Method and device for cleaning tube bundles

Abstract

A method for cleaning tube bundles with open end faces, in particular tube bundles of heat exchangers, air coolers, or condensers. A cleaning device which has at least one cleaning unit is positioned adjacently to the open ends of the tube bundle, and the at least one cleaning unit which has a high-pressure hose is then arranged in a successive manner by a controller so as to be flush with the respective tube of the tube bundle. The cleaning unit is inserted into the respective tube and supplied with a liquid under high-pressure. The aim of the invention is to improve such a method and device such that a reliable cleaning process is carried out without operating errors. This is achieved in that the insert depth is measured when inserting the at least one cleaning unit into the respective tube and monitored by the controller.

Claims

1. A device for cleaning of tube bundles with open end faces, especially tube bundles of heat exchangers, air coolers or condensers, comprising: a displacement unit, which comprises at least a first frame element and at least a second frame element, the first frame element and the second frame element being disposed perpendicular to each other, with at least one cleaning unit, which is disposed on the displacement unit, and comprises at least one high-pressure hose and at least one drive unit, where the high-pressure hose can be shoved into the tubes by the drive unit, and with a control unit, which is connected to the displacement unit and to the drive unit, wherein the cleaning unit comprises a measurement unit for metering and monitoring a respective depth of penetration Z of the high-pressure hose, the measurement unit is connected to the control unit, and the control unit comprises a storage and documentation unit or is connected to a storage and documentation unit, in which at least the respective measured depth of insertion can be stored.

2. A method for cleaning of tube bundles with open end faces, especially tube bundles of heat exchangers, air coolers or condensers, comprising the steps of: positioning a cleaning device according to claim 1 having the at least one cleaning unit adjacent to the open ends of the tube bundle and then arranging the cleaning unit comprising at least one high-pressure hose by the control unit successively flush with a particular tube of the tube bundle and inserting the cleaning unit into the particular tube and supplying the cleaning unit with a liquid under high pressure, wherein during the inserting of the at least one cleaning unit into the respective tube a depth of insertion is measured and monitored by the control unit.

3. The method according to claim 2, wherein the particular depth of insertion is saved in the control unit or in a storage and documentation unit connected to the control unit and documented for the particular cleaning process.

4. The method according to claim 3, wherein the documentation involves the construction of a three-dimensional fouling profile of the tube bundle.

5. The method according to claim 2, wherein a cleaning device has several parallel cleaning units, which are inserted at the same time into neighboring tubes and whose depth of insertion is metered and monitored independently of each other.

6. The method according to claim 2, wherein the arrangement and insertion movement of the cleaning unit is performed automatically or semi-automatically by the control unit with the aid of stored geometrical data of the tubes of the bundle.

7. The method according to claim 6, wherein the geometrical data of the tubes of the tube bundle is acquired by manual approaching of the tubes with the at least one cleaning unit.

8. The method according to claim 2, wherein the measurement of the depth of insertion is done by a servo motor of a drive unit for the high-pressure hose of a cleaning unit.

9. The method according to claim 8, wherein the torque D of the servo motor is metered continuously during the inserting of the high-pressure hose into the tube and the measured torque data is saved along with the respective depth of insertion in the control unit or in a storage and documentation unit connected to the control unit.

10. The method according to claim 9, wherein, upon rise in the torque of the servo motor beyond a predetermined value D.sub.V, the servo motor is switched off, switched to a free flushing mode, to the return stroke, or to a shaker mode.

11. The method according to claim 8, wherein a slip of the drive unit is monitored during the inserting of the high-pressure hose.

12. The method according to claim 2, wherein the measurement of the depth of insertion can be done by a sensing of markings applied on or in the high-pressure hose.

13. The method according to claim 2, wherein a displacement unit of the cleaning device is attached to the tube bundle.

14. The method according to claim 13, wherein the displacement unit of the cleaning device is attached to a flange of the tube bundle.

15. The method according to claim 2, wherein, before the first-time insertion of the at least one high-pressure hose into the tubes, an orientation of the cleaning device relative to the tube bundle is ascertained and the ascertained data is stored in the control unit and used for correction of a movement trajectory of the cleaning unit.

16. The method according to claim 2, wherein the first tube of the tube bundle being cleaned is approached manually.

17. The device according to claim 1, wherein the displacement unit comprises means of attachment to the tube bundle.

18. The device according to claim 1, wherein the first frame element comprises the means of attachment to the tube bundle and the second frame element is arranged on the first frame element so as to travel along the first frame element.

19. The device according to claim 1, wherein the cleaning unit is arranged to travel on the second frame element.

20. The device according to claim 1, wherein the drive unit comprises at least one driving roller for advancement of the high-pressure hose.

21. The device according to claim 20, wherein the drive unit comprises at least one pressing roller for pressing the high-pressure hose against the driving roller.

22. The device according to claim 20, wherein the drive unit comprises a slip monitoring unit for the driving roller.

23. The device according to claim 20, wherein the drive unit comprises at least one servo motor, which drives the driving roller.

24. The device according to claim 23, wherein the drive unit comprises a torque measuring unit for the measuring of a torque of the servo motor.

25. The device according to claim 1, wherein at the front end of the high-pressure hose there is arranged an exit nozzle.

26. The device according to claim 1, wherein the storage and documentation unit is designed for the storing, processing, preparing and evaluating of data accruing during the operation of the cleaning device and/or data which has been entered.

27. The device according to claim 1, wherein several parallel cleaning units are provided with their own drive unit, where each cleaning unit and/or each drive unit are outfitted with their own measuring unit.

28. The device according to claim 27, wherein the respective measuring unit comprises measuring sensors and measurement markings on a high-pressure hose interacting with the markings.

29. The device according to claim 28, wherein the particular measurement unit comprises roller sensors resting against the surface of the high-pressure hose.

30. The device according to claim 29, wherein the respective cleaning unit comprises a high-pressure hose with connected lance, which can be shoved into the respective tube.

31. A device for cleaning of tube bundles with open end faces, especially tube bundles of heat exchangers, air coolers or condensers, comprising: frame elements which can be traveled in horizontal and vertical direction by a control unit, in which is disposed at least one drive unit for a cleaning unit comprising a high-pressure hose and connected to the control unit, wherein the cleaning unit can be shoved by the drive unit into the tubes of the tube bundle, wherein the drive unit and/or the cleaning unit is outfitted with a measuring unit for measuring the respective depth of insertion of the cleaning unit in the respective tube, the measurement unit being connected to the control unit.

32. The device according to claim 31, wherein the respective cleaning unit is formed by a high-pressure hose with exit nozzle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is explained more closely below by means of the drawings, as an example. These show, each time in greatly simplified schematic representation:

(2) FIG. 1, the end face of an open tube bundle with the device of the invention attached to it,

(3) FIG. 2, a side view of FIG. 1,

(4) FIG. 3, a portion of a high-pressure hose with spaced-apart measurement markings,

(5) FIG. 4, a top view of the end face of an open tube bundle with a tube cleaning device of another embodiment,

(6) FIG. 5, another top view of the end face of the tube bundle with a displacement unit according to another embodiment,

(7) FIG. 6, a schematic representation of a driving unit of a drive unit, and

(8) FIGS. 7 and 8, two different encrustation situations in a tube with corresponding torque diagrams of a servo motor.

DETAILED DESCRIPTION OF THE INVENTION

(9) In the drawings, a tube bundle 1 is represented, for example that of a tube bundle heat exchanger, where the open end face can be seen, i.e., a closure cover or the like has been removed. The cover is normally attached to a flange or flange region 2 with fastening openings 3. The tube bundle 1 comprises, in the horizontal direction in the sense of FIG. 1, a plurality of parallel tubes 4, of which only a few are indicated.

(10) For the automatic cleaning of the tubes 4 of the tube bundle 1, a cleaning device according to the invention is provided, being generally indicated as 5.

(11) This device 5 comprises at least two frame elements, namely, a horizontal frame element 6 and a vertical frame element 7. These frame elements 6, 7 are thus arranged perpendicular to each other. The horizontal frame element 6 can travel in the direction of the double arrow 6a in the horizontal direction with a drive unit, not shown, the vertical frame element 7 can travel in the vertical direction in the sense of the double arrow 7a relative to the horizontal frame element 6 with a drive unit likewise not shown. A reversed arrangement is also possible. The two frame elements 6, 7 can be arranged on a cleaning cart (not shown), which can but need not have its own travel drive unit.

(12) The two drive units of the two frame elements 6 and 7 are connected to a control unit 50, not shown, which makes it possible to position a bearing point 8 on the frame element 7 at any given point of the end face of the tube bundle 1. At this bearing point 8 is attached a support frame 9, on which a cleaning unit 20 is arranged. The cleaning unit 20 comprises a high-pressure hose 11 and a drive unit 10 for the high-pressure hose 11.

(13) This drive unit 10, as shown in FIG. 2, has a tubular hose guide 12 as well as at least one driving roller 32, not shown, for inserting the hose 11 into a tube 4 of the tube bundle 1 or for pulling it out therefrom, i.e., for moving the hose 11 in the direction of the double arrow 13. The at least one driving roller 32, not shown, is connected to a drive, not shown, which in turn stands in connection with the control unit 50. The cleaning unit 20 of this sample embodiment comprises the high-pressure hose 11 shown, which has at its front free end a nozzle, not shown. At the rear, the high-pressure hose 11 is connected to a high-pressure pump or the like.

(14) A second or further cleaning units 20 can also be provided on the support frame 9 at a spacing, so that when the support frame 9 is positioned accordingly with respect to the tube bundle 1 several high-pressure hoses 11 can be shoved at the same time into neighboring tubes 4.

(15) The drive unit 10 and/or the cleaning unit 20, i.e., the high-pressure hose 11 in the sample embodiment, are outfitted with a measurement unit 40 for measuring the respective depth of insertion of the high-pressure hose 11 into the respective tube 4. In the sample embodiment shown, two measuring sensors 14 are provided at the input and output of the drive unit 10. The high-pressure hose 11 according to FIG. 3 is provided with markings 15 at equal spacings, e.g. in the form of magnetic strips, which can be detected by the sensors 14. The sensors 14 are connected to the control unit 50.

(16) In this way, it is possible to measure the respective depth of insertion of the high-pressure hose 11 of the respective cleaning unit 20 in the respective tube 4 and relay the measurement result to the control unit 50.

(17) The measurement of the depth of insertion of the respective high-pressure hose 11 into a tube 4 can basically be done in any given manner, e.g., it is also possible for each high-pressure hose 11 to move via its own servo motor 30 and for the depth of insertion to be measured via the servo motor 30 as the measuring unit 40.

(18) For the cleaning of a tube bundle 1, the device 5 is arranged at the end face of the open tube bundle 1, and then the further cleaning sequence is fully automatic. Preferably, the geometrical data of the tubes 4 of the tube bundle 1 is stored in the control unit 50, so that the control unit 50 automatically positions the respective cleaning unit 20 successively at the tubes 4 of the tube bundle 1.

(19) If the geometrical data of the tubes 4 of the tube bundle 1 is not known, this can be detected or acquired manually with the cleaning device 5. For this, an attendant by manual intervention in the control unit 50 consecutively traces or senses each tube 4 of the tube bundle 1 with the at least one cleaning unit 20, so that the cleaning unit 20, i.e., the tips of the high-pressure hose 11 for example, is situated at the entrance of the respective tube 4. In this way, all tube positions are detected and saved in the control unit 50. The geometrical data detected in this way can then be used for the subsequent cleaning process or later cleaning processes.

(20) The respective cleaning unit 20 or the high-pressure hose 11 is then introduced by the corresponding drive unit 10 into the respective tube 4 and water or the like is supplied under high pressure in order to carry out the cleaning process in the respective tube 4. Thanks to the respective measuring of the insertion depth, which can also be equal to zero when the entrance to a tube 4 is fully closed, the depth of insertion of each tube 4 is measured and monitored by the control unit 50. If no cleaning or only an incomplete cleaning of a tube 4 occurs, the control unit 50 can put out an error message directly, or also a warning message. In addition, the depth of insertion measured for each tube 4 is stored in the control unit 50 and documented for the respective cleaning process.

(21) It is thus documented for the user in distinctive manner after the end of the cleaning whether the cleaning has been done correctly for all tubes 4 or not. In the latter case, additional cleaning measures can then be taken, if need be.

(22) FIG. 4 shows another embodiment of a cleaning device 5, comprising a displacement unit 25 with a first frame element 60 and a second frame element 70. The first frame element 60 comprises fastening means 62a, b, which in the embodiment shown here are configured as lugs. These fastening means 62a, b are fastened to the flange 2 of the tube bundle 1. For this, the fastening openings 3 in the flange 2 are used.

(23) Arranged perpendicular to the firmly mounted first frame element 60 is the second frame element 70, which can travel by means of a driving unit 72 along the first frame element 60 in the direction of the arrow. On the second frame element 70 is arranged a further driving unit 74, which is connected to a support element 9, on which a cleaning unit 20 is arranged. The cleaning unit 20 comprises a drive unit 10 for two hoses 11 as well as a measurement unit 40.

(24) A second cleaning unit 20 can also be arranged on the support frame 9, which comprises like the first cleaning unit 20 a drive unit 10 for two hoses 11 as well as a measurement unit 40. The second cleaning unit 20 is shown in dotted lines.

(25) By means of the driving unit 74, the support frame 9 can travel in the direction of the arrow along the second frame element 70. The driving units 72 and 74 as well as the drive unit 10 and the measurement unit 40 are connected to a control unit 50, which has a storage and documentation unit 52. Moreover, a remote control 54 is provided, with which an attendant can relay commands to the control unit 50.

(26) Moreover, a coordinate system is indicated, whose zero point lies in the tube 4c, which serves as the reference tube in the present case. The tube 4c is located at the left end of the upper tube series and constitutes the starting point for the cleaning process. Starting from tube 4c, the tubes 4 are driven over in series, until all tubes 4 have been cleaned. Basically, any desired tube 4 can be chosen as the reference tube 4c.

(27) This coordinate system as well as the tube coordinates x and y situated in this coordinate system are stored in the control unit 50 or the storage and documentation unit 52. This geometrical data can be ordered from the manufacturer or operator of the tube bundle 1 and entered into the control unit 50. It is also possible to use the remote control 54 to manually travel over the tubes 4 individually and save the corresponding x, y data in the control unit 50 or the storage and documentation unit 52 and preferably also carry out the cleaning of the tubes 4 at the same time.

(28) With the aid of this data, the cleaning process can then be carried out, where only the tube 4c is approached manually. The process can then run fully or semi-automatically, while the switch from one tube series to the next can be done manually, for example. The saving of the depth of insertion for each tube can also be done manually with the remote control 54.

(29) In FIG. 5, the first frame element 60 is attached to the flange 2 in the same way as in FIG. 4. For stability reasons, it can be advantageous to arrange an additional first frame element 60 on the opposite side of the flange 2. The second frame element 70, not shown, can travel on both frame elements 60.

(30) Before the cleaning process is performed, one must check the orientation of the displacement unit 25 with respect to the tube arrangement. As a rule, the first frame element 60 might not be positioned in parallel with the tube series 82 on the flange 2, so that an angle offset a occurs. This angle offset a between the parallels 80 to the first frame element 60 and the tube series 82 is ascertained and saved in the control unit 50, so that this angle offset a can be factored into the local coordinates x, y of the tubes 4 and be taken into account when moving the cleaning unit 20.

(31) For this, the tube 4a for example is approached manually with the cleaning unit 20 and the position is memorized. Next, the cleaning unit 20 moves in front of the tube 4b and this position is likewise saved, from which the angle of the tube series 82 to the parallels 80 can then be ascertained.

(32) FIG. 6 shows schematically a drive unit 10 for the high-pressure hose 11, comprising two driving rollers 32 and 34, which are interconnected by a belt or chain drive 33. The driving roller 32 is driven by a servo motor 30, which is connected to the control unit 50.

(33) Pressing rollers 36 and 38 are arranged above the high-pressure hose 11 being transported and are used to press the high-pressure hose 11 against the driving rollers 32 and 34, thus largely preventing a slippage of the high-pressure hose 11 on the driving rollers 32, 34. The additional driving roller 34 and pressing roller 38 can be omitted when the high-pressure hose 11 and the driving rollers 32, 34 have appropriately roughened surfaces, so that no slippage on the driving rollers 32, 34 occurs.

(34) In front of the upper pressing roller 36, which is driven by the high-pressure hose 11 and has depressions or openings 37 arranged on a circle, there is arranged a roller sensor 44 by means of a sensor holder 46, which is connected to a slip monitoring unit 90. With the sensor 44, the rotational velocity of the pressing roller 36 is detected. This slip monitoring unit 90 is also connected to the servo motor 30 and the control unit 50.

(35) If the high-pressure hose 11 encounters an obstacle inside the tube 4 being cleaned, the high-pressure hose 11 is braked and there is a danger that the driving roller 32 will nevertheless continue to run. Since the depth of insertion is ascertained through the servo motor 30 and thus the servo motor 30 also forms the measuring unit 40, this would lead to an error in the determination of the depth of insertion. This problem can be recognized by means of the slip monitoring unit 90, so that the servo motor 30 is switched off at once and any further running of the driving roller 32 can be factored into the calculation of the depth of insertion.

(36) One of the pressing rollers 36, 38 can also be designed as a roller sensor when a high-pressure hose 11 with markings 15 is used, as shown in FIG. 3. This pressing roller 36, 38 in such an embodiment is part of the measurement unit 40 for measuring the depth of insertion and is connected to the control unit 50 or the storage and documentation unit 52.

(37) FIGS. 7 and 8 show various obstacles in the form of encrustations 16, 16a, 16b inside the tubes 4. Beneath the respective tubes 4 is a schematic diagram of the torque D as a function of the distance z traveled.

(38) The torque D of the servo motor 30 is constant upon shoving the high-pressure hose 11 into the tube 4 and it rises abruptly when the exit nozzle 18 disposed at the front end of the hose 11 encounters an obstacle in the form of an encrustation 16. The torque D is detected preferably with a torque measuring unit 30, which is arranged in or on the servo motor 30 (see FIG. 6).

(39) This rapid rise is shown in the diagram, this rise marking the depth of insertion z.sub.E.

(40) This obstacle cannot be eliminated with the aid of the high-pressure hose 11 and the exit nozzle 18, so that the cleaning process of the tube 4 is ended at this point. It can be read off from the value of the torque D that an impassable obstacle is located here. The corresponding data such as depth of insertion z.sub.E and torque D are saved in the control unit 50 or the storage and documentation unit 52.

(41) FIG. 8 shows a different situation, in which two smaller encrustations 16a, 16b are shown. When the high-pressure hose 11 comes up against the encrustation 16a with the exit nozzle 18, the torque of the servo motor 30 rises. If it is able to loosen this encrustation 16a, the advancement of the high-pressure hose 11 can continue, so that the torque of the servo motor 30 again drops until the high-pressure hose 11 encounters the next obstacle in the form of the encrustation 16b with the nozzle 18.

(42) If the encrustation 16b here can also be loosened and removed, the torque again drops and the advancement can likewise continue.

(43) Thus, from the plot of the torque curve, shown only schematically, one can read off how heavy the fouling or encrustation 16, 16a, b is inside the tube 4. Using the data z1 and z2, it is then also possible to localize the site precisely where this fouling occurs.

(44) Thus, with the aid of all the data, a three-dimensional fouling profile of the tube bundle 1 can be constructed, from which the location of the encrustations 16, 16a, b and the degree of the encrustation or fouling can be seen.

(45) A sample cleaning process for a tube bundle 1 can take place as follows:

(46) The individual frame elements 6, 7 or 60, 70 are delivered along with the cleaning unit or units 20 and the control unit 50 and assembled on site to form a cleaning device 5. First of all, the first frame element 6, 60 is mounted on the tube bundle 1 and then the second frame element 7, 70 is mounted on the first frame element 6, 60.

(47) The benefit of the device is, among other things, that the frame elements can be mounted on both horizontally oriented tube bundles 1 and vertically oriented tube bundles 1. The device 5 can be employed much more flexibly than is the case with tube cleaning devices of the prior art, which are mounted for example on a cart which has to travel up to the tube bundle 1 being cleaned, which is only possible in the case of horizontally situated tube bundles 1.

(48) Next, the angle offset a is ascertained and the working range is determined. For this, for corner points of a rectangle lying outside the tube bundle 1 are driven to. The end face of the tube bundle 1 is then situated inside the working zone in which the cleaning unit(s) 20 can travel.

(49) In the event of a first-time cleaning process for a tube bundle 1, it is necessary to enter the geometrical data into the control unit 50. If this geometrical data of the tubes 4 is provided by the operator or manufacturer of the tube bundle 1 and is then entered into the control unit 50, the cleaning process can be started after the data entry, and the cleaning process begins at a reference tube 4c which is approached manually. This can be, e.g., the first tube 4 of the first series of a tube bundle 1. The reference tube 4c can also be any given tube 4 of the tube bundle 1. If no geometrical data is available, the geometrical data is determined on site by means of a manual driving to the tubes 4 and preferably the tubes 4 will also be cleaned at the same time.

(50) If the cleaning unit 20 comes up against a tube 4 which is closed with a plug, the high-pressure hose 11 cannot move into the tube 4. Corresponding information is then assigned to this tube 4, that the high-pressure hose 11 could not enter it. This data is then saved in the storage and documentation unit 52.

(51) If the high-pressure hose 11 can move into the tube 4 being cleaned, there are two possibilities. Either the hose can be shoved entirely into the tube 4 as far as the opposite end. Then the cleaning can occur as planned and this cleaning outcome will likewise be documented by saving the tube data and the maximum depth of insertion reached.

(52) If the tube 4 can only be partly entered, the cleaning is not done according to plan. The maximum depth of insertion z.sub.E reached and optionally the torques occurring are ascertained, so that further conclusions can be drawn as to the degree of the fouling. This data is also then saved in the storage and documentation unit 52.

(53) If it is possible to remove the fouling by means of the inserted high-pressure hose 11, this also is saved and documented.

(54) Once all tubes 4 of a tube bundle 1 have been driven to, the cleaning process is ended.

(55) The method according to the invention ensures that no tube is inadvertently forgotten, as can happen with a traditional manual cleaning of the tubes.

(56) If several high-pressure hoses 11 are used at the same time, the cleaning time is further shortened. A travel of the cleaning unit 20 will always occur when all high-pressure hoses 11 have left their tubes 4. In particular, if one of the high-pressure hoses 11 has been driven out from the tube on account of an insurmountable obstacle, it must wait for the other high-pressure hoses 11 which can perform a complete cleaning of their tubes.

LIST OF REFERENCE SYMBOLS

(57) 1 tube bundle 2 flange region, flange 3 fastening openings 4 tube 4a, b, c tube 5 cleaning device 6 horizontal frame element 6a double arrow 7 vertical frame element 7a double arrow 8 bearing point 9 support frame 10 drive unit 11 high-pressure hose 12 hose guide 13 double arrow 14 sensors 15 markings 16 encrustation 16a, b encrustation 18 exit nozzle 20 cleaning unit 25 displacement unit 30 servo motor 32 driving roller 33 transmission element 34 driving roller 36 pressing roller 37 opening 38 pressing roller 39 torque measuring unit 40 measuring unit 44 roller sensor 46 sensor holder 50 control unit 52 storage and documentation unit 54 remote control 60 first frame element 62a, b fastening means 70 second frame element 72 driving unit 74 driving unit 80 parallels 82 tube series 90 slip monitoring unit