Flexible, spiral-wound hose for circulating fluids and / or solid particles

Abstract

The present invention relates to a flexible, circular-section pipe (1) for circulating fluids and / or solid particles, comprising a flexible, hollow tubular sheath (10) and a rigid rod (20). The flexible sheath (10), forming a cylindrical portion, is made from a flexible polymer material comprising a foam. The rigid rod (20) is characterized by a diameter equal to at least 70% of the thickness of the flexible polymer material of the flexible sheath (10) and is spirally wound, at least partially integrated within the flexible sheath (10), so as to form a spiral extending along the pipe (1). Abstract figure: Figure 1

Description

Title of the invention: Flexible spiral liquid circulation hose technical field

[0001] The present invention relates to the field of pipes and conduits and more specifically to a pipe for the circulation of fluids, in particular water, and / or solids, in particular granules. The invention relates in particular to a rigid spiral pipe. PRIOR TECHNOLOGY

[0002] Pipes are devices widely used in various applications, particularly for the circulation of liquids and solids. Water is one of the fluids that can be conveyed through such pipes. Solids can be granules, including seeds or powders.

[0003] The applications in which pipes are used to convey fluids and solids are numerous, ranging from industrial applications to domestic applications, such as supplying an agricultural machine or vacuuming wastewater.

[0004] In these applications, the important properties of the pipes used are their mass, their robustness and their flexibility.

[0005] The robustness of such pipes, in other words their mechanical strength, is indeed necessary, particularly to allow the transport of fluids and granules under pressure or vacuum (i.e., when the fluids or granules are drawn in), in order to slow their wear and reduce the risk of deformation during use. A pipe that is not sufficiently robust can become brittle, resulting in sagging or rupture.

[0006] The flexibility allows the hose to be adapted to the different configurations in which a user may want to use it, indoors or outdoors, and also allows for easier use.

[0007] These two properties can be antagonistic, since robustness can make the pipe less flexible, and flexibility can make the pipe more fragile, and therefore more likely to puncture.

[0008] A known solution is to make the pipe from a layer of textile sandwiched between at least two layers of polymer material. This widely used solution does not allow the production of pipes with an internal diameter greater than 50 mm. Furthermore, such pipes do not withstand vacuum and collapse when a high vacuum is applied.

[0009] Another known solution is to use a rigid spiral pipe, in which a rigid or semi-rigid rod is embedded and spirally wound in a polymer matrix The flexible material forms the outer polymer sheath of the pipe. This design provides resistance to vacuum pressure and allows for the manufacture of robust pipes with an internal diameter exceeding 50 mm. However, the flexibility of such pipes is generally limited.

[0010] Thus, given the desired length and cross-section for certain pipes, depending on the applications envisaged, it remains necessary to improve the compromise between mechanical strength and flexibility.

[0011] There is therefore a need for a simple and effective solution to improve these properties of fluid and / or solid particle circulation pipes. PRESENTATION OF THE INVENTION

[0012] More specifically, the invention relates to a flexible, circular-section fluid and / or solid particle circulation pipe comprising a flexible, hollow tubular sheath and a rigid rod, said flexible sheath forming a cylindrical portion being made from a flexible polymer material comprising a foam, said rigid rod being characterized by a diameter equal to at least 70% of the thickness of the flexible polymer material comprising a foam of the flexible sheath and being wound in a spiral at least partly integrated into the flexible sheath so as to form a spiral extending along the pipe.

[0013] The pipe according to the invention is thus strong due to the presence of the spiral, while remaining flexible and having a low linear mass. The force required to bend the pipe with low linear mass is less than that required to bend the heavier pipe, while maintaining identical mechanical characteristics.

[0014] Preferably, the inner diameter of the flexible sheath is between 12 millimeters and 500 millimeters. The inner diameter corresponds to the nominal diameter (DN).

[0015] In one embodiment, the rigid rod is characterized by a diameter equal to at least 100% of the thickness of the flexible polymer material comprising a foam of the flexible sheath and in particular at most equal to 150% of the thickness of the flexible sheath.

[0016] Advantageously, the flexible sheath is composed of a flexible polymer material whose Shore hardness before foam formation is between 50 ShA and 90 ShA.

[0017] Advantageously, in this embodiment, the flexible part is made of polyvinyl chloride (PVC). PVC thus makes it possible to achieve the desired Shore hardness while having impermeability and flexibility properties that are advantageous for pipe applications.

[0018] Preferably, the flexible sheath foam comprises at least one mineral or organic filler. For example, the type of filler in the flexible sheath foam could be titanium dioxide (TiO2), barium sulfate (BaSO4), calcium carbonate (CaCO3), mica, glass microbeads, etc. These fillers improve certain properties of the hose, depending on the intended end application.

[0019] Advantageously, the foam in the flexible sheath has a density corresponding to 90% or less of the density of the flexible polymer material of the flexible sheath before the foam is formed. The foam thus allows, for a given final volume of the sheath, a reduced mass of polymer material, which ensures the lightness of the hose according to the invention.

[0020] Preferably, the foam of the flexible sheath is formed by injecting gas, for example carbon dioxide or nitrogen gas, or by thermal activation of an expanding agent releasing a gas enabling the formation of the foam, said expanding agent being advantageously incorporated into the composition of the flexible polymer material of the flexible sheath.

[0021] In one embodiment, the rigid rod is made of a material having a Shore hardness between 50 ShD and 90 ShD.

[0022] Preferably in this embodiment, the rigid rod is formed of a thermoplastic material, which ensures the hardness of the rigid rod while being easy to shape.

[0023] Advantageously still, the rigid rod is formed from polyvinyl chloride.

[0024] Preferably, the rigid rod comprises up to 40% by mass of mineral or organic filler, preferably up to 20% by mass, which ensures the hardness of the rod as well as the mechanical properties of the rod necessary for the final application of the pipe.

[0025] Alternatively, the rigid rod can be made of a metallic material, such as iron, steel, stainless steel, copper, aluminum, with or without a surface treatment. PRESENTATION OF THE FIGURES

[0026] The invention will be better understood upon reading the following description, given solely by way of example, and referring to the accompanying drawings given by way of non-limiting examples, in which identical references are given to similar objects and on which:

[0027] Fig. 1 is a schematic representation of a pipe according to the invention;

[0028] Figure 2 is a schematic representation of a longitudinal cross-sectional view of the pipe according to the invention, in an embodiment where the diameter of the rigid rod is less than the thickness of the flexible sheath;

[0029] Fig. 3 is a schematic representation of a longitudinal cross-sectional view of the pipe according to the invention, in an embodiment where the diameter of the rigid rod is greater than the thickness of the flexible sheath and in which the rigid rod is covered by the flexible sheath;

[0030] The [Fig.4] is a graph representing the radius of curvature of a pipe resulting from a defined force, for a pipe of the prior art on the one hand and for a pipe according to the invention on the other hand;

[0031] Fig. 5 is a schematic representation of a longitudinal cross-sectional view of the pipe according to the invention, in an embodiment where the diameter of the rigid rod is greater than the thickness of the flexible sheath and whereby the rigid rod is not entirely covered by the flexible sheath.

[0032] It should be noted that the figures set out the invention in detail to enable implementation of the invention; although not limiting, said figures serve in particular to better define the invention where appropriate. DETAILED DESCRIPTION OF THE INVENTION

[0033] The invention relates to a pipe 1 as shown in [Fig.1].

[0034] Pipe 1

[0035] As shown in [Fig.1], the pipe 1 comprises a flexible sheath 10 and a rigid rod 20.

[0036] In the embodiments shown in the figures, the rigid rod 20 is contained inside the flexible sheath 10.

[0037] The pipe 1 has a hollow tube shape, characterized by an inner diameter and an outer diameter.

[0038] The internal diameter, also called the nominal diameter (DN), is the reference diameter for calculating the flow rate of fluid and / or solid particles, in particular water, in the pipe 1, during its use.

[0039] In a preferred embodiment, the internal diameter of the pipe 1 is between 12 millimeters and 500 millimeters, which corresponds respectively to a DN 12 and a DN 500.

[0040] Flexible sheath 10

[0041] The flexible sheath 10 of the pipe 1 allows the circulation of the fluid and / or solid particles, in particular without leaks.

[0042] The flexible sheath 10 is made from a polymer material foam in which an expanding agent has been incorporated, or into which gas has been injected during extrusion.

[0043] In the embodiment in which the foam contains a blowing agent, this blowing agent is preferably thermally activated. In this case, the blowing agent releases a gas that enables the formation of the foam.

[0044] The polymer material is preferably polyvinyl chloride, more commonly known as PVC. For the composition of the flexible sheath, the PVC is flexible and has a Shore hardness between 50 ShA and 90 ShA before foam formation.

[0045] The polymer foam material also comprises one or more types of mineral or organic fillers, depending on the intended applications. For example, the fillers may be titanium dioxide (TiO2), barium sulfate (BaSO4), calcium carbonate (CaCO3), talc, mica, or glass microbeads. In a first preferred embodiment, the filler used is calcium carbonate. In a second preferred embodiment, the filler used is titanium dioxide. Such fillers make it possible to obtain a mixture corresponding to the filled polymer foam material, which is homogeneous and exhibits high cohesion.

[0046] In particular, the percentage of filler added to the polymer material foam can reach 40% by mass. It is preferably less than or equal to 20% by mass.

[0047] Preferably, the foam consists of the flexible polymer material and bubbles formed by the release of nitrogen or carbon dioxide.

[0048] As previously stated, the foam of the flexible sheath 10 can be formed by thermal activation of an expanding agent releasing a gas enabling the formation of the foam.

[0049] The foam of the flexible sheath 10 can thus have a density corresponding to 90% or less of the density of the flexible polymer material of the flexible sheath 10 before the formation of the foam.

[0050] Rigid rod 20

[0051] As shown in Figures 2 and 3, the rigid rod 20 is wound in and around the flexible sheath 10 so as to form a spiral.

[0052] The spiral thus formed is included entirely or partly in the flexible sheath 10.

[0053] The diameter of the rigid rod 20 is at least equal to 70% of the thickness of the flexible sheath 10, in particular greater than or equal to 100% of the thickness of the flexible sheath 10. In particular, the diameter of the rigid rod 20 is also less than or equal to 150% of the thickness of the flexible sheath 10.

[0054] In the case where the diameter of the rigid rod 20 is less than the thickness of the flexible sheath 10, the rigid rod 20 is completely contained within the flexible sheath 10, as shown in [Fig.2].

[0055] In the case where the diameter of the rigid rod 20 is greater than the thickness of the flexible sheath 10, the rigid rod 20 creates protrusions in the flexible sheath 10, as shown in [Fig. 3]. These protrusions may be covered, as shown in [Fig. 3], or not, as shown in [Fig. 5], by the flexible sheath 10.

[0056] In a first embodiment, the rigid rod 20 is formed from a thermoplastic polymer material, such as PVC.

[0057] In a second embodiment, the rigid rod is formed of a metallic material, such as galvanized steel.

[0058] Advantageously, the rigid rod 20 is made of PVC that is more rigid than that used in the composition of the flexible sheath 10. Preferably, the Shore hardness of the rigid rod 20 is between 50 ShD and 90 ShD.

[0059] In order to obtain the desired properties of the rigid rod 20, in particular its hardness, mineral or organic fillers are added to the PVC, for example calcium carbonate (CaCO3), mica, ethylene-propylene-diene monomer rubbers (EPDM), fillers of vegetable origin, etc.

[0060] In particular, the percentage of charge is less than or equal to 40%; it is preferably less than or equal to 20%.

[0061] Preferably, the mass of the rigid rod 20 represents from 20 to 65% of the total mass of the pipe 1, preferably between 40 and 60%.

[0062] The pipe 1 thus composed can have a linear mass of 100 g / m to 20,000 g / m, depending on the nominal diameter of the pipe, for a density of 0.9 (at + / - 0.1), which represents a gain of 25% compared to existing pipes, with equivalent third-party characteristics and performance, in particular, for equivalent internal diameters of the pipe and liquid pressures flowing in the pipes.

[0063] In addition to the diameter, "equivalent characteristics and performance" refers in particular to the working pressure, burst pressure and vacuum resistance of the pipe.

[0064] As shown in [Fig.4], the pipe 1 according to the invention has better flexibility than pipes in the prior art, since for an equal applied force, the radius of curvature obtained with pipe 1 is smaller, in other words the pipe is more manageable and can be wound without breaking.

[0065] It should also be noted that the invention is not limited to the embodiments described above. Indeed, it will be apparent to a person skilled in the art that various modifications can be made to the embodiments described above, in light of the information just disclosed to them.

[0066] In the detailed presentation of the invention given above, the terms used should not be interpreted as limiting the invention to the mode of achievements set forth in this description, but must be interpreted to include all equivalents which can be predicted by a person skilled in the art by applying their general knowledge to the implementation of the teaching which has just been disclosed to them.

Claims

Demands

1. Pipe (1) for circulating fluid and / or solid particles, flexible and of circular cross-section, comprising a flexible sheath (10), hollow tubular, and a rigid rod (20), said flexible sheath (10) forming a cylindrical portion being made from a flexible polymer material comprising a foam, said rigid rod (20) being characterized by a diameter equal to at least 70% of the thickness of flexible polymer material comprising a foam of the flexible sheath (10) and being spirally wound at least partly integrated into the flexible sheath (10) so as to form a spiral extending along the pipe (1).

2. Pipe (1) according to the preceding claim, wherein the inner diameter of the flexible sheath (10) is between 12 millimeters and 500 millimeters.

3. Pipe (1) according to the preceding claim, wherein the rigid rod (20) is characterized by a diameter equal to at least 100% of the thickness of the flexible polymer material comprising a foam of the flexible sheath (10) and at most equal to 150% of said thickness.

4. Hose (1) according to any one of the preceding claims, wherein the flexible polymer material of the flexible sheath (10) has a Shore hardness between 50 ShA and 90 ShA, before foam formation.

5. Hose (1) according to any one of the preceding claims, wherein the foam of the flexible sheath (10) has a density corresponding to 90% or less of the density of the flexible polymer material of the flexible sheath (10) before foam formation.

6. Pipe (1) according to any one of the preceding claims, wherein the foam of the flexible sheath (10) is formed by injection of gas, such as carbon dioxide or nitrogen gas, or formed by thermal activation of an expanding agent releasing a gas enabling the formation of the foam.

7. Pipe (1) according to any one of the preceding claims, wherein the rigid rod (20) is formed of a thermoplastic polymer material.

8. 9 Pipe (1) according to the preceding claim, wherein the rigid rod (20) comprises up to 40% by mass of mineral or organic filler, preferably up to 20% by mass.

9. Pipe (1) according to any one of the preceding claims, wherein the rigid rod (20) has a Shore hardness between 50 ShD and 90 ShD.

10. Pipe (1) according to any one of the preceding claims, wherein the rigid rod (20) is formed of a metallic material.

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