EP3290855B1 - Device and method for high pressure cleaning of the tubes of a heat exchanger - Google Patents

Description

The invention relates to an apparatus and a method for high-pressure cleaning of pipes of heat exchangers. Heat exchangers are also referred to as tube bundle apparatus or heat exchangers. They have a large number of tubes arranged parallel to one another, which are arranged between an inlet region and in an outlet region. For cleaning, cleaning devices are mounted on one of the areas, a cleaning nozzle, which is located at the free end of a lance, inserted into the pipe to be cleaned. In this case, high-pressure water flows out of the nozzle. The nozzle usually has several, mostly different nozzle openings. Some of them are directed forward, in working direction and others backwards, against the advancing direction of the lance.

Under high pressure is generally understood water with a pressure of at least 800 bar, preferably higher, for example, over 1,000 or even over 1,500 bar.

Out WO 2006/021164 A1 an HD cleaning device for pipes of heat exchangers according to the preamble of claim 1 is known.

In the cleaning device after the DE 2807121 B2 the jet direction of the jets is continuously changed. It results due to the position of the nozzle jets a rotational movement, which leads to a rotation of the nozzle. In order not to turn the lance, a rotary union between nozzle and lance is necessary and provided.

From the JP S63 294497 A is a HD cleaning device for pipes of heat transfer for the simultaneous cleaning of at least three pipes known, the HD cleaning device has a connected to a drive motor reel, are wound on the HD hoses. The drive motor has two operating states. In an operating state, namely when inserting the HD hoses in the tubes, the reel is freely rotatable. In the other operating state, namely when the cleaning is finished, the drive motor pulls the HD Hoses out of the pipes. The HD hoses are wound onto the reel

For high-pressure cleaning, especially in the commercial sector, special and high safety regulations must be observed. Without adequate protection, water jets in the high-pressure area can be life-threatening for an operator. Thus, the federal cooperative rule BGR 500 u.a. wearing special protective clothing for those persons who are in the immediate vicinity of the cleaning process. But even with protective clothing, the use of high pressure equipment is always associated with a high risk, injuries can never be completely ruled out. In addition, the operation of a high-pressure cleaner due to the enormous forces exerted by the released water jets, a heavy physical work, which is a burden for the staff, especially for personnel in protective clothing. The protective clothing hinders physical work. It is therefore increasingly on cleaning devices that require no stay of a person in the immediate vicinity, but can be remotely controlled. Then the operator no longer needs to wear a protective suit, she can be protected in a cabin and work away from the actual cleaning process and carry out all necessary steps.

From the DE 34 18 835 A1 a high-pressure cleaning device for cleaning radioactively contaminated tube bundle is known. Through the pipes, a high-pressure hose is pushed, which carries at its front end a spray nozzle for the cleaning water. As a positioning device, a frame is provided in which two feed wheels, which receive the hose between them, are passable over the plane of the frame, this drive means are provided. The device is intended for automatic operation, since the tube bundles to be cleaned are radioactively contaminated, the stay of a person near the cleaning device is hazardous to health. The transport of the hose by means of the feed wheels is disadvantageous, soiling of the hose can cause the hose is not transported.

From the DE 297 23 349 U1 is an HD cleaning device for tubes of heat exchangers known in which an HD hose connected to a lance is, which has a nozzle at its front end. A positioning device allows the lance to be positioned and guided.

Peinemann, The Netherlands, offers an inside bundle cleaner which has five parallel lances, each connected to HD hoses wound on a reel to which a drive motor is associated. The lances are equipped with a nozzle at their free end. For propulsion, the HD hoses each engages and engages under a revolving chain with guide means that takes each HD hose in the forward or reverse direction. In this way, the lances are moved into the pipes to be cleaned and also pulled out again accordingly. However, it has turned out to be difficult to move the HD hoses back and forth mechanically through the chains in normal operation with all the dirt that occurs. Contamination of the hoses does not provide sufficient transport, for example if a hose is slippery. In addition, the HD hoses are heavily stressed and worn by the chains.

A disadvantage of this device is also that it is a relatively large unit, which is usually built only once and then operated locally. It is not suitable as a mobile device to be transported to different locations.

This is where the invention begins. It has made it its mission to further develop the cleaning device of the type mentioned in that with her faster work is possible and preferably the forward movement of the nozzles can be done controlled.

This object is achieved by an HD cleaning device having the features of claim 1

There is a nozzle directly connected to an HD hose. In the pipes to be cleaned, a part of the HD hose dips into the pipe. In a known manner, the propulsion is achieved by the jet propulsion. In each case, the jets exit the nozzles in each case towards the rear, jet jets directed counter to the working direction, which cause a recoil and, like a rocket, the nozzle drive forward. But this is also the HD hose located at the nozzle constantly pulled into a pipe. He is surrounded by the water of the backward nozzles and thereby wrapped and lubricated. The removed contaminants are moved substantially to the rear and not forward, so that no plug formation can occur at the front. Preferably, a part of the nozzle jets of a nozzle is directed forward to achieve cleaning effect there. The main part of the jets is directed to the rear, so that a total of a forward drive is obtained.

Due to the recoil principle can be dispensed with mechanical means of transport, such as chains. Since no lances are used, the cleaning device builds relatively short and is composed of fewer components than in the prior art. The reel can be arranged in the vicinity of the heat exchanger to be cleaned, without the length of the lances here pretending a distance between the two.

The guide unit has guide tubes for the individual HD hoses. The guide tubes have a lower end, which is dimensioned so that in particular the nozzle can not get into the guide tubes, preferably already a connection piece of the nozzle is so thick that it does not fit into the guide tube. The guide tubes form a safety catch for the HD hoses or their nozzle.

When the nozzle is withdrawn as far as possible, ie at the stop or just before the stop in a guide tube, it is still so far away from the mouths of the tubes and thus the plane, so they over the plane of arbitrary positions can be moved.

The guide tubes are sufficiently far inside to accommodate the HD tube with clearance. Preferably, the HD tube can also slide very well within the guide tubes, the inner surfaces are preferably lubricated. The outer diameter of the HD hoses is matched to the clear inner diameter of the pipes so that an annular cross-sectional area remains free, the surface of which is at least as large as the surface of the clear inner cross-section of the HD hoses. Preferably, the HD hoses are identical. Preferably, identical nozzles are used.

The leadership unit has the task of positioning the flexible HD hoses on the one hand and on the other hand to align. The guide tubes take care of being able to arrange the HD hoses equiaxially and in alignment with the individual tubes. Preferably, the distance of the guide tubes from each other can be varied, so that the guide unit can be adapted to different geometries of mirrors of heat exchangers. For this purpose, it is also advantageous to provide a transverse guide and form the guide unit with a carriage which is displaceable along the transverse guide. In this way different places can be reached in one direction. If in addition also at least one longitudinal guide, preferably two lateral longitudinal guides are provided which have fastening means for their attachment to the heat exchanger, wherein the longitudinal guides are arranged transversely to the transverse guide and each have a guide carriage which carries the transverse guide, can also move in a second Direction, which is transverse to the first, take place. So all tubes of the mirror can be reached.

In the guide unit, the HD hoses are arranged substantially in one row. Preferably, the guide tubes are arranged parallel to each other and in a plane.

The drive motor is rotatably connected via a gear with the reel. Preferably, this transmission is self-locking in Kraftrückflußweg and / or it is additionally provided a brake that prevents rotation of the reel in an unwanted direction of rotation.

The drive motor drives the reel either in one direction or in the other direction. In the first operating state of the engine, this provides sufficient torque to the reel that the HD hoses can be pulled out of the pipes together in operation against the forward drive. In this case, the drive motor drives the reel in the winding direction. The drive motor can also drive the reel in the unwinding direction. Since the forward movement is achieved by the forward drive of the nozzles, the drive motor is not responsible for the retraction of the nozzles in the individual tubes. The retraction into the tubes is rather due to the recoil. The engine specifies the speed at which the nozzles in the pipes progress.

The drive motor is operated in such a way that the HD hoses advance at a predetermined speed in the pipes. The drive motor brakes the unwinding of the reel. He works against the forward drive. If the drive motor did not slow forward, the nozzles would travel through the tubes at a higher speed. Accordingly, the free speed at which a nozzle with an HP hose runs through a pipe is higher than the speed at which the drive motor allows the nozzle to advance in the pipe. Due to the drive motor working against the forward drive, the HD hoses remain under a certain tension. They deviate as little as possible from a stretched arrangement.

If one of the nozzles gets stuck in the pipe, HD hose is still fed by the drive motor, which is in the 2nd operating state. The HD hose in question is no longer under tension, rather it can bulge, for example on the reel. As a result, it is possible to detect a faulty operating state. The pipe in question is then cleaned by other means.

It is advantageous if the HD hoses run as straight as possible from the guide unit to the reel. The HD hoses are tangential to the winding on the reel. If there is a deflection of the HD tubing between the guide unit and the reel, e.g. a 90 ° arc, it is advantageous to stiffen the bow, for example, there to provide a deflection roller. It should be avoided that when bow in the HD hoses bow significantly changes its shape.

In a third operating state, the drive motor is stopped. Even if the nozzles work then, they can not continue to advance in the pipes. So it is stopped the tunneling.

The method is achieved by the method according to claim 7. During the cleaning process and also at the transition from the cleaning of a pipe to another pipe, the respective nozzle is constantly flowed through with water. The high-pressure water is thus normally not switched off during the cleaning of a heat exchanger. This avoids dead times caused by switching on and off.

It is also advantageous that the noise of the beam impinging on the mirror then changes characteristically when a guide tube is positioned above the mouth of a tube. As a result, an operator is given a clear acoustic indication that is correctly positioned and the nozzle can now enter the pipe.

In practical testing, it has been found that the cleaning of pipes can be carried out at high speed. While the device of Peinemann with feed rates of typically 0.5 m / s is used, can be achieved with the invention feed rates of 2 m / s and more.

Fig. 1:

eine Seitenansicht der Reinigungsvorrichtung mit einem Antriebsmotor, einer Haspel und einer Führungseinheit, die sich oberhalb eines Spiegels eines Wärmetauschers mit vertikalen Rohren befindet, Blickrichtung ist die y-Richtung

Fig. 2:

eine Draufsicht auf die Reinigungsvorrichtung gemäß Fig. 1, Blickrichtung ist die z-Richtung,

Fig. 3:

eine Ansicht der Führungseinheit mit Blickrichtung in x-Richtung III in Fig. 2,

Fig. 4:

eine Draufsicht auf die Führungseinheit gemäß Fig. 3, Blickrichtung ist die x-Richtung,

Fig. 5:

eine perspektivische Darstellung der Führungseinheit, die von einer Querführung getragen ist, die ihrerseits von zwei Längsführungen getragen ist und

Fig. 6:

eine perspektivische Darstellung der Haspeleinheit.

Further advantages and features of the invention will become apparent from the remaining claims and the following description of a non-limiting embodiment of the invention, which is explained in more detail below with reference to the drawings. In this drawing show:

Fig. 1:

a side view of the cleaning device with a drive motor, a reel and a guide unit, which is located above a mirror of a heat exchanger with vertical tubes, viewing direction is the y-direction

Fig. 2:

a plan view of the cleaning device according to Fig. 1 , Viewing direction is the z-direction,

3:

a view of the guide unit looking in the x direction III in Fig. 2 .

4:

a plan view of the guide unit according to Fig. 3 , Viewing direction is the x-direction,

Fig. 5:

a perspective view of the guide unit, which is supported by a transverse guide, which in turn is supported by two longitudinal guides and

Fig. 6:

a perspective view of the reel unit.

For the following description, a right-handed x-y-z coordinate system is used.

The invention is particularly suitable for heat exchangers whose tubes extend in the vertical direction. But it is also suitable for heat exchangers with extending in the other direction pipes, such as horizontally extending pipes.

The Figures 1 and 2 show in principle a heat exchanger 20. In FIG. 2 the view goes to a plane 22 or mirror, from which pipes 24 of the heat exchanger 20 go out. They run downwards, in the z-direction. The plane 22 lies in the xy plane. The heat exchanger 20 is associated with an HD cleaning device. It has five parallel HD hoses 26, each carrying a nozzle 28 at one end. Such nozzles 28 are state of the art. How out FIG. 1 can be seen, the nozzle 28 is located just above the level 22. In this state, it can be moved over the individual tubes 24 and positioned as desired.

Above the level 22 is a guide unit 30 of the HD cleaning device. It has a total of five guide tubes 32, which are arranged parallel and in a plane 22, here specifically in the y-z plane. Other arrangements than in a plane 22 are possible, for example along a zigzag line. The guide tubes 32 terminate in a lower end 34. The guide tubes 32 each take a HD tube 26 with clearance and run it. The nozzle 28 and / or a fitting of the nozzle to the HD tube 26 have such large dimensions that they do not fit into a guide tube 32.

The guide unit 30 has an adjusting device 36. It allows to adjust the spacing of the individual guide tubes 32. For this purpose, oblong holes and screws are provided, see FIG. 4 , Specifically, the distance is set in the y-direction. The guide tubes 32 have tube axes which extend in the z-direction. They thus run in the same direction as the tubes 24.

It is a transverse guide 38 is provided, it extends at least over the diameter of the mirror 22. The guide unit 30 has a carriage, they can be moved by means of the carriage along the transverse guide 38 in the y direction. The transverse guide 38 can be positioned as desired, in the exemplary embodiment, it is positioned parallel to the y-direction.

Next, an angular adjustment 40 is provided. It is arranged between the carriage and the actual guide unit 30 and allows the actual guide unit 30 to pivot relative to the carriage about the z-direction as an axis, for example at an angle of ± 15 °. In this way, if the transverse guide 38 is not, as in FIG. 2 aligned exactly parallel to the rows of tubes 24, they are aligned parallel to these rows of tubes.

Furthermore, two longitudinal guides 42 are provided, which are formed for example as rails, as well as the transverse guide 38. The transverse guide 38 has at its ends guide carriage 44, with which it is guided in the two longitudinal guides 42 slidably. The two longitudinal guides 42 extend in the exemplary embodiment parallel to the x-axis. Transverse guide 38 and longitudinal guide 42 are in the xy plane. As FIG. 2 shows, the longitudinal guides 42 are outside the mirror 22. Overall, all the tubes 24 can be achieved via the transverse guide 38 and the longitudinal guide 42, possibly the angle adjustment 40.

When the terms "above" and "below" are used in the description, this refers to the z-direction. Positive z-direction goes down, the negative z-direction goes up. Thus, a first part is below a second part when the first part is in the positive z-direction below the second part.

Above the guide unit 30 are five guide means 46 for the HD hoses 26. These are essentially Teflon hoses in which the HD hoses 26 are guided. They extend all the way to a reel unit, which will be discussed in more detail below. It has a reel 48 on which the five HD hoses 26are wound up. There are also feed openings 49 for high pressure water at the other end of the HD hoses 26 are formed. As a result, high-pressure water supplied to the HP hoses 26 reaches the nozzles 28.

The reel 48 is rotatable about an axis which is parallel to the y-direction. It is rotationally driven by a drive motor 50. This is a control device (not shown) associated with, which allows to switch the drive motor 50 in several operating states. In a first operating state of the drive motor 50 drives the reel 48 in the winding, ie in FIG. 1 in the counterclockwise direction, while the HD tube is transported in the guide means 46 in the positive x-direction and pulled away from the tubes 24. In this first operating state, the drive motor 50 supplies a sufficiently large torque to the reel 48, that the HD hoses 26 can be pulled out of the tubes 24 in total against the forward drive.

In a second operating state, the drive motor 50 operates in the opposite direction, ie in the unwinding direction. The reel 48 then outputs the HD hoses 26 with a controlled, predetermined by the speed of the drive motor 50 speed. It is this speed at which the nozzles 28 advance within the tubes 24. The drive motor 50 has a braking effect on the forward movement of the nozzles 28. Without the braking effect, the nozzles 28 together with their HD hoses 26 would pass through the tubes 24 more quickly. They would not all get ahead at the same speed.

In the second operating state, the HD hoses 26 are not conveyed by the drive motor 50. Their forward movement is done exclusively by the forward drive due to the backward jets. The forward movement of the nozzles 28 is supplied by the driving force to the nozzles 28 from the recoil and not from the drive motor 50. Typical feed rates are 2 m / s plus minus 50%.

It is advantageous to arrange between the drive motor 50 and reel 48 a self-locking in the power return flow gear, for example, a worm gear. This avoids that the reel 48 can rotate faster than the drive motor 50 pretends. It is also advantageous to provide a brake for the reel 48, which is always controlled so that the reel 48 can not lead the drive motor 50.

As a drive motor 50 are hydraulic, air and electric motors into consideration. Air motors are advantageous, especially in conjunction with an air-controlled brake.

The HD pipe heat transfer device is designed for the simultaneous cleaning of at least 3 pipes and comprises a) at least 3 HP hoses, b) a nozzle at each free first end of each HP hose, the nozzle having orifices which jets emit during operation jets, the jets produce predominantly recoil during operation and cause a forward drive of the HD hose, c) a guide unit having a guide tube for each HD hose, each with a guide tube one of the HD hoses each game d) a reel on which the HD tubes coming from the guide unit are wound and feed ports for high pressure water at each second end of each single HD hose, and e) a drive motor, which is rotatably connected to the reel and having a plurality of operating states, wherein in a first operating state, the drive motor supplies sufficient torque to the reel to pull the HD hoses against the forward drive of the tubes.

LIST OF REFERENCE NUMBERS

20

Heat exchanger

22

Level, mirror

24

Tube

26

HP hose

28

jet

30

Guide unit

32

guide tube

34

lower end (from 32)

36

adjusting

38

width guide

40

angle adjustment

42

longitudinal guide

44

guide carriage

46

guide means

48

reel

49

feed ports

50

drive motor

Claims (9)

1. Device for high-pressure cleaning of tubes (24) of heat exchangers for simultaneously cleaning at least three tubes (24), the high-pressure cleaning device having

   - at least three high-pressure hoses (26),

   - a nozzle (28) at each free first end of each high-pressure hose (26), the nozzle (28) having nozzle openings from which, in use, nozzle jets exit, the nozzle jets producing, in use, predominantly recoil and causing forward propulsion of the high pressure hose (26) and, in use, the high-pressure hoses (26) being drawn into the tubes (24) due to the forward propulsion,

   - a guiding unit (30) and

   - a reel (48) on which the high-pressure hoses (26) coming from the guiding unit (30) are wound, wherein feed openings for high-pressure water are provided at each second end of each individual high-pressure hose (26), characterized

   - in that the guiding unit (30) has a guide tube (32) for each high-pressure hose, in each case one guide tube (32) receiving one of the high-pressure hoses (26) in each case with play, the guide tubes (32) being aligned parallel to one another and each guide tube (32) being located on the same axis as a tube, a free space remaining between a lower end of each guide tube (32) and a mouth of the tube,

   - and in that a drive motor (50) is provided which is rotatably connected to the reel (48) and has a plurality of operating states, the drive motor supplying sufficient torque to the reel (48) in a first operating state so that the reel (48) rotates in the winding direction and the high-pressure hoses (26) are pulled out of the tubes (24) during operation against the forward propulsion.
2. High-pressure cleaning device according to claim 1, characterized in that, in a second operating state, the drive motor rotates the reel (48) in the unwinding direction and determines the speed at which the high-pressure hoses (26), which are drawn into the tubes (24) in operation as a result of the forward propulsion, run into the tubes (24) and the high-pressure hoses (26) do not run into the tubes (24) at a higher speed than that determined by the drive motor.
3. High-pressure cleaning device according to one of the preceding claims, characterized in that the guiding unit (30) comprises an adjusting device (36) for adjusting the distance of the individual guide tubes (32) from each other.
4. High-pressure cleaning device according to one of the preceding claims, characterized in that it has a transverse guide (38), and in that the guiding unit (30) has a carriage which can be displaced adjustably along the transverse guide (38).
5. High-pressure cleaning device according to the preceding claim, characterized in that the guiding unit (30) has an angular displacement (40) which is arranged between the carriage and the rest of the guiding unit (30) and enables an angular displacement (40) of the guide tubes (32) relative to the longitudinal direction of the transverse guide (38).
6. High-pressure cleaning device according to one of claims 4 and 5, characterized in that it comprises at least one longitudinal guide (42) having fixing means for its fixing to the heat exchanger (20), extending transversely with respect to the transverse guide (38) and having a guide carriage (44) carrying the transverse guide (38).
7. Method for operating a high-pressure cleaning device having the features according to one of claims 1-6, characterized in that water flows continuously through the high-pressure hoses (26), in that drawn via the drive motor (50) and the reel (48) the nozzles (28) are located below the lower ends of the guide tubes (32) and outside a tube (24), in that the guiding unit (30) is moved until the nozzles (28) are positioned above tubes (24) to be cleaned, in that the drive motor is switched into the second operating state and thereby the nozzles (28) and the high-pressure hoses (26) attached to them immerse into the tubes (24) and clean them.
8. Method according to claim 7, characterized in that, after the cleaning of the tubes (24) into which the high-pressure hoses (26) are immersed has been completed, the drive motor (50) is brought into the first operating state and the high-pressure hoses (26) are pulled out of the tubes (24) against the forward propulsion.
9. Method according to claim 7 or 8, characterized in that, in a third operating state, the drive motor (50) stops any movement of the nozzles (28) within the tubes (24), even when water is supplied.

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