Title of Invention

A PRODUCT FOR THE INTERNAL COATING OF A PIPELINE COMPONENT AND A PROCESS AND MACHINE FOR INTERNAL COATING OF PIPELINE

Abstract

The invention relates to a product for the internal coating of a pipeline component (1), in particular a metal pipeline component, comprising an internal wall (4) of high curvature. This product comprises a solid charge and a liquid. The liquid is a solution of an alkali metal silicate and the solid charge comprises sand, between 20 and 30% by mass of a binder which sets chemically by reaction with the liquid, and between 4 and 10% by mass of plasticizing adjuvants. The solid charge and the liquid are intended to be mixed (in 5) with a liquid/binder ratio by mass of between approximately 0.35 and 0.45. Application to pipelines for discharge of waste water made of spheroidal graphite cast iron.

Full Text

The present invention relates to a product for the internal coating of a pipeline component, in particu¬lar a metal pipeline component, comprising an internal wall of high curvature. The present invention applies more particularly to pipelines for discharge of waste water made of spher¬oidal graphite cast iron. Such pipelines transport particularly aggressive media which can result, in particular in hot countries, in the development in these pipelines of corrosion of bacterial origin, for example of sulphuric type or more generally of acid type. In order to limit the effects of such corrosion, various types of internal coating for the protection of pipeline components are used. Thus, use is made, for example, of coatings obtained by curing mortars, in particular mortars based on high-alumina cement, or epoxy-based paints. The aim of the invention is to provide a particu¬larly effective coating which can be used industrially in an economical way for the purposes of protecting from corrosion pipeline components comprising an internal wall of high curvature. To this end, the subject-matter of the invention is a product for the internal coating of a pipeline com¬ponent, in particular a metal pipeline componenc, comprising an, internal wall of high, curvature, character¬ized in that it comprises a solid charge and a liquid, the liquid being a solution of an alKali metal silicate and the solid charge comprising sand, between 20 and 3 0% by mass of a binder which sets chemically by reaction with the liquid, and between 4 and 10% by mass of plasticizing adjuvants, the solid charge and the liquid being intended to be mixed with a liquid/binder ratio by mass of between approximately 0.35 and 0.45. According to specific embodiments, the coating product can comprise one or more of the following charac¬teristics: the solid charge comprises by mass, as plasticizing adjuvant, between 2 and 7% of fine silica, in particular with a particle size of less than 100 µm the solid charge comprises by mass, ss plasticizing adjuvant, between 0.4 and 0.6% of tripcly-phosphate; the solid charge also comprises, as plasticizing adjuvants, neopentyl glycol at less than 1% by mass and/or copper acetate at less than 0.5% by mass; and - the binder comprises, by mass, approximately 10% of fumed silica and 90% of fly ash and the liquid is a potassium silicate solution. Another subject-matter of the invention is a process for the internal coating of a pipeline component, in particular a metal pipeline component, comprising an internal wall of high curvature, starting with a coating product as defined above, characterized in that: - the solid charge and the liquid of the product are mixed with a liquid/binder of the solid charge ratio by mass of approximately 0.35 to 0.45, in order to cbtain a substantially homogeneous pasty mixture, the mixture obtained is deposited in a substantially uniform way over the internal wall of the said pipeline component, and - the deposited mixture is allowed to cure, in particular by heating the pipeline component, in order to form a main internal coating. According to specific embodiments, the process can comprise one or more of the following characteris¬tics : the pipeline component being substantially cylindrical with a circular base, the pipeline component is rotated about its axis in order to compact the deposit: by centrifuging, - the said compacting by centrifuging is out after the said deposition of the mixture on the said internal wall, the pipeline component being substantially cylindrical with a circular base, the mixture obtained is deposited on the internal wall of the pipeline componen-by extrusion using a nozzle and by helical relative movement of the nozzle with respect to the internal wall, in order to form a helical deposit of the mixture on the said internal wall, and - the rotational speed of the pipe during the compacting by centrifuging is much higher than che rotational speed of the pipe during the deposition of the mixture. Another subject-matter of the invention is a pipeline component, in particular a metal pipeline component, comprising an internal wall of high curvature coated internally with an internal coating obtained by a process as defined above, characterized in that the thickness of the main internal coating is between approx¬imately 1.5 and 15 mm. Another subject-matter of the invention is a pipeline component comprising a pipe, in particular a metal pipe, coated internally with an intermediate coating obtained by curing a mortar, in particular a mortar based on high-alumina cement, delimiting an internal wall of high curvature, this wall being coated with a main internal coating obtained by a process as defined above, characterized in that the thickness of the main coating is between approximately 1.5 and 8 mm. The pipeline component can be cylindrical with a circular base and its internal diameter can be between approximately 40 and 2000 mm. A final subject-matter of the invention is a machine for depositing a pasty mixture on an internal wall of a substantially cylindrical pipeline component with a circular base, in particular for the implement¬ation of a process as defined above, characterized in that it comprises an extrusion nozzle, exhibiting a feed orifice and a front oblong outlet opening, a mixer equipped with means for feeding with solid charge and with liquid in order to form the mixture, means for connecting the mixer to the feed orifice of the nozzle which are equipped with pumping means, means for supporting the nozzle in order to position the opening substantially parallel to the axis of the pipeline component and close to the internal wall of the pipeline component, and means for helical relative movement of the oblong opening with respect to the internal wall. Accordingly, the present invention provides a product for the internal coating of a pipeline component, in particular a metal pipeline component, comprising an internal wall of high curvature, characterized in that it comprises a solid charge and a liquid, the liquid being a solution of an alkali metal silicate and the solid charge comprising sand, between 20 and 30% by mass of a binder which sets chemically by reaction with the liquid, and between 4 and 10% by mass of plasticizing adjuvants, the solid charge and the liquid being intended to be mixed (in 5) with a liquid/binder ratio by mass of between approximately 0.35 and 0.45. Accordingly, the present invention also provides a process for the internal coating of a pipeline component, in particular a metal pipeline component, comprising an internal wall of high curvature, starting with a coating product as descried above, characterized in that: the solid charge and the liquid of the product are mixed (in 5) with a liquid/binder of the solid charge ratio by mass of approximately 0.35 to 0.45, in order to obtain a substantially homogeneous pasty mixture, the mixture obtained is deposited (in 6) in a substantially uniform way over the internal wall of the said pipeline component, and the deposited mixture is allowed to cure, in particular by heating the pipeline component, in order to- form a main internal coating. The invention will be better understood on reading the description which follows, given solely by way of example and made with reference to the appended drawings, in which: - Figure 1 is a partial lateral diagrammatic view illustrating a process for the internal coating of a pipeline component according to the invention, the pipeline component being partially represented in longi-tudinal section, - Figure 2 is an expanded cross-sectional view along the line II-II of the extrusion nozzle in Figure 1, - Figure 3 is a partial half-view in longitudinal section illustrating a pipeline component according to the invention, and Figure 4 is a view analogous to Figure 3 illustrating another pipeline component according to the invention. Figure 1 represents a pipeline component or pipe made of spheroidal graphite cast iron 1 intended to be used for the discharge of waste water, and a machine 2 for depositing a pasty mixture 3 on the internal wall 4 of the pipe. The internal diameter d of the pipe 11 of between 40 and 200-0 mm approximately, is typically approximately 1000 mm, and the wall 4 is thus of high curvature. The machine 2 essentially comprises a mixer 5 of the type of those used to prepare cement-based mortars, a nozzle 6 for extrusion of the mixture 3, means 7 for supporting the nozzle 5, a line 8 for conveying the mixture 3 to the nozzle 6 equipped with a pump 9, and means for helical movement of the pipe 1 with respect to the nozzle 6. These conventional means can comprise a trolley 10 0, movable longitudinally on the stationary supporting member 101 of the machine, equipped with means for holding the pipe, including rollers 102 coupled to a motor 103 in order to drive the pipe 1 in. rotation about its axis. The mixer 5 is equipped with stirring means 11 and with means for feeding with solid charge llA and with liquid IIB. As illustrated in Figures 1 and 2, the nozzle 6 is a metal part of cylindrical general shape positioned with its axis substantially parallel to the X-X axis of the pipe 1. This nozzle 6 is traversed by a channel 12 emerging, on the one hand, in a longitudinal rear race 13 of the nozzle 6, via a substantially circular orifice 14 and a convergent pipe 15 for feeding the no2zle 6, and, on the other hand, laterally, via a front slot 15 (on the left in Figure 1) for exiting from the nozzle 6. This slot 16 has a longitudinal axis substantially parallel to the axis of the nozzle 6. As seen in Figure 1, a front edge 17 of the nozzle 6, partially delimiting the slot 16, is inclined radially towards the outside and towards the front of the nozzle, so that the slot 16 splays outwards. The nozzle 6 is equipped at the rear of the slot 16 (on the right in Figure 1) with two annular flanges iS coaxial with the nozzle 6. These flanges 18, with the same radial thickness, are offset with respect tio one another. The flanges 13 are situated a short distance from a generator 19 of the wall 4 of the pipe 1. The nozzle 6 is directed so that the slot 16 faces the generator 19. The slot 16 is separated from the wall 4 by a predetermined distance. The area of the outlet cross-section of the slot 16 corresponds substantially to the area of the cross-section of the orifice 14 of the nozzle 6. The support means 7 are of conventional type for the person skilled in the art and are connected to the rear end 2 0 of the nozzle 6. These support means 7 are adapted in order to fix, on the one hand, the radial position of the nozzle 6 with respect to the wall 4 and the distance between the slot 16 and the wail 4, as described above, and, on the other hand, the position ct the nozzle 6 with respect to the stationary supporting member 101 of the machine. The line 8 is connected, on the one hand, to the feed orifice 14 of the nozzle 6 and, on the other hand, to an outlet 21 of the mixer 5. The means for moving the pipe 1 with respect to the nozzle 6 are adapted, on the one hand, so that the pipe 1 can move parallel to its axis at an adjustable constant rate r and, on the other hand, so that the pipe can rotate, simultaneously or otherwise with this axial movement, about its axis at an adjustable constant rate The pasty mixture 3 is obtained by mixing a product comprising a solid charge and a liquid. The liquid is a potassium silicate solution with a relative density typically of approximately 1.43. more generally between 1.4 and 1.5, and containing approxi¬mately 40% of dry matter. The solid charge comprises siliceous sand, a binder which sets chemically by reaction with the liquid, plasticizing adjuvants and glass fibres. The solid charge comprises approximately 23% by mass of chemical binder, with a particle size of less than 80 |im, composed of approximately 90% by mass of fly ash and of approximately 10% by mass of fumed silica. The solid charge also comprises four plasticizing adjuvants. The first plasticizing adjuvant is fine silica (with a particle size of less than 100 nm and with a mean diameter of between approximately 10 and 2 5 ).irrj and represents approximately 5% by mass of the solid charge. The second adjuvant is tripolyphosphate and represents approximately 0.4% by mass of the solid charge. The third and fourth plasticizing adjuvants, which are auxiliary adjuvants together representing less than 1.5% by mass of the main solid charge, are composed respectively of neopentyl glycol and of copper acetate. The remainder of the solid charge is siliceous sand with a particle size of between 80 µm and 800 µm. to which has been added a small amount of glass fibres, typically of the order of 0.5% by mass. The solid charge and the liquid are introducea into the mixer 5 with a liquid/binder ratio by mass of approximately 40%, that is to say with a liquid/solic charge ratio by mass of approximately 0.09. The solid charge and the liquid are mixed by the mixer 5 for several minutes in order to obtain a substan¬tially homogeneous mixture 3. The mixture 3 is subsequently conveyed to the nozzle 6, through the line 8, via the pump 9. This mixture 3 is deposited on the wall 4 by extrusion through the nozzle 6. The means for moving the pipe 1 simultaneously provide a movement of the pipe 1 parallel to its axis and a rotation of the pipe 1 about its axis (as shown diagrammatically by arrows in Figure 1), so that the slot 15 describes a helical movement with respect to the wall 4 while remaining at a constant distance from the latter and with its longitudinal axis parallel to the axis of the pipe 4. The relative movements and position of the slot 16 and of the wall 4 result, by an appropriate adjustment of the rates r and co, in the formation of a deposit 22 of the mixture 3 on the wall 4 in Che shape of a helical ribbon. The thickness e of the ribbon 22 corresponds substantially to the distance between the slot 16 and the wall 4 and thus to the radial extent of the flanges 13. It is preferably between 1.5 and 15 mm. The rates r and a are adjusted so that the successive turns 23 of the deposit 22 are contiguous. The internal surface 24 of the deposit 22 exhibits a helical groove 25 corresponding to Che junction of the successive turns 23. After having deposited the mixture 3 on the wall 4 as described above, the nozzle 6 is withdrawn from the pipe 1 and then the latter is rotated about its axis by virtue of the means for movement of the pipe 1. This operation maKes it possible, by centrifuging, to compact the deposit 22 and to smooth the surface 24, causing m particular the disappearance of the groove 25. The deposit 22 is preferably centrifuged with an acceleration greater than 60 g, for example of approximately 100 g. The rotational speed of the pipe 1 during the centrifug¬ing is much greater than the rotational speed of the pipe 1 during the deposition of the mixture 3. The pipe 1 is subsequently sealed at its longi¬tudinal ends in order to accelerate the curing of the deposited mixture 3, the pipe 4 being placed in an over. and being heated at between approximately 30 and ll0"C, preferably between 30 and 50°C. For this latter tempera¬ture range, the time necessary for heating can reach approximately 10 hours and, for higher temperatures, the time necessary for heating can reach approxlm.ateiy 1 hour. The setting and curing reaction is an exothermic chemical reaction which involves, on the one hand, the potassium silicate of the liquid and, on the other hand, the aluminosilicates and the silica of the solid charge [in particular of the binder) . A glass is then formed composed essentially of a three-dimensional lattice of Si04 and AIO4 tetrahedra. The K" ions are found in the spaces in the lattice and allow electrical balancing of the glass. The coating 26 (Figure 3) obtained by curing the deposit 22 is uniform and exhibits very good adhesion to the wall 4, in particular better adhesion than that ci the coatings obtained by curing cement-based mortars. This coating 26 also exhibits very good resistance to ovalization and to impacts and its porosity is lower than that of coatings obtained by curing cement-based mortars. The porosity of the coating 26 is in particular decreased by virtue of the centrifuging, described above, of the deposit 22. The thickness of the coating 26 obtained corresponds substantially to the thickness e of the deposit 22. Furthermore, this coating 26 exhibits very good resistance to corrosion in acid medium. For its part, the mixture 3 obtained exhibits good processing characteristics. Thus, the time during which this mixture can be processed is approximately 4 hours, that is to say that it can flow for up to approximately 4 hours between the time at which the solic charge and the liquid of the product begin to be mixed and the time at which the mixture obtained, Kept stir¬ring, is applied to the wall to be coated. Furthermore, the deposit 22 exhibits good adhesion to the wall 4 to be coated and it can thus be employed industrially on walls of high curvature, in particular on the internal walls of pipes with internal diameters of between 40 and 2000 mm. More generally, the solid charge of the product used to obtain the mixture 3 can comprise between 2 and 7% by mass of fine silica, between 0.4 and 0.6% by mass of tripolyphosphate, up to 1% by mass of neopentyl glycol, up to 0.5% by mass of copper acetate and between 20 and 30% by mass of binder, the remainder of the solid charge being mainly composed of siliceous sand an small amount of glass fibres. The liquid/binder ratio by mass for obtaining the mixture 3 is preferably between 0.35 and 0.45. Of course, the helical relative movement of the nozzle 5 and of the pipe 1 can also be obtained by rotating the pipe 1 about its axis and by moving the nozzle 6 parallel to the axis of the pipe 1, for example using a telescopic arm. The mixture 3 can also be deposited on the wall 4 using a turbine. Figure 4 illustrates the use of the internal coating product for a pipeline component 1 comprising a pipe made of spheroidal graphite cast iron 27, the internal wall 4 of which has been conventionally coaced beforehand with an intermediate coating 28 obtained by curing a mortar based on high-alumina cement. By using a process analogous to that described with respect to Figure 1, the mixture 3 obtained from the coating product was deposited on the internal wall 29, of high curvature, of the intermediate coating 28 and then the curing of this deposited mixture 3 resulted in the formation or a main coating 3 0 internally covering the intermediate coating 28. The thickness of the main coating 30 is preferab¬ly between approximately 1.5 and 8 mm. The coating 30 exhibits good adhesion to the intermediate coating 28, good impact strength and a lew porosity, and it offers, with the intermediate coating 28, good resistance to ovalization and very good resis¬tance to acid corrosion. WE CLAIM; 1. A product for the internal coating of a pipeline component (1), in particular a metal pipeline component, comprising an interna! wall {4; 29) of high curvature, characterized in that it comprises a solid charge and a liquid, the liquid being a solution of an alkali metal silicate and the solid charge comprising sand, between 20 and 30% by mass of a binder which sets chemically by reaction with the liquid, and between 4 and 10% by mass of piasticizing adjuvants, the solid charge and the liquid being intended to be mixed (in 5) with a liquid/binder ratio by mass of between approximately 0.35 and 0.45. 2. The coating product as claimed in claim 1, wherein the solid charge comprises by mass, as piasticizing adjuvant, between 2 and 7% of fine silica in particular with a particle size of less than 100 µm. 3. The coating product as claimed in claim 1 or 2, wherein the solid charge comprises by mass as piasticizing adjuvant, between 0.4 and 0,6% of tri-polyphosphate. 4. The coating product as claimed in anyone of claims 1 to 3, wherein the solid charge comprises, as piasticizing adjuvants, neopentyl glycol at less than 1% by mass and/or copper acetate at less than 0.5% by mass. 5. The coating product as claimed in anyone of claims 1 to 4, wherein the binder comprises, by mass, approximately 10% of filmed silica and 90% of fly ash and in that the liquid is a potassium silicate solution. 6. A process for the internal coating of a pipeline component (1), in particular a metal pipeline component, comprising an internal wall (4; 29) of high curvature, starting with a coating product as claimed in anyone of claims 1 to 5, characterized in that: the solid charge and the liquid of the product are mixed (in 5) with a liquid/binder of the solid charge ratio by mass of approximately 0.35 to 0.45, in order to obtain a substantially homogeneous pasty mixture (3), the mixture obtained is deposited (in 6) in a substantially uniform way over the internal wall (4; 29) of the said pipeline component (I), and the deposited mixture (3) is allowed to cure, in particular by heating the pipeline component (1), in order to form a main internal coating (27; 30). 7. The process as claimed in claim 6, wherein the pipeline component (1) being substantially cylindrical with a circular base, the pipeline component (1) is rotated about its axis in order to compact the deposit (22) by centrifuging. 8. The process as claimed in claim 7, wherein the said compacting by centrifuging is carried out after the said deposition of the mixture on the said internal wall (4; 29). 9. The process as claimed in anyone of claims 6 to 8, wherein the pipeline component (1) being substantially cylindrical with a circular base, the mixture obtained is deposited on the internal wall (4; 29) of the pipeline component by extrusion using a nozzle (6) and by helical relative movement of the nozzle (6) with respect to the internal wall (4; 29), in order to form a helical deposit (22) of the mixture (3) on the said internal wall (4; 29). 10. The process as claimed in claim 9, wherein the rotational speed of the pipe (1) during the compacting by centrifuging is much higher than the rotational speed of the pipe (1) during the deposition of the mixture (3). 11. The process as claimed in anyone of claims 6 to 10, wherein the thickness of the main internal coating is between approximately 1.5 and 15 mm. 12. The process as claimed in anyone of claims 6 to 10, wherein the pipeline component is coated internally with an intermediate coating (28) obtained by curing a mortar, in particular a mortar based on high-alumina cement, de¬limiting an internal wall (29) of high curvature, this wall (29) being coated with the main internal coating (30) obtained by a process as claimed in any one of claims 6 to 10, wherein the thickness of the main coating (30) is between approximately 1.5 and 8 mm. 13. The process as claimed in claim 11 or 12, wherein the pipeline component is cylindrical with a circular base and in that its internal diameter is between approximately 40 and 2000 mm. 14. A machine for the deposition of a pasty mixture (3) on an internal wall (4; 29) of a substantially cylindrical pipeline component with a circular base, in particular for the implementation of the process as claimed in claim 9 or 10, comprising an extrusion nozzle (6), exhibiting a feed orifice (14) and a front oblong outlet opening (16), a mixer (5) equipped with means (UA, llB) for feeding with solid charge and with liquid in order to form the mixture (3), means (8) for connecting the mixer to the feed orifice of the nozzle which are equipped with pumping means (9), means (7) for supporting the nozzle in order to position the opening (16) substantially parallel to the axis of the pipeline component (1) and close to the internal wall (4; 29) of the pipeline component, and means (100, 101, 102) for helical relative movement of the oblong opening (16) with respect to the internal wall (4; 29). 15. A product for the internal coating of a pipeline component substantially as herein described with reference to the accompanying drawings. 16. A process for the internal coating of a pipeline component substantially as herein described with reference to the accompanying drawings.

Documents:

2259-mas-1998 abstract.jpg

2259-mas-1998 abstract.pdf

2259-mas-1998 claims-duplicate.pdf

2259-mas-1998 claims.pdf

2259-mas-1998 correspondence-others.pdf

2259-mas-1998 correspondence-po.pdf

2259-mas-1998 description(complete)-duplicate.pdf

2259-mas-1998 description(complete).pdf

2259-mas-1998 drawings-duplicate.pdf

2259-mas-1998 drawings.pdf

2259-mas-1998 form-13.pdf

2259-mas-1998 form-19.pdf

2259-mas-1998 form-2.pdf

2259-mas-1998 form-26.pdf

2259-mas-1998 form-4.pdf

2259-mas-1998 form-6.pdf

2259-mas-1998 petition.pdf