Tank for storing products with horizontal emptying via a membrane, vehicle therewith, method for filling such a tank, method for emptying such a tank and method for squeezing products into such a tank

Description

Domaine technique

[0001] The present invention relates to a product storage tank with horizontal discharge via a membrane, and a vehicle, in particular a hydro-jetting truck, equipped with such a tank. État de la technique

[0002] The present invention applies to any type of tank (or cistern), mobile or fixed, which is intended for the storage of products and in particular semi-liquid products, pasty products or powdery solids.

[0003] Although not exclusively applicable, the present invention is particularly relevant to a tank on a waste collection vehicle, and especially to a sewer or industrial hydro-jetting truck. A sewer hydro-jetting truck is designed, in particular, to carry out cleaning and pumping operations on wastewater networks and sanitation structures, and an industrial hydro-jetting truck is designed for cleaning industrial equipment and installations.

[0004] Generally, emptying a hydro-jetting tank is done either by tilting the tank (or cistern), usually at a 40° angle, or by means of a movable partition that can move in both directions thanks to the pressure generated on either side of the partition. However, each of these two common solutions has drawbacks.

[0005] Document FR2107423 describes a tank for storing products that overcomes the drawbacks of conventional solutions (tilting or movable partition). This tank (comprising a shell with an opening at one rear longitudinal end and a door to close this opening) includes, in particular: a flexible membrane, impermeable to gases and liquids, intended to receive the products to be stored, said membrane having an opening, being arranged inside the tank so that its opening is opposite the opening of the shell, and being fixed according to an annular fixing zone to the inner face of the shell around its opening so as to create a so-called free, closed space between the membrane and the tank; and a system for generating a pressurization and a depressurization of the free space between the tank and the membrane.

[0006] The use of a flexible membrane allows for an efficient and lightweight drainage system, overcoming the drawbacks of conventional solutions. Furthermore, this tank can be emptied horizontally (without tipping), reducing the risk of the carrier and its equipment overturning when emptying the tank on uneven ground.

[0007] To facilitate pumping products into the membrane, a vacuum is created inside the membrane. To do this, the membrane is fixed at a distance from the rear of the shell, allowing access to the membrane to implement the vacuum.

[0008] This arrangement is not an optimal solution, as the tank is not completely emptied by the inversion and removal of the membrane. Furthermore, tank cleaning is not optimized.

[0009] One of the objectives of the present invention is to improve this membrane tank, in particular to remedy these drawbacks.

[0010] Furthermore, we know, from US document 4,082,124, of a tank which is divided, by a flexible diaphragm, into two chambers of variable volume, the first chamber of which is intended to store a fluid, making it easier to fill and empty by applying pressure or a vacuum in the second chamber. Exposé de l'invention

[0011] The present invention relates to a tank for storing products, in particular semi-liquid, pasty or powdery solid products, said tank comprising: a shell having a rear opening at a rear longitudinal end and a door adapted to close this opening; a flexible membrane, airtight and gas- and liquid-tight, intended to receive the products to be stored, said membrane having an opening, being arranged inside the tank and being fixed according to an annular fixing zone to the inner face of the shell so as to create a closed free space between the membrane and the tank; and a system for generating pressurization and depressurization of the free space between the tank and the membrane, said system comprising a vacuum generator configured to generate depressurization of an internal space inside the membrane, the membrane being configured for: to be able to be completely pressed against the inner face of the shell under the effect of a vacuum generated by said system; and to be able to be turned over and removed from the tank, through said open door, under the effect of a pressure generated by said system.

[0012] Moreover : The tank is provided with a niche formed inside and at the rear of the shell, arranged between the shell and the membrane, and opening, via a rear outlet, into the rear opening of the shell; the shell is provided with at least one through orifice opening into the interior of the niche, the vacuum generator being connected externally to said orifice; the membrane is fixed to the rear longitudinal end of the shell so that its opening coincides substantially with the rear opening of the shell; and a passage is formed from said orifice to the internal space of the membrane, via on one side the niche and on the other side a space between the rear of the membrane and the door which is convex towards the rear, said passage enabling said vacuum generator to generate a vacuum in the internal space of the membrane for the purpose of pumping products into said membrane.

[0013] Thus, thanks to the use of the flexible membrane, an efficient and lightweight drainage system is achieved. Furthermore, the tank can be emptied safely, quickly, and horizontally (without tipping), which reduces the risk of the carrier and its equipment overturning when emptying the tank on unstable terrain.

[0014] Furthermore, thanks to the membrane's position at the rear end of the shell, the membrane can be completely removed when the free space is pressurized. Thus, all the products stored in the membrane are evacuated when the membrane is inverted and (completely) removed from the tank, allowing for complete emptying of the tank and overcoming the aforementioned drawback.

[0015] Furthermore, the arrangement of the membrane at the rear end of the ferrule also allows for: to protect the entire ferrule; and to be able to easily and completely rinse the membrane when it is turned over and completely removed.

[0016] Furthermore, thanks to the passage formed from said orifice in the ferrule (to which the vacuum generator is linked) to the internal space of the membrane, it is possible, despite the arrangement of the membrane at the rear end of the ferrule, to generate a vacuum in this internal space of the membrane for the purpose of pumping products into the membrane.

[0017] In a preferred embodiment, the niche has, at its rear exit, a biconvex shape with two opposite convex surfaces of the same radius of curvature (i.e. two surfaces of the same shape and the same radius of curvature), so that the distance allocated to the fixing of the membrane (of circular cross-section) corresponds to the length of its perimeter, which notably avoids the appearance of false folds in the membrane.

[0018] Advantageously, the niche is formed from at least one added piece that is welded to the inner face of the ferrule, which makes it easy to manufacture. Furthermore, and advantageously, the niche is closed and watertight, except at its rear outlet and the orifice.

[0019] Furthermore, in a particular embodiment, the tank includes a suction cup fixed to the outer wall of the shell around the orifice. Advantageously, the suction cup is also equipped with an anti-overflow ball, which prevents products from being drawn into the vacuum generator when the internal space of the membrane is depressurized during product pumping.

[0020] In a particular embodiment: the front face of the membrane is substantially flat; the membrane has a length such that, when pressed against the inner face of the ferrule, its front end is situated longitudinally at the same level as the front end of the ferrule; and the tank includes a front bottom which is convex towards the front.

[0021] In addition, advantageously, the tank includes a pressure limiting device configured to be able to limit the pressure in the free space between the tank and the membrane.

[0022] Furthermore, advantageously, the tank includes at least two support tubes, capable of being brought from a retracted position to an extended position towards the rear of the tank when the membrane is taken out of the tank, and, in the extended position, the tubes are positioned substantially parallel to the longitudinal axis of the shell so as to be able to support the membrane during the pressure-vacuum movement.

[0023] In the context of the present invention, the membrane can be attached to the inner face of the tank in various ways. However, in a preferred embodiment, the membrane is secured by clamping it between, on the one hand, at least one (crown-shaped) plate fixed to the rear end of the tank on the inner face of the shell and on the recess, and on the other hand, at least one counter-plate. This allows the membrane to be attached to the tank easily, quickly, and efficiently.

[0024] Furthermore, advantageously, the membrane is made of a (relatively thin) composite material comprising different superimposed layers, formed respectively of at least a waterproof fabric (airtight and watertight), a fabric (providing the necessary mechanical resistance) and an antistatic skin (made of polytetrafluoroethylene), mechanically resistant to impacts and abrasion from solid waste and chemically resistant to attack from acids, bases, hydrocarbons, ...

[0025] The present invention also relates to a vehicle, in particular a hydro-jetting vehicle, which includes at least one tank such as that described above.

[0026] The present invention also relates to several methods for using said tank.

[0027] Firstly, it includes a tank filling process, said filling process comprising at least the following steps, consisting of: close the tank door; generate a vacuum in the free space between the tank and the membrane, using the vacuum system, so as to press the membrane against the inner face of the tank; generate a vacuum in the internal space using the vacuum generator so that atmospheric pressure pushes the products into this internal space, through a filling orifice, inside the membrane; and when filling is complete, stop maintaining the vacuum in the internal space.

[0028] Secondly, it also includes a method for emptying the tank, said emptying method comprising at least the following steps, consisting of: open the tank door; generate pressurization of the free space between the tank and the membrane, using the pressurization system, so as to push the membrane back and move it, this movement causing a complete reversal of the membrane and an ejection of the products through the open door; and when emptying is complete, stop pressurizing the free space.

[0029] Thirdly, it further comprises a process for dewatering products from the tank, said dewatering process comprising at least the following steps, consisting of: With the tank door closed, pressurize the free space between the tank and the membrane using the pressurization system to push the membrane back and move it. This movement compresses the products in the tank, causing the juices to separate and be discharged through an open drain (or decantation) port. When the spinning is complete, stop pressurizing the free space and close the drain port. Brève description des figures

[0030] The accompanying figures will clearly illustrate how the invention can be implemented. In these figures, identical reference numerals designate similar features. figure 1 This is a schematic cross-sectional view of a product storage tank in an open position. figure 2 This is a schematic cross-sectional view of the product storage tank in a closed position. figure 3 is a view similar to that of the figure 1 , in an open position, with the membrane fully extended. The figures 4A à 4C These are schematic cross-sectional views of a product storage tank, illustrating the various successive stages of membrane movement from a position pressed against the tank to a fully deployed position during tank emptying. figure 5 This is a partial rear view of the tank's shell, which features a niche. figure 6 is a partial schematic cross-sectional view of a preferred embodiment of a flexible, waterproof membrane. figure 7 This is a plan view of an example of a hydro-jetting truck equipped with, among other things, a product storage tank. figure 8 is a perspective view of an anti-overflow ball. Description détaillée

[0031] Tank 1, illustrating the invention and shown schematically on the figure 1 This tank is designed to receive and store products, for example, for transport. Tank 1 is suitable for storing various types of products. It is particularly well-suited for storing products such as semi-liquids, pastes, or powdered solids.

[0032] Tank 1 can be used in a variety of applications, as detailed below.

[0033] Tank 1 comprises, as shown in the figure 1 A ferrule 2, that is to say a hollow cylindrical part, with longitudinal axis XX. In the example shown, the ferrule 2 is made in the form of a straight cylinder. The ferrule of the tank may, however, have any other cylindrical shape within the scope of the present invention.

[0034] The ferrule 2 is closed by a bottom 3 at one longitudinal end, called the front end 4 (along the longitudinal axis XX), and it is provided with an opening 5 at the other longitudinal end, called the rear end 6. The terms "front" and "rear" are defined, in the following description, along the longitudinal axis XX, with "front" in the direction of an arrow F shown on the figures 1 And 2 and "back" in the opposite direction to that of arrow F.

[0035] Of course, within the framework of the present invention, the opening 5 could also be provided at the front end and the bottom 3 at the rear end of the tank.

[0036] Furthermore, the terms "internal" and "external" are defined with respect to the longitudinal axis XX, with "external" meaning away from the longitudinal axis XX, as illustrated by arrows G on the figures 1 And 2, and “internal” by approaching the longitudinal axis XX, in the opposite direction to that of the arrows G.

[0037] Tank 1 is arranged horizontally, that is to say, it is arranged so that its longitudinal axis XX is substantially parallel to the horizontal, illustrated by a double arrow H on the figures 1 And 2 .

[0038] The vertical direction is illustrated by an arrow Z. The term "up" is defined in the direction of the arrow Z and the term "down" is defined in the opposite direction to that of the arrow Z.

[0039] Tank 1 also includes a standard type door 7, located at the rear end 6 of tank 1 and configured to: completely free the opening 5 in an open position P1 as shown on the figure 1 ; and close the opening 5 in a closed position P2 as shown on the figure 2 .

[0040] To do this, the door 7 is linked, by usual hinges 8 represented schematically, to the tank 1, and it includes, for its operation, usual means not described further and not represented.

[0041] The ferrule 2, the bottom 3 and the door 7 of the tank 1 can be made of different metallic or composite materials, including stainless steel.

[0042] The tank 1 also includes a membrane 9 which is both flexible and impermeable to gases and liquids. This membrane 9 (with its inner face 9A) defines an internal space 11 (or storage space) intended to receive the stored products.

[0043] To achieve this, the membrane 9 is provided with an opening 10 (at the rear). The membrane 9 is a completely closed pocket (or envelope) except for the opening 10, and it is arranged inside the tank 1 so that this opening 10 is opposite the opening 5 of the ferrule 2, which is provided with the door 7.

[0044] The membrane 9 is fixed by its so-called open end 9C (at the level of the opening 10) on the inner face 12A of the ferrule 2 of the tank 1, all around its periphery, that is to say according to an annular fixing zone 27 so as to create a so-called free space 15, closed, between the membrane 9 and the tank 1. The membrane 9 is fixed to the rear of the ferrule 2, so that its opening 10 coincides substantially with the opening 5 of the ferrule 2, that is to say that the two openings 5 ​​and 10 are located in the same position longitudinally (along the axis XX).

[0045] Membrane 9 is configured to: to be able to be completely pressed against the inner face 12A of the ferrule 2 under the effect of a vacuum generated by a system 16 as shown on the figure 2 ; and be able to be turned over and removed from tank 1, through the open door 7, under the effect of pressure generated by system 16, as shown on the figure 3 .

[0046] Thus, thanks to the use of the flexible membrane 9, an efficient and lightweight drainage system is obtained. Furthermore, the tank 1 can be emptied safely, quickly, and horizontally (without tipping), which reduces the risk of the carrier and its equipment overturning when emptying the tank on unstable ground.

[0047] Furthermore, thanks to the arrangement of the membrane 9 at the rear end of the ferrule 2, the membrane 9 can be completely removed when the free space 15 is pressurized. In addition, all the products that were stored in the membrane 9 are evacuated when the membrane 9 is reversed and (completely) removed from the tank 1, as described below, which allows the tank 1 to be completely emptied.

[0048] The arrangement of membrane 9 at the rear end of ferrule 2 also allows: to protect the entire ferrule 2; and to be able to easily and completely rinse the membrane 9 when it is turned over and completely out.

[0049] By way of non-limiting illustration, membrane 9 has, for example, a thickness between 2 and 8 millimeters.

[0050] Furthermore, the tank 1 also includes the system 16 for generating a pressurization or a depressurization of the free space 15 between the tank 1 and the membrane 9. In a particular embodiment, the system 16 includes a compressed air generator 25 and a vacuum generator 26, as specified below.

[0051] In a preferred embodiment, system 16 includes a single piece of equipment that can perform both functions (pressurizing and depressurizing), namely either a vacuum pump that can be adapted for use as a compressor, or a hydro-ejector that can produce a pressure of 500 grams.

[0052] Furthermore : The tank 1 is provided with a niche 36 which is formed inside and at the rear of the ferrule 2, which is arranged between the ferrule 2 and the membrane 9 and which opens, via a rear outlet 37, into the rear opening 5 of the ferrule 2, as shown in the figures 1 à 3 ; and the ferrule 2 is provided with at least one orifice 38 through the wall of the ferrule 2, which opens into the interior of the niche 36, the vacuum generator 26 being connected externally to said orifice 38 (via a suction pot 44, as specified below).

[0053] Thus, passage 39, illustrated by an arrow J on the figure 2 is formed from said orifice 38 (to which the vacuum generator 26 is connected) to the internal space 11 of the membrane 9, via on the one hand the niche 36 and on the other hand a space 40 between the rear of the membrane 9 and the gate 7 which is convex towards the rear. This passage 39 allows said vacuum generator 26, despite the arrangement of the membrane 9 at the rear end of the ferrule 2, to have a path to generate a vacuum in the internal space 11 of the membrane 9 during pumping of products into said membrane 9, in order to facilitate pumping.

[0054] In a preferred embodiment, the niche 36 has, at its rear exit 37, a biconvex shape as shown in the figure 5 This biconvex shape consists of two opposing convex surfaces 41 and 42 with the same radius of curvature; that is, two surfaces 41 and 42 of the same shape and radius of curvature. Surface 41 corresponds to the inner surface of an arc of the ferrule 2, and surface 42 corresponds to the outer surface of an added piece 43. These surfaces 41 and 42 have the same length in cross-section. Thus, the distance allocated for attaching the membrane 9 (with a circular cross-section) to the rear of the ferrule 2, along the ferrule 2 and the recess 36, is equal to its perimeter. This prevents the formation of a crease in the membrane 9 when it is attached at its rear end and allows the use of a cylindrical membrane, which is simple to manufacture and less expensive.

[0055] Preferably, the niche 36 is formed of at least one added piece 43 ( figures 1 à 3 ) which is welded to the inner face 12A of the ferrule 2, thus allowing the niche 36 to be made easily and at a reduced cost. Furthermore, the niche 36 is closed and watertight, except at its rear outlet 37 and the orifice 38.

[0056] Furthermore, in a particular embodiment, the tank 1 also includes a suction pot 44. This suction pot 44, to which the vacuum generator 26 is linked, is fixed on the external wall 12B of the ferrule 2 around the orifice 38, as schematically represented in figures 1 to 3.

[0057] The suction pot 44 is equipped with an anti-overflow ball 45 shown on the figure 8 . This anti-overflow ball 45 prevents products from being drawn towards the vacuum generator 26, when the internal space 11 of the membrane 9 is depressurized during product pumping.

[0058] The anti-overflow ball 45 is mounted in a support 46. This support 46 comprises an upper ring 47, to which are attached four legs 48, evenly distributed around the periphery of the ring 47 and fixed orthogonally to it. Each leg 48 is provided with a foot 49 curved inwards. These feet 49 retain the anti-overflow ball 45. This anti-overflow ball 45 is capable of floating and, if necessary, of pressing itself against the ring 47 so as to close its opening 50 to block suction and prevent products from being drawn towards the vacuum generator 26.

[0059] The anti-overflow ball 45 is further connected by a spring 51 and a bracket 52 to the ring 47 to create electrical continuity, these parts being metallic. This has the particular advantage of preventing the generation of an electric arc during pumping in an ATEX-type atmosphere.

[0060] Furthermore, in a particular embodiment, as shown in the figure 2 : the front face 30 of the membrane 9 is substantially flat; the membrane 9 has a length such that, when pressed against the inner face 12A of the ferrule 2, its front end (or front face 30) is located longitudinally at the level of the front end of the ferrule 2; and the front bottom 3 of the tank 1 is convex towards the front.

[0061] This embodiment allows for a space of 23 ( figure 2 ) between the front face 30 of the membrane 9 and the front bottom 3 of the tank 1 when the membrane 9 is pressed against the inner face 12A of the ferrule 2. This space 23 is advantageous for aspiration and positioning of the membrane 9 against the inner face 12A of the ferrule 2.

[0062] Furthermore, tank 1 includes a pressure limiting device 31 which is isolated by a valve and which is configured to be able to limit the pressure in the free space 15 between tank 1 and membrane 9, through an orifice 53 provided in the upper part of the front bottom 3.

[0063] Within the framework of the present invention, the membrane 9 can be fixed in different ways to the inner face 12A of the tank 1.

[0064] However, in a preferred embodiment, the membrane 9 is fixed by clamping, which notably facilitates maintenance operations. To this end, a metal plate 13, shaped like a ring, is fixed, preferably welded, to the inner face 12A of the tank 1 all around the periphery of the tank 1, at the level of the fixing area 27 at the rear of the tank 1. The open end 9C of the membrane 9 is wedged and retained between this plate 13 and one or more fixing counter-plates 17, which are screwed onto the ring 13. For the sake of simplicity in the drawing, only sections of the plate 13 and the counter-plate 17 are shown on the figure 5 .

[0065] Furthermore, in a preferred embodiment, the membrane 9 is made of a composite material 18 comprising different superimposed layers having various properties to enable the membrane 9 to have the desired characteristics.

[0066] Preferably, membrane 9 comprises, as schematically represented on the figure 6 , at least one waterproof fabric 19 (or gas- and liquid-tight), a fabric 20 providing mechanical resistance to the membrane 9, and a skin 21, preferably made of polytetrafluoroethylene PTFE antistatic. The skin 21, which is provided on the inner face 9A of the membrane 9 intended to come into contact with the products, offers resistance to mechanical shocks, the chemical aggressiveness of the products, and product adhesion. A membrane 9 thus constructed exhibits appropriate flexibility and resistance to various types of aggression, enabling it to effectively perform its various intended functions. It also protects the shell 2 of the tank 1 against various potential aggressions, and since the membrane 9 is positioned at the rear of the shell 2, it protects the entire inner face 12A of the shell 2.

[0067] Furthermore, the system 16 for generating pressurization and depressurization includes an orifice 24 formed in the ferrule 2 and provided with conventional conduit connection means (not shown). The orifice 24 is formed on the top of the ferrule 2 at the front end 4 opposite the rear end 6, which is provided with the opening 5.

[0068] In the particular embodiment shown in the figures 1 And 2 , tank 1 includes, as a pressurization element, the compressed air generator 25 and, as a depressurization element, the vacuum generator 26.

[0069] Within the scope of the present invention: The compressed air generator 25 can be any type of standard generator capable of blowing compressed air into the free space 15 through the orifice 24, as illustrated by an arrow E1 on the figure 1 ; and the vacuum generator 26 can be any type of conventional vacuum generator, preferably pneumatic (but not exclusively), capable of generating a vacuum in the free space 15 through the orifice 24, as illustrated by an arrow E2 on the figure 2 .

[0070] In a preferred embodiment, the system 16 comprises a single piece of equipment which can perform both functions (pressurizing and depressurizing), namely either operate as a compressed air generator 25, or operate as a vacuum generator 26, as required.

[0071] In an alternative embodiment (not shown), two orifices can be provided, one for pressurization and the other for depressurization.

[0072] Pressurizing the free space 15 allows the membrane 9 to be pushed out (which is turned over and removed from the tank as shown in the diagram). figure 3 ) and to push the products contained in tank 1 to the rear, in order to discharge them through the open door 7, as described below with reference to figures 4A à 4C .

[0073] Depressurizing the free space 15 allows the membrane 9 to be pressed against the inner face 12A of the tank 1, bringing it into a "container" position so as to allow its internal storage space 11 to be filled through a filling orifice as specified below. The membrane 9 then conforms to the shape of the inner face 12A of the tank 1, as shown in the diagram. figure 2 notably.

[0074] The vacuum generator 26 is also configured to create a vacuum in the internal space 11 inside the membrane 9 for the purpose of pumping products into said membrane, as detailed below. To do this, the vacuum generator 26 is capable of generating a vacuum in the space 11 (via the passage 39) through the orifice 38, as illustrated by arrow E3 on the figure 2 .

[0075] In one embodiment variant, it is conceivable to provide two vacuum generators, for example such as vacuum generator 26, one of which is intended for depressurizing the free space 15 and the other for depressurizing the internal space 11.

[0076] Furthermore, in a particular embodiment, at least two support tubes (or bars) 35 are also provided, arranged at the rear of the tank 1 ( figures 4A à 4C These tubes 35 are arranged at the bottom of the tank 1, on either side of it. They are designed to be held and to slide in rings (or guides) 36 mounted on the tank 1.

[0077] These 35 tubes are configured to be able to be brought into a retracted position ( figures 4A et 4B ) or in an extended rearward position in which the tubes 35 are extended, as shown on the figure 4C The tubes 35 are then oriented horizontally. The tubes 35 are brought into the extended position by being pulled backwards by an operator. These tubes 35 support the diaphragm 9 when it is fully extended and no longer subjected to expulsion pressure, specifically during the transition from pressurization of the free space 15 to depressurization (or depressurization) of said free space 15.

[0078] Furthermore, the door 7 of the tank 1 is provided, in a lower part, with at least one orifice 28 for discharge (or draining or settling), fitted with a valve and a removable plug 29 capable of closing orifice 28 when it is in place ( figures 1 And 3 ) and to free the opening 28 when it is removed ( figure 2 ). The filling and / or draining port 28 also includes means for connecting a conduit (not shown).

[0079] The door 7 of tank 1 is also fitted with a pipe 34 equipped with all the usual equipment to allow the filling of tank 1, as shown only on the figure 2 for the sake of simplifying the drawing.

[0080] In an alternative embodiment (not shown), the tank 1 may have a single opening in the lower part, intended for both filling and evacuation (or emptying or decantation).

[0081] The tank 1, as described above, can be filled or loaded using a filling (or loading) process described below, with reference to the figure 2 .

[0082] To do this, door 7 is closed, and brought into the closed position P2.

[0083] Then, an appropriate vacuum is generated in the free space 15 (between the tank 1 and the membrane 9), using the vacuum generator 26 by vacuum pulling (as illustrated by arrow E2), so as to press the membrane 9 against the inner face 12A of the tank 1. Next, the vacuum is created in the internal space 11 through the orifice 38 using the vacuum generator 26 (as illustrated by arrow E3).

[0084] In this closed position P2, as shown on the figure 2 The products to be pumped, located outside the tank 1, are pushed under atmospheric pressure into the internal space 11 (in which a vacuum is created), using conventional pumping means (not shown), through a filling port provided in the tank 1, via the filling pipe 34, as illustrated by arrow B1. The products enter the membrane 9, into the internal storage space 11.

[0085] When the filling is complete, the vacuum generated in the internal space 11 is stopped using the vacuum generator 26.

[0086] If tank 1 is not completely filled, the products can be held in position (or secured), particularly to reduce the movement of the liquid mass. This is achieved by generating appropriate pressure in the free space 15 using the compressed air generator 25 to move the membrane 9 and adapt the volume of the storage space 11 to the volume of product contained within the membrane 9. This securing mechanism is especially advantageous when moving the tank, particularly when mounted on a vehicle, as it prevents unwanted movement of the liquids contained within the products during transport.

[0087] Tank 1, as described above, is also suitable for carrying out a dewatering of semi-liquid products, in particular sludge, contained in the internal storage space 11.

[0088] To do this, the rear door 7 of tank 1 is closed, as shown in the figure 2 The free space 15 between the inner face 12A of the tank 1 and the outer face 9B of the membrane 9 is pressurized using the compressed air generator 25. This pressurization compresses the semi-liquid products so as to generate a separation of the water and the juices which are found in the upper part of the tank 1 and which can be evacuated through the orifice 28 provided in the lower part of the door 7, as illustrated by a dashed arrow B2 (the valve being open and the plug 29 being of course removed in this case).

[0089] Furthermore, tank 1, as described above, can be emptied (or unloaded) while remaining horizontal, using an emptying (or unloading) method described below with reference to figures 4A à 4C .

[0090] To perform the draining, starting from the closed position P2 of the figure 4A with the membrane 9 in a position A1 in contact with the inner wall of the tank 1, the door 7 is opened, as shown by an arrow I, and it is brought into its open position P1 ( figure 4B ).

[0091] The free space 15, between the inner face 12A of the tank 1 and the outer face 9B of the membrane 9, is pressurized (controlled) using the system 16 to generate a pressurization, as illustrated by arrow E1.

[0092] Applying pressure allows the membrane 9 to be pushed back and moved, as illustrated by arrow K on the figure 4B .

[0093] More specifically, the pressurization allows the membrane 9 to move between position A1 (represented on the figure 4A ) in which it is pressed against the inner face 12A of the tank 1 and a position A2 (represented on the figure 4C ) in which it is completely turned around and deployed towards the back.

[0094] For pressurization, compressed air pressure is injected into free space 15. This compressed air can, for example, be stored in a 300-litre bottle at 10 bars.

[0095] When tank 1 is being filled, the membrane 9 remains pressed against the inner part of tank 1. During emptying, the membrane 9 turns around, expelling the products stored inside the membrane 9 outside tank 1. This allows for a rapid, efficient and complete evacuation of the products.

[0096] The movement of the membrane 9 therefore allows the products contained in the tank 1 to be forced back and discharged (or ejected) through the open door 7, as illustrated by an arrow D on the figure 4B .

[0097] The support tubes 35 are brought into the extended position (with an orientation substantially parallel to the axis of revolution of the ferrule 2) when the membrane 9 is removed from the tank 1, as shown in the figure 4C The tubes 35 support the membrane 9 when it is fully extended and no longer subjected to expulsion pressure, but is again drawn into the tank 1 by the generation of a vacuum in the free space 15 as illustrated by an arrow E2 on the figure 4C .

[0098] One advantage of tank 1 is its enhanced protection against the release of ATEX (a type of explosive) by the vacuum pump during specific pumping operations, such as pumping 5,000 liters from a 10,000-liter capacity. Once these 5,000 liters are pumped, the liquid can be blocked at the rear with the membrane. To pump the next 5,000 liters, simply pump again from the side with the membrane, thus recreating the vacuum without pumping ATEX, since the airtight membrane creates a vacuum. It is no longer necessary to degas tank 1 to repeat multiple pumping operations.

[0099] Tank 1, as described above, can correspond to any type of tank (or cistern) intended for the storage of products, particularly semi-liquid products, pastes, or powdered solids. The tank can be installed in a fixed location or mounted on mobile equipment (or vehicles), including a rolling vehicle.

[0100] In a preferred application, tank 1 is a tank of a waste collection vehicle, and more specifically of a hydro-jetting truck 32, as shown on the figure 7 The 32-liter hydro-jetting truck is designed, in particular, to carry out cleaning and pumping operations on wastewater networks or industrial waste (gasoline, fuel oil, oils, etc.) and sanitation structures. The 32-liter hydro-jetting truck is equipped with the necessary means for filling and emptying tank 1, including the pressurization and depressurization system.

[0101] Because the tank 1 empties horizontally, without needing to tilt it, the overall footprint is reduced, and many of the equipment components 33 of the hydro-jetting unit 32 can be arranged on or near tank 1. This allows the hydro-jetting unit to be built in two modules: the tank and its attached components, and an equipment module including a pumping system. These two modules are easily removable and adaptable from one carrier chassis to another. This equipment mobility, enabling the interchangeability of the carrier chassis, is a significant advantage in light of current environmental developments in carriers.

[0102] Tank 1, as described above, offers numerous advantages. First, the proposed solution has the following advantages: to completely empty the tank 1 when the membrane 9 is turned over and (completely) removed from the tank 1; to protect the entire internal surface of the ferrule 2 of the metal tank 1, using the membrane 9; and to be able to easily and completely rinse the membrane 9 when it is turned over and completely removed.

[0103] Tank 1, as described above, also offers other advantages, including: to maximize transport volume; to be a lightweight solution, with a payload gain of approximately 500 kilograms, in application to a hydro-jetting truck; to be able to empty the contents of tank 1 horizontally, without tipping (or dumping), which eliminates the need for the usual static or mobile devices designed to generate emptying, particularly by gravity; to be able to perform a safe, quick and complete emptying of tank 1; to be able to block liquids during transport; to be able to transport all types of products, including aggressive products, thanks to the membrane 9 which can be made resistant, particularly to petroleum or acidic products; to have a reduced footprint; to reduce construction and operating costs (compared to a conventional articulated device);to be able to secure emptying operations (by eliminating the instability of trucks with a tipping tank) and transport (by eliminating the mobility of the liquid mass of waste in the tank); and to increase productivity, for example, by dewatering the sludge by compression, in cases where water can be returned to the tank filling site.

Claims

1. A tank for storing products, in particular semi-liquid, pasty, or powdered solid products, said tank (1) comprising: - a shell (2) provided with a rear opening (5) at a rear longitudinal end (6) and a door (7) capable of closing this opening (5); - a flexible membrane (9) that is impermeable to gases and liquids, configured to receive the products to be stored, said membrane (9) being provided with an opening (10), being arranged inside the tank (1) and being attached along an annular attachment zone (27) to the inner surface (12A) of the shell (2) so as to create a so-called closed "free space" (15) between the membrane (9) and the tank (1); and - a system (16) for pressurizing and depressurizing the free space (15) between the tank (1) and the membrane (9), said system (16) comprising a vacuum generator (26) configured to create a vacuum in an inner space (11) within the membrane (9), the membrane (9) being configured to: • be completely pressed against the inner surface (12A) of the shell (2) under the effect of a vacuum generated by said system (16); and • be turned over and removed from the tank (1) through said open door (7) under the effect of pressurization generated by said system (16), the tank (1) being provided with a recess (36) which is formed inside and at the rear of the shell (2), arranged between the shell (2) and the membrane (9), and which opens into, via a rear outlet (37), the rear opening (5) of the shell (2); the shell (2) being provided with at least a through-orifice (38) opening into the inside of the recess (36), the vacuum generator (26) being connected from the outside to said orifice (38); the membrane (9) being secured to the rear longitudinal end (6) of the shell (2) such that its opening (10) substantially coincides with the rear opening (5) of the shell (2); and a passage (39) being formed from said orifice (38) to the inner space (11) of the membrane (9), via, on the one hand, the recess (36) and, on the other hand, a space (40) between the rear of the membrane (9) and the door (7), which is curved backward, said passage (39) allowing said vacuum generator (26) to create a vacuum in the inner space (11) of the membrane (9) for the purpose of pumping products into said membrane (9).

2. The tank according to claim 1, characterized in that the recess (36) has, at its rear outlet (37), a biconvex shape with two opposing convex surfaces (41, 42) having the same radius of curvature.

3. The tank according to one of claims 1 and 2, characterized in that the recess (36) is formed by at least one insert (43) that is welded to the inner face (12A) of the shell (2).

4. The tank according to any one of the preceding claims, characterized in that the recess (36) is closed and sealed, except at its rear outlet (37) and the orifice (38).

5. The tank according to any one of the preceding claims, characterized in that it comprises a suction pot (44) which is secured to the external wall (12B) of the shell (2) around the orifice (38).

6. The tank according to claim 5, characterized in that the suction pot (44) is provided with an anti-overflow ball (45).

7. The tank according to any of the preceding claims, characterized in that: - the front face (30) of the membrane (9) is substantially flat; - the membrane (9) has a length such that, when it is pressed against the inner face (12A) of the shell (2), its front end is located longitudinally at the same level as the front end of the shell (2); and - the tank (1) comprises a front bottom (3) that is curved forward.

8. The tank according to any one of the preceding claims, characterized in that it comprises a pressure-limiting device (31) configured to limit the pressure in the free space (15) between the tank (1) and the membrane (9).

9. The tank according to any one of the preceding claims, characterized in that it comprises at least two support tubes (35) capable of being moved from a retracted position to an extended position toward the rear of the tank (1) when the membrane (9) is removed from the tank (1), and in that, in the extended position, the tubes (35) are positioned substantially parallel to the longitudinal axis of the shell (2) so as to be able to support the membrane (9).

10. The tank according to any one of the preceding claims, characterized in that the membrane (9) is attached by clamping between, on the one hand, at least one plate (13) attached to the rear end of the tank (1) on the inner face (12A) of the shell (2) and on the recess (36), and, on the other hand, at least one counterplate (17).

11. The tank according to any one of the preceding claims, characterized in that the membrane (9) is made of a composite material (18) comprising different superimposed layers, formed of at least an impermeable fabric (19), a textile layer (20), and a skin (21) made of polytetrafluoroethylene.

12. A vehicle, in particular a sewer cleaning vehicle, characterized in that it comprises at least one tank (1) according to any one of claims 1 to 11.

13. A method for filling the tank (1) according to any one of claims 1 to 11, characterized in that it comprises at least the following steps, consisting of: - closing the door (7) of the tank (1); - generating a vacuum in the free space (15) between the tank (1) and the membrane (9) by means of the vacuum system (16), so as to press the membrane (9) against the inner surface (12A) of the tank (1); - generating a vacuum in the inner space (11) by means of the vacuum generator (26) so that the atmospheric pressure pushes the products into this inner space (11), through a filling orifice (28), inside the membrane (9); and - when the filling is completed, stopping the vacuum applied to the inner space (11).

14. A method for emptying the tank (1) according to any one of claims 1 to 11, characterized in that it comprises at least the following steps, consisting of: - opening the door (7) of the tank (1); - generating a pressurization of the free space (15) between the tank (1) and the membrane (9) by means of the pressurization system (16), so as to push back the membrane (9) and move it, this movement causing a complete inversion of the membrane (9) and an ejection of the products through the door (7) in the open position (P1); and - when the emptying is completed, stopping the pressurization of the free space (15).

15. A method for squeezing out products from the tank (1) according to any one of claims 1 to 11, characterized in that it comprises at least the following steps, consisting of: - the door (7) of the tank (1) being closed, generating a pressurization of the free space (15) between the tank (1) and the membrane (9) by means of the pressurization system (16), so as to push back the membrane (9) and move it, this movement compressing the products present in the tank (1) so as to generate a separation of the juices, which are discharged through a discharge orifice (28) which is opened; and - when the squeezing out is completed, stopping the pressurization of the free space (15) and closing the discharge orifice (28).