Feeding system, application unit and method for applying a powder coating material to a pipe

Abstract

A feeding system for feeding a powder coating material to a dispensing unit of said coating material has a tank (30) configured to contain the powder coating material; a first conduit (31) configured to be connected to said dispensing unit (16); a second conduit (32), which is in communication with the first conduit (31) and is configured to direct a flow of a fluid into the first conduit (31); a third conduit (33), which fluidically connects the tank (30) to the first conduit (31); and a conveying device (34), which is arranged within the tank (30) and is configured to feed the powder coating material to the third conduit (33).

Description

[0001] FEEDING SYSTEM, APPLICATION UNIT AND METHOD FOR APPLYING A POWDER COATING MATERIAL TO A PIPE

[0002] Cross-Reference to Related Applications This Patent Application claims priority from Italian Patent Application No . 102024000025833 filed on November 15, 2024, the entire disclosure of which is incorporated herein by reference .

[0003] Technical Field

[0004] This invention relates to a feeding system for feeding a powder coating material to a dispensing unit of said powder coating material .

[0005] Furthermore, this invention relates to an application unit and a method for applying said powder coating material to a pipe and a machine for internally coating a pipe .

[0006] State of the Art

[0007] In the oil and gas industry, it is common to use pipes made of pipe sections welded together in the field to convey fluids, such as hydrocarbons or liquids for service lines . Typically, each pipe section has a length of approximately 12 meters and comprises a hollow metal cylinder, usually made of steel, on the outer surface of which protective coatings with anti-corrosive, thermal insulation and mechanical functions are applied. The sections at the free ends of each pipe section are free of any coating, both internally and externally, since it would otherwise be damaged by the heat produced during welding in the field. Each of these uncoated sections is commonly called a "cutback" .

[0008] Generally, the construction of a long pipe of the type identified above is carried out directly at the installation site, which may be an underwater or land installation site, by welding these pipe sections to form a seamless pipe, commonly referred to as a "string" . In particular, at underwater installation sites, the construction of said pipes is carried out on board pipe-laying ships .

[0009] Once the welding between two pipe sections has been made, it is necessary to restore the field joint coating on the cutback area of the pipe and, if necessary, also protect the inner area around the weld. By way of example, the patent WO 2021 / 009709 describes a system for internally coating a pipe joint in the field with a layer of polymeric material made up of a two-component epoxy polymeric mixture in the liquid state .

[0010] If the fluids conveyed have high pressures, high temperatures, especially corrosive compositions, or if said conveyed fluids have combinations with such parameters as to determine an aggressive condition of corrosive attack, the anticorrosive protection requirements require coating solutions consisting of powder, thermosetting polymers, such as the "Fusion Bonded Epoxy" (EBE) that, to be applied, must be sprayed on the pre-heated pipe, where they polymerise and adhere to the metal surface, causing the complete curing of the powder applied.

[0011] As known from US 8, 800, 396 and GB 2, 258, 901, to perform field coating operations on the inner surface of a pipe, a machine is used, which is configured to advance inside the pipe and is equipped with a storage tank containing an EBE powder coating material and an applicator to dispense said coating material onto the inner surface of the pipe .

[0012] However, in currently known machines, the conveying of the powder coating material from the storage tank to the applicator is particularly problematic as the applicator is generally positioned inside the pipe, at a distance from the free end of this pipe . Known machines actually use high-pressure, high-flow pneumatic conveying systems that are often inefficient due to the high power required and the high air consumption in relation to the coating material conveyed .

[0013] In other words, currently known machines are equipped with fluidised bed powder conveying systems . This feature has a number of negative consequences, including high energy consumption, which is not compatible with the autonomy and compactness requirements of a machine operating within a metal pipe production line at the installation site .

[0014] In addition, known conveying systems do not guarantee precise and constant measuring of the powder coating material flow rate and the ratio of air to said powder coating material .

[0015] Subject of the Invention

[0016] One purpose of this invention is to provide a feeding system for feeding a powder coating material to a dispensing unit of said coating material that mitigates the drawbacks of the prior art .

[0017] In accordance with this invention, a feeding system for feeding a powder coating material to a dispensing unit of said coating material is provided, the feeding system comprising :

[0018] a tank configured to contain the powder coating material ;

[0019] - a first conduit configured to be connected to said dispensing unit;

[0020] a second conduit, which is in communication with the first conduit and is configured to direct a flow of a fluid into the first conduit;

[0021] - a third conduit, which fluidically connects the tank to the first conduit; and

[0022] - a conveying device, which is arranged within the tank and is configured to feed powder coating material to the third conduit .

[0023] Thanks to this invention, it is possible to precisely measure out the powder coating material fed to a dispensing unit, keeping the pressure of the fluid flow in the first and second conduit low and, consequently, limiting the power used .

[0024] From an operational point of view, the conveying device precisely controls the measuring of the powder coating material coming out of the tank, while the fluid flow in the first conduit determines the Venturi suction of the powder coating material from the third conduit into the first conduit . The combined action of the conveying device and the fluid flow in the first conduit allows precise measuring of the quantity of powder coating material fed to the dispensing unit without the need for a high-pressure fluid flow and without the flow rate and pressure fluctuations typical of a fully pneumatic supply.

[0025] In addition, with this invention, it is possible to limit the length of the feeding system measured from the tank to the dispensing unit and thus reduce the time it takes for the powder coating material to move from the tank to the application unit . In this way, the time during which the powder coating material is in contact with the fluid flow is limited and, as a result, the powder coating material does not have time to absorb any moisture contained in the fluid flow, eliminating the need to set up a system to treat the fluid flow entering the second conduit .

[0026] Specifically, the first conduit comprises a suction portion fluidically connected to the third conduit; the second conduit extends within said suction portion.

[0027] More specifically, the suction portion of the first conduit and the second conduit extend essentially coaxially.

[0028] In this way, the fluid flow can be precisely directed towards the dispensing unit, limiting load losses .

[0029] In particular, the suction portion of the first conduit has a lateral opening, which faces the second conduit and connects the third conduit to the first conduit .

[0030] In practice, the powder coating material is drawn into the first conduit upstream of the free end of the second conduit . In this way, a constant and homogeneous amount of powder coating material can be fed to the dispensing unit .

[0031] Specifically, the feeding system comprises an inflow unit, which is configured to feed a fluid flow into the second conduit .

[0032] In this way, the fluid flow rate in the first and second conduits can be precisely adjusted depending on the particular operating conditions .

[0033] Another purpose of this invention is to provide an application unit for applying a powder coating material to a pipe that mitigates the drawbacks of the prior art .

[0034] In accordance with this invention, an application unit for applying a powder coating material to a pipe is provided, the application unit comprising:

[0035] - the feeding system as described above; and

[0036] - a dispensing unit, which is connected to the first conduit of the feeding system and comprises a dispenser configured to dispense the powder coating material fed from the feeding system onto the pipe .

[0037] Thanks to the application unit, an FBE coating layer can be applied to the pipe, increasing the corrosion resistance of the pipe .

[0038] In accordance with a first embodiment, the dispenser comprises a rotating nozzle .

[0039] In this way, a j et of powder coating material can be directed onto the desired portion of the pipe .

[0040] In accordance with a second embodiment, the dispenser comprises a rotating body, preferably with an essentially conical shape, configured to centrifugally proj ect the powder coating material onto the pipe .

[0041] Due to the rotation of the rotating body, the powder coating material is evenly applied by centrifugal force diffusion .

[0042] Another purpose of this invention is to provide a machine for internally coating a pipe that mitigates the drawbacks of the prior art .

[0043] In accordance with this invention, a machine for internally coating a pipe extending along a longitudinal axis is provided, the machine comprising:

[0044] - an application unit as described above; and

[0045] - a cart, which supports the application unit and is configured to selectively advance within the pipe in a direction parallel to the longitudinal axis of the pipe .

[0046] In this way, the powder coating material can be applied to the inner surface of the pipe easily, quickly and economically .

[0047] Another purpose of this invention is to provide a method for applying a powder coating material to a pipe that mitigates the drawbacks of the prior art .

[0048] In accordance with this invention, a method for applying a powder coating material to a pipe is provided, the method comprising the steps of :

[0049] - containing a powder coating material in a tank of a feeding system;

[0050] - connecting a first conduit of the feeding system to a dispensing unit;

[0051] - conveying a flow of a fluid into the first conduit via a second conduit of the feeding system;

[0052] - fluidically connecting the tank to the first conduit via a third conduit of the feeding system;

[0053] feeding the powder coating material to the third conduit via a conveying device arranged within the tank; and - dispensing the powder coating material fed from the feeding system onto the pipe by means of the dispensing unit .

[0054] Thanks to this method, it is possible to apply a coating layer to the pipe, precisely measuring the amount of powder coating material and, at the same time, limiting the power required for applying said coating layer .

[0055] Brief Description of the Figures Additional characteristics and advantages of this invention will become clear from the following description of a non-limiting embodiment thereof, with reference to the accompanying figures, wherein:

[0056] Figure 1 is a cross-section view, with parts schematically depicted and parts removed for clarity, of a machine for internally coating a pipe produced in accordance with this invention;

[0057] - Figure 2 is a cross-section view, with parts removed for clarity, of an application unit of the machine in Figure 1 produced in accordance with a first embodiment of this invention;

[0058] - Figure 3 is a cross-section view, with parts removed for clarity, of the application unit of the machine in Figure 1 produced in accordance with a second embodiment of this invention; and

[0059] - Figure 4 is a cross-section view, with parts removed for clarity, of a feeding system of the application unit in Figure 2 .

[0060] Detailed Description of the Figures

[0061] With reference to Figure 1, the reference number 1 denotes, as a whole, a machine for internally coating a pipe 2 extending along a longitudinal axis Al .

[0062] In particular, the machine 1 is configured to internally coat a joint 3 of the pipe 2 and, by way of example, can be used on board pipe-laying ships or in an underwater or land-based environment .

[0063] The machine 1 comprises a finishing unit 4 for the inner surface of the pipe 2 configured to treat the inner surface of the pipe 2 ; an application unit 5 configured to apply a powder coating material to the pipe 2 ; and a locomotion unit 6 configured to move the finishing unit 4 and the application unit 5 within the pipe 2 along a direction D parallel to the longitudinal axis Al .

[0064] In particular, the finishing unit 4, application unit 5 and locomotion unit 6 are connected together . In the case described and illustrated here, the finishing unit 4 is connected at one end to the application unit 5 and at a second end to the locomotion unit 6, but other connection configurations between the finishing unit 4, application unit 5 and locomotion unit 6 are also possible . In particular, the locomotion unit 6 comprises a cart 7, which is configured to move within the pipe 2 along the direction D; and a motor unit 8, which is configured to provide the necessary propulsion to the locomotion unit 6 to move the entire machine 1 within the pipe 2 along the direction D.

[0065] Although only one locomotion unit 6 is shown in Figure 1, the machine 1 may comprise multiple, interconnected locomotion units 6.

[0066] In particular, the finishing unit 4 comprises at least one tank 9 configured to contain an abrasive material; a rotating wheel 10 configured to centrifugally emit the abrasive material onto the inner surface of the pipe 2 ; an abrasive material recovery device 11 ; and a containment chamber 12, delimited by two walls 13 and configured to contain the rotating wheel 10 and to delimit the portion of the pipe 2 on which the abrasive material is emitted.

[0067] In accordance with this invention, the machine 1 comprises a cart 14, which supports the application unit 5 and is configured to selectively advance within the pipe 2 along the direction D.

[0068] With reference to Figure 2, a first embodiment of the application unit 5 is shown. In the case described and illustrated herein, the application unit 5 comprises a feeding system 15 configured to feed a powder coating material, and a dispensing unit 16, which is connected to the feeding system 15 and comprises a dispenser 17 configured to dispense the powder coating material fed by the supply system 15 onto the pipe 2.

[0069] In accordance with a non-limiting embodiment of this invention, the powder coating material comprises a resin component and a hardener component in dry powder form of the Fusion Bonded Epoxy (EBE) type .

[0070] In particular, the dispenser 17 comprises a rotating body 18, which is configured to centrifugally propel the powder coating material onto the pipe 2. More specifically, the rotating body 18 is configured to rotate around a rotation axis A2 and, in particular, has an essentially conical shape and is provided with an internal cavity 19 connected to the feeding system 15 so as to receive the powder coating material .

[0071] In addition, the dispensing unit 16 comprises an actuating assembly 20 configured to actuate the dispenser 17 and, in particular, to control the rotation of the rotating body 18 about the rotation axis A2 . More specifically, the actuating assembly 20 comprises a motor 21, preferably an electric one; a rotating shaft 22 coupled integrally to the rotating body 18 ; and a transmission 23 configured to transmit a rotary motion from the motor 21 to the rotating shaft 22 .

[0072] With reference to Figure 3, a second embodiment of the application unit 5 is shown. In the case described and illustrated herein, the dispensing unit 16 comprises a dispenser 24 fitted with a rotating nozzle 25.

[0073] Specifically, the rotating nozzle 25 is configured to rotate about a rotation axis A3, is connected to the feeding system 15 so as to receive the powder coating material, and is configured to dispense the powder coating material in a direction essentially perpendicular to the rotation axis A3.

[0074] In addition, the dispensing unit 16 comprises an actuating assembly 26 configured to actuate the dispenser 24 and, in particular, to control the rotation of the rotating nozzle 25 about the rotation axis A3. More specifically, the actuating assembly 26 comprises a motor 27, preferably an electric one; a rotating shaft 28 coupled integrally to the rotating nozzle 25; and a transmission 29 configured to transmit a rotary motion from the motor 27 to the rotating shaft 28 .

[0075] With reference to Figure 4, the feeding system 15 comprises a tank 30 configured to contain the powder coating material; a conduit 31 configured to be connected to the dispensing unit 16 (Figures 1-3) ; a second conduit 32, which is in communication with the first conduit 31 and is configured to direct a flow of a fluid, such air, into the first conduit 31 ; a third conduit 33, which fluidically connects the tank 30 to the first conduit 31 ; and a conveying device 34, which is arranged within the tank 30 and is configured to feed the powder coating material to the third conduit 33.

[0076] In particular, the first conduit 31 comprises a suction portion 35, which is fluidically connected to the third conduit 33 and extends along a longitudinal axis A4 . The second conduit 32 extends along the longitudinal axis A4 within the suction portion 35. In practice, the suction portion 35 of the first conduit 31 and the second conduit 32 extend along the longitudinal axis A4 essentially coaxially.

[0077] More specifically, the suction portion 35 and the second conduit 32 delimit a cylindrical cavity 36 between them.

[0078] In the non-limiting example of this invention described and illustrated herein, the suction portion 35 of the first conduit 31 has a lateral opening 37, which faces the second conduit 32 and connects the third conduit 33 to the first conduit 31. In other words, the lateral opening 37 is formed in the suction portion 35 of the first conduit 31 and directly faces a side wall of the second conduit 32.

[0079] In particular, the tank 30 is configured to contain enough powder coating material to guarantee the required working autonomy.

[0080] In accordance with an embodiment not shown in the accompanying figures, the tank 30 has a first compartment, which has a first volume and is configured to store the powder coating material; and a second compartment, which is separate from the first compartment, has a second volume that is smaller than the first volume, and integrates the conveying device 34 within it .

[0081] In addition, the feeding system 15 comprises an inflow unit 38, which is configured to feed a fluid flow into the second conduit 32. In particular, the inflow unit 38 comprises a fan and / or compressor .

[0082] In particular, the conduit 32 comprises an intake manifold 39 and the inflow unit 38 is arranged within the conduit 38, downstream of the intake manifold 39. In other words, the inflow unit 38 is integrated into the conduit 32.

[0083] In the non-limiting example of this invention that is described and illustrated herein, the conveying device 34 comprises a motorised mechanical conveyor, not shown in the accompanying figures, for feeding the powder coating material to the conduit 33. By way of example, the mechanical conveyor may comprise a worm screw and / or a conveyor belt and / or a piston.

[0084] In accordance with one embodiment, the feeding system 15 comprises an actuator, not shown in the accompanying figures, which is configured to operate the conveying device 34 .

[0085] In use and with reference to Figure 1, the machine 1 is introduced into the pipe 2 and is moved via the locomotion unit 6 so that it runs along the direction D and places the finishing unit 4 in the vicinity of the joint 3. More specifically, the finishing unit 4 is positioned so that the joint 3 is enclosed between the walls 13 of the containment chamber 12 .

[0086] Subsequently, the abrasive material is fed from the tank 9 to the rotating wheel 10, which rotates and centrifugally releases the abrasive material onto the inner surface of the pipe 2 at the joint 3 in order to eliminate irregularities on the inner surface of the pipe 2 caused by the welding process and facilitate the subsequent application of the polymer . The abrasive material is recovered by the recovery device 11 for possible reuse later in a further finishing process .

[0087] At the end of the finishing process, the machine 1 is again moved by the locomotion unit 6 along the direction D in order to place the application unit 5 in the vicinity of the joint 3 and begin the process of applying the powder coating material to the pipe 2, which is heated to a given temperature .

[0088] At this stage, with reference to Figure 4, the conveying device 34 feeds the powder coating material to the conduit 33. At the same time, the inflow unit 38 feeds a flow of a fluid into the second conduit 32, which conveys said fluid flow into the first conduit 31 to the dispensing unit 16. The fluid flowing in the conduit 31 sucks the powder coating material into the conduit 31 by the Venturi effect and conveys the sucked-up coating material to the dispensing unit 16.

[0089] The combined action of the conveying device 34 and the fluid flow into the conduit 31 allows precise measuring of the amount of powder coating material fed to the dispensing unit 16.

[0090] With reference to Figure 2, the actuating assembly 20 controls the rotation around the rotation axis A2 of the rotating body 18, which proj ects the powder coating material fed by the feeding system 15 onto the joint 3 of the pipe 2 by centrifugal force .

[0091] When the powder coating material comes into contact with the pipe 2 at a certain temperature, the powder components of the coating material melt and react with each other through curing, forming a coating layer on the inner surface of the pipe 2.

[0092] Although this description describes a machine 1 for internally coating a pipe 2, it is understood that the application unit 5 and, in particular, the feeding system 15 can also be used for external coating operations of the pipe 2 .

[0093] It is understood that variations may be made to the present invention without however departing from the scope of protection of the appended claims .

Claims

CLAIMS1. A feeding system for feeding a powder coating material to a dispensing unit of said coating material, the feeding system ( 15) comprising:- a tank (30) configured to contain the powder coating material ;- a first conduit (31 ) configured to be connected to said dispensing unit ( 16) ;- a second conduit (32 ) , which is in communication with the first conduit (31 ) and is configured to direct a flow of a fluid into the first conduit (31 ) ;- a third conduit (33) , which fluidically connects the tank (30) to the first conduit (31 ) ; and- a conveying device (34 ) , which is arranged within the tank (30) and is configured to feed powder coating material to the third conduit (33) .

2. The feeding system as claimed in Claim 1, wherein the first conduit (31 ) comprises a suction portion (35) fluidically connected to the third conduit (33) ; the second conduit (32 ) extending within said suction portion (35) .

3. The feeding system as claimed in Claim 2, wherein the suction portion (35) of the first conduit (31 ) and the second conduit (32 ) extend substantially coaxially.

4. The feeding system as claimed in Claim 2 or 3, wherein the suction portion (35) of the first conduit (31 ) has a lateral opening (37 ) , which faces the second conduit (32 ) and connects the third conduit (33) to the first conduit (31 ) .

5. The feeding system as claimed in any one of the foregoing Claims, and comprising an inflow unit (38 ) , which is configured to feed a flow of a fluid in the second conduit6. An application unit for applying a powder coating material to a pipe, the application unit (5) comprising:- the feeding system ( 15) as claimed in any one of the foregoing Claims; and- a dispensing unit ( 16) , which is connected to the first conduit (31 ) of the feeding system (15) and comprises a dispenser ( 17 ; 24 ) configured to dispense onto the pipe (2 ) the powder coating material fed from the feeding system ( 15) .

7. The application unit as claimed in Claim 6, wherein the dispenser (24 ) comprises a rotating nozzle (25) .

8. The application unit as claimed in Claim 6, wherein the dispenser ( 17 ) comprises a rotating body ( 18 ) , preferably of a substantially conical shape, configured to centrifugally proj ect the powder coating material onto the pipe ( 2 ) .

9. The application unit as claimed in any one of Claims 6 to 8, wherein the dispensing unit ( 16) comprises an actuating assembly (20; 26) configured to actuate the dispenser ( 17 ; 24 ) .

10. A machine for internally coating a pipe extending along a longitudinal axis, the machine ( 1 ) comprising:- an application unit (5) as claimed in any one of Claims 6 to 9; and- a cart ( 14) , which carries the application unit (5) and is configured to selectively advance within the pipe (2) in a direction (D) parallel to the longitudinal axis (Al ) of the pipe ( 2 ) .

11. The machine as claimed in Claim 10, and comprising a finishing unit (4 ) of the inner surface of the pipe (2 )configured to treat the inner surface of the pipe ( 2 ) , and a locomotion unit ( 6 ) configured to move the application unit ( 5 ) and the finishing unit ( 4 ) within the pipe ( 2 ) .12 . A method for applying a powder coating material to a pipe , the method comprising the steps of :- containing a powder coating material in a tank ( 30 ) of a feeding system ( 15 ) ;- connecting a first conduit ( 31 ) of the feeding system ( 15 ) to a dispensing unit ( 16 ) ;- fluidically conveying a flow of a fluid into the first conduit ( 31 ) via a second conduit ( 32 ) of the feeding system ( 15 ) ;- fluidically connecting the tank ( 30 ) to the first conduit ( 31 ) via a third conduit ( 33 ) of the feeding system ( 15 ) ;feeding the powder coating material to the third conduit ( 33 ) via a conveying device ( 34 ) arranged within the tank ( 30 ) ; and- dispensing the powder coating material fed from the feeding system ( 15 ) onto the pipe ( 2 ) by means of the dispensing unit ( 16 ) .

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