panel 10 is resiliently anchored to the smaller staples 18 on the inner face or the element 4, the cover flap 19 of this panel being anchored by means of a further row of staples 18 and rope 22.

In FIG. 6, a row of staples 28 is welded around the outer edge of the hoop 8 and the securing tape 16 of the two adjacent panels 9 have their eyelets 15 engaged over the staples 28 and secured by a rope 22. The right hand portion of FIG. 6 shows a web 29 of the framework 5, the web carrying a ring of staples 30 over which are engaged eyelets 15 of a further tape 16 locked by means of a further rope 22.

FIG. 7 shows an arrangement by which the outer skin 12 of two adjacent panels may be made continuous across the outer edge of the hoop 8.

It will be noted that the inner skin 11 in the arrangement described above is impervious to most if not all of the liquids likely to be carried in the tank and there is thus little or no likelihood of the panels absorbing spillages and subsequently giving rise to concealed corrosion of the tank wall 2. Further, this impervious inner skin would prevent any corrosive material present in the insulation from attacking the tank walls. This would be particularly important if a foamed plastics material such as polyurethane were used in place of the kapok. The inner skin may also provide a degree of sacrificial cathodic protection for the tank walls. Such cathodic protection is provided by the aluminum foil mentioned above, although other suitable materials such as zinc may be employed.