WO2020136255A1

WO2020136255A1 - Device for circulating a fluid

Info

Publication number: WO2020136255A1
Application number: PCT/EP2019/087095
Authority: WO
Inventors: Julien NALLET; Alain CARRY; Frédéric ZAMI-PIERRE
Original assignee: Saint-Gobain Performance Plastics France
Priority date: 2018-12-27
Filing date: 2019-12-27
Publication date: 2020-07-02
Also published as: FR3091318A1

Abstract

The present invention relates to a device for circulating a fluid by precessional or precessional-nutational motion. This device can be particularly suitable for use in a pumping system, and in particular for pumping corrosive fluids. The device can include a moving means driven by a precessional motion between two fixed means so that a fluid is suctioned through an inlet of an enclosure, and then subjected to a centrifugal force to expel it to an outlet of the enclosure. The friction and shear effects are minimized, and the design, manufacture and maintenance of the device is simplified.

Description

DEVICE FOR CIRCULATING A FLUID

DESCRIPTION

The present invention relates to a device for circulating a fluid by precessional or precessional-nutational motion. This device is particularly suitable for use in a pumping system, and in particular for pumping corrosive fluids.

Axial or centrifugal rotary pumps are nowadays very widespread systems for pumping fluids, in particular liquids. However, they are unsuitable for pumping certain corrosive liquids that are likely to degrade the various components.

Indeed, this type of pump generally comprises metal parts for which it is generally sought to prevent any contact with the pumped liquids. For example, this type of pump generally comprises a propeller, or a similar device, rotated in a chamber by means of a rotation shaft. Rotation of the propeller moves the fluid from one or more inlets to one or more outlets. This rotation shaft is commonly made of a metal alloy to give it a certain mechanical strength. It can be cladded to protect it from the pumped liquid. It is also common to use gaskets at the junctions between the enclosure and the rotation shaft, in particular at the bearings disposed between the shaft and the enclosure.

However, although this cladding and these seals can be made of a material resistant to the corrosive nature of the pumped liquid, they degrade under the effect of the mechanical friction of the liquid and abrasion between the shaft and the other parts. This degradation can cause infiltrations of the liquid towards the rotation shaft, and possibly towards the other metallic parts, thus causing the gradual destruction thereof under the effect of the chemical attacks by the infiltrated fluid.

A first solution to this problem may be to use peristaltic pumps, also called roller pumps. These pumps comprise a flexible tube compressed against the wall by rollers or roller units arranged on a rotating rotor. The fluid is suctioned through one of the ports of the tube by the rotation of the rollers or roller units which then ensure the displacement in the tube. The main advantage of this first solution is that the fluid is only in contact with the walls of the tube. The other components of the pump are then protected from any deterioration by the fluid.

However, this type of pump has several disadvantages. First, the tube can degrade rapidly under the effect of repeated compressive stresses. It must be changed regularly. This is particularly the case for fluoropolymer tubes used, for example, in the transport of corrosive fluids, such as acids or bases. Next, with this type of pump, it is difficult to obtain high, linear flow rates, due in particular to the low speed of rotation of the rollers or roller units.

There are also so-called nutational motion pumps whose arrangement makes it possible to minimize the contacts between the fluid and the constituent elements thereof. For example, patent application WO 02/095235A describes a pump comprising a circular chamber in which a circular plate is driven by a nutational motion. The chamber comprises a fluid inlet disposed in the axis of the chamber and a peripherally disposed fluid outlet. The fluid is circulated between the inlet and the outlet by the nutational motion of the circular plate.

A first disadvantage with this type of pump is the difficulty of obtaining high flows. A second disadvantage is that there is a gap between the shaft through which the circular plate is driven by a nutational motion, and the hub in which this shaft moves. The fluid can enter this gap and be sheared. In addition, it may be trapped and accumulate there. The cleaning of this gap is hard because it is difficult to access. It may then be necessary to disassemble the pump for effective cleaning. If the cleaning is not properly performed, there may be a risk that the accumulated fluid may contaminate any other fluid that later circulates in the pump.

Patent application WO 2010/047602A describes another type of nutational motion pump. It also comprises a circular chamber in which a circular plate is driven in a nutational motion. The nutational motion is ensured by means of a sphere which forms the central part of the circular plate. This sphere is itself driven by a nutational motion thanks to the rotation of an oblique shaft which is inserted in said sphere. Two friction joints, respectively integral with the two opposite walls on either side of the circular plate, are arranged on the opposite caps of the sphere. These two joints make it possible to keep the sphere in the center of the chamber while giving it sufficient freedom to make possible the movement thereof by nutation.

The main disadvantage of this type of pump is the gradual wear of the friction joints under the effect of the abrasion by the sphere and the friction of the liquid moving in the pump. This wear is likely to induce filtrations of the fluid towards the other

components of the pump. If the fluid is corrosive, these components can be degraded, and particles of material resulting from this degradation can contaminate the fluid. The fluid can also undergo significant shear at these two joints. The rheological properties thereof can be altered. The present invention solves these problems. In particular, it can make it possible to obtain high flow rates, to reduce the risks of shearing the fluid, as well as mechanical friction phenomena that may degrade the components and/or cause infiltration.

The object of the invention is a device for circulating a fluid that can include:

- a first moving means with a first circular main face and a second circular main face opposite the first circular main face,

- a first fixed means with a conical main face,

- a second fixed means with a conical main face,

- an enclosure in which are arranged the two fixed means and the moving means,

- an inlet for a fluid in the enclosure,

- an outlet of said fluid from the enclosure, wherein

- the conical main faces of the first and second fixed means are opposite one another,

- the axes of revolution of the conical main faces of the first and second fixed means are coaxial,

- the first moving means can be disposed between the first and second fixed means so that the first circular main face of the first moving means is substantially parallel to a generatrix of the conical main face of the first fixed means to form a first compartment, and the second circular main face of the first moving means is substantially parallel to a generatrix of the conical main face of the second fixed means to form a second compartment,

- the first moving means can include a fluid communication channel between the first and second compartments disposed near the center of the first and second circular faces of said moving means,

- the fluid inlet can communicate with the first compartment and can be arranged so that the fluid can be introduced near the center of the circular main face of the first moving means,

- the outlet can communicate with the first and second compartments and can be disposed at the periphery of the enclosure, and

- when the device is in use, the first moving means can be driven by a precessional motion around the axis of revolution of the conical main face of the first fixed means and around the axis of revolution of the conical main face of the second fixed means.

The invention also relates to a pumping system that can include a device for circulating a fluid as described above.

Fig. 1 is a schematic sectional representation of a first embodiment of a device for circulating fluids according to the invention.

Fig. 2 is a sectional and perspective representation of a second embodiment of a device for circulating a fluid according to the invention.

Fig. 3 is a sectional representation of the second embodiment of Figure 2.

Fig. 4 is a sectional and perspective representation of a third embodiment of a device for circulating a fluid according to the invention.

Fig. 5 is a sectional representation of the third embodiment of Figure 4.

In order to facilitate the understanding of the present invention, it is now described and illustrated with reference to the elements of the drawings in their different views.

The characteristics of a device for circulating a fluid according to the invention are illustrated by the drawings of Figures 1, 2, 3, 4 and 5.

Said device 1000 for circulating a fluid may include:

- a first moving means 1001 with a first circular main face 1001a and a second circular main face 1001b opposite the first circular main face 1001a,

- a first fixed means 1002 with a conical main face 1002a,

- a second fixed means 1003 with a conical main face 1003 a,

- an enclosure 1004 in which are arranged the two fixed means 1002, 1003 and the moving means 1001,

- an inlet 1005 for a fluid in the enclosure,

- an outlet 1006 for said fluid from the enclosure, wherein

- the conical main faces 1002a, 1003a of the first and second fixed means 1002, 1003 can be opposite one another,

- the axes of revolution of the conical main faces 1002a, 1003a of the first and second fixed means 1002, 1003 can be coaxial,

- the first moving means 1001 can be disposed between the first and second fixed means 1002, 1003 so that the first circular main face of the first moving means 1001a can be substantially parallel to a generatrix of the conical main face 1002a of the first fixed means 1002 to form a first compartment 1007, and the second circular main face 1001b of the first moving means can be substantially parallel to a generatrix of the conical main face 1003a of the second fixed means 1003 to form a second compartment 1008,

- the first moving means 1001 can include a fluid communication channel between the first and second compartments 1007, 1008 disposed near the center of the first and second circular faces 1001a, 1001b of said moving means 1001,

- the fluid inlet 1005 can communicate with the first compartment 1007 and is arranged so that the fluid is introduced near the center of the circular main face 1001a of the first moving means 1001,

- the outlet 1006 can communicate with the first and second compartments 1007, 1008 and is disposed at the periphery of the enclosure 1004, and

- when the device is in use, the first moving means 1001 can be driven by a precessional motion around the axis of revolution of the conical main face 1002a of the first fixed means 1002 and around the axis of revolution of the conical main face 1003 a of the second fixed means 1003.

Within the meaning of the invention, precessional motion of the first moving means 1001 can be understood to refer to movement of said first moving means 1001 such that the axis A of circular symmetry of at least one of the two circular main faces of said first moving means 1001 is rotated about the axis B of revolution of the conical main face 1002a of the first fixed means 1002 and around the axis B’ of revolution of the conical main face 1003 a of the second fixed means 1003. In the present case, the axes B and B' can be coaxial and form the same axis (B, B'). The axis A can form a certain angle 5 with the axis (B, B'). According to some embodiments of the invention, the two circular main faces of the first moving means may have the same axis of symmetry A.

The precessional motion can also be defined using Euler angles. There is a first orthonormal coordinate system xyz whose z-axis corresponds to the axis (B, B'), the plane formed by the x and y axes then being perpendicular to the axis (B, B'). There is a second orthonormal coordinate system x'y'z’ whose z-axis corresponds to the axis A, the plane formed by the axes x' and y' then being perpendicular to the axis A., and parallel to or conflated with one of the circular surfaces of the first moving means. The coordinate systems xyz and x'y'z’ have same origin. The intersection of the plane xy and the plane x'y’ forms a line N called the line of the nodal points. The angles formed between the x- axis and the line N, the z-axis and the z’-axis, and the x’-axis and the line N are respectively called the first, second and third Euler angles. The precessional motion can then be defined as the variation of the first Euler angle. The axis A of symmetry can be conflated with an axis of rotation of the first moving means on itself. However, the precessional motion of the first moving means 1001 does not imply that said first moving means 1001 is rotated on itself with respect to the axis of symmetry of at least one of the circular main faces thereof 1001a, 1001b, although it may be in some embodiments of the invention.

The first moving means 1001 can be driven with a precessional motion in two different ways.

According to the first way, the precessional motion can be performed with a constant inclination of the circular main faces 1001a, 1001b of the first moving means 1001 with respect to the plane xy defined above. The movement of the first moving means 1001 is in such a case similar, without being identical, to that of the equatorial plane of a planet with respect to the plane of the ecliptic. The trajectory of a point of a circular main face of the first moving means 1001 observed laterally does not vary or does so only slightly along the z axis during the movement.

According to the second way, the precessional motion can be performed with a variable inclination of the circular main faces 1001a, 1001b of the first moving means with respect to the plane xy defined above. The movement of the first means 1001 is in such a case similar, without being identical to, that of an Euler’s disk. The trajectory of a point of a circular main face of the moving means observed laterally varies along the z axis during the movement.

The device 1000 for circulating a fluid according to the invention operates in the following manner. When the device 1000 is in use, the precessional motion of the first moving means 1001 creates a suction of the fluid through the inlet 1005 in the first compartment 1007, and in the second compartment 1008 via one or more communication channels 1010. The fluid is set in motion in the first and second compartments 1007, 1008 by the precessional motion of the first moving means 1001. It is then expelled through the outlet 1006 due to the effect of a centrifugal force. The aspiration of the fluid in the first and second compartments 1007, 1008 makes possible a uniform circulation of the fluid with a large and linear flow.

The type of fluid that can be circulated by the device 1000 according to the invention is mainly a liquid fluid. It is not excluded, however, that certain gases may also be circulated by the device.

The value of the half-angle at the apex of the conical main faces 1002a, 1002b of the first and second fixed means 1002, 1003 depends on the type of fluid, in particular the viscosity thereof, and the desired flow rates. The value of the angles may advantageously be at least about 0.5° and not greater than about 35°.

A feature of the device 1000 of the invention is that the fixed means 1002, 1003 and the moving means 1001 undergo little or no friction force likely to cause the degradation thereof. The risk of infiltration of the fluid towards the other components of the device due to the degradation thereof is therefore considerably reduced. This is advantageous when the fluid is a corrosive liquid, such as an acid or a base. The risk of contamination of the fluid by particles of material resulting from this degradation is also reduced. This is a particular advantage when the purity of the circulating fluid must be preserved. The risk of fluid shear is also reduced.

Another corresponding advantage related to the reduction or the absence of friction force and other types of mechanical stress is that the fixed means 1002, 1003 and the moving means 1004, as well as the enclosure 1004, can be made from a material sensitive to mechanical forces and yet suitable for contact with the fluid being circulated. This is particularly the case for fluoropolymer-type materials, for example

polytetrafluoroethylene (PTFE) or perfluoroalkoxy (PFA), which are suitable for contact with corrosive fluids but are sensitive to mechanical deformations. It is also possible to coat with such materials only those surfaces of the fixed and moving means, and of the enclosure, that are in direct contact with the fluid.

In this sense, in one embodiment of the device according to the invention, the fixed means, the moving means and the enclosure are manufactured from fluoropolymer, or coated with same on the surfaces thereof in contact with the fluid.

Another advantage of the device 1000 according to the invention is that it can be designed to be easily removable, and thus facilitate cleaning. For this, the enclosure 1004 may be, for example, in two parts 1004a, 1004b, as illustrated by the

embodiments shown in the drawings of the figures. The upper part 1004a of the enclosure 1004 can then be opened in order to easily access the fixed means 1002,

1003 and the moving means 1001. The cleaning thereof is thus facilitated.

In embodiments of the device 1000 for circulating a fluid according to the invention, the circular main faces 1001a, 1001c of the first moving means 1001 and the conical main faces 1002a, 1003a of the first and second fixed means 1002, 1003 can be in contact. Such contact can ensure that the pressure exerted on the fluid by the moving means 1001 is sufficient to cause without fully moving without any part remaining stationary between said main faces. In these embodiments, it is preferable in such cases to use a fluid having a certain lubricating power to minimize the risk of friction in the contact zone, or to use fixed and moving means consisting of materials that make it possible to obtain such an effect.

In the context of the development of the device according to the invention, it has nevertheless surprisingly been found that the absence of contact between the circular main faces 1001a, 1001b of the first moving means 1001 and the conical main faces 1002a, 1003a of the first and second fixed means 1002, 1003 was not detrimental to the performance of said device, especially in terms of flow. In other words, the pressure exerted on the fluid by the moving means 1001 to cause displacement is sufficient. The main advantage is the elimination of any risk of friction between said faces.

In this sense, in an advantageous embodiment of the device according to the invention, the circular main faces 1001a, 1001b of the first moving means 1001 and the conical main faces 1002a, 1003a of the first and second fixed means 1002, 1003 are not in contact.

The first circular main face 1001a and the second circular main face 1001b of the first moving means 1001 can then be advantageously spaced apart from the conical main face of the first fixed means and the conical main face of the second fixed means, respectively, by a distance of at least about 50 pm and not greater than about 1000 pm, preferably at least about 200 pm and not greater than about 500 pm.

The first moving means 1001 may include a fluid communication channel between the first and second compartments 1007, 1008. As illustrated, by way of example, in the perspective drawings of Figures 2 and 4, it may also comprise a plurality of fluid communication channels 1001 between the first and second compartments 1007, 1008. The inlets and outlets of the channels 1001 open radially onto the first and second circular faces of said moving means. This plurality of channels 1010 in such an

arrangement makes possible uniform fluid communication between the first and second compartments 1007, 1008.

In order to minimize the pressure losses during the circulation of a fluid by the device 1000 according to the invention, it is preferable that there is a certain seal between the first and second compartments 1007, 1008 between the peripheral edge 1001c of the first moving means 1001 and the lateral inner wall of the enclosure 1004. For this, the lateral inner wall of the enclosure 1004 may advantageously form a spherical zone 1004c with which the peripheral edge 1001c of the moving means is in contact. The peripheral edge 1001c of the moving means 1001 has a shape complementary to the spherical zone 1004c so that when the device 1000 is in use, the first and second compartments 1007,

1008 are sealed off from one another relative to said peripheral edge 1001c of the moving means 1001.

The physical contact between the peripheral edge 1001c of the first moving means 1001 and the spherical zone 1004c of the lateral internal wall of the enclosure 1004 makes possible the seal between the first and second compartments 1007, 1008 with respect to the peripheral edge 1001c of the moving means 1001. It is then preferable to use a fluid having a certain lubricating power to minimize the risk of friction in the contact zone, or to use an enclosure 1004 and a moving means 1001 formed of, or coated at the contact surface with, materials that make possible such an effect.

In the context of the development of the device according to the invention, it has nonetheless surprisingly been found that the absence of contact between the peripheral edge 1001c of the first moving means 1001 and the spherical zone 1004c of the lateral internal wall of the enclosure 1004 was not detrimental to the performance of said device. In this sense, in an advantageous embodiment of the device for circulating a fluid according to the invention, the lateral internal wall of the enclosure 1004 forms a spherical zone 1004c from which the peripheral edge 1001c of the moving means 1001 is separated by a distance of at least about 50 pm and not greater than about 1000 pm, preferably at least about 200 pm and not greater than about 500 pm, said peripheral edge of the moving means having a shape complementary to the spherical zone so that when the device is in use, the first and second compartments are sealed off from one another with respect to said peripheral edge of the moving means. The advantage is the elimination of any risk of friction between contact surfaces.

Thus, in an advantageous embodiment of the device of the invention, illustrated by the drawings of Figures 1 through 5, the first moving means 1001 may be in the form of a disk. The lateral internal walls of the enclosure 1004 can form a spherical zone 1004c all around the periphery of the interior of said enclosure 1004.

According to the embodiments of the device of the invention, one of the two fixed means 1002, 1003 is integrated in the enclosure 1004 and the conical main face thereof, 1002a or 1003a, is constituted by a portion of the inner wall of the enclosure 1004. As an illustrative example, in the drawings of Figures 1 through 5, the first fixed means 1002 is integrated into the upper inner wall of the enclosure 1004. In particular, it directly consists of a portion of the upper inner wall of the first part 1004a of the enclosure 1004. This results in a simplification of the design and assembly of the device. According to some possible embodiments of the device of the invention, the first moving means 1001 may further be driven by a nutational motion. This nutational motion may be advantageous for increasing the flow rate of the fluid at the outlet of the device.

Within the meaning of the invention, nutational motion of the first moving means 1001 is understood to refer to the movement of the first moving means such that the angle 5 between the axis A of circular symmetry of at least one of the two circular main faces thereof 1001a, 1001b, and the axis B of revolution of the conical main face 1002a of the second fixed means and/or the axis B' of revolution of the conical main face 1003a of the second fixed means 1003 varies. According to the above definition of Euler angles, a nutation of the first moving means 1001

corresponds to a variation of the second Euler angle. This variation is usually

periodic.

According to other possible embodiments of the invention, the first moving means 1001 can also be driven by a rotational movement on itself relative to the axis of symmetry of at least one of the circular main faces thereof. The rotation of the moving means 1001 may be useful to increase the intensity of the centrifugal force on the moving fluid in the device.

Within the meaning of the invention, rotation of the first moving means 1001 is understood to refer to the rotation of the moving means 1001 on itself around the axis A of circular symmetry of at least one of the two main faces 1001a, 1001b, regardless of the precessional motion thereof. According to the above definition of Euler angles, a rotation of the first moving means 1001 on itself corresponds to a variation of the third Euler angle.

The first moving means 1001 can be set in precessional motion using

different mechanical drive means.

In one embodiment of the device of the invention, illustrated by the drawing of Figure 1, the first moving means 1001 is integral with a spacer 1011 in which is inserted a rotary shaft 1012. The circular main surfaces 1001a, 1001b are inclined relative to the axis of the spacer 1011 which coincides with the axes B, B’ of revolution of the conical main faces 1002a, 1003a of the first and second fixed means 1002, 1003. The moving means 1001 can be fixed on the spacer 1001 to form a single piece, so that the circular main faces 1001a, 1001b are inclined relative to the xy-plane perpendicular to the axis B, B’ defined above. In the drawing, the axis of rotation of the rotary shaft and the axis of the spacer 1011 coincide with the axis B, B'. The spacer 1011 passes through the bottom wall of the enclosure 1004 and the second fixed means 1003 along the axis of revolution thereof B, B'. In this configuration, the first moving means 1001 is driven by a

precessional motion by the rotation of the rotary shaft 1012. It is not driven by a rotational movement on itself with respect to the axis A of circular symmetry of the circular main faces 1001a, 1001b.

In other embodiments of the device according to the invention, illustrated by the drawings of Figures 2 through 5, the first moving means 1001 is secured to a spacer 2001 in which a rotary shaft 2002 having an oblique position relative to the axes of revolution of the conical main faces 1002a, 1003a of the first and second fixed means 1002, 1003, in other words with respect to the axis B, B', is inserted. The circular main surfaces 1001a, 1001b are perpendicular to the axis of the spacer 2001. A mechanical bearing 2003, for example a ball or needle bearing, is disposed between the spacer 2001 and the rotary shaft 2002. The spacer 1011 may pass through the bottom wall of the enclosure 1004 and the second fixed means 1003 along the axis of revolution thereof B, B'. When the rotary shaft is rotating, the first moving means 1001 is driven by a precessional motion. The bearing makes possible the suppression of the rotation of the moving means 1001 on itself with respect to the axis A of circular symmetry of the circular main faces 1001a, 1001b. The advantage of these embodiments is the absence of friction phenomenon at the junction between the rotary shaft 2002, the first moving means 1001 and the second fixed means 1003. It does not require the use of friction joints, as in devices of the prior art. In addition, the degradation of the parts by friction effect is reduced and the fluid shear at the junction is eliminated.

In one embodiment of the device, illustrated by the drawings of Figures 2 and 3, the spacer 2001 and the second fixed means 1003 are secured to one another by means of a connecting means 2004 to form the same piece 2006, the first moving means 1001 being fixed on the spacer 2001 using a suitable fastening means 2005. The connecting means may be rigid or flexible. The connecting means 2004 and the second fixed means 1003 can form a single piece. The design and manufacture of the device are advantageously simplified. The fastening means 2005 may be, for example, a snap-fit, of the clipping type, or a method of assembly by screwing, nailing, riveting or via the use of a key or a pin.

In an alternative embodiment of the device, illustrated by the drawings of Figures 4 and 5, the first moving means 1001, the second fixed means 1003, the spacer 2001 and the connecting means 2004 between the spacer 2001 and the second fixed means 1003 forms a single piece 4001. A mechanical bearing 2003, for example a ball or needle bearing, is disposed between the spacer 2001 and the rotary shaft 2002. When the rotary shaft 2002 is rotating, the first moving means 1001 is driven by a precessional motion.

The bearing makes possible the suppression of the rotation of the moving means 1001 on itself with respect to the axis A of circular symmetry of the circular main faces 1001a, 1001b. This embodiment provides the same advantages as the previous embodiment in addition to further simplifying the design, manufacture and maintenance of the device. In particular, the piece 4001 can be produced by injection or three-dimensional printing. It can be easily replaced if it becomes defective.

It should be emphasized that a particular advantage of the device 1000 of the invention is that it can be designed so that a reduced number of parts is required for the assembly thereof. For example, in the embodiment of the drawings of Figures 4 and 5, apart from the rotary shaft 2002, the device comprises only three assembled pieces: The two upper and lower parts 1004a, 1004b of the enclosure 1004 and the single piece 4001.

It is also possible to form an enclosure 1004 from a single piece. In this case only two pieces are necessary for the assembly of the device.

In an advantageous embodiment of the device 1000 of the invention, the two upper and lower parts 1004a, 1004b of the enclosure 1004 and the single piece 4001 form a single piece. Such a part can in particular be obtained using three-dimensional printing manufacturing methods.

The invention also relates to a fluid pumping system comprising a device for circulating a fluid according to the invention. The device can in particular constitute the body of the pumping system.

The invention also relates to the use of a device for circulating a fluid according to the invention in any pumping system or assembly for pumping fluids, especially liquid fluids.

When the device according to the invention is used in a system for pumping liquid fluids, flow rates at least about 2.5 L/min and not greater than about 12.5 L/min can be obtained with pressures at least about 0.5 bar and not greater than about 3 bar and precession speeds of at least about 8000 and not greater than about 10000 rpm. The precession speed corresponds to the speed of rotation of the first moving means around the axes of revolution of the conical main faces of the first and second fixed means.

Many different aspects and embodiments are possible. Some of those aspects and embodiments are described herein. After reading this specification, skilled artisans will appreciate that those aspects and embodiments are only illustrative and do not limit the scope of the present invention. Embodiments may be in accordance with any one or more of the embodiments as listed below.

Embodiment 1. A device (1000) for circulating a fluid comprising: a first moving means (1001) having a first circular main face (1001a) and a second circular main face (1001b) opposite the first circular main face (1001a), a first fixed means (1002) having a conical main face (1002a), a second fixed means (1003) having a conical main face (1003a), an enclosure (1004) in which are arranged the two fixed means (1002, 1003) and the moving means (1001), an inlet (1005) for a fluid in the enclosure, an outlet (1006) for said fluid from the enclosure, wherein the conical main faces (1002a, 1002b) of the first and second fixed means (1002, 1003) are opposite one another, the axes (B, B’) of revolution of the conical main faces (1002a, 1003a) of the first and second fixed means (1002, 1003) are coaxial, the first moving means (1001) is disposed between the first and second fixed means (1002, 1003) so that the first circular main face (1001a) of the first moving means (1001) is substantially parallel to a generatrix of the conical main face (1002a) of the first fixed means (1002) to form a first compartment (1007), and the second circular main face (1001b) of the first moving means (1001) is substantially parallel to a generatrix of the conical main face (1003a) of the second fixed means (1003) to form a second compartment (1008), the first moving means (1001) comprises a fluid

communication channel (1010) between the first and second compartments (1007), (1008) disposed near the center of the first and second circular faces (1001a, 1001b) of said moving means (1001), the fluid inlet (1005) communicates with the first compartment (1007) and is arranged so that the fluid is introduced near the center of the circular main face (1001a) of the first moving means (1001), the outlet (1006) communicates with the first and second compartments (1007, 1008) and is disposed at the periphery of the enclosure (1004), and when the device (1000) is in use, the first moving means (1001) is driven by a precessional motion around the axis (B) of revolution of the conical main face (1002a) of the first fixed means (1001) and around the axis (B’) of revolution of the conical main face (1003a) of the second fixed means (1003).

Embodiment 2. The device (1000) for circulating a fluid according to embodiment

1, such that the circular main faces (1001a, 1001b) of the first moving means (1001) and the conical main faces (1002a, 1003a) of the first and second fixed means (1002, 1003) are not in contact.

Embodiment 3. The device (1000) for circulating a fluid according to embodiment

2, such that the first circular main face (1001a) and the second circular main face (1001b) of the first moving means (1001) are respectively spaced apart from the conical main face (1002a) of the first fixed means (1002) and the conical main face (1003) of the second fixed means (1003) by a distance of at least about 50 pm and not greater than about 1000 pm, preferably at least about 200 pm and not greater than about 500 pm.

Embodiment 4. The device (1000) for circulating a fluid according to any one of embodiments 1 through 3, such that the first moving means (1001) comprises a plurality of channels (1010) communicating the fluid between the first and second compartments (1007, 1008), said inlets and outlets of the channels (1010) radially opening on the first and second circular faces (1001a, 1001b) of said moving means (1001).

Embodiment 5. The device (1000) for circulating a fluid according to any one of embodiments 1 through 4, such that the lateral internal walls of the enclosure (1004) form a spherical zone (1004c) with which the peripheral edge (1001c) of the moving means (1001) is in contact, said peripheral edge (1001c) of the moving means (1001) having a shape complementary to the spherical zone (1004c) so that when the device (1000) is in use, the first and second compartments (1007, 1008) are sealed off from one another with respect to said peripheral edge (1001c) of the moving means (1001).

Embodiment 6. The device (1000) for circulating a fluid according to any one of embodiments 1 through 4, such that the lateral internal walls of the enclosure (1004) form a spherical zone (1004c) of which the peripheral edge (1001c) of the moving means (1001) is spaced a distance of at least about 50 pm and not greater than about 1000 pm, preferably at least about 200 pm and not greater than about 500 pm, said peripheral edge (1001c) of the moving means (1001) having a complementary shape to the spherical zone (1004c) so that, when the device (1000) is in use, the first and second compartments (1007, 1008) are sealed off from each other with respect to said peripheral edge (1001c) of the moving means (1000).

Embodiment 7. The device (1000) for circulating a fluid according to any one of embodiments 1 through 6, such that one of the two fixed means (1002, 1003) is integrated into the enclosure (1004) and the conical main face thereof is constituted by a portion of the inner wall of the enclosure (1004).

Embodiment 8. The device (1000) for circulating a fluid according to any one of embodiments 1 through 7, such that the first moving means (1001) is further driven by a nutational motion.

Embodiment 9. The device (1000) for circulating a fluid according to any one of embodiments 1 through 8, such that the first moving means (1001) is furthermore rotated on itself relative to the axis of symmetry of at least one of the circular main faces thereof (1001a, 1001b).

Embodiment 10. The device (1000) for circulating a fluid according to any one of embodiments 1 through 8, such that the first moving means (1001) is integral with a spacer (1011) into which a rotating shaft (1012) is inserted, and that the circular main surfaces (1001a, 1001b) are inclined with respect to the axis of the spacer (1011) which coincides with the axes (B, B') of revolution of the conical main faces (1002a, 1003a) of the first and second fixed means (1002, 1003).

Embodiment 11. The device (1000) for circulating a fluid according to any one of embodiments 1 through 8, such that the first moving means (1001) is integral with a spacer (2001) in which a rotary shaft (2002) is inserted having an oblique position relative to the axes (B, B') of revolution of the conical main faces (1002a, 1003a) of the first and second fixed means (1002, 1003), the circular main surfaces (1001a, 1001b) being perpendicular to the axis of the spacer (2001), and furthermore in that a bearing (2003) is disposed between the spacer (2001) and the rotary shaft (2002).

Embodiment 12. The device (1000) for circulating a fluid according to embodiment

11, such that the spacer (2001) and the second fixed means (1003) are secured to one another via a connecting means (2004) to form a single piece, the first moving means being fastened on the spacer (2001) using a suitable fastening means (2005).

Embodiment 13. The device (1000) for circulating a fluid according to embodiment

12, such that the first moving means (1001), the second fixed means (1003), the spacer (2001) and the connecting means (2004) between the spacer (2001) and the second fixed means (1003) form a single piece (4001).

Embodiment 14. The device (1000) for circulating a fluid according to any one of embodiments 1 through 13, such that the fixed means (1002, 1003), the moving means (1001) and the enclosure (1004) are manufactured from fluoropolymer, or coated with same on the surfaces thereof in contact with the fluid.

Embodiment 15. A use of a fluid circulation device according to any one of embodiments 1 through 14 in a pumping system.

Embodiment 16. A pumping system comprising a device for circulating a fluid according to any one of embodiments 1 through 14.

Claims

1. A device (1000) for circulating a fluid comprising

a first moving means (1001) having a first circular main face (1001a) and a second circular main face (1001b) opposite the first circular main face (1001a), a first fixed means (1002) having a conical main face (1002a),

a second fixed means (1003) having a conical main face (1003a),

an enclosure (1004) in which are arranged the two fixed means (1002, 1003) and the moving means (1001),

an inlet (1005) for a fluid in the enclosure,

an outlet (1006) for said fluid from the enclosure, wherein

the conical main faces (1002a, 1002b) of the first and second fixed means (1002, 1003) are opposite one another,

the axes (B, B’) of revolution of the conical main faces (1002a, 1003a) of the first and second fixed means (1002, 1003) are coaxial,

the first moving means (1001) is disposed between the first and second fixed means (1002, 1003) so that the first circular main face (1001a) of the first moving means (1001) is substantially parallel to a generatrix of the conical main face (1002a) of the first fixed means (1002) to form a first compartment (1007), and the second circular main face (1001b) of the first moving means (1001) is substantially parallel to a generatrix of the conical main face (1003a) of the second fixed means (1003) to form a second compartment (1008),

the first moving means (1001) comprises a fluid communication channel (1010) between the first and second compartments (1007), (1008) disposed near the center of the first and second circular faces (1001a, 1001b) of said moving means (1001), the fluid inlet (1005) communicates with the first compartment (1007) and is arranged so that the fluid is introduced near the center of the circular main face (1001a) of the first moving means (1001),

the outlet (1006) communicates with the first and second compartments (1007, 1008) and is disposed at the periphery of the enclosure (1004), and

when the device (1000) is in use, the first moving means (1001) is driven by a precessional motion around the axis (B) of revolution of the conical main face (1002a) of the first fixed means (1001) and around the axis (B’) of revolution of the conical main face (1003a) of the second fixed means (1003).

2. The device (1000) for circulating a fluid according to claim 1, such that the circular main faces (1001a, 1001b) of the first moving means (1001) and the conical main faces (1002a, 1003a) of the first and second fixed means (1002, 1003) are not in contact.

3. The device (1000) for circulating a fluid according to claim 2, such that the first circular main face (1001a) and the second circular main face (1001b) of the first moving means (1001) are respectively spaced apart from the conical main face (1002a) of the first fixed means (1002) and the conical main face (1003) of the second fixed means (1003) by a distance of at least about 50 pm and not greater than about 1000 pm.

4. The device (1000) for circulating a fluid according to any one of claims 1 through 3, such that the first moving means (1001) comprises a plurality of channels (1010) communicating the fluid between the first and second compartments (1007, 1008), said inlets and outlets of the channels (1010) radially opening on the first and second circular faces (1001a, 1001b) of said moving means (1001).

5. The device (1000) for circulating a fluid according to any one of claims 1 through 4, such that the lateral internal walls of the enclosure (1004) form a spherical zone (1004c) with which the peripheral edge (1001c) of the moving means (1001) is in contact, said peripheral edge (1001c) of the moving means (1001) having a shape complementary to the spherical zone (1004c) so that when the device

(1000) is in use, the first and second compartments (1007, 1008) are sealed off from one another with respect to said peripheral edge (1001c) of the moving means (1001).

6. The device (1000) for circulating a fluid according to any one of claims 1 through 4, such that the lateral internal walls of the enclosure (1004) form a spherical zone (1004c) of which the peripheral edge (1001c) of the moving means (1001) is spaced a distance of at least about 50 pm and not greater than about 1000 pm, said peripheral edge (1001c) of the moving means (1001) having a complementary shape to the spherical zone (1004c) so that, when the device (1000) is in use, the first and second compartments (1007, 1008) are sealed off from each other with respect to said peripheral edge (1001c) of the moving means (1000).

7. The device (1000) for circulating a fluid according to any one of claims 1 through 6, such that one of the two fixed means (1002, 1003) is integrated into the enclosure (1004) and the conical main face thereof is constituted by a portion of the inner wall of the enclosure (1004).

8. The device (1000) for circulating a fluid according to any one of claims 1 through

7, such that the first moving means ( 1001) is further driven by a nutational motion.

9. The device (1000) for circulating a fluid according to any one of claims 1 through 8, such that the first moving means (1001) is furthermore rotated on itself relative to the axis of symmetry of at least one of the circular main faces thereof (1001a, 1001b).

10. The device (1000) for circulating a fluid according to any one of claims 1 through 8, such that the first moving means (1001) is integral with a spacer (1011) into which a rotating shaft (1012) is inserted, and that the circular main surfaces (1001a, 1001b) are inclined with respect to the axis of the spacer (1011) which coincides with the axes (B, B') of revolution of the conical main faces (1002a, 1003a) of the first and second fixed means (1002, 1003).

11. The device (1000) for circulating a fluid according to any one of claims 1 through 8, such that the first moving means (1001) is integral with a spacer (2001) in which a rotary shaft (2002) is inserted having an oblique position relative to the axes (B, B') of revolution of the conical main faces (1002a, 1003a) of the first and second fixed means (1002, 1003), the circular main surfaces (1001a, 1001b) being perpendicular to the axis of the spacer (2001), and furthermore in that a bearing (2003) is disposed between the spacer (2001) and the rotary shaft (2002).

12. The device (1000) for circulating a fluid according to claim 11, such that the spacer (2001) and the second fixed means (1003) are secured to one another via a connecting means (2004) to form a single piece, the first moving means being fastened on the spacer (2001) using a suitable fastening means (2005).

13. The device (1000) for circulating a fluid according to claim 12, such that the first moving means (1001), the second fixed means (1003), the spacer (2001) and the connecting means (2004) between the spacer (2001) and the second fixed means (1003) form a single piece (4001).

14. Use of a fluid circulation device according to any one of claims 1 through 13

in a pumping system.

15. A pumping system comprising a device for circulating a fluid according to any one of claims 1 through 13.