INSULATED TANK CONTAINER

Abstract: In order to obtain a particularly light and cheap construction, the tank container consists of a thin inner shell (4) and outside this semi-hard or hard insulation (6, 8, 10, 11) which has the capacity to take up and transfer stresses in various directions and is firmly glued to the inner shell. An outer shell (5, 7, 9) with a framework (1) may be disposed outside the insulation. As an alternative, the insulation may be introduced, foamed and hardened in situ between preformed shells.

Description: Insulated tank container Technical field The present invention relates to an insulated tan container, preferably but not exclusively of the type which comprises a framework and which can be transferred between different vehicles etc. Prior art Conventional insulated tank containers have such a thick inner body plate that this carries the stresses of the load and any internal excess pressure. In other words, the tank or container is self-supporting and the insula¬ tion situated on the outside (with a protective outer skin) has, in principle, no other function than just to insulate- The tank normally rests on its chassis through rigid brackets or so-called saddles. In some cases, according to current standards, certain external loads are permitted on the insulation. The thickness. of the body can thus be reduced somewhat, if blows and shocks from the outside can be damped by the insulation. For so-called cryotanks, there is also the possibility, according to the standards, of including an outer shell to take up the load, but these tanks are spherical be¬ cause of the pressure, so that the only additional purpose of the insulation is to hold the shellsapart. A conventional tank container is therefore both heavy and expensive. The invention A considerably lighter and cheaper construction is achieved according to the invention, according to which an insulated tank container consists of a preferably thin inner shell without any demands on carrying capacity and outside this a semi-hard or hard insulation which has the capacity to take up and transfer stresses in various directions and which is firmly glued . to or otherwise integrated with the inner shell. β The inner shell (the container) has an arcuate or purely rectangular cross-section to accommodate as large an amount of liquid as possible. The arcuate shape must be selected for liquids which involve hygiene because th 5 washing apparatus used does not reach into corners. The container walls are exposed by the liquid to forces which are transferred to the insulation in the form of compressive stresses, shear stresses and some¬ times moderate tensile stresses, all of which can be tak 10 up and transferred by the semi-hard or hard insulation. Thus, together, the inner shell and the insulation form a load-bearing unit. The insulation may have a protective layer on the outside. Another and preferred embodiment is that a preferabl 15 load-bearing outer shell is firmly glued to or otherwise integrated with the insulation, the outer shell perferab comprising protective rigid corner strips. The insulation may essentially consist of preformed, preferably disc-shaped parts glued to the inner and the 20 outer shell. The inner shell preferably consists of a preshaped container of a material which is suitable in view of the contents, while the outer shell is built up of rigid corner strips and discs of a material without any demand 25 for resistance to the contents of the container, and the preferably disc-shaped insulating parts are glued to sai discs before mounting and are glued to the container during the mounting. After the mounting of the inner shell, the various 3.0 disc-shaped insulating parts and the outer shell, certai remaining, unfilled spaces remain between the shells. These can be filled with injected insulating material in foamed form, which hardens in situ. An alternative method of production is to introduce 35 (inject) foam and harden all the .insulating material in situ between preformed shells. Particularly if the inner shell is very thin and therefore lacks the necessary carrying capacity, there may be some kind of contour-retaining elements in the inner shell during manufacture, which are later removed. The necessary pipes, valves, etc. are mainly disposed in the insulation so that the tank container has a smooth exterior which is an advantage from several points of view. Brief Description of the Drawings The invention will be described in more detail below with reference to the accompanying drawings in which Figs. 1-3 illustrate typical steps in the coming into existance of a tank container according to the invention and Figs. 4-6 show, on a smaller scale, three sections through the finished tank container (along the lines IV-IV of Fig. 6, V-V of Fig. 4 and VI-VI of Fig. 5 respectively. Description of preferred embodiments Fig. 1 shows an assembled tank container frame 1, which preferably consists of a plurality of rigid corner strips welded together, for example of aluminium with a typical thickness of 4 mm. Such a frame for a so-called half-high 20* container has a frame weight of about 280 kg. This frame 1 is placed on a bottom covering plate 2, to which there are glued substantially disc-shaped bottom insulating parts 3 with suitable recesses for emptying pipes and valves only indicated in Fig. 6. These parts 3, like all the insulating parts de¬ scribed below, are made of a semi-hard or hard insulating material with the capacity to take up and transfer stresses in various directions, for example foam plas¬ tics of' the Divinycell ® type. The bottom covering plate 2, like all the covering plates described below, can be made of aluminium with a thickness of 1.25 mm for example. Fig. 2 illustrates the introduction of three inner tanks 4 of a material which is resistant to the intended contents of the tank or which is selected to meet the hygiene demands. On the other hand, in principle, the are no demands on the carrying capacity of the tanks. the present case, the three tanks are made of stainle plate 1.25 mm thick and then have a total weight of 540 kg. Fig. 3 illustrates the application of the remaini parts to the tank container: side covering plates 5 w glued-on side insulating parts 6, end covering plates with glued-on end insulating parts 8, an upper coveri plate 9 with glued-on upper insulating parts 10 and insulating partitions 11 between adjacent tanks. With the embodiment illustrated and described, th total weight of the covering plates is about 140 kg a of the insulation (Divinycell (^§ with a density of 60 kg/m 3 at the bottom and 45 kg/m3 otherwise) about 160 kg. The total weight of the tank container shown (in¬ cluding certain other equipment not shown) is about 1200 kg, which may be compared with the weight of 2400 kg for a corresponding conventionally insulated tank container. In both cases the volume of the container 3 is about 14.5 m . After suitable adhesive has been supplied to all t surfaces which are to be glued in the construction, th is to say, in principle, all the free surfaces before the assembly described above with reference to Figs. 1 the whole construction may appropriately be placed in "bag" from which the air is sucked out, while at the same time the interior of the tanks 4 is heated up. As a result vacuum adhesion is brought about. When the glueing operation is finished, any residu spaces can be filled with injected foam plastics which hardens in situ. In Figs. 4-6 the reference numerals for the variou insulating parts have been omitted for the sake of clarity; all the hatched surfaces consist of insulatio O.-. It should be observed that the embodiment described is merely an example of various possibilities. In partic¬ ular, it should be noted that the outer shell and the insulation together as an integrated unit can give the necessary stability and load-bearing capacity. In such a case, the insulation should have some kind of protective outer layer. Another important modification is that the insulation can be injected, foamed and hardened in situ between pre- formed shells. ■ ζ,\} \ EA _ GXPI ■ - IPO _&> '

Claims: CLAIMS : 1. An insulated tank container, characterized in that it consists of a preferably thin inner shell (4) w out any demands on load-bearing capacity and outside th semihard or hard insulation (3, 6, 8, 10, 11) which has the capacity to take up and transfer stresses in variou directions and which is firmly glued to or otherwise integrated with the inner shell and with the rigid end frames of the tank container. 2. A tank container as claimed in claim 1, characterized in that a preferably load-bearing outer shell (2, 5, 7, 9) firmly glued to or otherwise integrated with the insula tion, the outer shell preferably comprising protective rigid corner strips (1) . 3. A tank container as claimed in claim 2, characterized in that the insulation essentially consists of preformed, preferably disc-shaped parts (3, 6, 8, 10, 11) glued to the inner (4) and the outer shell (2, 5, 7, 9). 4. A tank container as claimed in claim 3, characterized in that the inner shell consists of a preformed tank (4) o a material which is suitable in view of the intended co tents and that the outer shell is built up of rigid cor strips (1) and discs (2, 5, 7, 9) of a material with no demands on resistance to the contents of the tank, and preferably disc-shaped insulating parts (3, 6, 8, 10, 1 are glued to said discs before assembly and are glued t the tank during the assembly. 5. A tank container as claimed in claim 4, characterized in that the remaining space between shell and insulating discs is filled with injected insulating material in foamed form. BU E _C.V.P 6. A tank container as claimed in claim 2, characterized in that the insulation is introduced, foamed and hardened in situ between preformed shells. 7. A tank container as claimed in one of the preceding claims, characterized in that, during production, there is a contour-maintaining element in the inner shell (4) , particularly if this is very thin. 8. A tank container as claimed in one of the preceding claims, characterized in that necessary pipes, valves etc are mainly disposed in the insulation.

Inventors: BJURLING A
Applicants: BJURLING A, DYNATRANS AB
Application year: 1980
Main classification: B65D90
IPC codes: B65D88, B65D90, F17C3