US3811460A - Tank structure for the storage and distribution of several fluids, particularly hydrocarbons - Google Patents

Abstract

A tank for the storage and distribution of a plurality of fluids from several storage chambers located in an enclosure, wherein each of said chambers is limited by at least one fluid-tight wall made of a flexible material which, when unfolded, substantially fills the whole internal volume of the enclosure without being subjected to excessive stresses, and which is provided with inlet and outlet valves for fluid stored in said chambers, said storage chambers being surrounded by a housing of a volume greater than the overall volume of said chambers, the excess volume forming an auxiliary chamber fed with pressurized auxiliary fluid from a source outside said housing, said pressure being transmitted from said auxiliary fluid to said wall of flexible material of each storage chamber and thus to the fluid stored therein.

Description

United States Patent 1191 Capdevielle et al.

[111 3,811,460 May 21, 1974 TANK STRUCTURE FOR THE STORAGE AND DISTRIBUTION OF SEVERAL FLUIDS, PARTICULARLY HYDROCARBONS [75] Inventors: Pierre Capdevielle, Garches;

Francois Kermarrec, Reeil-Malmaison, both of France [73] Assignees: Institut Francais du Petrole des Carburants et Lubrifiants, Malmaison; Societe Anonyme pour Tous Appareillages Mecaniques (SATAM), La Courneuve, both of, France [22] Filed: Jan. 8, 1973 [21] Appl. No.: 321,966

Related US. Application Data [60] Division of Ser. No. 107,740, Jan. 19, 1971 abandoned, and a continuation-in-part of Set. No.

887,679, Dec. 23, 1969, abandoned.

[52] U.S.' Cl. 137/255, 220/85 B [51] Int. Cl B65d 25/00, B65d 85/00 Field of Search 137/236, 588, 255-264; 222/94, 395; 220/22, 85 B, 63 R; 6l/0.5; 23/2726 [56] References Cited UNITED STATES PATENTS 2,468,954 5/1949 Bonham 137/255 X 3,144,953 8/1964 Taylor 220/85 13 x 3,172,556 3/1965 Strefel 220/85 13 x 3 275 ,4 1s 9/2 39 Nee 220/35 B x 3,722,751 3/1973 Blsclglia 220/85 B x 3,727,795 4/1973 W1llsey 220/35 B x Primary Examiner-Henry T. Klinksiek Assistant Examiner-Robert J. Miller Attorney, Agent, or Firm-Craig & Antonelli 57] ABSTRACT A tank for the storage and distribution of a plurality of fluids from several storage chambers located in an enclosure, wherein each of said chambers is limitedby at least one fluid-tight wall made of a flexible material which, when unfolded, substantially fills the whole internal volume of the enclosure without being subjected to excessive stresses, and which is provided with inlet and outlet valves for fluid stored in said chambers, said storage chambers being surrounded by a housing of a volume greater than the overall volume of said'chambers, the excess volume forming an auxiliary chamber fed with pressurized auxiliary fluid from a source outside said housing, said pressure being transmitted from said auxiliary fluid to said wall of flexible material of each storage chamber and thus to the fluid stored therein.

2 Claims, 11 Drawing Figures f'ATENTEUHAY m4 7 3.811.460

SHEET 1 OF 5 I FIGJ Pmmmmm 1974 $811,460 SHEET 1; 0F 5 PATENTEDMY 21 1914 3 L 8 1 L46 0 sum 5 0F 5 FIG.7A FIG.6

1 TANK STRUCTURE FOR THE STORAGE AND DISTRIBUTION OF SEVERAL FLUIDS, PARTICULARLY HYDROCARBONS The present application is a divisional application of application Ser. No. 107,740 filed Jan. 19 1971 now abandoned which is a continuation-in-part application of application Ser. No. 887,679, filed Dec. 23, 1969, now abandoned.

The present invention relates to a new tank structure permitting storage of a plurality of fluids without any contact between these fluids, this structure being specially adapted to the application of a process where each of said fluids is delivered by means of an auxiliary pressurized fluid forcing out of the tank the fluid to be distributed.

A tank according to the invention may, in particular,

be used for storing and distributing hydrocarbons in a storage plant, such as, for example, in a filling station,

but it should be understood that this particular application, which will be described in detail in the following, does not constitute any limitation forthe invention.

The main object of the present invention is to permit the distribution of each of said fluids separately by means of one and the samepressurized auxiliary fluid.

An additional object of the invention is to separate the fluids to be distributed and the auxiliary fluid, so as to suppress the risks of the formation of emulsions and of the dissolution into the auxiliary fluid of some components of the fluids to be distributed, this emulsion and this dissolution being liable to occur at the interfaces between the fluids in contact with one another.

Another object of the invention is to suppress the risks of a pollution of the fluids to be distributed, through the auxiliary fluid.

' These objects are achieved, according to the invention with a tank for storing and delivering a plurality of fluids. including a plurality of storage chambers,

wherein each of said storage chambers is bounded by at least one fluid tight wall made ofa flexiblematerial and is provided with means for introduction and discharge of the stored fluid, said means including intake and discharge valves, said storage chambers being surrounded by a housing, the volume of which is greater than the overall volume of said storage chambers, so that the volume of said housing in excess of said storage chambers constitutes a compartment for pressurized fluid. in communication with a source of pressurized auxiliary fluid, external to said housing, which transmits this pressure to the wall of flexible material of each storage chamber and thus to the fluid stored therejm According to a first embodiment of the invention, the tank includes a container of elongated shape, interio'rly divided into adjacent chambers through flexible membranes, said container being located within a housing receiving the auxiliary fluid.

According toa second embodiment of the invention, the storage chambers of the'tank have an elongated shape and are located side by side within one and the same housing.

In a third embodiment of the invention, the different storage chambers of the tank comprise a central chamber of elongated shape surrounded by at least one annular chamber, these chambers having a bottom and lateral walls made of a flexible material and. the assembly of said chambers being located within the housing 2 receiving the auxiliary fluid, so that the pressure of the latter, acting on the bottom of each of said chambers, moves this bottom toward the interiorof thechamber, turning like a glove finger the wall of said compartment as the fluid contained therein is discharged.

According to a fourth embodiment of the invention, the tank includes a deformable bag constituting a container of elongated shape, internally provided with two walls made of a flexible material, arranged longitudinally and limiting'three fluid tight storage chambers adapted to receive three separate fluids, said container being surrounded by a housing which is adapted to receive said auxiliary fluid.

According to a fifth embodiment of the invention a tank of elongated shape is constituted by a container which may be made of a flexible or rigid material, including internally three walls or membranes made of a flexible material, arranged longitudinally and forming substantially a triangular prism the lateral edges of which are in contact with the internal wall of said container, these walls limiting four fluid-tight chambers, namely a chamber receiving said pressurized auxiliary fluid and three storage chambers which may receive respectively three separate fluids.

According to a further embodiment of the invention, the tank includes a rigid or flexible container internally provided with one or several walls made,,at least partly, of a flexible material and connected to the internal wall of said container at one or two points or along one or two lines of fixation, so that said container and said walls limit at least one fluid tight storage chamber and at least one fluid-tight housing receiving said auxiliary fluid.

Non-limitative embodiments of the invention will be the attached drawings, wher'ein:

FIG. 1 illustrates a first embodiment of the invention,

FIG. 2 represents a second embodiment,

FIG. 2A isa top view of this second embodiment, the cover of the safety pit and the pipe being not illustrated,

' FIG. 3 illustrates a third embodiment,

FIG. 4 shows a fourth embodiment,

FIGS. 5 and 5A relates to a fifth embodiment, of the kind shown by FIG. 4,

'FIGS. 6 and 7 show two other embodiments of the invention,

FIG. 7A illustrates an alternative embodiment of the arrangement of the supply and discharge pipes of a type illustrated in FIG. 7.

FIG. 8 shows another example of tank preferably used in the preferred embodiment of the invention.

The same reference numerals designate like elements in the different drawings.

In FIG. 1, illustrating the first embodiment of the invention, in its application to the storage and distribution of fuel in a filling station, the tank is buried and located in a safety pit land includes a housing 2 of flexible or rigid material, for example constituted by a metallic tubular container, this housing containing a fluid ,kept under pressure and surrounding the three storage chambers 3, 4 and 5 of the tank (this number of storage chambers being obviously not limitative) which contain different fluids such as, respectively, ordinary gasoline,

premium grade gasoline, or gasoline having a high octane number, and gas oil.

The walls of each of these storage chambers are constituted, at least partly, by a membrane of deformable material, which may or not be elastic, capable to resist to the hydrocarbon which is contained therein.

One may for example use, for constituting this membrane, materials made of synthetic polymers, such as elastomeric and thermoplastic materials resisting hydrocarbons. It will possible to select an elastomer of the non-limitative following list: Kel-F (trade name for the copolymer of fluorovinylidene and monochlorotrifluorethylene), iviton (trade name for the copolymer of fluorovinylidene and hexafluoropropylene), fluorosilastene (trade name for polyfluorosiloxane), silicone (trade name for polysiloxane), hypalon (trade name for chlorosulfonated polyethylene), perbunan or hycar (trade names for butadiene or acrylonitrile), neoprene (trade name for polychloroprene), natural rubber (natural polymer of isoprene), butyl" (trade name for the copolymer of isobutylene and isoprene), polyurethane, Rilsan (or Polyamide 11) etc It will also be possible to choose a plastic material having a good flexibility, such as polyethylene, polyvinylchloride, polypropylene.

The storage chambers of the tank may be filled up with hydrocarbons through the pipes 6, 7 and 8 respectively, by pumping these hydrocarbons through pumps 9, l and ll..The distribution of the pressurized hydrocarbons will be effected from the distribution places 12, 13 and 14 through the distribution pipes l5, l6 and I7. 1

By actuating the valves 18, 19, and the valves 12a, 13a and 140, it is possible to switch from the position for filling the tank storage chambers to the position for distributing the fluids contained in these storage chambers and vice-versa.

An auxiliary pressurized fluid supplied through the pipe 21 into the space comprised between chambers 3, 4, 5 of the tank and the housing 2, enables the hydrocarbons contained in each of these chambers to be kept under pressure, thereby allowing their distribution by simply opening a valve (valve 120, 13a, 140) at each of the distribution places 12, 13 and 14.

This auxiliary fluid may be constituted by a gas under pressure, such as, for example, compressed air or by a liquid.

In the considered embodiment the auxiliary fluid is water under pressure supplied from a water tower 22.

This water tower is provided with an overflow 23 for maintaining a constant water level in the main tank.

Under the water tower 22, a tank 25 receives the overflow from the main tank 24, which is supplied from the secondary tank 25 through a pump 26.

In this first embodiment of the invention, the chambers 3, 4 and 5 of the tank, which have an elongated shape, are located end to end within the housing 2 which is placed horizontally.

In the second embodiment illustrated by FIGS. 2 and 2A, the housing 2 is placed vertically in the pit l and the chambers 3, 4 and 5 are located side by side, these chambers being elongated substantially over the whole height of the housing2.

In the third embodiment of the invention, illustrated in FIG. 3, the different chambers of the tank are constituted by a central container 27 of elongated shape surrounded with chambers 28, 29 of substantially annular shape, these chambers having lateral walls and a bottom of deformable material and the assembly of these chambers being located within the housing 30 receiving the auxiliary fluid supplied through pipe 31.

The admission of the hydrocarbons into the three chambers and the discharge of these hydrocarbons are effected by means of the pipes 32, 33 and 34 respectively. When the distribution valves for the fuel are open, the pressure of the auxiliary fluid is applied to the bottom of the corresponding storage chamber, so caus ing the raising of this bottom telescopically toward the interior of this chamber.

FIG. 4 represents another embodiment of the tank 7 wherein a deformable bag 35, forming a container of elongated shape and the upper wall of which has been removed from the drawing so as to better show the internal arrangement of the walls, is contained within a housing 36 which is supplied with pressurized auxiliary fluid through pipe 37.

This bag includes internally two walls 38 and 39 of a deformable material, arranged longitudinally, these walls limiting three fluid- tight storage chambers 40, 41 and 42 intended to contain respectively the three fluids which are to be stored and distributed.

According to: the preferred, but non limitative embodiment, the two walls are on one side, connected to the bag 35 at points located close to each other or even along a common lateral edge which enables the pipes 43, 44 and 45 to be grouped in a confined space, these pipes being used for filling the chambers 40, 41 and 42 for distributing the hydrocarbons which are contained in these chambers."

In the preferred embodiment illustrated in FIG. 5 as seen from above, the tank has an elongated shape and comprises a rigid or flexible container 46 which is internally provided with three walls or membranes made of a deformable material, optionally elastic 47, 48 and 49, arranged longitudinally and constituting substantially a prism the lateral edges of which are secured to the internal wall of container 46, these walls limiting four fluid tight chambers including a central chamber 50 which receives the pressurized auxiliary fluid from the pipe 51 and three peripheral storage chambers 52,53 and 54 which may respectively receive three separate fuels, through pipes 55, 56 and 57 respectively, which may also be used for discharging the hydrocarbons by simply actuating valves such as valves 18, 19 and 20 and 12a, 13a, 1411 (FIG. 1) located at the ground surface.

It will obviously also be possible, without departing from the scope of the present invention, to use separate pipes for filling the storage chambers of the tanks and for discharging the fluids which are contained in these chambers.

A convenient embodiment of the chambers 52, 53 and 54 is illustrated in FIG. 5A.

It consists in using a bag of flexible material 58 which is inflated and in forming therewith chambers by pinch ing and soldering, in a substantially analogous way as in the manufacturing of the different partitions of' a pneumatic mattress.

Thereafter the three chambers, which preferably have the same volume, are folded into a triangle and placed into the container 46, each chamber being prov vided beforehand with a pipe where through is effected the filling of this chamber with fuel and serving optlonally for the dischargeof this fuel from the chamber.

An opening, which is for example centrally located, provided through the container 46 permits the introduction of the pressurized auxiliary fluid which fills the space 50 remaining free between container 46 and bag 58.

In the embodiment illustrated in FIG. 6, the tank includes a container 59 which is internally provided with three walls 60, 61 and 62 (this number being by no way limitative) which are at least partly made of a flexible material (which may or not be elastic) and connected to the internal wall of container 59 at two points, or more generally, along two fixation lines (two generatrices, if the tank has a cylindric shape). These walls limit fluid- tight chambers 63, 64, 65 and 66, one at least of which may receive the auxiliary fluid while the other are storage chambers.

According to an alternative embodiment illustrated in FIG. 7, the three walls or membranes 60, 61 and 62 are folded on themselvesand connected to the internal wall of container 59 substantially at one and the same point or along a same fixation line (along one and the same generatrix in the case of a cylindrical tank).

In FIGS. 6 and 7, reference numerals 67 to 70 designate the pipes used for the supply and discharge of the fluids stored in the tank and of the auxiliary fluid.

FIG. 8 shows an advantageous arrangement for the supply to and discharge from the different chambers of a tank according to the invention, this arrangement being in this embodiment used in a tank of the type illustrated in FIG. 7.

Pipes 67a to 7011 supplied with fluid through the mouthpieces 67b to 70h respectively are arranged sub stantially coaxially. Y

The choice of the materials constituting these pipes will be made by those skilled in the art for each particular utilization and it should be decided in each particular case whether flexible or rigid pipes are to be used for constituting the pipes 67a and 70a arranged coaxially.

The embodiments according to FIGS. 7 and 8 are examples illustrating the preferred ways for the carrying out of the invention referred to in the introductory part according to which the tight wall of flexible material limiting each storage chamber is designed with a sufficient surface so as to expand to substantially the whole internal volume of said enclosure when said compartment is filled up with fluid, while still avoiding to subject said flexible wall to excessive stresses, liable to result in a tearing thereof. In particular, according to the embodiments illustrated in FIGS. 7 and 8,.the flexible bags 60, 61 and 62 may be made of a plastic material of small thickness, the wall of each bag having a sufficient surface for permitting an expansion of any chamber substantially to the whole volume of the tank structure by application of said wall against the inner wall of the tank under the effect ofa small overpressure inside said chamber or by the mere unfolding of said wall of flexible material, which is normally in a folded state when the capacity of said chamber is only partially used.

. In particular, when several hydrocarbons have to bestored in the same tank structure. this wall may be formed, at least partly. of one or more thermoplastic materials based on polyoleflns, polyamides and/or polyesters.

More particularly. there will be used a high molecular weight polyethylene, a polyamide of the type known under the trade mark. Rilsan, or the l lpolyamide, the vinylidene polychloride or the ethylene glycol polyterepthalate.

These materials have a good resistance to the attack by hydrocarbons in general, as well as by the water used as auxiliary pressurized fluid.

The thickness of said flexible walls limiting the various storage chambers of the tank will be for example between 20 and 500 microns, in most cases between 50 and I50 microns, and particularly around microns.

The flexible wall separating the hydrocarbons stored in the tank structure from the water used as auxiliary pressurized fluid will advantageously consist of composite membranes formed, for example of a polyethylene film which constitutes a substantially water-proof seal, coupled with a polyamide such as nylon (trade mark), hydrocarbon proof, or of a polyethylene film (water-proof) associated to a film of Rilsan (l lpolyamide) etc these examples being, however, not limitative. I

In such an embodiment, the flexible wall will be so positioned that the water-proof film is placed in contact with water while the hydrocarbon-proof film must be on the side in contact with hydrocarbons.

By selecting, for constituting the various chambers of the tank, bagsformed of thermoplastic material having each a maximum capacity substantially equal to the internal volume of enclosure or housing 59, these bags (FIGS. 7 and 7A) may be utilized in any proportion of their maximum capacity for storing separate fluids (the walls of the various bags thus forming folds as indicated in 71 and 72 in FIGS. 7and 8) and it will be. still possi- I ble as store a single fluid in the tank, for example, in bag 62 which may than be used nearly at its maximum capacity (FIG.'7A) by mere unfolding of its wall without subjecting the same to any other stresses than those resulting from a very small differential pressure, only a very small residual volume 73 being left for the pressurized auxiliary fluid between said bag wall and the internal wall of housing 59. v

The other storage bags (60 and 61) are accordingly collapsed inside bag 62 (FIG. 7A).

It is also possible to make use of any other bag such as 60 or 61 substantially at its maximum capacity in place of bag 62.

The tank structure according to the invention, as hereabove described, offers the essential advantage of providing storage depots or tank assemblies with a high 7 operation adaptiveness, since each tank may be used for storage as well of a single fluid as of several separate ones, without contact therebetween, each fluid filling any portion of the tank volume.

These tank compartments may be advantageously used for storing complementary amounts of fuels, i.e., fuels the consumption of which vary oppositely, such as gasolines and fuel-oil used for heating purpose, these two types of fuel being subject to seasonal variations of their consumption with respective consumption peaks at different periods of the year for example, in Europe a maximum consumption of gasoline during the summer season and a maximum consumption of fuel oil during winter (more particularly in January and February). It is thus possible to reduce the overall capacity of storage required for both types of fuels by storing in at least two compartments of at least one tank of the aforesaid type at least two fluids pertaining to groups of fluids whose seasonal consumption vary oppositely.

In such a tankthe storage capacity left free by the withdrawal of one fluid pertaining to one group will be used for storing additional amounts of a fluid pertaining to the other group so as to take into account the seasonal variations of the consumptions.

In other words the present invention is also concerned with a method for storage of a plurality of fuels in complementary amounts, in separate compartments of. a tank, each compartment being limited by at least onetight wall of flexible material, all the compartments being surrounded with an enclosure the total volume of which is at least equal to the total volume of liquid to be stored, the tight wall limiting each compartment having such a surface as to make possible the substantially complete filling of the whole enclosure internal volume by expansion of said compartment, when filled with liquid, without subjecting said wall to excessive stresses.

The method of the invention therefore consists in filling at least one of said compartments withadditional fuel amounts corresponding at most to the volume liberated by the withdrawal of another fuel gag fined in another compartment, thereby using for the storage of one fluid the space left free in the enclosure by ihiww anothe rfluidam a- From the foregoing description, one skilled in the art can ascertain the essential characteristics of this invention and, without departing from the spirit and scope tions. Consequently such changes and modifications are properly, equitably and intended to be within the full range of equivalence of the following claims.

What we claim is:

l. A tank for the storage and distribution of a plurality of fluids, including a container surrounding several fluid-tight chambers of variable volumes provided with inlet and outlet valves means for the fluids stored in said chambers and at least one auxiliary chamber maintaining the stored fluids under substantially steady pressure, this auxiliary chamber forming with said storage chambers an assembly of adjacent chambers separated from one another through membranes of very small stiffness, adapted to continuously provide for a substantial equalization of the pressure in the different chambers, said auxiliary chamber being connected to a source of pressurized auxiliary fluid, said tank comprising a container of elongated shape, including internally three fluid-tight chambers, each of which is limited by a wall of a flexible material and forming substantially a triangular prism the lateral edges of which are in contact with the internal wall of said container, the interior of the prism forming a fourth chamber.

2. A tank according to claim 1, wherein said three fluid-tight chambers are constituted by a rectangular bag folded along two straight lines parallel to two edges of said bag.

Claims (2)

1. A tank for the storage and distribution of a plurality of fluids, including a container surrounding several fluid-tight chambers of variable volumes provided with inlet and outlet valves means for the fluids stored in said chambers and at least one auxiliary chaMber maintaining the stored fluids under substantially steady pressure, this auxiliary chamber forming with said storage chambers an assembly of adjacent chambers separated from one another through membranes of very small stiffness, adapted to continuously provide for a substantial equalization of the pressure in the different chambers, said auxiliary chamber being connected to a source of pressurized auxiliary fluid, said tank comprising a container of elongated shape, including internally three fluid-tight chambers, each of which is limited by a wall of a flexible material and forming substantially a triangular prism the lateral edges of which are in contact with the internal wall of said container, the interior of the prism forming a fourth chamber.

2. A tank according to claim 1, wherein said three fluid-tight chambers are constituted by a rectangular bag folded along two straight lines parallel to two edges of said bag.

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