Device for stripping or cleaning with very high pressure or ultra high pressure fluid, for cleaning the interior of a tube

Abstract

Device for stripping or cleaning with very high pressure or ultra high pressure fluid, for cleaning the interior of a tube The invention relates to a device (1) for stripping with very high pressure fluid the interior of a tube comprising, between an upstream inlet end (11), and a downstream outlet end (12), a flexible sheath (2) in which said fluid circulates, a first end (21) of said sheath being connected to means for generating and supplying fluid, a second end of said sheath being provided with a cleaning head. Said device comprises rotational drive means and means for generating a linear advance speed of said sheath. Said rotational drive means of the sheath constitute means for storing said sheath in rolled-up form, and means for winding and unwinding it, and consist of a rotary drum (7) coupled to motor means (8).Said means for generating a linear advance speed of said sheath consist, downstream of the drum, of a guide conduit (13) for the sheath and which, on the side of said drum, is tangent to the largest winding diameter of said sheath. Said conduit brings said sheath from its winding in the drum to the axis of rotation of said drum and is integral with a flange (14) closing the drum and being able to rotate, by motor means (15), at a rotation speed different from that of the drum (7). Figure for the abstract: Fig. 1.

Description

Title of the invention: Device for stripping or cleaning with very high pressure or ultra high pressure fluid, for cleaning the interior of a tube

[0001] The present invention relates to the field of very 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 device for very high pressure stripping of the interior of tubes.

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

[0004] In the state of the art, devices are known for cleaning tubes or pipes made of steel, stainless steel, plastic or concrete, comprising a cleaning head, or ferret, of generally cylindrical shape and provided 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 stripped by means of the pressure of the fluid, thanks to the orifices generating propellant jets. More particularly, the pressure drives the cleaning head into rotation through inclined lateral orifices, generating rotation jets, while the flexible sheath, connected to a high-pressure pump, and which supplies the cleaning head with fluid, is also rotated.

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

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

[0008] It is also conceivable that this cleaning head is provided with a motor for driving the assembly.

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

[0010] When the cleaning head is provided with motor means, this increases its bulk, resulting in particular in an increase in its section, which makes it difficult to use in small diameter pipes, even though the scaling of the tube already reduces the passage section inside it.

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

[0012] Furthermore, existing systems are generally only suitable for short tube lengths, of the order of 10 to 15 m at most.

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

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

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

[0016] Thus, it is clear from the above that, in existing devices, the flexible sheaths comprise 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] Consequently, in prior art pipe interior stripping devices, it is difficult to achieve precise regulation of the rotation speed of the flexible sheaths, as well as their advance speed within the tube.

[0018] As a result, in certain cases, the speed of advance of the flexible sheath and the cleaning head within the tube to be cleaned may prove to be irregular, causing non-uniform or partial stripping over the entire length of the tube, which promotes faster adhesion of the scale where residues have not previously been correctly removed.

[0019] In order to attempt to address this problem, document EP 2 066 462 discloses a method 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 comprises means for motorizing the longitudinal advance of the flexible sheath, as well as means for driving it in rotation, around its longitudinal axis, said sheath being provided, at one of its ends, with a cleaning head.

[0021] Here, the device comprises first front means for driving the sheath in rotation around its longitudinal axis, located near the bundle of tubes to stripping, as well as second rear means for driving the sheath in rotation around its longitudinal axis, which are located between said first driving means and means for generating the high pressure fluid circulating in the sheath.

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

[0023] In this rotating housing, the sheath is secured by means adapted to a rotor for driving it in rotation while a system of rollers allows, depending on the case, to push the sheath into the tubes to be stripped or to extract it from them.

[0024] As for the rear means for driving the sheath in rotation, these are more specifically positioned at the level of the connection means between the high-pressure fluid supply pipe and the sheath. They comprise motor means and means for transmitting the rotational movement.

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

[0026] Furthermore, and above all, the flexible sheath must systematically be in a deployed configuration over its entire length, which results, on the one hand, in a certain amount of space, and, on the other hand, in the presence of rectilinear ramps for the circulation of carriages supporting the second rear means for rotating the sheath.

[0027] The present invention is intended to be able to remedy, at least in part, the drawbacks of the devices and methods for stripping tubes of the state of the 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 making it possible to obtain precise and controlled advance and rotation speeds of said flexible sheath.

[0028] To this end, the invention relates to a device for stripping or cleaning using very high pressure or ultra high pressure fluid, for cleaning the inside of a tube comprising, between an upstream inlet end and a downstream outlet end, a flexible sheath in which said fluid circulates, a first end of said flexible sheath being connected, near said upstream end, to means for generating and supplying fluid, while a second end of said sheath is provided with a cleaning head, said device further comprising means for driving in rotation and means for generating a linear advance speed of said flexible sheath, said device being characterized in that said means for driving in rotation of the flexible sheath also constitute means for storing said sheath in a wound form, as well as means for winding and unwinding it, and consist of a rotating drum which is coupled to first motor means, while said means for generating a linear advance speed of said sheath consist, downstream of the drum, of a guide duct in which the flexible sheath passes and which, on the side of said drum, is tangent to the largest winding diameter of said sheath, said guide duct bringing said sheath from its winding in the drum to the axis of rotation of said drum, said guide duct being integral with a flange closing the drum and being rotatable, by second motor means,at a different rotation speed than the drum.

[0029] According to particular embodiments of the device of the invention:

[0030] - said first and second motor means are each equipped with means of management of the rotation speed, respectively, of the drum and of the guide duct, so that the rotation speed of the latter can be reduced or increased relative to the rotation speed of said drum so that said flexible sheath is capable, as the case may be, respectively, of entering the tube to be stripped or of exiting it;

[0031] - said drum has an internal diameter of between 500 and 1000 mm suitable for allow the winding of a flexible sheath with a linear length of at least 30 m;

[0032] - said guide duct consists of a curved rod having a helical portion with decreasing radius, to facilitate the routing of the flexible sheath 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;

[0033] - the connection between the second motor means and said flange is presented in the form of form of a structure comprising a plurality of spacers for rotating said guide duct secured to the flange.

[0034] Other aims and advantages of the present invention will appear during the description which follows relating to embodiments which are given only as indicative and non-limiting examples.

[0035] Understanding of this description will be facilitated by referring to the attached drawings in which:

[0036] [Fig-1] represents a schematic and perspective view of an embodiment of an ultra-high pressure stripping device according to the invention.

[0037] [Fig.2] represents a schematic and perspective view similar to [Fig.l], from another angle, of a device according to the invention.

[0038] With reference to the figures of the attached drawings, then, a device 1 for stripping or cleaning with very high pressure or ultra high pressure fluid.

[0039] The device 1 in accordance with 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 interior of tubes, conduits, or pipes of industrial installations, with which condensers, exchangers, water boxes or the like are equipped in particular.

[0040] Thus, by means of the present device 1, it is possible, for example, to eliminate scale, or other impurities or residues, inside such tubes, which are likely to form and accumulate, sometimes in very large quantities, in the tubes or the like through which water passes, and resulting, among other things, in a reduction of the useful section of these tubes.

[0041] 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.

[0042] A first end 21 of this flexible sheath 2 is, for this purpose, connected, through suitable connection means, to means for generating very high pressure fluid, such fluid generation means being external to said device 1 and therefore not being shown in the figures.

[0043] Advantageously, these fluid generation and supply means consist of a compressor capable of delivering a fluid at very high pressure, or even at ultra high pressure, in particular greater than 1400 bar, or even greater than 2000 bar, and of suitable connection means between these generation means and the present stripping device 1 of the invention.

[0044] Most preferably, these connection means between the high-pressure fluid generation means and said flexible sheath 2 are constituted by, on the one hand, a conduit for conveying this fluid external to the device 1, not shown in the figures, from said generation means to the inlet 11 of the stripping device 1, and, on the other hand, by internal connection means 3 to the device 1 allowing the high-pressure fluid to be conveyed from the inlet 11 of the device 1 to the upstream end 21 of said flexible sheath 2.

[0045] More specifically, these internal connection means 3 to the device 1 comprise at least a first cylindrical conduit 4 whose upstream end 41 is particularly visible in [Fig. 2], downstream of which there is a rotating joint 31, and a second rigid supply conduit 5 connecting said first cylindrical conduit 4 and the first end 21 of the flexible sheath 2 to the means, for example, of a connecting plate 6 comprising suitable securing means in order to guarantee the sealing of the passage of the fluid between the second rigid supply pipe 3 and the first end 21 of said flexible sheath 2.

[0046] At its second end, opposite the first 21, and not visible in the attached figures, said flexible sheath 2 is preferably provided with a cleaning head which is intended to be crossed by the very high pressure fluid circulating in said sheath 2 for spraying this fluid against the scaled internal walls of the tube to be stripped.

[0047] For this purpose, the cleaning head at the free end of the sheath 2 may comprise an internal channel making it possible to bring the fluid at very high pressure from the flexible sheath 2 to a plurality of orifices or spray nozzles arranged around the entire periphery of said cleaning head, for lateral projection of jets of fluid under pressure, but also towards the front, and towards the rear of the head, when the latter progresses inside the tube to be stripped.

[0048] In order to allow 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 driving said flexible sheath 2 in rotation, as well as, on the other hand, means for generating a linear advance speed of this sheath 2.

[0049] In particular, and according to the present invention, said means for driving the flexible sheath 2 in rotation also constitute means for storing the latter in a wound form, as well as means for passing said flexible sheath 2 from a wound form to an unwound form, and vice versa.

[0050] Thus, and as visible in the figures of the attached drawings, such means for driving in rotation as well as for storing said flexible sheath 2 consist of a rotating drum 7 coupled to first motor means 8.

[0051] More particularly, and as illustrated in the figures, said motor means 8 drive a chain 9, belt or similar, itself driving in rotation a first hollow shaft 10 connected to said drum 7 at its axis for driving it in rotation.

[0052] As regards now the rotary drum 7, the latter comprises, more preferably, 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 thereof.

[0053] Said two circular flat plates 71, 72 are connected to each other by a plurality of rollers 73 so as to form a cylinder with an internal diameter d of between 500 and 1000 mm, most preferably equal to 600 mm, in order to allow the reception, in rolled form, of a flexible sheath 2 having a length of at least 30 linear meters.

[0054] Furthermore, most preferably, an oblong slot 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 thereof.

[0055] As regards now said means for 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.

[0056] More particularly, on the side of the downstream circular flat plate 72 of said rotating drum 7, said guide duct 13 is tangent to the largest winding diameter of the flexible sheath 7, and this guide duct 13 is shaped so as to bring the flexible sheath 2 from its winding inside the drum 7 into the axis of rotation of said drum 7 and outside of it.

[0057] For this purpose, said guide duct 13 is in the form of a curved rod having a helical portion with decreasing radius, to facilitate the routing of the flexible sheath 2 inside said guide duct 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.

[0058] 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 able to rotate by second motor means 15.

[0059] Let us then note here that, the flange 14 being capable of closing the drum 13 at its downstream side, the downstream circular flat plate 72 can be optional.

[0060] Here again, the motor means 15 drive a second chain 16, belt or similar, itself driving in rotation a second hollow shaft 17 connected to said flange 14.

[0061] The connection between the rotational drive means 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 rotational drive of said guide duct 13 secured to the flange 14, independently of the rotational drive of the rotary drum 7.

[0062] Thus, according to a particular characteristic of the tube stripping device 1 of the invention, said guide conduit 13 can be driven at a rotation speed different from the rotation speed at which the rotating drum 7 is driven.

[0063] 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 duct 13, or guide rod 13, so that the rotation speed of the latter can be reduced or increased relative to the rotation speed of said drum 7.

[0064] By this means, when the rotation speed of the guide rod 13 is lower than the rotation speed of the rotating drum 7, the flexible sheath 2, engaged in the guide rod 13 and the end of which having the cleaning head is located at the outlet 12 of the 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 stripped and advance within it.

[0065] On the contrary, when the rotation speed of the guide rod 13 is greater than the rotation speed of the rotating drum 7, the flexible sheath 2 can be extracted from the tube to be stripped.

[0066] Thus, the first and second motor means 8, 15 are advantageously equipped with encoders as means for managing their respective rotation speeds, allowing control of the speed of advancement of the flexible sheath 2 within the tube which is to be stripped.

[0067] As regards the operation of the tube stripping device 1 according to the present invention, this is explained in more detail below, as is the path of the very high pressure or ultra high pressure fluid within said device 1.

[0068] 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 conduit 4, which is located in the axis of rotation of the drum 7 of the stripping device 1 of the invention, said conduit 4 passing into the first hollow shaft 10, still in the axis of rotation of said drum 7.

[0069] Arriving in the immediate vicinity of the upstream circular flat plate 71 of said drum, and upstream of the latter, 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.

[0070] The fluid is then conveyed, by means of the second rigid supply pipe 5, the latter being of curved shape, from the center of the upstream circular flat plate 71 of the drum 7, corresponding to the axis of rotation thereof, towards the junction between said rigid supply pipe 5 and the first end 21 of the flexible sheath 2 preferably located at the external diameter of the upstream circular flat plate 71.

[0071] The high-pressure fluid then circulates within this sheath 2, from its first end 21 towards 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.

[0072] 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.

[0073] The front guide rod 13 is also rotated 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.

[0074] The rotation speed of said guide rod 13 is then reduced relative to the rotation speed of the drum 7, thanks to the management means (encoder) with which the second motor means 15 are equipped, in order to generate a linear advance speed at the outlet of the flexible sheath 2 allowing the entry and movement of the cleaning head inside the tube to be stripped.

[0075] 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 the latter has been stripped.

[0076] The stripping device 1 according to the present invention proposes a particularly interesting solution making it possible to work at pressures, as regards the cleaning fluid circulating in the flexible sheath 2, called “UHP” (ultra high pressure), for example pressures of the order of 2000 bar, or even beyond.

[0077] Furthermore, through the system for driving the drum 7 and the guide rod 13, which is carried out by means of motors 8, 15, respectively, and provided with encoders, it becomes possible to exactly regulate the rotation speeds of said drum 7 and said rod 13, independently of one another.

[0078] These precise speeds ultimately allow fine adjustment of the parameters for descaling or stripping the tubes.

[0079] Furthermore, the characteristics of the stripping device 1 of the invention, in particular the means for managing the motors 8, 15, make it possible to know the speeds of advance and rotation of the flexible sheath 2, and therefore to make a precise measurement of the length of the flexible sheath 2 which has been unwound 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.

[0080] In other words, the whole system is "intelligent", and working with electric motors allows for a precise synchronization between the guide rod 13 and the rotating drum 7, which has many advantages.

[0081] In fact, here we have the possibility of only performing a rotation of the sheath flexible 2, without advancing the latter, or even to carry out rapid controlled stops for safety, whether for the operator or for the machine.

Claims

Claims

1. Device (1) for stripping or cleaning with very high pressure or ultra high pressure fluid, for cleaning the interior of a tube comprising, between an upstream inlet end (11), and a downstream outlet end (12), a flexible sheath (2) in which said fluid circulates, a first end (21) of said flexible sheath (2) being connected, near said upstream end (11) to means for generating and supplying fluid, while a second end of said sheath (2) is provided with a cleaning head, said device (1) further comprising means for driving in rotation and means for generating a linear advance speed of said flexible sheath (2), said device (1) being characterized in that said means for driving in rotation of the flexible sheath (2) also constitute means for storing said sheath (2) in a wound form,as well as means for winding and unwinding the latter, and consist of a rotating drum (7) which is coupled to first motor means (8), while said means for generating a linear advance speed of said sheath (2) consist, downstream of the drum (7), of a guide duct (13) in which the flexible sheath (2) passes and which, on the side of said drum (7), is tangent to the largest winding diameter of said sheath (2), said guide duct (13) bringing said sheath (2) from its winding in the drum (7) to the axis of rotation of said drum (7), said guide duct (13) being integral with a flange (14) closing the drum (7) and being drivable in rotation, by second motor means (15), at a rotation speed different from that of the drum (7).

2. Device (1) for stripping or cleaning the inside of a tube according to claim 1 characterized in that said first and second motor means (8, 15) are each equipped with means for managing the rotation speed, respectively, of the drum (7) and of the guide conduit (13), so that the rotation speed of the latter can be reduced or increased relative to the rotation speed of said drum (7) so that said flexible sheath (2) is capable, as the case may be, respectively, of entering the tube to be stripped or of exiting it.

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

4. Device (1) for stripping or cleaning the inside of a tube according to any one of the preceding claims, characterized in that said guide duct (13) consists of a curved rod having a helical portion with decreasing radius, to promote the path of the flexible sheath (2) inside said guide duct (13) and its passage from its wound form in the rotating drum (7) to its unwound form and in the axis of rotation downstream of said drum (7).

5. Device (1) for stripping or cleaning the interior of a tube according to any one of the preceding claims, characterized 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 driving in rotation said guide conduit (13) secured to the flange (14).

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