Cleaning or stripping device with very high pressure or ultra high pressure fluid for cleaning the inside of a tube

Abstract

The invention relates to a device (1) for ultra-high-pressure fluid cleaning of the inside of a tube comprising, between an upstream inlet end (11) and a downstream outlet end (12), a flexible sheath (2) through which said fluid flows, a first end (21) of said sheath being connected to fluid generation and supply means, and a second end of said sheath being equipped with a cleaning head. The device includes means for rotating the sheath and means for generating a linear feed speed. These means for rotating the sheath constitute means for storing said sheath in coiled form, and for winding and unwinding it, and consist of a rotating drum (7) coupled to motor means (8).The means for generating a linear feed speed of the sheath consist, downstream of the drum, of a guide conduit (13) for the sheath which, on the side of the drum, is tangent to the largest winding diameter of the sheath. The conduit brings the sheath from its winding in the drum to the axis of rotation of the drum and is integral with a flange (14) closing the drum and being driveable in rotation, by drive means (15), at a rotational speed different from that of the drum (7).

Description

[0001] The present invention relates to the field of ultra-high pressure hydrodynamic cleaning of industrial installations and, more particularly, the internal stripping of condenser tubes, heat exchangers, or similar devices.

[0002] The present invention relates more specifically to a very high pressure stripping device for the inside of tubes.

[0003] In certain industrial installations, such as nuclear power plants for example, scaling of the tubes constitutes a real economic scourge and generates significant losses in the efficiency of these installations.

[0004] In the state of the art, devices are known for cleaning steel, stainless steel, plastic or concrete tubes or pipes, comprising a cleaning head, or auger, generally cylindrical in shape and equipped with a plurality of orifices or nozzles for spraying a high-pressure fluid, in particular water, said cleaning head being positioned at the end of a flexible sheath.

[0005] The cleaning head is propelled inside the pipe to be cleaned by means of fluid pressure, through orifices that generate propulsion jets. More specifically, the pressure causes the cleaning head to rotate through inclined lateral orifices, generating rotational jets, while the flexible hose, connected to a high-pressure pump and supplying the cleaning head with fluid, is also rotated.

[0006] The stripping of the inside of the tubes is carried out by means of, on the one hand, these propulsion jets and rotation of the head, and, possibly, on the other hand, by means of jets arriving through additional orifices, for example located on the front face of the cleaning head.

[0007] The rotation and driving of the flexible hose can therefore be a consequence of the rotation control of the cleaning head, under the effect of hydraulic pressure.

[0008] Il It is also conceivable that this cleaning head could be equipped with a motor to drive the assembly.

[0009] However, when the rotation is due to hydraulic pressure, there is a resulting loss of efficiency in the stripping, because some of the hydraulic power is not used for this stripping, but for the drive.

[0010] When the cleaning head is equipped with motors, this increases its size, resulting in an increase in its cross-section, which makes it difficult to use in small diameter pipes, even though the scaling of the tube already reduces the passage cross-section inside it.

[0011] Il It is therefore necessary to limit the dimensions of the cleaning heads, which inevitably leads to a limitation of the energy available for stripping the tubes.

[0012] In addition, existing systems are generally only suitable for short tube lengths, on the order of 10 to 15 m maximum.

[0013] For stripping longer pipes, there are very high pressure systems that allow for satisfactory removal of deposits.

[0014] That being said, the flexible ducts here must have particularly long lengths, taking into account the linear length of the pipes, an additional distance for passing bends, and an additional length needed to allow rotation.

[0015] The flexible sheaths can then reach about thirty meters in length, and it becomes complicated to control their twisting, as well as their winding / unwinding.

[0016] Thus, it follows from the above that, in existing devices, the flexible sheaths have a rotating end tool, in the form of the cleaning head, but are not, in themselves, driven in rotation over their entire length, nor in longitudinal translation.

[0017] Therefore, in state-of-the-art pipe cleaning devices, it is difficult to obtain precise regulation of the rotation speed of the flexible sheaths, as well as their advancement speed within the tube.

[0018] Il As a result, in some cases, the advance speed of the flexible sheath and the cleaning head within the tube to be cleaned may be irregular, resulting in uneven or partial cleaning over the entire length of the tube, which promotes faster scaling where residues have not been previously removed properly.

[0019] In an attempt to address this problem, we know, from document EP 2 066 462, a process and a device for carrying out stripping operations on a bundle of tubes, under the action of a fluid propelled at high pressure, between 1500 and 3800 bar.

[0020] This device includes means for motorizing the longitudinal advance of the flexible sheath, as well as means for driving its rotation around its longitudinal axis, the sheath being equipped, at one of its ends, with a cleaning head.

[0021] Here, the device includes first means for driving the sheath in rotation around its longitudinal axis, located near the bundle of tubes to be stripped, and second means for driving the sheath in rotation around its longitudinal axis, which are located between said first means and means for generating the high-pressure fluid circulating in the sheath.

[0022] The first means forward consist of a rotating box ensuring the guidance of the sheath, creating and maintaining its rotational movement, and controlling the translational movement and advance of this sheath.

[0023] In this rotating housing, the sheath is secured by means adapted to a rotor for its rotational drive, while a roller system allows, as appropriate, the sheath to be pushed into the tubes to be stripped or extracted from them.

[0024] As for the rear means for rotating the duct, these are specifically positioned at the connection points between the high-pressure fluid supply line and the duct. They include drive means and means for transmitting the rotational motion.

[0025] The device proposed here, although interesting in terms of stripping efficiency, is of complex design, requiring the arrangement of numerous means for the rotation and advancement of the sheath, as well as a synchronization between the first front means and the second rear means of driving the rotation of the flexible sheath.

[0026] Furthermore, and most importantly, the flexible duct must systematically be in a configuration deployed over its entire length, which results in, on the one hand, a certain bulkiness, and, on the other hand, the presence of straight ramps for the circulation of trolleys supporting the second rear means of rotational drive of the duct.

[0027] WO 2007 / 133544 A2, US 2013 / 042894 A1 and US 3077314 A disclose other known very high pressure or ultra high pressure fluid stripping or cleaning devices. WO 2007 / 133544 A2 specifically discloses the preamble to claim 1.

[0028] The present invention aims to remedy, at least in part, the drawbacks of the devices and methods for stripping tubes in the prior art, by proposing a system for winding and unwinding a rotating flexible sheath, the latter supporting, at its end, a tube cleaning head, for working pressures greater than 1400 bar (ultra high pressures), while allowing precise and controlled advance and rotation speeds of said flexible sheath.

[0029] For this purpose, the invention relates to a very high pressure or ultra high pressure fluid stripping or cleaning device, for cleaning the inside of a tube as defined in claim 1.

[0030] According to particular embodiments of the device of the invention: The said first and second drive means are each equipped with means for managing the rotational speed, respectively, of the drum and the guide duct, so that the rotational speed of the latter can be decreased or increased relative to the rotational speed of said drum so that said flexible duct is able, as the case may be, respectively, to enter or exit the tube to be cleaned; said drum has an internal diameter between 500 and 1000 mm suitable for winding a flexible duct with a linear length of at least 30 m; said guide duct consists of a curved rod having a helical portion with a decreasing radius, to facilitate the movement of the flexible duct inside said guide duct and its passage from its wound form in the rotating drum to its unwound form and in the axis of rotation downstream of said drum;The connection between the second drive means and said flange is in the form of a structure comprising a plurality of spacers for a rotational drive of said guide conduit attached to the flange.

[0031] Other objects and advantages of the present invention will become apparent during the following description relating to embodiments which are given only as indicative and non-limiting examples.

[0032] Understanding this description will be facilitated by referring to the attached drawings, in which: [ Fig.1 [ ] represents a schematic and perspective view of an embodiment of an ultra-high pressure stripping device according to the invention. Fig.2 ] represents a schematic and perspective view similar to the figure 1 , from another angle, of a device conforming to the invention.

[0033] With reference to the figures in the attached drawings, then, a device 1 for stripping or cleaning with very high pressure or ultra high pressure fluid.

[0034] Device 1 according to the present invention and which will be described in detail below will find a particularly interesting application in the field of hydrodynamics, and more specifically in the field of maintenance of the inside of tubes, conduits, or pipes of industrial installations, which are equipped in particular with condensers, exchangers, water boxes or the like.

[0035] Thus, by means of the present device 1, it is conceivable, for example, to eliminate scale, or other impurities or residues, inside such tubes, which may form and accumulate, sometimes in very large quantities, in tubes or the like through which water passes, and resulting, among other things, in a reduction of the useful cross-section of these tubes.

[0036] Such a high-pressure stripping device 1 according to the invention comprises, between an upstream end 11 constituting the inlet of said device 1, and a downstream end 12 constituting the outlet thereof, a flexible sheath 2, within which a very high pressure or ultra high pressure fluid, consisting in particular of pure water, is capable of circulating.

[0037] A first end 21 of this flexible sheath 2 is, for this purpose, connected, through suitable connecting means, to very high pressure fluid generation means, such fluid generation means being external to said device 1 and not, consequently, being represented in the figures.

[0038] Advantageously, these means of generating and supplying fluid consist of a compressor capable of delivering a fluid at very high pressure, or even ultra-high pressure, in particular above 1400 bar, or even above 2000 bar, and of suitable connection means between these means of generating and the present stripping device 1 of the invention.

[0039] Preferably, these means of connection between the means of generating high pressure fluid and said flexible sheath 2 consist of, on the one hand, a conduit for conveying this fluid external to the device 1, not shown in the figures, from said generating means to the inlet 11 of the stripping device 1, and, on the other hand, internal connection means 3 to the device 1 allowing the conveyance of the high pressure fluid from the inlet 11 of the device 1 to the upstream end 21 of said flexible sheath 2.

[0040] More specifically, these internal connection means 3 to the device 1 comprise at least one first cylindrical conduit 4, the upstream end 41 of which is particularly visible on the figure 2 downstream of which is a rotating joint 31, and a second rigid supply line 5 connecting said first cylindrical line 4 and the first end 21 of the flexible sheath 2 by means, for example, of a connecting plate 6 having suitable fastening means to ensure the tightness of the passage of the fluid between the second rigid supply line 3 and the first end 21 of said flexible sheath 2.

[0041] At its second end, opposite the first 21, and not visible in the attached figures, said flexible sheath 2 is preferably equipped with a cleaning head which is intended to be traversed by the very high pressure fluid circulating in said sheath 2 for a spraying of this fluid against the scaled internal walls of the tube to be cleaned.

[0042] For this purpose, the cleaning head at the free end of the sheath 2 may include an internal channel allowing the fluid to be brought at very high pressure from the flexible sheath 2 to a plurality of orifices or spray nozzles provided around the entire perimeter of said cleaning head, for a lateral projection of jets of pressurized fluid, but also forwards and backwards from the head, when it progresses inside the tube to be cleaned.

[0043] In order to enable such progression of the cleaning head in the tubes to be descaled, the stripping device 1 of the invention comprises, on the one hand, means for rotating said flexible sheath 2, and, on the other hand, means for generating a linear advance speed of this sheath 2.

[0044] In particular, and according to the present invention, said means for rotating the flexible sheath 2 also constitute means for storing it in a coiled form, as well as means for passing said flexible sheath 2 from a coiled form to an uncoiled form, and vice versa.

[0045] Thus, and as can be seen in the figures of the attached drawings, such means of rotational drive and storage of said flexible sheath 2 consist of a rotating drum 7 coupled to first motor means 8.

[0046] More particularly, and as illustrated in the figures, said motor means 8 drive a chain 9, belt or similar, which in turn drives in rotation a first hollow shaft 10 connected to said drum 7 at the level of its axis for the rotational drive of the latter.

[0047] As regards the rotating drum 7, it more preferably comprises two circular flat plates, namely a first upstream plate 71 located on the side of the inlet 11 of said device 1, and a second downstream plate 72 located on the side of the outlet 12 of said device.

[0048] The two circular flat plates 71, 72 are connected to each other by a plurality of rollers 73 so as to form a cylinder of internal diameter d between 500 and 1000 mm, preferably equal to 600 mm, in order to allow the reception, in coiled form, of a flexible sheath 2 having a length of at least 30 linear meters.

[0049] Furthermore, preferably, an oblong opening 74 is provided at the level of the first upstream circular flat plate 71 so as to allow the passage of said flexible sheath 2 from the outside of the drum 7, towards the inside of it.

[0050] As regards the said means of generating a linear advance speed of the flexible sheath 2 within the tube to be cleaned, these consist, downstream of the rotating drum 7, of a guide conduit 13 in which the flexible sheath 2 can pass.

[0051] According to the invention, on the side of the downstream circular flat plate 72 of said rotating drum 7, said guide conduit 13 is tangent to the largest winding diameter of the flexible sheath 7, and this guide conduit 13 is shaped so as to bring the flexible sheath 2 from its winding inside the drum 7 to the axis of rotation of said drum 7 and outside of it.

[0052] For this purpose, said guide conduit 13 is in the form of a curved rod having a helical portion with decreasing radius, to facilitate the path of the flexible sheath 2 inside said guide conduit 13 and its passage from its wound form in the cylinder of the rotating drum 7 to its unwound form and in the axis of rotation and downstream of said drum 7.

[0053] It should also be noted that this guide conduit 13 is made integral with a flange 14 closing the drum 7, said flange 14 being driveable in rotation, by second drive means 15.

[0054] Note here that, since the flange 14 is capable of closing the drum 13 at its downstream side, the downstream circular flat plate 72 may be optional.

[0055] Here again, the motor means 15 drive a second chain 16, belt or similar, which in turn drives in rotation a second hollow shaft 17 connected to said flange 14.

[0056] The connection between the means of rotational drive and said flange 14 is presented here, most preferably, and in accordance with what is illustrated in the attached figures, in the form of a structure 18 comprising a plurality of spacers 181, 182, 183, in particular three in number, for a rotational drive of said guide conduit 13 attached to the flange 14, this independently of the rotational drive of the rotating drum 7.

[0057] Thus, according to a particular feature of the tube stripping device 1 of the invention, said guide conduit 13 can be driven at a different rotational speed than the rotational speed at which the rotating drum 7 is driven.

[0058] More specifically, in the stripping device 1 according to the present invention, each of the first motor means 8 and the second motor means are equipped with means for managing the rotation speed, respectively, of the drum 7 and the guide conduit 13, or guide rod 13, so that the rotation speed of the latter can be decreased or increased relative to the rotation speed of said drum 7.

[0059] By this means, when the rotation speed of the guide rod 13 is less than the rotation speed of the rotating drum 7, the flexible sleeve 2, engaged in the guide rod 13 and whose end presenting the cleaning head is at the outlet 12 of device 1 can enter, under the effect of the difference in rotation speeds between the drum 7 and the rod 13, giving it a linear advance speed, into the tube to be cleaned and advance within it.

[0060] On the contrary, when the rotational speed of the guide rod 13 is greater than the rotational speed of the rotating drum 7, the flexible sheath 2 can be extracted from the stripping tube.

[0061] Thus, the first and second motor means 8, 15, are advantageously equipped with encoders as means of managing their respective rotation speeds, allowing control of the advance speed of the flexible sheath 2 within the tube that needs to be stripped.

[0062] As regards the operation of the tube stripping device 1 according to the present invention, this is explained in more detail below, as well as the path of the very high pressure or ultra high pressure fluid within said device 1.

[0063] The fluid arrives, from the fluid generation means, at very high pressure or ultra high pressure, external to the device 1, at the level of the inlet of the first cylindrical pipe 4, which is located in the axis of rotation of the drum 7 of the stripping device 1 of the invention, said pipe 4 passing in the first hollow shaft 10, always in the axis of rotation of said drum 7.

[0064] Upon arriving in the immediate vicinity of the upstream circular flat plate 71 of said drum, and upstream of it, the very high pressure or ultra high pressure fluid passes from said first cylindrical pipe 4 into the second rigid supply pipe 5, these two pipes 4, 5 being connected through suitable and sealed connection means.

[0065] The fluid is then conveyed, by means of the second rigid supply line 5, which is curved, from the center of the upstream circular flat plate 71 of the drum 7, corresponding to the axis of rotation of the latter, to the junction between said rigid supply line 5 and the first end 21 of the flexible sheath 2 located preferably at the level of the external diameter of the upstream circular flat plate 71.

[0066] The high-pressure fluid then circulates within this sheath 2, from its first end 21 to the opposite end of said sheath 2, from where it can be sprayed by nozzles or orifices provided at the level of the cleaning head advancing within the tube or conduit to be stripped.

[0067] Indeed, in parallel, the drum 7 is driven in rotation by the motor 8 equipped with an encoder in order to precisely manage the speed of rotation and the number of revolutions made, which allows the rotation of the wound flexible sheath 2, a portion of which is wound within said drum 7.

[0068] The front guide rod 13 is also set in rotation by the second motor means 15, which are initially coupled to the first motor means 8 for driving the drum 7 for a desired rotation speed of the flexible sheath 2.

[0069] The rotation speed of said guide rod 13 is then reduced relative to the rotation speed of the drum 7, thanks to the control means (encoder) with which the second motor means 15 are equipped, in order to generate a linear advance speed at the exit of the flexible sheath 2 allowing the entry and movement of the cleaning head inside the tube to be stripped.

[0070] Once the tube cleaning operation is complete, an acceleration of the rotation speed of the guide rod 13, relative to the rotation speed of the drum 7, allows the reverse path and an exit of the flexible sheath 2 and its cleaning head from the tube once it has been cleaned.

[0071] The stripping device 1 according to the present invention offers a particularly interesting solution allowing work at pressures, with regard to the cleaning fluid circulating in the flexible sheath 2, known as "UHP" (ultra high pressure), for example pressures of the order of 2000 bar, or even beyond.

[0072] Furthermore, through the drive system of the drum 7 and the guide rod 13, which is carried out by means of motors 8, 15, respectively, and equipped with encoders, it becomes possible to regulate exactly the rotation speeds of said drum 7 and said rod 13, independently of each other.

[0073] These precise speeds ultimately allow for fine adjustment of the descaling or stripping parameters of the tubes.

[0074] Furthermore, the characteristics of the stripping device 1 of the invention, in particular the means of managing the motors 8, 15, make it possible to know the advance and rotation speeds of the flexible sheath 2, and therefore to make a precise measurement of the length of the flexible sheath 2 which has been unrolled and, consequently of the distance which is traveled, within the tube to be stripped, by the cleaning head with which said sheath 2 is equipped at its downstream end.

[0075] In other words, the whole system is "intelligent", and working with electric motors allows for precise synchronization between the guide rod 13 and the rotating drum 7, which has many advantages.

[0076] Indeed, here we have the possibility of performing only a rotation of the flexible sheath 2, without advancing the latter, or even of performing rapid controlled stops for safety, whether for the operator or for the machine.

Claims

1. A device (1) for stripping or cleaning with very high pressure or ultra high pressure fluid, for cleaning the inside of a tube including, between an upstream inlet end (11), and a downstream outlet end (12), a flexible sheath (2) wherein said fluid flows, a first end (21) of said flexible sheath (2) being connected, near said upstream end (11) to fluid generation and supply means, whereas a second end of said sheath (2) is provided with a cleaning head, said device (1) further including rotating means and means for generating a linear advance speed of said flexible sheath (2), device wherein said means for rotating the flexible sheath (2) also form means for storing said sheath (2) in a rolled shape, as well as means for rolling and unrolling same, and consist of a rotary drum (7) which is coupled to first motor means (8), whereas said means for generating a linear advance speed of said sheath (2) consist, downstream of the drum (7), of a guide duct (13) wherein the flexible sheath (2) passes and which, on the side of said drum (7), is tangent to the largest rolling diameter of said sheath (2), said guide duct (13) conveying said sheath (2) from its rolling in the drum (7) into the axis of rotation of said drum (7), the device being characterised in that said guide duct (13) is integral with a flange (14) closing the drum (7) and rotatable, by second motor means (15) forming part of the device, at a different rotational speed from that of the drum (7).

2. The device (1) for stripping or cleaning the inside of a tube according to claim 1, characterised in that said first and second motor means (8, 15) are each equipped with means for managing the rotational speed, respectively, of the drum (7) and the guide duct (13), such that the rotational speed of the latter can be decreased or increased relative to the rotational speed of said drum (7) so that said flexible sheath (2) is capable, according to the circumstances, respectively, of entering or coming out of the tube to be stripped.

3. The device (1) for stripping or cleaning the inside of a tube according to claim 1 or claim 2 characterised in that said drum (7) has an internal diameter between 500 and 1000 mm capable of allowing the rolling of a flexible sheath (2) having a linear length of at least 30 m.

4. The device (1) for stripping or cleaning the inside of a tube according to any one of the preceding claims, characterised in that said guide duct (13) consists of a curved pipe having a helical portion with a decreasing radius, to promote the routing of the flexible sheath (2) inside said guide duct (13) and its transition from its rolled shape in the rotary drum (7) to its unrolled shape and into the axis of rotation downstream of said drum (7).

5. The device (1) for stripping or cleaning the inside of a tube according to any one of the preceding claims, characterised in that the connection between the second motor means (15) and said flange (14) is in the form of a structure (18) comprising a plurality of spacers (181, 182, 183) for rotating said guide duct (13) secured to the flange (14).

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