DEVICE FOR THE SEMI-AUTOMATED CLEANING OF BUNDLE-TUBE HEAT EXCHANGERS, BUNDLE-TUBE HEAT EXCHANGER CLEANING ARRANGEMENT AND BLASTING METHOD FOR CLEANING AN INNER TUBE SURFACE OF A BUNDLE-TUBE HEAT EXCHANGER

Description

[0001] The invention relates to a device for the semi-automatic cleaning of tube-bundle heat exchangers with a plurality of tubes. Furthermore, the invention comprises a tube-bundle heat exchanger cleaning arrangement and a blasting method for cleaning an inner tube surface of a tube of a tube-bundle heat exchanger.

[0002] Various methods for cleaning the inside of pipes, especially those of shell-and-tube heat exchangers, are known in the art. Shell-and-tube heat exchanger pipes typically have an inside diameter ranging from 6 mm to 60 mm and can be made of various materials, such as steel, stainless steel, copper, bronze, titanium, or graphite. High-pressure water jets with a pressure of 2,800 bar or more are typically used for internal pipe cleaning. The pressure must be adjusted to the stability of the pipes. A high-pressure jet nozzle is typically guided through the pipe using lances or hoses. With small inside pipe diameters, this can result in significant pressure losses, which limit the cleaning effect.

[0003] DE 10 2015 218 114 A1 discloses a method for cleaning tube bundles using a cleaning lance. The cleaning lance is mounted on a cleaning device with an XY displacement device. It is inserted into the tubes of the tube bundle to be cleaned.

[0004] EP 1 256 761 A2 discloses a method and a device for online boiler cleaning of waste incineration plants, which use a heat-resistant flexible hose hanging vertically from above.

[0005] From DE 202 01 322 U1 a blasting device for cleaning outer pipe surfaces in pipe bundles is known, which preferably uses two or more nozzles, in particular arranged in opposite directions, as well as a deflection device for deflecting a blasting agent in the direction of the pipe outer surfaces.

[0006] From US 2017 / 0321975 A1, a cleaning device for heat exchangers is known which uses an ultra-high pressure hose which is inserted into the heat exchanger and is used in particular to remove sediment deposits.

[0007] From EP 1 035 947 B1 and WO 1999 / 029470 A1 it is known to use dry ice as a blasting agent for cleaning inner pipe surfaces by means of a gaseous blasting medium via a deflector body that is guided through the pipe at a reduced speed. In addition, the effect of the dry ice can be enhanced by adding other blasting agents. However, the cooling effect of the dry ice is not sufficient to remove or clean residues if these residues do not react to the cold. However, the additional use of abrasive blasting agents requires extremely robust holding cables to slow the deflector body guided through the pipe below the speed of the blasting medium. However, the cold caused by the dry ice leads to embrittlement of the holding cable and thus causes brittleness and rapid wear.It has also been shown that dry ice cleaning, when combined with solid blasting media, does not improve the cleaning quality or only improves it to a very small extent.

[0008] From the subsequently published German patent application 10 2018 130 100.6, a stationary arrangement for cleaning the inside of a pipe is known, in which a deflection body held by a holding cable is inserted into the pipe and a gaseous blasting medium with an added blasting agent is guided through the pipe via a blasting adapter.

[0009] The object of the present invention is to provide a device for cleaning the inside of a plurality of tubes of a tube bundle heat exchanger as well as a tube bundle heat exchanger cleaning arrangement and a blasting method.

[0010] To achieve this object, the invention has the features of patent claim 1. Accordingly, the device for the semi-automatic cleaning of tubes of a tube bundle heat exchanger comprises at least one guide rail extending longitudinally in a transverse direction, at least one carriage movable along the guide rail in the transverse direction, as well as a jet device and a fastening device for securing the guide rail to the tube bundle heat exchanger.The blasting device provides a connection for a gaseous and / or liquid blasting medium and a blasting agent, a blasting adapter designed for frontal contact with a tube of the shell-and-tube heat exchanger, a controllable pressure module assigned to the blasting adapter so that the blasting adapter can be pressed against the tube, a deflector for the blasting agent and the blasting medium that can be inserted into the tube, a durable retaining cable that holds the deflector and is also suitable for use with abrasive blasting media, and a feed module for the retaining cable. In any case, the blasting adapter and / or the deflector of the blasting device can be moved transversely with the carriage.

[0011] The particular advantage of the invention is that by providing the guide rail with the carriage and the blasting device attached to the carriage, the latter can be positioned easily, quickly, and precisely. This makes it possible to clean and / or polish a large number of tubes of the shell-and-tube heat exchanger automatically within a short period of time. Furthermore, the fastening device allows the device to be fixed relative to the shell-and-tube heat exchanger in such a way that precise positioning is ensured.

[0012] According to a preferred embodiment of the invention, the fastening device provides at least one clamping module with adjustable clamping jaws for clamping the guide rail to the shell-and-tube heat exchanger. For example, the guide rail is secured relative to the shell-and-tube heat exchanger by clamping the clamping jaws against an inner tube surface of a tube of the shell-and-tube heat exchanger used to fasten the device. Advantageously, by clamping the device to the inner tube surface, the exact positioning of the device relative to the shell-and-tube heat exchanger can be achieved in a particularly simple manner, with the result that the effort required to position the device relative to the pipe to be cleaned is minimal and the cleaning progress is rapid.

[0013] According to a further development of the invention, the pressing module provides a drive unit, in particular a spindle drive or a pneumatically actuated cylinder for pressing the jet adapter against the pipe. Advantageously, the provision of the drive unit allows the pressing process to be automated and therefore carried out quickly. Manual operation is not required. Furthermore, the contact pressure can be selected, adjusted, and monitored as needed.

[0014] According to a further development of the invention, the feed module provides a storage roller for the retaining cable. For example, the storage roller can be associated with a drive for feeding the retaining cable and, consequently, for changing the position of the deflection body in the pipe.

[0015] According to a further development of the invention, the feed module can provide a roller guide for feeding and / or force-fitting the retaining cable. For example, a roller of the roller guide can be driven to advance the retaining cable and to determine or adjust the position of the deflection body in the pipe to be cleaned.

[0016] To achieve this object, the invention has the features of patent claim 6. Accordingly, a tube bundle heat exchanger cleaning arrangement comprises a device according to the invention and a tube bundle heat exchanger with a plurality of horizontally and vertically adjacent tubes. The guide rail of the device extends horizontally and / or vertically, and individual elements of the fastening device protrude, at least in sections, into at least one tube of the tube bundle heat exchanger used to fasten the device. In this way, the device is fastened to the tube bundle heat exchanger and simultaneously aligned relative to it.

[0017] The particular advantage of the invention is that the tubes of a shell-and-tube heat exchanger can be cleaned quickly and reliably using the device according to the invention. The device and the shell-and-tube heat exchanger are aligned with each other, so that horizontally and / or vertically adjacent tubes of the shell-and-tube heat exchanger can be cleaned sequentially without the need to reposition or re-fix the device according to the invention.

[0018] According to a preferred embodiment of the invention, the fastening device provides at least one clamping module with adjustable clamping jaws, wherein the clamping jaws are clamped against an inner surface of the pipe used to fasten the device. For example, the tubes of the shell-and-tube heat exchanger are elongated in a longitudinal direction and oriented orthogonally to the transverse direction of the guide rail of the device according to the invention.

[0019] According to a further development of the invention, the tube bundle heat exchanger cleaning arrangement provides a holding device for the height-adjustable suspension of the device relative to the tube bundle heat exchanger. In particular, the holding device can comprise a balancer. By providing the holding device with the balancer, it is possible to easily change the horizontal or vertical position of the device with minimal effort. The device can thus be easily moved vertically and repositioned for cleaning another row of tubes.

[0020] To achieve the object, the invention has the features of patent claim 10. Accordingly, according to the blasting method according to the invention for cleaning and / or polishing an inner tube surface of a tube of a shell and tube heat exchanger, a gaseous and / or liquid blasting medium to which a blasting agent is added flows around a deflecting body introduced into the tube to be cleaned, wherein the deflecting body is adapted to an inner tube cross-section with regard to its cross-sectional shape, but is dimensioned smaller than the inner tube cross-section and a minimum annular gap of 0.75 mm is formed to the inner tube surface, through which the blasting medium with the blasting agent flows during cleaning.The deflector is guided through the pipe to be cleaned at a defined speed by means of a retaining cable, which is connected to a blasting adapter pressed against the end face of the pipe to be cleaned and used to supply the blasting medium mixed with the blasting agent. The minimum speed of the blasting medium is 12 m / s. The speed of the deflector is between 1 m / min and 18 m / min, depending on requirements. The blasting adapter and the deflector are held on a carriage, and the carriage is guided along a guide rail extending longitudinally in a transverse direction.

[0021] The particular advantage of the invention is that, using the blasting method according to the invention, a large number of tubes of a shell-and-tube heat exchanger can be cleaned within a short period of time. The blasting adapter and deflector, which are part of a blasting device, are guided sequentially to the tubes to be cleaned using the carriage guided along the guide rail and positioned relative to each tube to be cleaned.

[0022] According to a preferred embodiment of the invention, the retaining cable is fed via a controllable drive. This advantageously allows the speed at which the deflector is guided through the pipe to be cleaned to be adjusted or variably selected as needed.

[0023] According to a further development of the invention, the jet adapter is pressed against the end face of the pipe to be cleaned by means of a drive unit. The drive unit, for example, provides a spindle drive or a pneumatically actuated cylinder. Advantageously, the provision of the drive unit allows for automated pressing of the jet adapter.

[0024] According to a further development of the invention, to clean a plurality of tubes of the shell-and-tube heat exchanger, the carriage with the jet adapter and the deflection body is first moved horizontally along a plurality of laterally adjacent tubes of a first row of tubes. The vertical position of the guide rail, with the carriage held thereon, is then readjusted for cleaning horizontally adjacent tubes of a second row of tubes, which is provided above and / or below the first row of tubes to be cleaned. For horizontal adjustment, a holding device with a balancer can be provided, for example.

[0025] According to a further development of the invention, hard particles with a round or sharp-edged surface are used as blasting media. Alternatively, soft blasting media made of plastic or water-soluble substances or liquids such as water with or without additives, degreasers such as paraffin, and other soluble liquids can be used. For example, dry snow or dry ice can be used as blasting media for cleaning pipes made of plastic, graphite, or fiberglass.

[0026] According to a further development of the invention, in order to adjust the cleaning or polishing effect on an inner pipe surface of the pipe to be cleaned, the pressure of the blasting medium and / or the quality of the blasting medium can be adjusted and / or changed and / or selected and / or regulated as required.

[0027] Further advantages, features, and details of the invention can be derived from the further subclaims and the following description. Features mentioned therein may be essential to the invention individually or in any combination. Features and details of the device and / or the tube bundle heat exchanger cleaning arrangement described according to the invention naturally also apply in connection with the blasting method according to the invention, and vice versa. Thus, the disclosure of the individual aspects of the invention can always be referenced reciprocally. The drawings serve merely as examples to clarify the invention and are not limiting in nature.

[0028] It shows: Fig. 1 a schematic diagram of a tube bundle heat exchanger cleaning arrangement with a device for the semi-automatic cleaning of inner tube surfaces of a tube of a tube bundle heat exchanger.

[0029] A tube bundle heat exchanger cleaning arrangement comprises as essential components a tube bundle heat exchanger 1 with a plurality of tubes 2 which are adjacent to one another and extend in a longitudinal direction 3, a device 5 for cleaning the tubes 2 of the tube bundle heat exchanger 1 and a holding device (not shown) which serves for the height-variable suspension of the device 5 relative to the tube bundle heat exchanger 1.

[0030] The tube bundle heat exchanger 1 comprises a plurality of tubes 2 arranged in rows adjacent to one another, as well as above and below one another. The device 5 serves for the semi-automatic cleaning of an inner surface 4 of the tubes 2.

[0031] The device 5 provides a guide rail 6 extending longitudinally in a transverse direction 7 and a fastening device with two clamping modules 9 held on the guide rail 6. In the present example, the guide rail 6 extends horizontally. The clamping modules 9 protrude in sections into two tubes 2.2 of the tube bundle heat exchanger 1 that serve to fasten the device 5 to the tube bundle heat exchanger 1. In order to secure the device 5 to the tube bundle heat exchanger 1 and to position the device 5 relative to the tube bundle heat exchanger 1, the clamping modules 9 of the fastening device provide clamping jaws 10. The clamping jaws 10 are adjustable and, in the assembled state, are clamped against the inner tube surfaces 4 of the two tubes 2.2 of the tube bundle heat exchanger 1 that serve to fasten the device 5.

[0032] The device 5 further provides a carriage 8, which is displaceable in the transverse direction 7 along the guide rail 6 and is held thereon. A blasting device is provided on the carriage 8 of the device 5. The blasting device comprises a blasting adapter 11, which can be pressed onto the end face of a pipe 2.1 of the shell-and-tube heat exchanger 1 to be cleaned, a deflection body 14 provided in the pipe 2.1 to be cleaned, and a holding cable 15. The deflection body 14 is provided on the holding cable 15. The holding cable 15 is guided via the blasting adapter 11 into the pipe 2.1 to be cleaned. A feed module is used to feed the holding cable 15, which provides a roller guide 16 with a driven roller 17, a pressure roller 18, and a roller drive 19 assigned to the driven roller 17. A cylinder 20 with a piston rod 21 is assigned to the pressure roller 18 of the roller guide 16.The retaining cable 15 is held frictionally between the pressure roller 18 and the driven roller 17. The driven roller 17 can be rotated via the roller drive 19 of the roller guide 16, so that the retaining cable 15 is displaced in a longitudinal direction between the rollers 17, 18.

[0033] To press the jet adapter 11 onto the pipe 2.1 to be cleaned, the jet device provides a pressing module with a cylinder 12 and a piston rod 13.

[0034] Two receptacles 22 are also provided on the carriage 8. The device 5 is connected to the holding device (not shown) via the receptacles 22. The holding device can, for example, provide a balancer. By providing the balancer, the device 5 can be easily displaced vertically, i.e., perpendicular to the longitudinal direction 3 of the tubes 2 of the shell-and-tube heat exchanger 1 and perpendicular to the transverse direction 7 of the guide rail 6.

[0035] For the sequential, semi-automated cleaning of the tubes 2 of the tube bundle heat exchanger 1, the device 5 is first attached to the tube bundle heat exchanger 1 by means of the fastening device comprising the clamping modules 9. By inserting the clamping modules 9 with the clamping jaws 10 in sections into the tubes 2.2 of the tube bundle heat exchanger 1 used to fasten the device 5, in addition to the fastening of the device 5 to the tube bundle heat exchanger 1, an exact positioning of the device 5 relative to the tube bundle heat exchanger 1 is also ensured.

[0036] The carriage 8 is then positioned in front of the pipe 2.1 to be cleaned of the tube bundle heat exchanger 1 such that the deflection body 14 can be inserted into the pipe 2.1 to be cleaned and the blasting adapter 11 can be pressed against the end face of the pipe 2.1 to be cleaned by means of the pressing module. Subsequently, a gaseous or liquid blasting medium, for example compressed air, and a blasting agent, for example plastic granulate, are supplied, for example via hoses (not shown), and guided into the pipe 2.1 to be cleaned via connections (not shown) of the device 5 and the blasting adapter 11 such that the blasting medium mixed with the blasting agent flows around the deflection body 14 and through an annular gap 23 formed between the deflection body 14 and the inner pipe surface 4 of the pipe 2.1 to be cleaned. The cross-sectional shape of the deflection body 14 is adapted to an inner pipe cross-section.

[0037] To clean the inner surface 4 of pipe 2.1, the deflector 14 is guided through pipe 2.1 in the longitudinal direction 3 of the pipe. It is held by the retaining cable 15 against the pressure of the blasting medium mixed with the blasting agent and moved forward and / or backward at a speed that, depending on the nature of the pipe 2.1, ranges from 1 m / min to 18 m / min. The cleaning effect can be adjusted or regulated by the pressure of the blasting medium and the quality or quantity of the blasting agent.

[0038] After cleaning the pipe 2.1 to be cleaned, the supply of the blasting medium containing the blasting agent is stopped. The blasting adapter 11 is removed from the pipe 2.1 to be cleaned. The deflector 14 is also removed from the pipe 2.1 to be cleaned. The carriage 8, with the blasting adapter 11, is moved horizontally in the transverse direction 7 of the device 5 and positioned in front of the next pipe 2.

[0039] After all tubes 2 of a first row have been cleaned, the fixture 5 can be removed from the shell-and-tube heat exchanger 1. To do this, the clamping jaws 10 are loosened and removed from the tube 2.2 used to secure the fixture 5. The fixture 5 is then moved vertically to a second row of tubes. At the second row of tubes, the fixture 5 is repositioned using the clamping jaws 10 of the clamping modules 9, and the cleaning process is repeated.

[0040] Identical components and component functions are identified by the same reference symbols. List of reference symbols

[0041] 1 Tube bundle heat exchanger 2 Tube 2.1 Pipe to be cleaned 2.2 Pipe used to fasten the device 3 Longitudinal direction 4 Inner tube surface 5 Device 6 Guide rail 7 Transverse direction 8 Slide 9 Clamping module 10 Clamping jaws 11 Jet adapter 12 Cylinder 13 Piston rod 14 Deflection body 15 Holding cable 16 Roller guide 17 Driven roller 18 Pressure roller 19 Roller drive 20 Cylinder 21 Piston rod 22 Mount 23 Annular gap

Claims

1. Apparatus (5) for partially automated cleaning of tube bundle heat exchangers (1) having a plurality of tubes (2, 2.1, 2.2) comprising a blasting device having a connection for a gaseous and / or liquid blasting medium and a blasting agent, having a blasting adapter (11) designed for front contact with a tube (2.1) of the tube bundle heat exchanger (1) to be cleaned, having a deflection body (14) for the blasting agent and / or blasting medium that can be inserted into the tube (2.1) to be cleaned, having a robust retention cable (15), which retains the deflection body (14) and is also suitable for the use of abrasive blasting agents, and having a feed module for the retention cable (15), characterised in that - the apparatus further has a guide rail (6) which is longitudinally extended in a transverse direction (7) and a carriage (8) that can be moved along the guide rail (6) in the transverse direction (7), - the blasting device is fitted with a controllable pressure module, which is associated with the blasting adapter (11) in such a way that the blasting adapter (11) can be pressed against the tube (2.1) to be cleaned by means of the pressure module, wherein in any case the blasting adapter (11) and / or the deflection body (14) of the blasting device can be moved with the carriage (8) in the transverse direction (7), - the apparatus comprises an attachment device for attaching the guide rail (6) to the tube bundle heat exchanger (1).

2. Apparatus (5) according to Claim 1, characterised in that the attachment device provides at least one clamping module (9) with adjustable clamping jaws (10) for clamping the guide rail (6) to the tube bundle heat exchanger (1).

3. Apparatus (5) according to Claim 1 or 2, characterised in that the pressure module provides a controllable drive unit and in particular a spindle drive and / or a pneumatically actuated cylinder (12) for pressing the blasting adapter (11) against the tube (2.1) to be cleaned.

4. Apparatus (5) according to one of Claims 1 to 3, characterised in that the feed module provides a supply reel for the retention cable (15) and / or a roller guide (16) for guiding and / or clamping the retention cable (15) in a force-locking manner and / or in that the supply reel and / or at least one roller (17) of the roller guide (16) is driven.

5. Apparatus (5) according to Claim 4, characterised in that the retention cable (15) is guided to the deflection body (14) via the blasting adapter (11).

6. Tube bundle heat exchanger cleaning assembly having an apparatus (5) according to one of Claims 1 to 5 and having a tube bundle heat exchanger (1), wherein the tube bundle heat exchanger (1) has a plurality of horizontally and vertically adjacent tubes (2, 2.1, 2.2), wherein the guide rail (6) of the apparatus (5) is provided horizontally and / or vertically extended and in any case individual elements of the attachment device protrude in sections into at least one tube (2.2) of the tube bundle heat exchanger (1) used to attach the apparatus (5) and are applied to the tube (2.2) of the tube bundle heat exchanger (1) used to attach the apparatus (5) in such a way that the apparatus (5) is attached to the tube bundle heat exchanger (1) and / or is aligned relative to the tubes (2, 2.1, 2.2) of the tube bundle heat exchanger (1).

7. Tube bundle heat exchanger cleaning assembly according to Claim 6, characterised in that the attachment device has at least one clamping module (9) with adjustable clamping jaws (10) and in that the clamping jaws (10) are clamped against an inner tube surface (4) of the tube (2.2) used to attach the apparatus (5).

8. Tube bundle heat exchanger cleaning assembly according to Claim 6 or 7, characterised in that the tubes (2, 2.1, 2.2) of the tube bundle heat exchanger (1) are longitudinally extended and a longitudinal direction (3) of the tubes (2, 2.1, 2.2) is provided orthogonal to the transverse direction (7) of the guide rail (6) of the apparatus (5).

9. Tube bundle heat exchanger cleaning assembly according to one of Claims 6 to 8, characterised in that a holding device is provided with a balancer and associated with the apparatus (5) for height-variable suspension of the apparatus (5) relative to the tube bundle heat exchanger (1).

10. Blasting method for cleaning an inner tube surface (4) of a tube (2.1) of a tube bundle heat exchanger (1) by means of an apparatus according to one of Claims 1 to 5, wherein a gaseous and / or liquid blasting medium, mixed with a blasting agent, flows around a deflection body (14) inserted into the tube (2.1) to be cleaned, wherein the deflection body (14) is adapted to an inner tube cross-section with respect to its cross-sectional shape, but is dimensioned smaller than the inner tube cross-section and an annular gap of at least 0.75 mm is formed to the inner tube surface (4), through which the blasting medium flows with the blasting agent during cleaning, wherein the deflection body (14) is guided through the tube (2.1) to be cleaned at a defined speed by means of a retention cable (15), which is fed via a blasting adapter (11) pressed against the front of the tube (2.1) to be cleaned and used to feed the blasting medium mixed with the blasting agent, wherein a minimum speed of the blasting medium is 12 m / s and the speed of the deflection body (14) is between 1 m / min and 18 m / min depending on requirements.

11. Blasting method according to Claim 10, characterised in that the retention cable (15) is fed via a driven roller (17) and / or in that the blasting adapter (11) is pressed against the front of the tube (2.1) to be cleaned by means of a drive unit.

12. Blasting method according to Claim 10 or 11, characterised in that for the sequential cleaning of a plurality of tubes (2, 2.1, 2.2) of the tube bundle heat exchanger (1), the carriage (8) with the blasting adapter (11) and the deflection body (14) is initially moved horizontally along a plurality of laterally adjacent tubes (2, 2.1, 2.2) of a first tube row and in that a vertical position of the guide rail (6) with the carriage (8) held thereon is then re-adjusted for cleaning tubes (2, 2.1, 2.2) of a second tube row, which is arranged above and / or below the previously cleaned first tube row.

13. Blasting method according to one of Claims 1 to 12, characterised in that hard particles with round and / or sharp surfaces and / or a soft blasting medium made of plastic or water-soluble substances or of liquids such as water with and without additives, grease solvents such as paraffin or other soluble liquids are used as blasting agent and in that dry snow or dry ice is preferably used as blasting agent to clean tubes (2. 2.1, 2.2) made of plastic, graphite or glass fibre.

14. Blasting method according to one of Claims 10 to 13, characterised in that in order to adjust the cleaning action on the inner tube surface (4) of the tube (2.1) to be cleaned, the pressure of the blasting medium and / or the nature of the blasting agent is adjusted and / or changed and / or controlled.