DEVICE FOR STORING AT LEAST ONE BULK MATERIAL

Abstract

The invention relates to a device for storing at least one bulk material (35), said device comprising: a container (30) in which said bulk material, selected from the group composed of liquids and powdered materials, can be introduced, said container having a lower face (31) suitable to be able to be subjected to the weight of said bulk material introduced into said container, a force measuring device comprising at least one force sensor (1) arranged beneath the base (31) of said container (30) and in contact with said base (31), each force sensor and the base of the container being arranged such that said force measuring device is only partially subjected to the weight of said bulk material introduced into said container.

Claims

1/ A device for storing at least one bulk material, said device comprising: a container in which said bulk material, selected from the group consisting of liquids and powdered materials, can be introduced, said container having a base suitable to be able to be subjected to the weight of said bulk material introduced into said container, a force measuring device comprising at least one force sensor arranged beneath the base of said container and in contact with said base, each force sensor and the base of the container being arranged such that said force measuring device is only partially subjected to the weight of said bulk material introduced into said container.

2/ The device according to claim 1, wherein said device comprises a support having an upper face for receiving the base of said container, the base of the container, the support and each force sensor being arranged such that at least one part of the base of the container is supported in direct contact with the upper receiving face, said upper receiving face being suitable to be able to be subjected at least partially to the weight of said bulk material introduced into said container.

3/ The device according to claim 1, wherein each force sensor comprises at least one strain gauge.

4/ The device according to claim 1, wherein each force sensor comprises a housing incorporating two strain gauges and one deformation element, the two strain gauges being fixed to said deformation element.

5/ The device according to claim 4, wherein each strain gauge has at least one electrical characteristic which varies as a function of its deformation, each force sensor being arranged such that said electrical characteristic varies as a function of a state of deformation of said deformation element.

6/ The device according to claim 5, wherein said device comprises an electronic circuit: connected electrically to each strain gauge, suitable for measuring said electrical characteristic of each strain gauge, and for outputting a signal, named measuring signal, representing said electrical characteristic of each strain gauge.

7/ The device according to claim 1, wherein each force sensor has a smallest dimension between 1 mm and 15 mm.

8/ The device according to claim 1, wherein each force sensor has a substantially planar upper face, named contact face, said contact face being suitable to be able to be in contact with said base of the container.

9/ The device according to claim 2, wherein each force sensor has a lower fixing face suitable to be able to allow fixing of said force sensor to the upper receiving face of the support.

10/ The device according to claim 1, wherein said force measuring device comprises a single force sensor.

11/ The device according to claim 1, wherein said container has a maximum capacity between 500 L and 1,200 L.

12/ The device according to claim 1, said container is generally in the shape of substantially a cube.

13/ The device according to claim 1, said container has an opening suitable for allowing the introduction of said bulk material inside said container.

14/ The device according to claim 1, said container has a base formed of at least one flexible material.

15/ The device according to claim 1, wherein said device comprises a wireless communication module.

16/ The device according to claim 1, wherein said device comprises an electric accumulator.

Description

[0059] Other aims, features and advantages of the invention will become apparent upon reading the following description given by way of non-limiting example of some possible embodiments thereof, and which makes reference to the attached figures in which:

[0060] FIG. 1 is a schematic perspective view of a device in accordance with a first embodiment of the invention,

[0061] FIG. 2 is a schematic perspective view of the device of FIG. 1 in which the container has been removed,

[0062] FIG. 3 is a diagram of the force sensor and of the secondary electronic housing of a device in accordance with the invention,

[0063] FIG. 4 is a schematic perspective view of the interior of a force sensor of a device in accordance with the invention,

[0064] FIG. 5 is a schematic sectional view of a device in accordance with a second embodiment of the invention,

[0065] FIG. 6 is a diagram showing a result of the filling level of a container of a device in accordance with the invention.

[0066] The figures are not necessarily drawn to scale, in particular in terms of thickness, this being for illustrative purposes.

[0067] The device in accordance with the first embodiment of the invention shown in FIGS. 1 to 2 comprises: [0068] a container 10 in which said bulk material, selected from the group composed of liquids and powdered materials, can be introduced, said container having a base suitable to be able to be subjected to the weight of a bulk material introduced into the container, [0069] a force measuring device comprising a single force sensor 1 arranged beneath the base of the container 10 and in contact with said base so as to be only partially subjected to the weight of said bulk material introduced into said container, [0070] a support 16 having an upper face 18 for receiving the container 10, said face being suitable to be able to be subjected at least in part to the weight of the bulk material introduced into the container.

[0071] In this first embodiment, the container 10 and the support 16 form an intermediate bulk container of the type comprising a support 16 having the form of a pallet allowing the device to be handled by a forklift truck. The support 16 is likewise accompanied by a mesh structure 17 (or mesh cage) suitable for receiving, protecting and mechanically reinforcing the container 10. The mesh structure 17 is generally made of metal and the pallet-like base of the support 16 can be made of a polymer material, of wood or even of a metal material or polymer-matrix composite material.

[0072] The container 10 is generally substantially in the shape of a cube. The container 10 has an opening 12 formed by a twist-off cap suitable for allowing the introduction of said bulk material inside the container, the opening 12 being arranged on the upper face 11, opposite the base of the container. The illustrated container 10 likewise comprises a liquid outlet in the form of a valve 14 provided at the bottom of one face on one side of the container.

[0073] In this first embodiment of a storage device in accordance with the invention, the force measuring device comprises a single force sensor 1, a single force sensor on which the container only partially rests being sufficient to allow reliable determination of the filling rate of the container and/or a variation in the filling rate of the container. However, there is nothing to prevent the force measuring device from comprising several force sensors, for example two, three, four or even five force sensors (identical or different, preferably identical). The use of a force measuring device comprising at least two force sensors allows the precision of the determination of the filling level to be increased by e.g. making two or three measurements of the filling level of said container in order to compare them.

[0074] The force sensor 1 is arranged in contact with the lower face of the container (forming the base of the container) and on the outside of the container. The force sensor 1 has an upper, substantially planar, contact face suitable to be able to be in contact with said base of the container 10. The force sensor 1 has a lower fixing face suitable to be able to allow fixing of said force sensor to the upper receiving face 18 of the support.

[0075] In the first illustrated embodiment, as shown in FIG. 2, the force sensor 1 is arranged substantially beneath the centre of the base of the container 10. However, there is nothing to prevent it being arranged at any other location between the base of the container and the support so long as the force sensor 1 is arranged substantially completely below the base of the container and on the face of the support for receiving said base.

[0076] The force sensor 1 is connected electrically by a cable 2 to a secondary housing 3 comprising an electrical accumulator (a battery pack 4) and a printed circuit board 5 connected to the battery pack 4. The printed circuit board 5 is composed of a module for acquiring the electrical signal from the force sensor 1 and a module for wireless communication which can return the data, e.g. over a low-power wireless network (also called LPWAN®). The secondary electronic housing 3 likewise comprises an antenna 6.

[0077] FIG. 3 is a schematic illustration of the force sensor 1 and of the secondary housing 3 which are electrically connected to one another.

[0078] The data collected are, for example, location, temperature or state of the vessel (full/empty, dirty/clean . . . ).

[0079] These data are, for example, sent with a sending frequency of one hour. The frequency of sending the data, the ON/OFF periods of the force sensor 1 or even the warning thresholds can be remotely parametrised.

[0080] FIG. 4 is a schematic illustration of the components of the force sensor 1. The force sensor 1 comprises an external housing (not shown in FIG. 4) incorporating two strain gauges 24, 25 coated with a resin 29, a deformation element 20, a base 21 on which the deformation element 20 rests, and a piston 22 which can transmit a force (indicated by the arrow shown in FIG. 4) to the tip of the deformation element 20. The force indicated by the arrow shown in FIG. 4 arises from the effect of the weight of the container and the bulk material contained in the container on the contact face of the housing of the force sensor, itself transmitted to the piston 22. The two strain gauges are fixed to the deformation element 20. Each strain gauge 24, 25 has at least one electrical characteristic which varies as a function of its deformation, the force sensor being arranged such that said electrical characteristic varies as a function of a state of deformation of the deformation element 20. The deformation element 20 can be in various forms different from that shown in FIG. 4, e.g. the form of a strip, beam or rod or even a spiral. The deformation element 20 can be formed of a metal material (in particular metal alloys), a ceramic material, a polymer material or a composite material.

[0081] The device further comprises an electronic circuit: [0082] connected electrically to each strain gauge 24, 25 by cables 27, 28, [0083] suitable for measuring said electrical characteristic of each strain gauge 24, 25, and for outputting a measuring signal, representing said electrical characteristic of each strain gauge.

[0084] The strain gauges 24, 25 are resistive strain gauges, i.e. the resistance thereof varies as a function of the deformation of the deformation part 20 which itself depends on the force exerted by the base of the container on the piston 22.

[0085] The second embodiment shown in the sectional view of FIG. 5 differs from the first embodiment in that it relates to a foldable intermediate bulk container comprising a container 30 formed of a sack 33 of flexible material arranged inside a rigid container 37 which can be folded into a configuration having a size less than its normal usage configuration. The container comprising the flexible sack 33 is arranged on a pallet. The device comprises a support 36 in the form of a pallet allowing the device to be handled by a forklift truck.

[0086] The container 30 has an opening 32 suitable for allowing the introduction of a bulk material 35 inside said container, the opening being arranged on the upper face, opposite the base 31 of the container.

[0087] The force sensor 1 is arranged in contact with the base of the flexible sack 33, in contact with it and on the outside thereof. In the second embodiment shown in FIG. 5, the force sensor 1 is arranged substantially in the centre beneath the base 31 of the container 30. However, there is nothing to prevent it being arranged at another location between the base of the container and the support 36, for example closer to one edge of the sack 33 of flexible material of the container. The results of measuring the filling rate of the container of an intermediate bulk container vary from one container to another (different material properties, geometries . . . ). A sensor placed beneath an intermediate bulk container returns a electrical resistance value which is converted into a deformation value (principle of a strain gauge). For an intermediate bulk container filled with 1.000 L of water, for example a deformation of 0.055% of the deformation element 20 is obtained and a deformation of 0.035% is obtained for 500 L of water. A law allows the volume (filling percentage or rate) to be linked with the deformation of the deformation element 20 of the force sensor 1, this law being able to be determined in particular from the first total filling of the container from its initial empty state, the measured force variation thus being considered as a variation of 0% to 100% of filling. The rate of introducing the bulk material into the container during this first filling does not need to be constant but can vary and the filling can be continuous or intermittent (in several filling steps). It is not necessary to know the maximum capacity of the container, nor the mass density of the bulk material introduced into the container, but these data can of course also allow the determined filling level to be refined. During emptying, the evolution of the force captured by the force sensor and the comparison of any value corresponding to the first maximum value captured by the force sensor (associated with a filling rate of 100%) allows a deduction to be made therefrom (using a mathematical law established based on particular parameters relating to the container and the type of bulk material in particular) as to the remaining volume in the container or a filling rate value and thus for example allows a warning to be given when this filling rate approaches zero or falls e.g. below 10%, 20% or even 30%. Despite a few approximations, the inventors have surprisingly noted that such a method allows a result to be obtained which has a precision between 2% and 20%, e.g. of the order of 10%, such a precision being largely sufficient and reliable for most applications and industries using such intermediate bulk containers.

[0088] FIG. 6 shows an example of presenting the result of measuring the filling rate of the container. The filling rate is shown in the form of an arc of a circle which can range from a minimum value 42 (of zero, i.e. 0%) to a maximum value 44 (of 100, i.e. 100%). The determined effective value 46 (100 in the example shown in FIG. 6) is shown beneath the arc of a circle.

[0089] The invention can cover numerous variants and applications other than those described above. In particular, it goes without saying that, unless stated otherwise, the different structural and functional features of each of the embodiments described above do not have to be considered as being combined and/or closely and/or inextricably linked with each other, but in contrast considered as simple juxtapositions. Furthermore, the structural and/or functional features of the different embodiments described above can form, in their entirety or in part, any different juxtaposition or any different combination. For example, containers having more complex shapes can be used. Furthermore, there is nothing to prevent the use of types of force sensors other than strain gauge sensors, for example hydraulic, pneumatic, piezoelectric force sensors or even beam deflection sensors.