EP1918671A1 - Cleaning device for heat exchanger and heat exchanger - Google Patents

Abstract

The device (8) has a cleaning unit (9) with a delivery opening for a cleaning medium, where the cleaning unit is extendable and retractable into an inner space of a heat-exchanger i.e. boiler (1). The cleaning unit is supported on a movable slide (13) that is arranged on a rotary disk (14) and is movable in a radial direction of the rotary disk back and forth. The rotary disk is arranged swivelably above the heat-exchanger, so that each point of the inner space of the heat-exchanger is movable with the cleaning unit, where the cleaning unit is accessible from above the heat-exchanger.

Description

The invention relates to a cleaning device for the inner surfaces of a heat exchanger, in particular a boiler. Furthermore, the invention relates to a heat exchanger with such a cleaning device.

Heat exchangers are known, for example, from conventional power plants, waste incineration plants or plants operated with organic fuels. These heat exchangers serve to transmit the thermal energy of a first fluid, for example a flue gas, contactlessly to a second fluid. The second fluid may, for example, be deionized water (eg in the case of the steam generator of a conventional power plant) or a non-boiling heat transfer fluid (for example thermal oil).

There are now various applications in which the inner surfaces of the heat exchanger and in particular the heat-transferring contact surfaces must be periodically cleaned to ensure full functionality of the device.

This problem is particularly present when thermal energy is to be transferred from smoke or combustion gases. Such combustion gases usually contain metal vapors and dusts, which gradually occupy the inner surfaces of the heat exchanger and thus hinder the heat transfer. This can ultimately lead to a massive constriction or even complete obstruction of the smoke or combustion gas flow path.

Therefore, various devices and methods are known in the art for periodically removing such contaminants from the interior surfaces of the heat exchanger.

It is known to remove the impurities mentioned with an air or water stream as a cleaning medium. The cleaning can be done both during standstill of the system and during operation.

Due to the hot inner surfaces of the heat exchanger (up to 1000 ° C) a stream of water directed to a corresponding inner surface evaporates instantaneously, whereby an explosive multiplication of the volume of the cleaning medium occurs. As a result, dust deposits or the like can be effectively removed.

From the DE 103 40 790 B3 a device for cleaning a flue of a combustion plant is known. In this case, a leading the cleaning medium hose is introduced into the flue gas to be cleaned. The cleaning medium can then be conducted to the inner walls of the flue gas duct via an end nozzle head of the hose.

In this device, however, is disadvantageous that it is only suitable for cleaning flat and easily accessible inner surfaces of the heat exchanger. The centrally arranged and accordingly far away from the cleaned-off inner surfaces cleaning device can not fully act on irregularly designed heat transfer surfaces, such as coils, with cleaning medium. If, in the presence of more distant and / or crooked Wärmeübertragerflächen these surfaces are achieved by the cleaning medium, however, the volume flow of the cleaning medium must be greatly increased. As a result, the operating and investment costs rise sharply. Furthermore, the heat transfer surfaces, which are arranged directly in the vicinity of the nozzle head, exposed to a strong thermal shock due to the large volume flow of the cleaning medium. Finally, the large volume flow of the cleaning medium leads to an undesirable total cooling of the heat exchanger, whereby the efficiency of the entire system decreases.

From the DE 201 22 403 U1 is a boiler of a combustion plant with a cleaning system known.

By means of the cleaning system disclosed there, a hose leading the cleaning medium can be introduced into the interior of the trigger to be cleaned. The hose has at its end a rotating nozzle head, which can be driven by the cleaning medium. As a result, an all-reaching beam or spray cone can be realized within the deduction to be cleaned.

In this device, however, is disadvantageous that the nozzle head has a complicated mechanism, on the one hand requires high initial investment and on the other hand, due to the high operating temperature and the aggressive ambient media has an increased susceptibility together with a short life. Furthermore, due to the aforementioned mechanism, the nozzle head has too large external dimensions in order to be able to achieve narrowly subdivided or angled inner surfaces of the heat exchanger.

The present invention is therefore based on the object to provide a cleaning device for the inner surfaces of a heat exchanger, with a cost-effective, gentle, reliable and thorough cleaning of the inner surfaces is possible. A further object of the present invention is to specify a heat exchanger which is cost-effective, gentle, reliable and thoroughly cleanable.

• einem Reinigungsmittel mit zumindest einer Abgabeöffnung für ein Reinigungsmedium, wobei das Reinigungsmittel in den Innenraum eines Wärmeübertragers ein- und ausfahrbar ist,
• wobei das Reinigungsmittel auf einem beweglichen Schlitten gelagert ist,
• wobei der Schlitten auf einem Drehteller angeordnet ist und in radialer Richtung des Drehtellers hin- und her bewegbar ist,
• und wobei der Drehteller oberhalb eines Wärmeübertragers drehbar anordenbar ist,

so dass jeder Punkt des von oben zugänglichen Innenraums eines Wärmeübertragers mit dem Reinigungsmittel anfahrbar ist.According to the invention the above object is achieved with regard to a cleaning device having the features of patent claim 1. Thereafter, a cleaning device for the inner surfaces of a heat exchanger, in particular a boiler, with the following features:

• a cleaning agent having at least one discharge opening for a cleaning medium, wherein the cleaning agent is retractable and extendable into the interior of a heat exchanger,
• wherein the cleaning agent is mounted on a movable carriage,
• wherein the carriage is arranged on a turntable and is movable back and forth in the radial direction of the turntable,
• and wherein the turntable is rotatably arrangeable above a heat exchanger,

so that each point of the accessible from above the interior of a heat exchanger with the detergent is approachable.

The cleaning device according to the invention makes it possible to reach any point in the interior of the heat exchanger to be cleaned with the cleaning agent, whereby a particularly thorough cleaning even narrowly divided or crooked inner surfaces is possible. In order to be reachable for the cleaning agent, the heat exchanger can have a removable housing cover or several openings for introducing the cleaning agent.

In accordance with the invention, it is possible for the cleaning agent to be brought directly to any part of the inner surface of the heat exchanger, after which the use of the cleaning medium (for example water or air) can be carried out in a particularly targeted manner. Therefore, the cleaning device can be operated with a reduced cleaning medium volume flow. As a result, excessive cooling of immediately adjacent heat transfer surfaces (so-called thermal shock) can be avoided. Furthermore, the amount of cleaning medium can be reduced overall since the cleaning medium can be used in a more metered manner.

The invention also makes it possible to use a cleaning device of simple mechanical construction and a very compact cleaning agent, which on the one hand enables a reduced capital expenditure and, on the other hand, an excellent accessibility to very narrow subdivisions of the interior of the heat exchanger.

The cleaning device according to the invention is particularly advantageous if the heat-transmitting inner surfaces of the heat exchanger to be cleaned consist of pipes, pipe beating, pipe baskets or the like. With the cleaning device, the spaces between adjacent pipes (pipe gusset) can be cleaned very thoroughly. In this case, the cleaning agent can be brought particularly close to the uneven heat transfer surfaces. Furthermore, the discharge opening or let the discharge openings of the cleaning agent can be particularly precisely aligned to such areas. It is only possible with the cleaning device according to the invention to approach such narrow and winding areas at all with a cleaning agent. This cleaning option is not known in systems according to the prior art, which provide the cleaning meter wide flue gas ducts with flat inner surfaces.

Consequently, a cleaning device for the inner surfaces of a heat exchanger is specified, with the cost-effective, gentle, reliable and thorough cleaning of these inner surfaces is possible.

In a further development of the invention, predetermined positions or housing openings of a heat exchanger can be automatically and possibly sequentially approached with the cleaning agent. In other words, this means that the system according to the invention can be programmable such that it automatically carries out the cleaning of the inner surfaces of a heat exchanger arranged below the cleaning device at predetermined time intervals. In this case, the cleaning device can successively approach different housing openings formed in the heat exchanger and clean the underlying inner areas, in particular heating pipes or the like. Accordingly, a fully automatic cleaning of a heat exchanger is made possible with the cleaning device according to the invention.

Preferably, the intended cleaning device as a cleaning agent on a cleaning medium leading hose with an end cleaning head with at least one discharge opening for a cleaning medium. Due to the axial flexibility of the hose this can be stored in a small footprint, for example, when rolled up.

In a further preferred manner, the cleaning device has a delivery unit and / or a guide unit for the hose. By a conveyor unit, the entry or exit movement of the hose can be accurately controlled in the heat exchanger to be cleaned. By a guide unit an exact positioning of the tube in the radial direction is reached. Furthermore, unwanted twisting of the tube is avoidable.

With regard to a particularly compact design of the cleaning device, the hose can be rolled up and unrolled in a drum rotatably mounted in the carriage. As a result, on the one hand, a low ceiling height of the location of the device according to the invention can be realized, and at the same time, the hose can be stored in a space-saving and gentle manner.

Advantageously, the drum has a horizontal axis of rotation. Furthermore, the drum can be driven by a frequency-controlled gear motor, whereby a particularly precise up and rolling movement of the hose is ensured.

In view of the lowest possible twistability of the hose, a development of the invention is preferred in which the hose has a low axial moment of resistance at the same time increased polar resistance moment. In other words, this means that the hose has increased flexibility with simultaneously increased torsional stability. Increased torsional stability prevents twisting of the hose during the cleaning operation, so that the position of the dispensing opening or the dispensing openings for the cleaning medium can not change undesirably.

With regard to increased durability and temperature stability of the hose, a development is preferred in which the hose is made of temperature-resistant steel, in particular as a corrugated hose or as a bellows, and optionally can be cooled by the cleaning medium.

With regard to enabling a particularly effective cleaning of the inner surfaces of the heat exchanger, the end-side cleaning head of the hose may have a nozzle or one or more, in particular opposite pairs of nozzles for discharging the cleaning medium. As a result, the discharge rate and the precision of the cleaning medium jet can be significantly increased.

In this case, an embodiment is preferred in which the nozzle or the nozzles are aligned horizontally or slightly inclined upward. As a result, the ceiling of the heat exchanger can be cleaned and at the same time an effective cleaning possibility for substantially horizontally oriented pipe interspaces is created, as they occur, for example, when using tubular baskets as heat transfer surfaces.

With regard to a particularly effective cleaning option for such pipe interspaces, the axial spacing of adjacent nozzle pairs can be substantially correspond to the distance to be cleaned between pipe spaces (gusset). This means that in each case a nozzle pair can clean a substantially horizontally extending tube gap. The adjacent pairs of nozzles are offset in the axial direction of the tube in each case by exactly one pipe diameter, so that they can each aim in the nearest pipe gap or gusset. In addition to a particularly effective cleaning option for the pipe interstices, this also specifies a development in which a temperature shock can be avoided by direct impact of the cleaning medium on the respective center of the heating pipe.

In a further embodiment, in view of a particularly thorough cleanability of the inner surfaces of the heat exchanger, the orientation of the nozzle or the nozzles during the cleaning operation adjustable and / or the position of the cleaning head within the heat exchanger during the cleaning operation changeable. As a result, inaccessible or twisted inner surfaces can be specifically approached with the cleaning head according to the invention and completely cleaned during the cleaning operation.

In an alternative embodiment of the invention, the cleaning device as a cleaning agent on a lance with at least one discharge opening for the cleaning medium. In this case, a blowing lance has the advantage that it is not only vertically, but also horizontally and / or obliquely in the respective housing opening on or extendable. With regard to a particularly long durability and temperature resistance of the lance this can be made of temperature-resistant steel and optionally be cooled by the cleaning medium. Furthermore, the lance may have one or more nozzles according to the aforementioned embodiments.

Furthermore, the above-mentioned object is achieved with respect to a heat exchanger with the features of claim 8. Thereafter, a heat exchanger, in particular a boiler, for non-contact transmission of the heat energy of a first fluid, in particular flue gas, to a second fluid, in particular a heat transfer fluid or water, wherein the heat exchanger has periodically to be cleaned inner surfaces, a cleaning device according to the invention.

The heat exchanger according to the invention may have a box or cylindrical shape or any other conventional form. The shape of a vertical cylinder is particularly suitable if, as heat transfer surfaces, heating coils or upright, optionally concentric, and multi-layer tubular baskets are to be used.

In a preferred development of the invention, the entire heat exchanger has a removable housing cover or at least one cleaning opening for maintenance or for standstill cleaning. In this case, in the housing cover also a cleaning opening (for example, as a manhole) may be formed. The housing cover preferably extends over the entire upper side of the heat exchanger housing. Accordingly, a suitable housing cover for a heat exchanger according to the invention in the form of a vertical cylinder has a circular disk shape.

In a particularly preferred manner, the heat exchanger according to the invention has a plurality of top-lying, closable housing openings for retracting the cleaning agent. As a result, an almost unlimited variability of the heat exchanger according to the invention is achieved in connection with the arbitrarily positionable cleaning device, since each area to be cleaned off can be provided with a corresponding housing opening so that the entire contents of the heat exchanger can be reached by the cleaning device or by the cleaning agent.

With regard to facilitated accessibility and closeability of the housing openings, an embodiment is preferred in which the housing openings are formed as a nozzle and, if appropriate, can be closed by flange-on lids.

In a development of the invention, the housing openings have automatic shut-off devices for introducing and removing the cleaning agent. Such shut-off devices can be provided both in flat housing openings as well as in the aforementioned nozzle. By this shut-off is optimally cleanability of the heat exchanger during operation, since leakage of flue gases through the shut-off devices can be prevented to the greatest extent possible.

The heat-transmitting inner surfaces of the heat exchanger may have a planar or even a tubular design. In view of an increased heat transfer surface, however, an embodiment is preferred in which the second fluid in pipes through the interior of the heat exchanger can be guided.

With regard to a particularly good utilization of the existing interior, the heat-transferring inner surfaces can be designed as multi-layer, concentrically arranged tubular baskets. A tube basket has the shape of a stationary heating coil. In this case, the windings can rest on one another or be spaced apart in the axial direction.

Fig.1

eine schematische seitliche Schnittansicht eines Ausführungsbeispiels des erfindungsgemäßen Wärmeübertragers, der mit einem Ausführungsbeispiel der erfindungsgemäßen Reinigungsvorrichtung ausgerüstet ist, und

Fig. 2

eine schematische Draufsicht auf das Innere des erfindungsgemäßen Wärmeübertragers gemäß gezeigtem Ausführungsbeispiel.

There are now various possibilities for designing and developing the teaching of the present invention in an advantageous manner. For this purpose, on the one hand to the subordinate claims, on the other hand, to refer to the following explanation of a preferred embodiment of the inventive devices with reference to the drawings. In conjunction with the explanation of the preferred embodiments with reference to the drawings, generally preferred embodiments and developments of the teaching are explained. In the drawing shows

Fig.1

a schematic sectional side view of an embodiment of the heat exchanger according to the invention, which is equipped with an embodiment of the cleaning device according to the invention, and

Fig. 2

a schematic plan view of the interior of the heat exchanger according to the invention according to the embodiment shown.

Fig. 1 shows a schematic side sectional view of a first embodiment of the heat exchanger according to the invention and the cleaning device according to the invention. Shown is first a heat exchanger, here as Heating boiler 1 is formed. The boiler 1 has a circular cross-sectional area and is horizontal, that is arranged upright. On the upper side, the boiler 1 has a plurality of closable housing openings 2, of which only three are shown in the sectional view. In this boiler 1, the housing openings 2 are formed in a removable cover 3 of the boiler 1. By removing the lid 3, the interior of the boiler 1 is accessible for maintenance or shutdown cleaning.

The housing openings 2 are formed in the lid 3 as a nozzle 4, whereby they can be closed by flangeable cover or other suitable devices.

The boiler 1 has inside extended internal surfaces 5, which must be cleaned regularly, since the boiler 1 is flowed through during operation of dust-carrying flue gas.

The proportion of the inner surfaces 5, which serves as a heat-transferring surface in the embodiment shown, is formed in the embodiment shown by two concentric tube baskets 6. These are two tube coils which are in one another, through which the second, heat-absorbing fluid can be guided. The first, heat-emitting fluid flows through the interior of the heat exchanger. In the embodiment shown, the first fluid is smoke or combustion gases.

During operation, dust and other contaminants deposit on the inner surfaces 5. Of these, in particular the spaces between the pipe turns of the tube baskets 6 are affected. These tube spaces 7 are also referred to as gussets. Here, a lot of dust and other dirt can settle and hinder the heat transfer to the second fluid.

For cleanability of the boiler 1, the heat exchanger is associated with a cleaning device 8 according to the invention.

The cleaning device 8 consists of a cleaning agent 9, which is designed here as a hose 10. Furthermore, a cleaning head 11 for discharging the cleaning medium is assigned to the end of the hose 10.

The hose 10 is made of temperature-resistant steel in the form of a corrugated hose. He is flexible, but at the same time has an increased polar moment of resistance, which counteracts a twisting of the hose 10.

The hose 10 serves both as a supply line for the cleaning medium and for positioning of the cleaning head 11 for discharging the medium. He is thereby cooled by the flowing cleaning medium.

The use of the cleaning device 8 can be carried out both during operation of the heat exchanger at temperatures up to about 1000 ° C and during the standstill of the device.

The tube 10 is up on a drum 12 and unrolled, which on the one hand a particularly gentle use of the tube 10 and on the other hand, a space-saving storage of not retracted into the boiler 1 section of the tube 10 is made possible.

In accordance with the invention, the cleaning agent 9, in this case designed as a hose 10, is mounted on a movable carriage 13. For this purpose, the drum 12 is rotatable, but fixedly connected to the carriage 13. The carriage 13 is arranged on a turntable 14 and is displaceable on this in the radial direction.

The turntable 14 is in turn rotatably disposed above the boiler 1. In this way, any desired point of the upper side of the boiler 1 can be approached in accordance with the invention with the cleaning agent 9.

The cleaning device according to the invention is particularly suitable for cylindrically shaped boiler 1, since the turntable 14 in this case, the entire top of the boiler 1 can operate.

For insertion and removal of the cleaning agent 9, the nozzle 4 of the boiler 1 are provided with automatic shut-15. As a result, an automatic operation of the entire device is possible because unneeded nozzle 4 are automatically closed. Furthermore, the heat exchanger according to the invention can be cleaned during operation, as can be prevented by the automatic shut-off devices 15 leakage of flue gas to the greatest extent possible.

The lifting and lowering movement of the hose 10 is controllable via a conveyor unit 16. A further provided guide unit 17 ensures that the tube is not undesirably twisted, which could change the position of the discharge openings for the cleaning medium. The supply of the cleaning medium to the drum 12 via a compression means 18, a pressure relief 19, a pressure accumulator 20, a flexible connection 21, a filter 22, a pressure monitoring means 23, a valve control 24 and a rotary feedthrough 25th

For cleaning the inner surfaces 5 of the boiler 1, the cleaning head 11 on an opposite pair of nozzles 26, in which case only the front nozzle 26 is visible. The nozzles 26 are aligned so that they exactly in each case in the closest pipe gap 7 einzielen with a correspondingly accurate height adjustment of the cleaning head 11 in order to clean it very thoroughly.

The cleaning head 11 may also have a plurality of horizontally spaced nozzle pairs, wherein the distance between the nozzle pairs may each correspond to the distance between two adjacent pipe spaces 7.

Due to the adjustability of the nozzles 26 on the tube interspaces 7 is prevented that an excessive volume flow of the cleaning medium meets the central region of the heat-transmitting tubes, which could set during the cleaning operation, a thermal shock with a corresponding failure of the heating tubes. This makes it possible in accordance with the invention to introduce the discharge openings for the cleaning medium directly to the area to be cleaned, but without damaging the boiler 1.

To clean the pipe interspaces 7, the nozzles 26 are aligned substantially horizontally. The nozzles 26 may also be designed to be adjustable within the cleaning head 11. Furthermore, by a variability of the position of the cleaning head 11 during operation, the entire area below the respective housing opening 2 (from the lid 3 to the bottom of the boiler 1) are approached.

Fig. 2 shows a plan view of the boiler 1 of the heat transfer according to the invention from Fig. 1. The boiler 1 has a circular base and has the shape of a vertical cylinder. The inner surfaces 5 consist on the one hand of the inner walls of the housing and on the other hand of the heat-transmitting inner surfaces 5, which are formed as two concentric tube baskets 6. In this illustration, it becomes clear how difficult it is to access the inner surfaces 5 for cleaning devices.

On the upper side of the boiler 1 are a plurality of housing openings 2, which can be approached with the cleaning agent 9 of the cleaning device according to the invention in a particularly simple manner.

In this case, the cleaning agent 9 can be supplied by rotating the turntable and corresponding displacement of the carriage of any housing opening 2, after which a thorough cleaning of any small portion of the boiler 1 can be done.

In the heat exchanger according to the invention and with the cleaning device according to the invention, the cleaning medium can be dispensed particularly sparingly, since it is particularly suitable for use. As a result, both operating and investment costs can be reduced.

Furthermore, the heat exchanger according to the invention does not contain a cleaning device which has a complicated and trouble-prone mechanism. This ensures a particularly long service life and reliability of the heat exchanger according to the invention .

Finally, it should be emphasized that the exemplary embodiments described above discuss the claimed teaching, but did not restrict it to the exemplary embodiment.

Claims (11)

Cleaning device for the inner surfaces of a heat exchanger, in particular a boiler (1), with a cleaning agent (9) having at least one discharge opening for a cleaning medium, wherein the cleaning agent (9) in the interior of a heat exchanger and retractable, wherein the cleaning means (9 ) is mounted on a movable carriage (13), wherein the carriage (13) on a turntable (14) is arranged and in the radial direction of the turntable (13) reciprocally movable, and wherein the turntable (14) above a Heat exchanger is rotatable can be arranged, so that each point of the accessible from above the interior of a heat exchanger with the cleaning agent (9) is approachable. Cleaning device according to claim 1, characterized in that with the cleaning agent (9) predetermined positions or housing openings (2) of a heat exchanger are automatically and, if appropriate, successively approachable. Cleaning device according to claim 1 or 2, characterized in that the cleaning agent (9) has a cleaning medium leading hose (10) having an end cleaning head (11), wherein optionally the hose movement by a conveyor unit (16) and / or a guide unit ( 17) is controllable. Cleaning device according to claim 3, characterized in that the hose (10) in a in the carriage (13) rotatably mounted drum (12) and is unrolled, wherein optionally the drum (12) has a horizontal axis of rotation and / or of a frequency-controlled geared motor is driven. Cleaning device according to claim 3 or 4, characterized in that the hose (10) has a low axial moment of resistance at the same time increased polar moment of resistance and / or the hose (10) made of temperature-resistant steel, in particular as a corrugated hose or bellows, is formed and possibly . Can be cooled by the cleaning medium. Cleaning device according to one of claims 3 to 5, characterized in that the cleaning head (11) has a nozzle (26) or one or more, in particular opposite, nozzle pairs for discharging the cleaning medium, optionally wherein the nozzle or the nozzles (26 ) are aligned horizontally or slightly upwards and / or the axial spacing of adjacent pairs of nozzles essentially corresponds to the distance between pipe interspaces (7) (gusset) within a heat exchanger and / or the alignment of the nozzle or nozzles (26) during cleaning the cleaning operation is adjustable and / or the position of the cleaning head (11) is variable during the cleaning operation. Cleaning device according to claim 1 or 2, characterized in that the cleaning agent (9) has a cleaning lance leading lance. Heat exchanger, in particular a heating boiler (1), for non-contact transmission of the heat energy of a first fluid, in particular flue gas, to a second fluid, in particular a heat transfer fluid or water, wherein the heat exchanger has periodically to be cleaned inner surfaces, characterized by a cleaning device according to one of claims 1 to 7th Heat exchanger according to claim 8, characterized by a box or cylindrical shape and / or by a removable housing cover (3) and / or a cleaning opening for maintenance or for standstill cleaning. Heat exchanger according to claim 8 or 9, characterized by a plurality of overhead, lockable housing openings (2) for retracting the cleaning agent (9), in particular wherein the housing openings (2) are designed as stubs (4) and can be closed by flange-mounted cover and if necessary / or the housing openings (2) have automatic shut-off devices (15) for introducing and removing the cleaning agent (9). Heat exchanger according to one of claims 8 to 10, characterized by planar and / or tubular heat-transmitting inner surfaces (5), optionally wherein the heat-transferring inner surfaces (5) as a cylindrical tubular basket (6) or as a multi-layer, in particular concentric tube baskets (6) are formed.

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