DK180366B2 - Cleaning head and apparatus for a method for cleaning boiler surfaces in an incineration plant - Google Patents

Abstract

When cleaning open boiler draft surfaces in an open draft (17, 18, 19) of an incineration plant in use, a device with a rotating nozzle head mounted on a line (7) with cleaning liquid is used. During a first cleaning, the nozzle head (4) is rotated in one direction and during a second cleaning, it is rotated in the opposite direction, which has an improved cleaning effect.

Description

DK 180366 B2 1

Technical area

The present invention relates to an apparatus for a method for cleaning open boiler draft surfaces in an incineration plant. The invention also relates to a cleaning head.

Background engineering

In devices for cleaning boiler surfaces in an incinerator, it is known to use a nozzle head with several nozzles to supply a cleaning liquid to the boiler surfaces to be cleaned, where the nozzle head is rotated and moved linearly into and out of the combustion chamber. An apparatus of this kind is known from US 5 579 726, which describes such a device for cleaning a boiler in use, where the device comprises a lance and a rotating nozzle head which is mounted on the end of the lance, as well as means for providing linear movement into and out of the combustion chamber and means for rotating the cleaning head.

The lance in this device is a rigid construction, and the rotary and linear movements are provided by means of motors mounted externally on the combustion chamber to be cleaned. In all constructions shown and described in this document, the linear movement is in the horizontal direction, and therefore the lance must have a rigid construction. Another cleaning device is known from DE 1 262 496.

Another principle for a vertical movement is described in EP1291598, where the nozzle head comprises a turbine and a gear so that the head rotates more slowly than the turbine.

In order to achieve the best possible results for boiler cleaning, there is a constant need for improvement.

Description of the invention

It is the purpose of the present invention to provide an improvement in the technical field. In particular, it is an object to provide an improved apparatus for a method of cleaning open boiler draft surfaces in an open draft of an incineration plant in use of the type specified above.

The procedure includes:

DK 180366 B2 2 - to provide an apparatus with a cleaning head, where the cleaning head is mounted on a line that carries cleaning liquid to the cleaning head, where the cleaning head has a rotating nozzle head, preferably driven by the flow of the cleaning liquid through the cleaning head, - to introduce this cleaning head into the open draft and remove deposits on the boiler draft surfaces by spraying cleaning liquid from the cleaning head against the boiler draft surfaces during the cleaning with rotation from the nozzle head; and that a first cleaning is done with rotation 1 one direction and a second cleaning with rotation 1 an opposite direction.

The device comprises a cleaning head for immersion in an open draft of a combustion plant in use for cleaning open boiler draft surfaces by spraying cleaning liquid from the cleaning head towards the boiler draft surfaces during cleaning. The cleaning head is mounted on the line that carries cleaning liquid to the cleaning head, where the cleaning head comprises a turbine chamber and a rotatably connected nozzle head with several nozzles from which the cleaning liquid can be sprayed out towards the boiler draw surfaces during rotation of the nozzle head. The turbine chamber contains a turbine that is driven by cleaning fluid in its flow from the line to the nozzles, where an exchange between the turbine and the nozzle head reduces the speed of the nozzle head's rotation in relation to the turbine.

The apparatus is characterized in that it comprises a first and a second nozzle head, where the first and second nozzle heads have mutually opposite rotation, where the turbine chamber contains a turbine flange with channels that lead cleaning fluid from the line to the turbine, where the turbine has an axis of rotation and turbine blades having a normal to their surface, where the normal is angled at an angle w to the axis of rotation, where the ducts are inclined at an angle v to the axis of rotation to impinge on the turbine at a steep angle of attack, where the ratio viw is in the range 0.1 to 0.9, preferably between 0.2 and 0.8, and where the angle v is in the range 25-35 degrees, and the angle w of the normal in the range 40-50 degrees.

Another object of the present invention is to provide a cleaning head for a method for cleaning open boiler draft surfaces in an open draft of an incineration plant in use.

DK 180366 B2 3

The method includes: - providing an apparatus with the cleaning head, where the cleaning head is mounted on a line that carries cleaning liquid to the cleaning head, where the cleaning head has a rotating nozzle head, preferably driven by the flow of the cleaning liquid through the cleaning head, - introducing this cleaning head into the open draw and remove coatings on the boiler drawing surfaces by spraying cleaning liquid from the cleaning head against the boiler drawing surfaces during the cleaning with rotation from the nozzle head; and that a first cleaning is done with rotation 1 one direction and a second cleaning with rotation in an opposite direction;

The cleaning head includes a coupling to the line carrying the cleaning liquid, which carries the cleaning liquid to the cleaning head. The cleaning head comprises a turbine chamber and the rotatably connected nozzle head with several nozzles from which the cleaning liquid can be sprayed out towards the boiler draft surfaces during rotation of the nozzle head. The turbine chamber contains a turbine that is driven by cleaning fluid in its flow from the line to the nozzles, where an exchange between the turbine and the nozzle head reduces the speed of the nozzle head's rotation in relation to the turbine. The turbine chamber contains a turbine flange with channels that conduct cleaning fluid from the line to the turbine, where the turbine has an axis of rotation and turbine blades that have a normal to their surface, where the normal is angled by an angle w relative to the axis of rotation.

The cleaning head is characterized by the fact that the channels are inclined at an angle v in relation to the axis of rotation in order to hit the turbine under a relatively steep angle of incidence, that the angle v is in the range of 25-35 degrees, and the normal angle w in the range of 40-50 degrees.

This purpose is achieved with a method for cleaning open boiler draft surfaces in an open draft of an incineration plant in use as explained in the following.

The method includes - providing an apparatus with a cleaning head mounted on a line, typically at the end of the line, for example flexible hose, which carries cleaning liquid to the cleaning head, where the cleaning head has a rotating nozzle head that is driven by the cleaning liquid itself

DK 180366 B2 4 flow through the cleaning head, for example by means of a turbine and gear as explained in EP1291598, - to carry out a cleaning by introducing, for example immersing, this cleaning head into the open draft and - to remove coatings on the boiler draft surfaces by spray cleaning fluid from the cleaning head against the boiler draw surfaces during cleaning with rotation from the nozzle head.

It has been found that the method of immersing a cleaning head as described in EP1291598 can be improved by a very simple measure, where the direction of rotation is changed periodically between rotating the nozzle head counter-clockwise and clockwise. By changing the direction of rotation, it has been shown that not only corners are cleaned more effectively, but also surfaces, as the strong expansion of the liquid during evaporation in contact with the walls works better if it takes place at changing angles of incidence on the wall. In addition, crevices and behind pipes can be reached more easily. Experimental results with such an approach far exceed what one would expect from a theoretical consideration.

The device is then provided in one embodiment with a cleaning head, where the direction of rotation of the nozzle head can be changed. A suitable gear then switches between the directions of rotation. Alternatively, the apparatus comprises a single cleaning head with two nozzle heads, for example arranged in extension of each other and driven simultaneously in opposite directions by a gear connected to each nozzle head for rotation thereof in opposite directions. In another alternative, a first cleaning head is replaced with another corresponding cleaning head between a first and a second cleaning, where the first and second cleaning heads have nozzle heads with opposite rotation. For example, the device is designed for cleaning with only one cleaning head at a time, and where the two cleaning heads are designed with a coupling for optional mounting of one or the other cleaning head on the line.

Using two nozzle heads with different directions of rotation instead of a single one with a mechanism to change the direction of rotation results in a simpler construction that is typically more robust than adding mechanical elements, for example gears, to change the direction of rotation in a single cleaning head. It may at first seem like a simple one

DK 180366 B2 consideration, but it should be remembered that the nozzle head is immersed in the boiler, but it is in operation, which means that the nozzle head is introduced, for example immersed, in an aggressive flue gas environment where a temperature of 800-1000 degrees prevails celsius and where the water that is sprayed on the walls expands 1500-1700 times with a corresponding turbulence in the 5 draft, which puts a significant load on the nozzle head, regardless of the fact that it is continuously cooled by the water that runs through the nozzle head. In order to provide high reliability and long-term durability, a simple construction of the nozzle head is preferable.

It has also been found that it is not necessary to change direction every time the nozzle head is immersed. For example, it is sufficient to change direction after a number of cleaning processes of 2 to 14 times, for example after two weeks of use. In practice, this means that two unidirectional rotating nozzle heads with opposite rotation directions can be used, where the cleaning heads are changed after a number of cleaning processes.

The cleaning head is then mounted on a line for introduction into the open draft and during cleaning, for example a flexible hose in case of hoisting, typically steel-reinforced hose. The flexible hose is advantageously a bellows-type metal hose, preferably made of stainless steel. It is typically immersed through an opening located at the top of the open feature to be cleaned and directed downwards while supplying cleaning fluid to the nozzles for delivery to the surfaces to be cleaned in an efficient manner. The flexible hose construction minimizes the size of the space required to introduce the cleaning device into the open draft, which enables the use of the device in connection with existing plant 1 essentially without changes to it.

Alternatively, the cleaning head is inserted with a rigid wire, such as a hollow rod, in a horizontal or oblique direction.

Since the device is placed inside the open draft only during the cleaning operations, the construction can be relatively simple, as the cleaning liquid will largely keep the construction cold during the cleaning operation, and the construction will therefore not have to withstand the high temperatures of typically 800-1000 degrees Celsius inside the open draft of the incinerator in use.

DK 180366 B2 6

In practical embodiments, the cleaning head comprises a turbine chamber and a rotatably connected nozzle head with several nozzles, from which the cleaning liquid is sprayed out towards the boiler draft surfaces during rotation of the nozzle head. The turbine chamber contains a turbine which is driven by the cleaning liquid 1 its flow from the line, for example the hose, to the nozzles, where a gear exchange between the turbine and the nozzle head drives the nozzle head and reduces the speed of the nozzle head's rotation in relation to the turbine. A typical rotation speed for the nozzle head is between 1 and 50, preferably between 5 and 10, revolutions per revolution. minute.

In some embodiments, the apparatus includes a mechanism for providing substantially linear, for example vertical, movement of the nozzle head within the open draft.

For example, the mechanism includes a hose reel with a drive unit for lowering and raising the cleaning head on the flexible hose, for example on the end of the flexible hose, downwards and upwards within the open draw. For example, the drive unit for the hose reel is a speed controlled geared motor.

Typically, cleaning liquid is supplied to the nozzle head from a feed water pump, which carries the cleaning liquid through the line, for example the flexible hose, at a predetermined pressure.

For example, the feed water pump is pressure-controlled to a pressure level of less than 10 bar for the cleaning liquid.

It is an advantage that the nozzles of the nozzle head are of a type which keeps the jet flowing from the nozzles concentrated with only less resolution in droplets. In particular, it is noted here that there can be a distance of 10-20 meters from the nozzle to the wall of the draft, and atomization is then undesirable, not least because of the high turbulence due to the strong expansion of the cleaning liquid during evaporation.

It has also been shown to be advantageous in certain situations to reduce the amount of water.

This is not a simple problem, as a reduction in the amount of water can mean that the water jet does not maintain its direction during rotation to hit the wall several meters away if it is not strong enough. It must therefore be ensured that the water jet has the right pressure. With a nozzle head according to the prior art, as described in EP1291598, it has been shown to cause problems of the above kind at a lower amount of water supply.

DK 180366 B2 7

In particular, it has been shown that a lower amount of water does not manage to drive the turbine sufficiently powerfully so that the rotation becomes slower. A completely new dimensioning is complex, as it must not only be ensured that the head rotates sufficiently, but also that there is still sufficient pressure and flow in the water to provide a satisfactory cleaning of the boiler.

This problem has been solved in a simple way in relation to the cleaning head in EP1291598 by slanting the cleaning liquid inlet channels to the turbine. By hitting the turbine with the cleaning fluid at a steeper angle, it has surprisingly been shown that there is more traction on the turbine with less consumption of a cleaning fluid, for example water, at the same time that there is sufficient pressure on the nozzle to produce a jet of range of several meters for cleaning the walls of the boiler hood.

For example, the turbine chamber contains a turbine flange with channels that lead cleaning fluid from the line to the turbine. The turbine has an axis of rotation and turbine blades that have a surface with a normal extending perpendicularly from the surface. The normal of the turbine blade is angled by an angle w in relation to the turbine's axis of rotation. In a particularly advantageous embodiment, the ducts are inclined at an angle v in relation to the axis of rotation in order to hit the turbine under a correspondingly steeper angle of incidence. For example, the ratio v:w is in the range 0.1 to 0.9, preferably between 0.2 and 0.8. For example, the angle v is in the range 20-40 degrees. As an example, the angle v is in the range 25-35 degrees, such as around 30 degrees, and the angle w of the normal is in the range 40-50 degrees, such as around 45 degrees. In the latter specific case, the ratio is then v:w=30:45=0.67.

Preferred embodiments of the cleaning apparatus according to the present invention, the advantages of which will be described in the following detailed part of the present invention, are shown in the subclaims.

Short drawing description

In the following detailed description of the present invention, the invention will be explained in more detail with reference to an embodiment of an apparatus for cleaning open boiler draft surfaces in an incineration plant according to the invention and shown in the drawing, where

DK 180366 B2 8 fig. 1 — schematically shows an incineration plant in which the present invention is implemented, fig. 2 schematically shows a cleaning head in cross-section, which is known from the prior art and which can in principle be used for the improved cleaning method, fig. 3 — schematically shows a hose reel with a drive unit for controlled lowering and raising of the cleaning head and a pump unit for supplying cleaning liquid to the flexible hose, and fig. 4 — shows a set of two nozzle heads with opposite direction of rotation; fig. 5 — shows a special view of two opposite turbines with a) perspective towards the turbine blade and b) with perspective on top of the turbine flange.

Description of the preferred embodiment

The combustion plant shown in fig. 1 comprises three successive open drafts 17, 18, 19, where heat is transferred from flue gases to boiler tubes covering the walls of the open drafts 17, 18, 19. After the open drafts 17, 18, 19, a superheater 20 or several such superheaters or other boiler structures. In such a plant, it is desired to keep the heat exchanger surfaces clean in the open drafts 17, 18, 19 in order to reduce the heat transmission resistance from flue gases to boiler tubes.

The purification device implemented in the incinerator shown in fig. 1, which in principle is known from EP1291598, comprises a cleaning head 1, as shown in FIG. 2, mounted on the end of a flexible hose 7 for introduction and immersion inside the open draft 17 through an opening 16 centrally located at the top of the open draft 17. The linear movement of the cleaning head 1 inside the open draft 17 is provided by the rotating hose reel 6, on which the hose 7 is mounted.

The rotation of the nozzle head 4, as shown in fig. 2, is provided by means of a turbine 2 driven by cleaning fluid, for example water, which enters the cleaning head 1 from the flexible hose 7 and is supplied to the turbine 2 in the turbine chamber 22 through channels 21 in a turbine flange 23 in which the turbine 2 is the camp. In order to reduce the rotational speed of the nozzle head 4, there is an exchange 3 between the turbine 2 and the nozzle head 4. The exchange comprises an external toothed gear 31 placed on the turbine shaft, which drives a

DK 180366 B2 9 gear wheel 32, the shaft of which by means of an external toothing 33 drives a gear 34 which is attached to the cleaning head 4.

Several nozzles 5 are mounted on the nozzle head 4 to distribute the cleaning liquid in different directions during the rotation of the nozzle head 4.

As shown in fig. 3, the hose reel 6 is suspended for rotation on a shaft which is driven by a drive unit 8 for the hose reel 6, where the drive unit 8 comprises an electric motor 9 and a reduction gear mechanism 10. As is also shown in fig. 3, the electric motor 9 is controlled from a control unit 15, which controls motor speed and the direction of rotation of the motor 9.

As is also shown in fig. 3, the cleaning liquid is supplied to the hose 7 by means of a pump unit 11, which comprises an electric motor 12, which drives a pump 13. The electric motor 12 is controlled by the control unit 15 to be able to control the pressure of the cleaning liquid supplied to the flexible hose 7 The connection between the pump 13 and the hose reel 6 includes a rotation coupling 14 to allow the hose reel 6 to rotate relative to the fixed pump 13.

As can be seen from fig. 1, each of the open features 17, 18, 19 has a centrally located opening 16 for inserting the cleaning head 1 and the flexible hose 7 and for lowering and raising the cleaning head 1 downwards and upwards in the open features 17, 18, 19. During immersion and lifting of the cleaning head 1, cleaning liquid is supplied through the flexible hose 7, whereby the nozzle head 4 is rotated, and cleaning liquid is supplied to the inner surfaces of the open features 17, 18, 19 through nozzles 5. These nozzles 5 are dimensioned to supply a concentrated jet of cleaning fluid to the inner surfaces of the open features 17, 18, 19 substantially without the concentrated jets dissolving into droplets. The cleaning liquid is preferably water, which evaporates when it hits the inner surfaces of the open features 17, 18, 19, whereby the water expands to a volume approximately 1500-1700 times its original volume, which expansion provides the forces necessary to remove dirt from the affected surfaces. As already mentioned, the cleaning is carried out during use, i.e. the combustion plant burns fuel and produces heat, and the surfaces to be cleaned have a high temperature, which is necessary to provide evaporation of the cleaning liquid.

DK 180366 B2 10

In the case that cleaning is carried out during the plant's operation, the cleaning can be carried out at any time it is deemed necessary, e.g. by recorded rising temperature of flue gases entering the superheater 20, due to dirt on the boiler surfaces, which reduces the heat transmission from the flue gases in the open drafts 17, 18, 19. It is thus possible to maintain the temperature of the flue gases in a controlled manner, that goes into the superheater 20, below a desired maximum temperature of e.g. 600-650°C.

In this way, corrosion on the superheater tubes is reduced, and furthermore, a reduction in the temperature of the flue gases in the superheater 20 leads to less sticky deposits on the superheater surfaces. In a typical incinerator, cleaning of each open draft 17, 18, 19 is carried out approximately every week, e.g. one of each of the open features 17, 18, 19 is cleaned every other day.

In this way, it has proven possible to lower the temperature of the flue gases at the entrance to the superheater 20 by approx. 100°C.

In an experimental set-up, the cleaning liquid used was water and was supplied to the flexible hose 7 by a jerk of approx. 4 - 5 bar on top of the open features 17, 18, 19, and the nozzle head was provided with 6 nozzles. The time involved in cleaning a single open feature 17 was approx. 5-10 minutes and approx. 1,000 I of water was used for the purification.

Due to the fact that the cleaning system must only be used approx. once a week, a single cleaning system can serve several open drafts 17, 18, 19 by providing suitable means for introducing the cleaning head 1 and the flexible hose 7 through the corresponding openings 16.

Although the invention is described above in connection with a preferred embodiment of the invention as shown in the figures, it will be clear to a person skilled in the field that several deviations are conceivable within the scope of the following claims, such as deviations which, among other things, includes providing multiple openings 16 for each of the open features 17, 18, 19 to be cleaned, in order to move the cleaning head 1 up and down closer to the surfaces where the openings 16 are spaced from the central part of each open feature 17 , 18, 19, providing automatic means for opening and closing the openings 16, providing several cleaning systems, e.g. a cleaning system for each open feature 17,18, 19, where each such cleaning system comprises its respective cleaning head 1, flexible hose 7 and hose reel 6, etc.

DK 180366 B2 11

Fig. 4 shows a set of cleaning heads 1 with turbine chamber 22 and nozzle heads 4 with nozzles 5 oriented to jet in opposite directions. In addition, turbines 2 are provided inside the nozzle heads, which are respectively oppositely oriented, as shown in fig. So.

The turbine blades 28 have an oblique orientation in relation to the axis of rotation 27. The normal 29 to the surface of the turbine blades 28 has an angle w in relation to the axis of rotation 27 of the turbine 2. In the case of bending turbine blades, the normal 29 is the average normal in the area where the cleaning fluid from the channel 21 hits the turbine blade 28 .

In order to increase the pressure of cleaning liquid on the turbine 2, the channels 21 in the turbine flange 23 are inclined at an angle v in relation to the axis of rotation 27, which is indicated by the inclined line 25 in fig. 5b in relation to the dashed line 26, which is parallel to the axis of rotation 27.

It is noted that the corresponding line 25" in the second turbine flange is inclined in the opposite direction and adapted to the second turbine, which has an opposite direction of rotation. By being inclined, the channels 21 cause a more targeted force effect on the turbine blades 28, which has proven to be an advantage especially with less water flow, which reduces water consumption without impairing the cleaning ability. For example, the ratio v:w is in the range 0.1 to 0.8, preferably between 0.2 and 0.8. In the example shown, the angle v is about 30 degrees, and the angle w of the normal is about 45 degrees, so the ratio is about v:w=30:45=0.67. FIG. 5c shows a line drawing of the turbine flange 23.

Claims (8)

DK 180366 B2 12 PATENT CLAIM 1. Apparatus for a method for cleaning open boiler draft surfaces in an open draft (17, 18, 19) of an incinerator in use, where the method comprises - providing an apparatus with a cleaning head (1), where the cleaning head (1) is mounted on a line (7) that carries cleaning liquid to the cleaning head (1), where the cleaning head (1) has a rotating nozzle head (4), preferably driven by the flow of the cleaning liquid through the cleaning head (1), - to introduce this cleaning head (1) in the open draft and remove deposits on the boiler draft surfaces by spraying cleaning liquid from the cleaning head (1) against the boiler draft surfaces during the cleaning with rotation from the nozzle head (4); and that a first cleaning is done with rotation in one direction and a second cleaning with rotation in an opposite direction; where the device comprises a cleaning head (1) for immersion in an open draft (17, 18, 19) of a combustion plant in use for cleaning open boiler draft surfaces by spraying cleaning liquid from the cleaning head (1) against the boiler draft surfaces during cleaning; where the cleaning head (1) is mounted on the line (7) that carries cleaning liquid to the cleaning head (1), where the cleaning head (1) comprises a turbine chamber (22) and a rotatably connected nozzle head (4) with several nozzles ( 5) from which the cleaning liquid can be sprayed out towards the boiler draft surfaces during rotation of the nozzle head (4), where the turbine chamber contains a turbine (2) which is driven by cleaning liquid in its flow from the line (7) to the nozzles (5), where an exchange ( 3) between the turbine (2) and the nozzle head (4) reduces the speed of rotation of the nozzle head (1) relative to the turbine (2); characterized in that the device comprises a first and a second nozzle head (4), where the first and second nozzle heads have mutually opposite rotation, where the turbine chamber contains a turbine flange with channels (21) that lead cleaning liquid from the line (7) to the turbine (2), where the turbine (2) has an axis of rotation (27) and turbine blades (28) that have a normal to their surface, where the normal is angled by an angle w relative to the axis of rotation (27), where the channels (21) is inclined at an angle v in relation to the axis of rotation (27) in order to hit the turbine under a relatively steep angle of incidence, where the ratio v:w is in the range 0.1 to 0.9, preferably between 0.2 and 0.8, and where the angle v is in the range 25-35 degrees, and the angle w of the normal in the range 40-50 degrees. DK 180366 B2 13 2. Apparatus according to claim 1, characterized in that the second cleaning is carried out after the first cleaning, and where between the first and the second cleaning a first cleaning head is replaced with another corresponding cleaning head, where the first and the second cleaning head have nozzle heads with opposite rotation. 3. Apparatus according to claim 1 or 2, characterized in that the cleaning liquid from the nozzles (5) is sprayed out towards the boiler draw surfaces during rotation of the nozzle head (4). 4. Apparatus according to claim 1, characterized in that the apparatus comprises a first and a second cleaning head (1), where the first cleaning head (1) comprises the first nozzle head (4) and the second cleaning head (1) comprises the second nozzle head ( 4). 5. Device according to claim 4, characterized in that the device is designed for cleaning with only one cleaning head at a time, and where the two cleaning heads (1) are designed with a coupling for optional mounting of one or the other cleaning head on the line ( 7). 6. A cleaning head for a method for cleaning open boiler draft surfaces in an open draft (17, 18, 19) of an incineration plant in use, where the method comprises: - providing an apparatus with the cleaning head (1), where the cleaning head (1) is mounted on a line (7) that carries cleaning liquid to the cleaning head (1), where the cleaning head (1) has a rotating nozzle head (4), preferably driven by the flow of the cleaning liquid through the cleaning head (1), - to introduce this cleaning head (1) into the open draft and remove deposits on the boiler draft surfaces by spraying cleaning liquid from the cleaning head (1) against the boiler draft surfaces during the cleaning with rotation from the nozzle head (4); and that a first cleaning is done with rotation in one direction and a second cleaning with rotation in an opposite direction; where the cleaning head (1) comprises a coupling to the cleaning liquid-carrying line (7) that carries cleaning liquid to the cleaning head (1), where the cleaning head (1) comprises a turbine chamber (22) and the rotatably connected nozzle head (4) with several nozzles (5 ) from which the cleaning liquid can be sprayed out towards the boiler draft surfaces during rotation of the nozzle head (4), where the turbine chamber contains a turbine (2) which is driven by cleaning liquid in its flow from the line (7) to the nozzles (5), where an exchange (3 ) between the turbine (2) and DK 180366 B2 14 the nozzle head (4) reduces the speed of the nozzle head (1) rotation in relation to the turbine (2); where the turbine chamber contains a turbine flange with channels (21) that conducts cleaning fluid from the line (7) to the turbine (2), where the turbine (2) has a rotation axis (27) and turbine blades (28) that have a normal to their surface, where the normal is angled by an angle w in relation to the axis of rotation (27), characterized by the fact that the channels (21) are inclined at an angle v in relation to the axis of rotation (27) in order to hit the turbine under a steep angle of incidence, that the angle v is in the range 25-35 degrees, and the angle w of the normal in the range 40-50 degrees. 7. The cleaning head according to claim 6, characterized in that the method further comprises that the second cleaning is carried out after the first cleaning, and where between the first and the second cleaning a first cleaning head is replaced with another corresponding cleaning head, where the first and the other cleaning head has nozzle heads with opposite rotation. 8. Cleaning head according to claim 6, characterized in that the channels (21) are inclined at an angle v in relation to the axis of rotation (27) in order to hit the turbine under a steep angle of incidence, where the ratio v:w is in the range 0.1 to 0.9 , preferably between 0.2 and 0.8.