ITUD20110147A1 - PIPING FOR THE TRANSFER OF ABRASIVE MATERIALS, WHICH CONCRETE OR SIMILAR OR SIMILAR MATERIALS, AND ITS IMPLEMENTATION PROCEDURE - Google Patents

Description

Description of the invention having as title:

"PIPE FOR THE TRANSFER OF ABRASIVE MATERIALS, SUCH AS CONCRETE OR SIMILAR OR SIMILAR MATERIALS, AND ITS REALIZATION PROCEDURE"

FIELD OF APPLICATION

The present invention relates to a pipe for the transfer of abrasive materials, such as concrete or similar or similar materials, for example usable for truck mixers, truck-mounted pumps or the like. Here and in the following of the description and the claims, the term pipe includes both pipes having a substantially longitudinal development and curved pipes.

The present invention also relates to the process for making a pipeline for transferring abrasive materials.

STATE OF THE TECHNIQUE

Pipes for the transfer of concrete made of metallic material are known, which are subjected to suitable surface heat treatments in order to increase their resistance to wear.

The heat treatments usually used are surface hardening, carburizing, nitriding or other heat treatments suitable for increasing the surface hardness of the pipes.

However, such known pipes have the drawback that the hardening treatment has a very limited degree of penetration, and therefore only a very reduced thickness of the pipe possesses characteristics of resistance to wear. Once this has been removed, due to the abrasion process, the use of the pipe is compromised in a short time.

Furthermore, the aforementioned surface hardening treatments are very expensive both in terms of cost and time required.

Pipes are also known, and in particular sections of pipes highly stressed, such as curved parts, comprising inserts arranged on the internal surface made of wear-resistant material such as cast iron, ceramic or composite materials, which are inserted into, or co-fused with, a coating layer of lighter and softer material such as steel, aluminum or the like.

Pipes are also known which comprise an internal layer with high hardness and therefore high resistance to wear, and an outermost layer made of non-metallic and impact-resistant material.

In both cases, it is possible to obtain, in the internal part, a good resistance to wear, by means of inserts and, in the external part, a good mechanical and impact resistance, with the coating layer, and at the same time guarantee the resistance. to the bending loads to which the pipe is subjected due to its own weight and the concrete passing through it, and to the pressure exerted by the concrete during its pumping. The aforementioned known pipes have the drawback of being very heavy, and therefore meet the need for lightening which are required for example for their application on articulated arms, truck-mounted pumps or the like.

An object of the present invention is to provide and develop a method for making a pipeline for the transfer of abrasive material, such as concrete, which is light and at the same time has characteristics of resistance to wear and mechanical resistance at least comparable. if not higher than the common pipes.

A further object of the present invention is to provide a pipe for the transfer of concrete which is simple and economical to make.

In order to obviate the drawbacks of the known art and to obtain these and further objects and advantages, the Applicant has studied, tested and implemented the present invention.

EXPOSURE OF THE FOUND

The present invention is expressed and characterized in the independent claims. The dependent claims disclose other characteristics of the present invention or variants of the main solution idea.

In accordance with the aforementioned purposes, a pipe for the transfer of abrasive material, such as concrete, or similar or similar materials, comprises a cylindrical tubular body defining an external surface and an internal surface through which it is suitable for sliding abrasive material. , such as concrete, or other similar or similar material.

According to a characteristic aspect of the present invention, the tubular body is made of a fiber-reinforced composite material and comprises a plurality of fibers arranged superimposed on each other and embedded in a polymeric material, which in turn also defines at least one uniform substantially continuous layer in proximity of the internal surface of the aforesaid tubular body.

In particular, the polymeric material has both the function of wrapping and integrating the fibers together. The fibers give the pipeline structural and mechanical resistance to the action of internal pressure exerted by the flowing material. The fibers are tied together and compacted to protect them from any abrasion action exerted by the concrete. This polymeric material, at least in proximity to the uniform layer, has a reduced hardness, a high elasticity, and is selected from a group comprising polypropylene, polyamide, thermoplastic elastomers, polyurethane resins, epoxy resins, or the like.

In fact, the Applicant has found that, thanks to the high elasticity of the polymeric material, the abrasive particles impact against the internal surface during the passage of the pipe, rebound and their impact energy is dampened. This damping action allows to attenuate the abrasion and surface removal effect of the pipe.

In the pipes of the known art, on the other hand, with the hardening treatments or the possible insertion or realization of inserts or layers with high hardness, the concrete particles, during repeated impacts, discharge all their energy against the internal surface, wearing it progressively. According to a further aspect, the aforesaid polymeric material has a hardness between 50 and 100 Shore A, preferably between 60 and 90 Shore A, even more preferably between 70 and 80 Shore A.

In embodiments it is possible to provide that the uniform layer of polymeric material has a thickness ranging from about 10% to about 70%, preferably between 20% and 60%, even more preferably between 30% and 50% of the overall thickness of the pipe.

According to a further aspect, the fibers are selected from a group comprising glass fibers, basalt fibers, ceramic fibers, carbon fibers, or combinations thereof.

According to another aspect, the tubular body comprises first fibers and second fibers arranged transversely with respect to the first fibers, to define a plurality of woven meshes which overlap each other.

In one embodiment, the first fibers and the second fibers are arranged together at an angle of about 90 °.

In other embodiments, the first and second fibers are arranged crossed with each other at an angle between 20 ° and 70 °, preferably between 30 ° and 60 °, even more preferably between 40 ° and 50 °.

To allow the coupling of joints, the ends of the pipes must provide for an appropriate increase in the thickness of the pipe, for example by modifying the method of lamination of the fibers.

In particular, it is possible to foresee two different ways of making the ends, that is with fabric with deviated fibers and with fabric with enveloping fibers.

The realization of the ends with deviated fibers foresees the interposition, between one layer of fabric and the next and in the end section, of a further fabric layer of extension equal to the thickening section to be obtained. However, these fibers are always embedded in the polymeric material.

The realization of the ends with wrapping fibers foresees that the end part of the fibers is suitably folded on itself, according to a "U" conformation, towards the central part of the longitudinal extension of the pipe and for a determined section. Also in this case the fibers are embedded in the polymeric material.

The present invention also relates to the process for making a pipe as described above.

ILLUSTRATION OF DRAWINGS

These and other characteristics of the present invention will become clear from the following description of a preferential embodiment, given by way of non-limiting example, with reference to the attached drawings in which:

- fig. 1 is a perspective representation of a pipe for the transfer of concrete according to the present invention;

- fig. 2 is a perspective view of a variant of fig. 1;

- fig. 3 is a schematic sectional view of the pipe of fig. 1;

- fig. 4 is a schematic sectional view of a variant of fig. 3;

- fig. 5 is a schematic representation of the arrangement of fibers in a pipe according to the present invention;

- fig. 6 is a view of a variant of fig. 5; - fig. 7 is a schematic sectional representation of a portion of fig. 1;

- fig. 8 is a variant of fig. 7

- fig. 9 is a variant of fig. 4.

To facilitate understanding, identical reference numbers have been used wherever possible to identify identical common elements in the figures. It should be understood that elements and features of one embodiment can be conveniently incorporated into other embodiments without further specification.

DESCRIPTION OF SOME PREFERENTIAL FORMS OF

REALIZATION

With reference to fig. 1, a pipe for the transfer of abrasive materials, such as concrete for example, is indicated as a whole with the reference number 10, and comprises a tubular body 11 of substantially circular section and substantially longitudinal development, provided with a first end 12, and a second end 13

The tubular body 11 can develop longitudinally along an axis of development X which is straight (fig. 1).

The present invention is similarly applied also to curved pipes 110 (fig. 2), ie in which the tubular body 11 develops along an arc-shaped development axis X.

In other embodiments, the tubular body 11 can also develop according to straight, curved or mixed development axes.

The tubular body 11 has, in this case, a substantially circular section, although in other embodiments it can have different shapes such as rectangular, polygonal, elliptical.

The tubular body 11 is made of a fiber-reinforced composite material which comprises an overlap of several woven links 19 which are completely embedded in a polymeric material 20.

The polymeric material 20, at least in proximity to the internal surface 16 of the aforementioned tubular body 11, defines a uniform layer 23 of substantially constant thickness of said polymeric material, which is not affected by the aforementioned woven meshes 19.

The aforesaid uniform layer 23, being made of the same polymeric material 20 integrating the woven meshes 19, is substantially in continuity with the same polymeric material 20, which integrates the woven meshes 19.

The tubular body 11 has, in this case, an overall thickness S of about 6 mm, which can vary in proximity to the ends 12, 13.

In one embodiment (fig. 4), the aforementioned uniform layer of polymeric material 20 not affected by the woven mesh 19, on the side of the internal surface 16 of the tubular body 11, has a thickness T which varies from about 10% to about 70% of the overall thickness S of the pipe, preferably between 20% and 60%, even more preferably between 30% and 50%.

In particular, the uniform layer 23 of polymeric material 20 has a thickness T which can vary from about 1 mm to about 10 mm.

The woven meshes 19 (Figs. 5 and 6) comprise at least a plurality of first fibers 21 and a plurality of second fibers 22 woven transversely with respect to the first fibers 21 and according to a succession of superimposed layers substantially adjacent to each other.

In particular, in a first embodiment (fig. 5), the first fibers 21 are arranged according to a weaving angle a of about 90 ° with respect to the development axis X of the pipe 10, while the second fibers 22 are substantially arranged parallel to the same development axis X.

In another embodiment (fig. 6), the first fibers 21 and the second fibers 22 are woven according to a mutual weaving angle β comprised between about 20 ° and 70 ° and, in this case, of about 60 ° .

In a preferential embodiment, in order to obtain a uniform resistance along the extension of the tubular body 11, both the first 21 and the second fibers 22 are arranged symmetrically with respect to the development axis X of the tubular body 11.

The polymeric material 20 has high elasticity, low hardness, and is selected from a group comprising polypropylene, polyamide, thermoplastic elastomers, polyurethane resins, epoxy resins, or the like.

The polymeric material 20 has a hardness between 50 and 100 Shore A, preferably between 60 and 90 Shore A, even more preferably between 70 and 80 Shore A.

The woven meshes 19 are made of fibers selected from a group comprising glass fibers, basalt fibers, ceramic fibers, carbon fibers, metallic fibers, natural fibers, or a combination thereof.

The tubular body 11 thus made has therefore a thickness of polymeric material 20, towards its internal part which, having high elasticity, performs an anti-abrasion function with respect to the passing flow.

In fact, when the abrasive particles impact against the internal surface 16 of the tubular body 11, they are rebounded by the same polymeric material, which in turn absorbs the impact energy of the particles themselves.

The woven meshes 19 give the pipe 10 the desired mechanical strength and, by way of example only, the pipe 10 is able to withstand maximum internal pressure levels of about 140 - 170 bar.

Since the woven links 19 are completely embedded in the polymeric material 20, the latter are protected from the particle abrasion process.

The first end 12 and the second end 13 have a thickness greater than that of the tubular body 11, in order to allow the connection of further pipes by means of substantially known connection means.

To obtain an increase in the thickness of the ends 12 and 13 (fig. 7) near the end, the woven stitches 19 are folded on themselves in the direction of the central part of the tubular body 11. Similarly to what has been described above, also in this area the woven meshes 19 are completely embedded in the polymeric material 20.

Specifically, each of the woven mesh 19 comprises a first portion 24a which extends substantially for the entire length of the pipe 10, a second portion 24b which extends transversely to the thickness of the pipe 10, and a third portion 24c which extends substantially parallel with respect to the first section 24a. Furthermore, the woven stitches 19, alternately with each other, are respectively folded transversely towards the internal part of the thickness with their fourth portion 24d, or interrupted in proximity to the third portion 24c. Each of the fourth portions 24d, or at least some of them, are folded in turn parallel to the longitudinal extension of the pipe 10, with a fifth portion 24e thereof, and extend along the extension of the pipe.

In this way it is possible to define a greater tear resistance near the ends when a further pipeline is connected to it.

In another embodiment (fig. 8), the increase in thickness near the ends 12, 13 is obtained by alternating the layers of woven meshes 19 with second layers of woven meshes 27, which extend only for a certain length from the end 12, 13. This analogously to what is described with reference to fig. 7, allows to define the desired thickness increase.

The present invention also relates to the process for making a pipe 10, in which a step for defining the tubular body 11 is provided.

In particular, a first sub-phase is envisaged in which both the first fibers 21 and the second fibers 22 are woven on a female-type mold to define the woven mesh 19.

The female-type mold is made of two or more pieces divided between them and which define an internal cavity of cylindrical shape with a prevalently longitudinal development and having a diameter substantially equal to the external diameter of the pipe 10 to be obtained.

During this phase a number of woven meshes 19 are superimposed to determine the mechanical resistance of the pipe itself. Specifically, the woven meshes 19 are arranged adherent to the internal surface of the internal cavity of the mold.

Subsequently, during a second sub-phase, the polymeric material 20 is injected into the mold to drown the woven meshes 19 completely inside it and to define at least the uniform layer 23 in proximity to the internal surface 16 of the pipe itself. This is followed by a polymerization step of the injected polymeric material to give the tubular body 11 under construction a certain lift.

In embodiments of the process, it can be envisaged that during the injection of the polymeric material, the internal cavity of the mold is subjected to an internal pressure such as to keep both the polymeric material itself and the woven meshes 19 as adherent as possible to the surface. inside the mold. The application of an internal pressure of this type makes it possible to maintain the overlapping woven links 19, adhering to each other, thus limiting discontinuity effects, usually accentuated at the ends of the flaps of each woven mesh 19, which can trigger the process of wear from part of the concrete.

During the aforementioned first sub-phase, it is also possible to provide for the realization of the ends of the tubular body 11. In particular, during the first sub-phase, the terminal parts of the woven stitches 19 can be folded back on themselves, in accordance with what is described with reference to fig. . 7, or the alternating arrangement of the aforementioned woven stitches 19 and of the second layers of woven stitches 27, in accordance with what is described with reference to fig. 8.

During the second sub-phase, the injected polymeric material defines both the tubular body 11 and the ends 12 and 13.

According to a variant of the process, it is possible to foresee the use of a plurality of composite sheets made with basic monomers which, once polymerized, define the polymeric material with which the pipe is made. The aforementioned composite sheets are wrapped and superimposed on each other to define the thickness of the pipe to be obtained. In at least some of these composite sheets the woven meshes 19 are incorporated. The overlapping of the composite sheets provided with the woven meshes 19 and those without woven meshes 19 is defined according to the thicknesses and characteristics that the pipe section 10 must have. you want to get. Subsequently, as described above, one proceeds with the polymerization of the basic monomers of the composite sheets to give the pipe the desired mechanical and structural strength. Also in this case it can be foreseen that an internal pressure is imposed inside the mold to keep the aforementioned composite sheets adherent to the walls during the polymerization phase.

It is clear that modifications and / or additions of parts can be made to the pipeline for the transfer of abrasive material and to the related manufacturing process described up to now, without thereby departing from the scope of the present invention.

For example, it is possible to provide that at least the internal part of the tubular body 11, or at least the uniform layer 23, is subjected to a treatment to give greater elasticity to the polymeric material 20 and to increase the impact damping effect of the concrete particles. .

Furthermore, the step of making the cylindrical body 11 can be carried out with known filament winding techniques.

In other embodiments, it can be envisaged that in the vicinity of areas of the pipeline 10, which during use are subjected to high stresses, there is an increase in the presence of fibers 21, 22, or a more concentrated overlap of woven mesh 19.

Furthermore, in proximity of the ends 12, 13, instead of providing for a thickening of the same by increasing the presence of fibers, it is possible to provide for the insertion of reinforcing inserts 30 made of hard material and arranged in the internal surface of the pipe 10, as shown in fig. 9.

Specifically, the aforementioned reinforcement inserts 30 arranged in proximity to the ends 12 or 13 of the pipe 10, extend circumferentially for a determined angular sector, in this case about 120 ° between them, and are at least partially integrated into the thickness of the uniform layer. 23 of polymeric material.

Each of the inserts 30 is, in fact, adherent to the uniform layer 23 so that, during the repeated impacts of the concrete particles against the walls of the inserts 30, the uniform layer 23 exerts a damping action on the latter and therefore of dissipation of the impact energy possessed by the particles. This allows a consequent reduction in the wear action exerted by the concrete on the inserts 30 themselves.

In this case the inserts, for example made of steel, guarantee the coupling with junction elements that are usually connected in these areas.

Claims (11)

CLAIMS 1. Pipe for the transfer of abrasive material, such as concrete, comprising at least one tubular body (11) defining an external surface (17) and an internal surface (16) through which the abrasive material is suitable for flowing, characterized by the fact that said tubular body (11) is made of fiber-reinforced composite material and comprises a plurality of fibers (21, 22) superimposed on each other and embedded in a polymeric material (20) to define the thickness (S) of said tubular body (11) , that said polymeric material (20) in turn also defines a uniform layer (23) substantially continuous at the internal surface (16) of said tubular body (11), and that said polymeric material (20) has a high elasticity and a low hardness, and is selected from a group comprising at least polypropylene, polyamide, thermoplastic elastomers, polyurethane resins, epoxy resins. 2. Pipe as in claim 1, characterized in that said polymeric material (20) has a hardness between 50 and 100 Shore A, preferably between 60 and 90 Shore A, even more preferably between 70 and 80 Shore A. 3. Pipe as in claim 1 or 2, characterized in that said uniform layer (23) of polymeric material (20) is not affected by said fibers (21, 22), and has a thickness (T) comprised between 10% and 70%, preferably between 20% and 60%, even more preferably between 30% and 50% of the overall thickness (S) of said tubular body (11). 4. Piping as in claim 1, 2 or 3, characterized in that said fibers (21, 22) are selected from a group comprising glass fibers, basalt fibers, ceramic fibers, carbon fibers, metal fibers, natural fibers, or their combinations. 5. Pipe as in one or the other of the preceding claims, characterized in that it comprises a plurality of first fibers (21) and second fibers (22) arranged transversely to said first fibers (21) to define a plurality of woven meshes (19) superimposed. 6. Pipe as in claim 5, characterized in that said first fibers (21) are arranged crossed with respect to said second fibers (22) according to an angle equal to or less than about 90 °, preferably between 20 ° and 70 °, plus preferably between 30 ° and 60 °, even more preferably between 40 ° and 50 °. 7. Pipe as in one or the other of the preceding claims, characterized in that it comprises at least a first end (12), and a second end (13), having a thickness greater than the thickness (S) of said tubular body ( 11), and that at least in correspondence of one of said first end (12) and said second end (13), said woven fibers (21, 22) are arranged folded on themselves towards the central part of said tubular body (11) , and embedded in said polymeric material (20). 8. Pipe as in one or the other of claims 1 to 7, characterized in that it comprises at least a first end (12), and a second end (13), having a thickness greater than the thickness (S) of said tubular body (11), and which at least in proximity of said first end (12) and said second end (13) is provided with further layers of fibers (27) arranged alternately with said woven fibers (21, 22) which extend in said tubular body (11). 9. Process for making a pipeline for the transfer of abrasive material, such as concrete, comprising at least one step in which a tubular body (11) is made defining an external surface (17) and an internal surface (16) through which It is suitable for sliding the abrasive material, characterized by the fact that during said phase a plurality of overlapping fibers (21, 22) are embedded in a polymeric material (20) to define the thickness (S) of said tubular body (11 ) and, in turn, also a uniform layer (23) substantially continuous in correspondence with the internal surface (16) of said tubular body (11), said polymeric material having a high elasticity and a low hardness, and being selected in a group comprising at least polypropylene, polyamide, thermoplastic elastomers, polyurethane resins, epoxy resins. 10. Process as in claim 9, characterized in that said manufacturing step of the tubular body (11) comprises a first sub-step during which said fibers (21, 22) are woven on a female-type mold to define an overlap of several woven mesh (19), and a second sub-phase during which said polymeric material (20) is injected into said woven mesh (19), to drown the latter completely inside it and to define at least said uniform layer (23) of polymeric material (20). 11. Process as in claim 9, characterized in that before said step of making the tubular body (11) said plurality of fibers (21, 22) are woven to define a woven mesh (19) and monomer elements are integrated with them which subsequently define, after polymerization, said polymeric material (20), said woven mesh (19) and said basic monomer elements defining a composite sheet, and that said step of making the tubular body (11) comprises a first sub-step in wherein said composite sheet is arranged in a female-type mold adhering to the internal surface of said mold, and a second sub-phase in which said basic monomer elements are polymerized to form said polymeric material (20).