|
(11) | EP 0 013 591 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
|
|
|
|
|||||||||||||||||||||||||||
| (54) | Bulk liquid container |
| (57) A bulk liquid container (1) has two expansible liquid carrying compartments which
can be independently filled, if desired with different liquids. A first compartment
is bounded by a rigid end wall (2), an extensible first sleeve (6) of oil- resisting
rubber or the like formed with a series of preformed corrugations, and a first rigid
member (5) movable within rigid outer walls (3) and can be filled or emptied by means
of a valve (10) and de-aired by means of another valve (11). The second compartment
is bounded by the first rigid member (5), an extensible second sleeve (7) also provided
with a series of preformed corrugations, and a second rigid member (4) which can either
slide within the rigid outer walls or can comprise a fixed end wall. |
[0002] Liquids are frequently transported, in circumstances where the use of a pipeline is impracticable, in vehicles, aircraft or ships fitted with bulk liquid containers. A major factor contributing to the expense of transporting liquids in bulk in such containers is that, after delivery of a load, the containers must usually make the return trip empty since it is often not feasible or is too time-consuming or expensive to clean the container for transport of a different liquid on the return trip.
[0003] A proposal has been made for a road or rail tanker vehicle that can carry a different liquid on the return trip from that carried on the outward trip, thus enabling the haulier to earn revenue on both trips. In such a vehicle the container is divided by two transverse partitions approximately one quarter and three quarters of the way along the container so as to provide three compartments. On the outward journey the middle compartment may be filled with, for example, oil whilst on the return journey the other two compartments may be filled with sulphuric acid. It is a disadvantage of this proposal that the capacity on each trip is only 50% of the total volume of the container. Furthermore on the one trip the load is entirely in the middle of the container whilst on the other trip the load is entirely at the ends of the container. Due to this factor it is difficult to ensure stability of the vehicle and the chassis must be correspondingly strengthed.
[0004] There is thus a need to provide a bulk liquid container that can be used to carry different liquids on different trips without the need to subject the interior of the container to a careful cleaning operation and that does not suffer the stability problems of the above- mentioned three-compartment container.
[0005] The invention accordingly seeks to provide a bulk liquid container which can be used to carry a full load of one liquid on one trip and to carry a full load of a different liquid on another trip. It also seeks to provide a bulk liquid container that can be used at different times for transporting different liquids, in each case a full load of each being carried, and that does not require cleaning between trips on which different liquids are to be carried. It also seeks to provide a bulk liquid container having at least two compartments capable of carrying liquid each of which can be fully loaded with liquid, the stability of which container is not appreciably affected whichever of the two compartments is filled with liquid.
[0006] According to the present invention a bulk liquid container comprises
(a) a rigid end wall;
(b) rigid protective outer walls which together with said rigid end wall define a cargo space;
(c) a rigid first member extending between the outer walls and movable in the cargo space between an inner position and an outer position;
(d) an extensible first sleeve of flexible liquid impermeable material provided with a series of preformed corrugations, the ends of which sleeve are respectively secured in fluid tight fashion peripherally to said rigid end wall and said first member adjacent said outer walls so that said first sleeve is axially extensible in concertina-like fashion in the direction of movement of said first member, and so that said first sleeve, said first member and said end wall together form an expansible liquid tight first vessel in said cargo space;
(e) first spacer means within the first vessel and in spaced relation from said outer walls to space said first member from said end wall in the unexpanded condition of said first vessel corresponding to said inner position of said first member, there being in said inner position of said first member a first stowage space around said first spacer means between said first member, said end wall and said outer walls;
(f) a rigid second member extending between the outer walls;
(g) an extensible second sleeve of flexible liquid impermeable material provided with a series of preformed corrugations, the ends of which are respectively secured in fluid tight fashion peripherally to said first member and said second member adjacent said outer walis so that said second sleeve is axially extensible in the direction of movement of said first member, and so that said sleeve, said first member and said second member together form an expansible liquid tight second vessel in said cargo space; and
(h) second spacer means within the second vessel. and in spaced relation from said outer walls to space said first and second members one from another in the unexpanded condition of said second vessel, there being in the unexpanded condition of said second vessel a second stowage space around said second spacer means between said first and second members and said outer walls, whereby said first and second vessels may be filled independently with liquid and said first and/or second sleeve is or are supported externally of their respective vessels against pressure from within by said outer walls and said first and second sleeves are protected from external damaging influences by said outer walls.
[0007] The first spacer means can be attached to, or be formed integrally with, the end wall or the first member. Similarly the second spacer means can be attached to, or be formed integrally with, the first member or the second member.
[0008] In one preferred embodiment of the invention the second member comprises a further rigid end wall which bounds the cargo space together with the first-mentioned end wall and the outer walls. In an alternative preferred embodiment the second member is movable relative to the outer walls. In the latter embodiment the container can be used for a solid cargo, e.g. copper ingots, when both vessels are empty.
[0009] Each of the first and second vessels may be fitted with loading and unloading valves and with a de-airing valve. The same valve may serve both for loading and for unloading.
[0010] In a preferred embodiment the extensible - first and/or second sleeve is or are provided with a plurality of rigid members peripherally encircling the respective-sleeve at spaced intervals therealong to maintain the shape of the sleeve and to hold the sleeve adjacent the rigid outer walls.
[0011] In order that the invention may be clearly understood and readily carried into effect some preferred embodiments thereof will now be described, by way of example only, with reference to the accompanying diagrammatic drawings, wherein:-
Figure 1 is a perspective view of a first form of bulk liquid container according to the invention, which has been sectioned to show its interior construction, filled with a first liquid;
Figure 2 is a similar sectional view of the container of Figure 1, filled with a second liquid;
Figures 3 and 4 are perspective sectional views of a second form of bulk liquid container according to the invention;
Figure 5 is a perspective view, partially cut away, of a third form of bulk liquid container according to the invention; and
Figure 6 is a detail section view through one of the flexible sleeves of the container of Figure 5.
[0012] Referring to Figures 1 and 2 of the drawings, a bulk liquid container 1 has a rigid base 2, rigid protective outer walls 3, and a rigid roof 4 affixed to the top of the outer walls.3. A rigid platform 5 extends between the outer walls and can slide vertically relative thereto. Between platform 5 and base 2 there extends a flexible first sleeve 6 made of a flexible liquid impermeable material, such as oil- resisting rubber, and pleated so as to provide a series of preformed corrugations enabling the sleeve 6 to extend in concertina-like fashion in the direction of movement of platform 5. Sleeve 6 is attached peripherally at its ends to base 2 and to platform 5 so that base 2, platform 5 and sleeve 6 together form an expansible liquid tight first vessel within the container 1.
[0013] A second sleeve 7, of a similar construction to that of first sleeve 6, is secured peripherally to the underside of roof 4 and to platform 5 so as to form therewith an expansible liquid tight second vessel within the container 1.
[0014] The method of sealing the sleeves 6 and 7 to the base 2, the platform 5 and the roof 4 may be, for example, that described in my British Patent Specification No. 1216333 or that described in my British Patent Specification No. 1377475. Tie-belts may be provided at intervals around the sleeves 6 and 7 to ensure correct sleeve extension in accordance with the teachings of my British Patent Specification No. 1298488. The disclosure of each of these three British patent specifications is herein incorporated by reference.
[0015] A manhole 8 is provided in roof 4 to permit internal inspection of the sleeve 7 of the second vessel. Similarly a manhole 9 is provided in the base 2 to permit internal inspection of the sleeve 6.
[0016] For filling and emptying the first vessel there is provided.a loading/unloading valve 10. Reference numeral 11 indicates a de-airing valve which is connected by a flexible pipe 12 the upper open end of which is fastened adjacent the underside of platform 5. This de-airing arrangement can be, for example, similar to that described and illustrated in my British Patent Specifications 1216333 and 1298488.
[0017] Filling and emptying of the second vessel is via a loading/unloading valve 13, whilst de-airing can be effected using valve 14. A flexible pipe (not shown) may be connected at one end-adjacent the upper side of platform 5 and at the other end to valve 13 to enable the second vessel to be emptied when desired. This flexible pipe may be arranged in a similar manner to the flexible pipe of the de-airing arrangement of my British Patent Specifications Nos. 1216333 and 1298488.
[0018] Spacer elements 15 are attached to the underside of platform 5. These ensure that, when the first vessel is empty, as illustrated in Figure 1, there is a sufficient stowage space adjacent the outer walls for the sleeve 6 in its collapsed condition. Hence damage to sleeve 6 is minimised.
[0019] In a similar manner roof 4 has a number of spacer elements 16 fitted to its underside to ensure safe stowage of the fully collapsed sleeve 7, as shown in Figure 2.
[0020] It will be appreciated by those skilled in the art that, when one of the vessels is completely full, the liquid holds platform 5 in position as shown '; in Figure 1 or Figure 2. Hence slopping and surging of the liquid cannot occur. It will usually be desirable to pressurise the vessel slightly, e.g. to a pressure of about 0.2 kg/cm2 gauge, when it is fully loaded.
[0021] Container 1 can be used for storage. It can also be mounted on a suitable chassis to form a road or rail tanker. Its second vessel can be filled with liquid as shown in Figure 1. Upon emptying liquid from the second vessel its first vessel can be filled with a different liquid as shown in Figure 2. It will be appreciated that, because the load is distributed uniformly along the length of the container, the design of the chassis can be in accordance with usual practice.
[0022] Furthermore the effective load capacity of the container when filled with either liquid is in excess of 50% of the overall volume of the container and can, in suitable cases, exceed 85% or even 90% of the overall volume of the container. It is not necessary to clean the interior of the container between trips even though a different liquid may be carried on the outward trip from that carried on the return trip.
[0023] A second embodiment is shown in Figures 3 and 4, in which the reference numerals have the same meaning as in Figures 1 and 2. In this embodiment, the construction of which is generally similar to that of Figures 1 and 2, there is a second platform 17 and sleeve 7 is secured between the two platforms 5 and 17. Access to the interior of sleeve 7 for inspection purposes is by means of manhole 18. Spacers 19 are fixed to the underside of platform 17 to prevent damage to sleeve 7 when this is in its collapsed condition. Filling and emptying of the second vessel is achieved by means of loading/unloading valve 20 to which access is gained via port 21 and, if necessary, manhole 22.
[0025] The container of Figures 3 and 4, whilst having two vessels for liquid, can also be used for carriage of solids when the platforms 5 and 17 are in the positions shown in Figure 4. Loading and unloading of such solid cargo, e.g. copper ingots, can be facilitated by provision of a suitable door or doors (not shown) in the outer walls 3.
[0026] When carrying a solid cargo in the container of Figures 3 and 4 it will usually be desirable to brace platform 17 against roof 4 by means, for example, of composite adjustable bracing members of the type. described and illustrated in my British Patent Specifications Nos. 1216333 and 1298488.
[0027] In Figure 5 a generally cylindrical bulk liquid container 24 has, end walls 25, 26 and a movable partition 27 to which are attached spacer elements 28, 29. A first flexible sleeve 30 of liquid impermeable material in concertina form with preformed corrugations is fastened peripherally in liquid tight fashion to end wall 25 and partition 27, whilst a similar sleeve 31 is secured between end wall 26 and partition 27. As can be seen from Figure 6, each sleeve is constructed of fabric 32 with an internal polymer layer 33. To maintain the shape of each sleeve a plurality of metal rings 34 is bonded thereto. The external diameter of rings 34 is slightly less than the internal diameter of container 24 so as to facilitate expansion and contraction of the concertina-like folds of the sleeves.
[0028] A loading/unloading valve 35 and a de-airing valve 36 are fitted in end wall 25. A corresponding loading/unloading valve 37 and a corresponding de-airing valve 38 are fitted in end wall 26.
[0029] Container 24 can be mounted. on a suitable chassis to form a road vehicle or a rail vehicle. Provision may be made to permit tilting of the container relative to the chassis upon arrival at its destination to facilitate emptying of the vessels. During transit, of course, the container can be locked firmly to the chassis to prevent tilting whilst the vehicle is in motion.
[0030] Although container 24 has been shown as cylindrical, it is not necessary that it should be of circular cross-section. Thus, for example, the container may be of semi-elliptical or similar cross-section to facilitate accommodation within an aircraft fuselage.
[0031] Although the illustrated bulk/liquid containers have two expansible liquid tight vessels, it will be appreciated that more than two such vessels can be provided if desired. For example, instead of having two sleeves 30, 31 and the single movable partition 27 of the embodiment of Figure 5, it is possible to construct a bulk liquid container according to the invention with three compartments by replacing partition 27 by a pair of partitions with a further flexible sleeve fastened between them to make a third expansible liquid tight vessel. Each of these three vessels are provided with spacers similar to spacers 28, 29 to ensure that the corresponding flexible sleeve is not damaged in the collapsed condition of that vessel. More than three vessels, e.g. four vessels, can be provided if desired. However it will usually suffice to provide a container with two expansible liquid tight vessels.
[0032] In the illustrated embodiments the load distribution of the fully loaded container remains substantially the same, whichever vessel is filled with liquid. Thus a vehicle fitted with such a container exhibits improved stability compared with the prior art container described above which has two fixed transverse partitions and three compartments.
(a) a rigid end wall;
(b) rigid protective outer walls which together with said rigid end wall define a cargo space;
(c) a rigid first member extending between the outer walls and movable in the cargo space between an inner position and an outer position;
(d) an extensible first sleeve of flexible liquid impermeable material provided with a series of preformed corrugations, the ends of which sleeve are respectively secured in fluid tight fashion peripherally to said rigid end wall and first first member adjacent said outer walls so that said first sleeve is axially extensible in concertina-like fashion in the direction of movement of said first member, and so that said first sleeve, said first member and said end wall together form an expansible liquid tight first vessel in said cargo space;
(e) first spacer means within the first vessel and in spaced relation from said outer walls to space said first member from said end wall in the unexpanded condition of said first vessel corresponding to said inner position of said first member, there being in said inner position of said first member a first stowage space around said first spacer means between said first member, said end wall and said outer walls;
(f) a rigid second member extending between the outer walls;
(g) an extensible second sleeve of flexible liquid impermeable material provided with a series of preformed corrugations, the ends of which are respectively secured in fluid tight fashion peripherally to said first member and said second member adjacent said outer wails so that said second sleeve is axially extensible in the direction of movement of said first member, and so that said sleeve, said first member and said second member together form an expansible liquid tight second vessel in said cargo space; and
(h) second spacer means within the second vessel and in spaced relation from said outer walls to space said first and second members one from another in the unexpanded condition of said second vessel, there being in the unexpanded condition of said second vessel a second stowage space around said second spacer means between said first and second members and said outer walls, whereby said first and second vessels may be filled independently with liquid and said first and/or second sleeve is or are supported externally of their respective vessels against pressure from within by said outer walls and said first and second sleeves'are protected from external damaging influences by said outer walls.