Retractable cleaning nozzle

Abstract

A retractable cleaning nozzle for spraying the inner surface of a pipe or tank. The cleaning nozzle comprises a nozzle housing configured to be fixedly mounted in a hole of a side wall of the pipe or tank and having a front side arranged to face the interior of the pipe or tank and a rear side arranged to face away from the interior of the pipe or tank, an inlet port configured for receiving a cleaning fluid, and a cylindrical inner bore defining a central axis with an axial direction. The inner bore is open towards the front side of the nozzle housing. The cleaning nozzle comprises a first plug movably arranged within the bore of the nozzle housing in the axial direction between a retracted position and an extended position. The first plug has a sleeve-shaped body comprising a first set of spray holes. The cleaning nozzle comprises a second plug arranged within a space defined by the sleeve-shaped body of the first plug and configured for closing a flow path from the inlet port to the first set of holes of the first plug when the first plug is in the retracted position.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a retractable cleaning nozzle for spraying the inner surface of a pipe or tank, and a method for spraying the inner surface of a pipe or tank using a retractable cleaning nozzle.

[0002] The retractable cleaning nozzle according to the present disclosure can be installed in the wall of a tank or pipe that needs to be cleaned periodically, such as for example in the pharmaceutical industry, the food processing industry, the brewing industry, the chemical industry, etc. BACKGROUND

[0003] In the field of cleaning nozzles for spraying the inner surface of a pipe or tank, there is a continuous need for further improvements in terms of cleaning efficiency and high hygienic standards.

[0004] For example, document EP0295325A1 shows a retractable cleaning nozzle which in the retracted state can be substantially flush with the inner surface of a tank, while providing a radial oriented spray of cleaning fluid when set in the extended state.

[0005] This type of retractable cleaning nozzle provides a high level of hygienic standards, since the embedded installation in the retracted state effectively reduces the space for holding fluid products, thereby reducing the risk of bacterial breeding.

[0006] However, even with these activities in the field, there is still a need for further improvements in cleaning nozzles in terms of cleaning efficiency combined with high hygienic standards. SUMMARY

[0007] It is an object of the present disclosure to provide a retractable cleaning nozzle which is improved in terms of cleaning efficiency and high hygienic standards. This object is at least partially achieved by the features of the independent claims.

[0008] According to a first aspect of the present disclosure, a retractable cleaning nozzle for spraying an inner surface of a pipe or tank is provided. The cleaning nozzle comprises a nozzle housing configured to be stationary mounted in a bore of a side wall of the pipe or tank and having a front side arranged to face towards the interior of the pipe or tank and a rear side arranged to face away from the interior of the pipe or tank, an inlet port configured for receiving a cleaning fluid, and a cylindrical inner bore with a central axis defining an axial direction, wherein the inner bore is open towards the front side of the nozzle housing; a first plug movably arranged within the bore of the nozzle housing in the axial direction between a retracted position and an extended position, wherein the first plug has a sleeve-shaped body with a front wall closing a front portion of the sleeve-shaped body, wherein the front wall of the sleeve-shaped body comprises a first set of spray holes configured to spray the cleaning fluid substantially in the axial direction, wherein the sleeve-shaped body of the first plug comprises a second set of spray holes configured to spray the cleaning fluid substantially in a radial direction perpendicular to the axial direction, wherein in the retracted position of the first plug, the front surface of the first plug is substantially flush with the front surface of the nozzle housing, and wherein in the extended position of the first plug, the front portion of the first plug comprising the first set of spray holes and the second set of spray holes extends beyond the front surface of the nozzle housing for allowing to spray the inner surface of the pipe or tank; and a second plug arranged within the space defined by the sleeve-shaped body of the first plug and configured to close a flow path from the inlet port to the first set of holes of the first plug when the first plug is in the retracted position.

[0009] According to a second aspect of the present disclosure, a method for spraying an inner surface of a pipe or tank using a retractable cleaning nozzle is provided. The cleaning nozzle has a nozzle housing stationary mounted in a bore of a side wall of the pipe or tank, wherein the nozzle housing has a front side facing towards the interior of the pipe or tank and a rear side facing away from the interior of the pipe or tank. The nozzle housing further has an inlet port for receiving a cleaning liquid, a cylindrical inner bore with a central axis defining an axial direction, a first plug movably arranged within the bore in the axial direction, and a second plug. The method comprises controlling a linear actuator operably connected to the movable first plug for moving the first plug from a retracted position to an extended position in which a front portion of the first plug comprising a first set of spray holes and a second set of spray holes extends into the tank or pipe, thereby starting a spraying of the cleaning fluid substantially in the axial direction via the first set of spray holes of the first plug and starting a spraying of the cleaning fluid substantially in a radial direction perpendicular to the axial direction via the second set of spray holes of the first plug; and controlling the linear actuator for moving the first plug from the extended position to the retracted position in which the front surface of the first plug is substantially flush with the front surface of the nozzle housing and in which the second plug closes a flow path from the inlet port to the first set of spray holes of the first plug.

[0010] In this way, the cleaning nozzle can still be mounted substantially flush with the inner surface of the tank or pipe, thereby maintaining a high hygienic standard, while at the same time providing an improved cleaning efficiency due to the forward and lateral combined spraying of the cleaning fluid in the extended operating state of the nozzle.

[0011] Further advantages are achieved by implementing one or several of the features of the dependent claims.

[0012] In some example embodiments, the retractable cleaning nozzle further comprises a first sealing arrangement for sealing the first plug against the nozzle housing, in particular for sealing an annular space between the first plug and the nozzle housing, and a second sealing arrangement for sealing the second plug against the first plug, in particular for sealing an annular space between the second plug and the first plug. Using said annular spaces for sealing the flow of cleaning liquid allows the use of cost-effective, reliable and easy-to-replace sealing rings.

[0013] In some example embodiments, which can be combined with any one or more of the above-described embodiments, the first sealing arrangement is arranged for sealing an annular space between a radially outer surface of the first plug and a radially inner surface of the nozzle housing. Using said annular space for sealing the flow of cleaning liquid allows the use of cost-effective, reliable and easy-to-replace sealing rings.

[0014] In some example embodiments, which can be combined with any one or more of the above-described embodiments, the second sealing arrangement is arranged for sealing the second plug against the first plug only in the retracted position of the first plug. Thereby, the automatic shut-off and sealing of the jet is achieved by moving the first plug from the extended position to the retracted position only.

[0015] In some example embodiments, which can be combined with any one or more of the above-described embodiments, the first plug further has a central cylindrical operating rod extending in the axial direction, and the second plug has a central cylindrical bore extending in the axial direction and configured to receive the operating rod of the first plug. The centrally arranged operating rod allows a compact design and implementation of the rotatable first plug.

[0016] In some example embodiments, which can be combined with any one or more of the above-described embodiments, the retractable cleaning nozzle further comprises a third sealing arrangement for sealing an annular space between a radially inner surface of the second plug and a radially outer surface of the first plug. Thereby, there is no leakage along said operating rod.

[0017] In some example embodiments, which can be combined with any one or more of the above-described embodiments, the first sealing arrangement is arranged for sealing the first plug against the nozzle housing only in the retracted position of the first plug. Thereby, in the retracted position, the first sealing arrangement can be located close to the front side of the first plug and thus provides very little space for the working product.

[0018] In some example embodiments, which can be combined with any one or more of the embodiments described above, the first and second sealing arrangements, in particular the first, second and third sealing arrangements, are located substantially in the same radial plane when the first plug is in the retracted position. This can allow for good sealing performance due to good force transmission through the seals in the retracted position.

[0019] In some example embodiments, which can be combined with any one or more of the embodiments described above, the retractable cleaning nozzle further comprises a fourth sealing arrangement for sealing the first plug against the nozzle housing in the extended position of the first plug. Thereby, more cleaning liquid is forced to be ejected via the dedicated spray hole.

[0020] In some example embodiments, which can be combined with any one or more of the embodiments described above, the second and fourth sealing arrangements, in particular the second, third and fourth sealing arrangements, are located substantially in the same radial plane when the first plug is in the extended position. This can allow for good sealing performance due to good force transmission through the seals in the extended position.

[0021] In some example embodiments, which can be combined with any one or more of the embodiments described above, the first sealing arrangement and / or the second sealing arrangement and / or the third sealing arrangement and / or the fourth sealing arrangement is a sealing ring, in particular an O-ring. This provides a cost-effective design.

[0022] In some example embodiments, which can be combined with any one or more of the embodiments described above, the nozzle housing as well as the first plug and the second plug are made of stainless steel or the like. This provides a robust, reliable and hygienic design.

[0023] In some example embodiments, which can be combined with any one or more of the embodiments described above, the first sealing arrangement is mounted in an annular recess in a radially outer surface of the front portion of the sleeve-shaped body of the first plug, and the fourth sealing arrangement is mounted in an annular recess in a radially outer surface of the rear portion of the sleeve-shaped body of the first plug. Thereby, the automatic shut-off and sealing of the ejection flow is achieved only by moving the first plug from the extended position to the retracted position.

[0024] In some example embodiments, which can be combined with any one or more of the embodiments described above, the substantially flat front surface of the first plug extends in radial direction to the first sealing arrangement. This guarantees that the volume for the working product to enter the cleaning nozzle is very small.

[0025] In some example embodiments, which can be combined with any one or more of the embodiments described above, the second plug comprises a central cylindrical shaft having a radially outwardly extending flange at its front end, wherein a front facing, preferably flat, surface of the flange abuts a corresponding rear facing surface of the front wall of the first plug. This guarantees a very small volume for the working product to enter the cleaning nozzle.

[0026] In some example embodiments, which can be combined with any one or more of the embodiments described above, the first set of spray holes is closed on a rear side of said spray holes by a second plug. This guarantees a very small volume for the working product to enter the cleaning nozzle.

[0027] In some example embodiments, which can be combined with any one or more of the embodiments described above, the retractable cleaning nozzle is free of components located in the front of the first set of spray holes. Thereby, the cleaning nozzle can have a flat front surface which is flush with the surrounding surface of the tube or tank.

[0028] In some example embodiments, which can be combined with any one or more of the embodiments described above, a second sealing arrangement is mounted in an annular recess in the radially outer surface of the flange of the second plug, and a third sealing arrangement is mounted in an annular recess in the radially inner surface of the flange of the second plug. This can allow for good sealing performance due to good force transmission through the seals.

[0029] In some example embodiments, which can be combined with any one or more of the embodiments described above, the nozzle housing serves as an inlet port for receiving a cleaning fluid, and the cleaning fluid is configured to flow, in the extended position of the first plug, from the inlet port to the first set of spray holes and the second set of spray holes via an annular passage defined by the second sealing arrangement and the radially inner surface of the sleeve-shaped portion of the first plug. Thereby, an easily sealed flow path to the first set of spray holes and the second set of spray holes is provided.

[0030] In some example embodiments, which can be combined with any one or more of the embodiments described above, the nozzle housing serves as an inlet port for receiving a cleaning fluid, and the cleaning fluid is configured to stop the spraying, in the retracted position of the first plug, by means of the first sealing arrangement and the second sealing arrangement. Thereby, an easily sealed flow path to the first set of spray holes and the second set of spray holes is provided.

[0031] In some example embodiments, which can be combined with any one or more of the embodiments described above, the retractable cleaning nozzle further comprises a linear actuator operably connected to the movable first plug for controlling the movement of the first plug between the retracted position and the extended position. Thereby, an accurate and reliable control of the movement of the first plug is achieved.

[0032] In some example embodiments, which can be combined with any one or more of the embodiments described above, the linear actuator comprises a fixed actuator housing, a linearly movable actuation member, and a drive member operatively connected with the actuation member, wherein the fixed actuator housing is rigidly attached to the fixed nozzle housing, and the actuation member is operatively connected to the first plug for controlling the movement of the movable first plug between the retracted position and the extended position. Thereby, an accurate and reliable control of the movement of the first plug is achieved.

[0033] In some example embodiments, which can be combined with any one or more of the embodiments described above, the retractable cleaning nozzle further comprises a rotation mechanism arranged to cause the first plug to angularly displace a predetermined angle, such as for example in the range of 5-175 degrees, in particular in the range of 20-110 degrees, around its central longitudinal axis during each activation event involving moving the first plug from the retracted position to the extended position and back again to the retracted position. Thereby, an accurate and reliable control of the rotational movement of the first plug is achieved.

[0034] In some example embodiments, which can be combined with any one or more of the embodiments described above, the rotation mechanism is arranged to cause the first plug to angularly displace a first predetermined angle around its central longitudinal axis during the movement of the first plug from the retracted position to the extended position, and to cause the first plug to angularly displace a second predetermined angle around its central longitudinal axis during the movement of the first plug from the extended position to the retracted position. Thereby, the rotation mechanism can be made more compact.

[0035] In some example embodiments, which can be combined with any one or more of the embodiments described above, the rotation mechanism comprises at least one radially extending guide member rotatably connected with the first plug, and a cam member rotatably connected with the fixed nozzle housing or the actuator housing, or at least one radially extending guide member rotatably connected with the fixed nozzle housing or the actuator housing, and a cam member rotatably connected with the first plug; wherein the cam member has at least one cam surface which is inclined with respect to the axial direction and configured for interacting with the at least one radially extending guide member upon movement of the first plug from the retracted position to the extended position and back again to the retracted position for causing a controlled rotation of the first plug. The use of a cam member interacting with a guide member allows a cost-effective and reliable combination of axial and rotational movement using only a linear actuator.

[0036] In some example embodiments, which can be combined with any one or more of the embodiments described above, the rotation mechanism comprises a set of at least two radially protruding guide members rotationally connected with the piston of the pneumatic linear actuator, and a cam member rotationally secured to the stationary actuator housing, wherein the piston is rigidly connected and rotationally secured to the first plug, and wherein the cam member has at least two cam surfaces which are inclined with respect to the axial direction and configured for interacting with the radially protruding guide members upon movement of the piston and the first plug from the retracted position to the extended position and back to the retracted position for causing a controlled rotation of the piston and the first plug. Thereby, the rotation mechanism can be implemented in the linear actuator.

[0037] In some example embodiments, which can be combined with any one or more of the embodiments described above, the cam member of the rotation mechanism comprises a first annular sleeve and a second annular sleeve which are connected to each other and axially overlapping, wherein each of the first annular sleeve and the second annular sleeve comprises at least one cam surface which is inclined with respect to the axial direction, wherein the at least one radially protruding guide member is configured for interacting with the at least one cam surface of the first annular sleeve when the first plug is moved from the retracted position to the extended position, and wherein the at least one radially protruding guide member is configured for interacting with the at least one cam surface of the second annular sleeve when the first plug is moved from the extended position to the retracted position. This provides a compact cam member with simplified manufacturing.

[0038] In some example embodiments, which can be combined with any one or more of the embodiments described above, the rotation mechanism is arranged such that 4-24 consecutive activation events, in particular 6-12 consecutive activation events, will cause the first plug to perform one full rotation. This allows to increase the injection pressure due to the reduced spray hole area.

[0039] In some example embodiments, which can be combined with any one or more of the embodiments described above, the linear actuator is a pneumatic or hydraulic operated single-acting cylinder-piston actuator with a mechanical spring for biasing the piston towards a rear position of the piston, wherein the cylinder-piston actuator further comprises a bearing arranged between the mechanical spring and the piston for simplifying the relative rotation of the mechanical spring and the piston. This provides a simplified control of the actuator.

[0040] In some exemplary embodiments, which can be combined with any one or more of the above-described embodiments, the second plug is arranged movably in axial direction relative to the first plug and spring-loaded towards the front side of the nozzle housing for providing improved sealing contact with the first plug, in particular with the front wall and / or the sleeve-shaped body of the first plug. This provides improved sealing performance between the first plug and the second plug.

[0041] In some exemplary embodiments, which can be combined with any one or more of the above-described embodiments, the linear actuator is a pneumatic or hydraulically operated cylinder-piston actuator, wherein the second plug extends into the actuator housing, and wherein the mechanical spring of the second plug is located in the actuator housing and abuts the rear side of the second plug and the front side of the piston. This provides a compact design.

[0042] In some exemplary embodiments, which can be combined with any one or more of the above-described embodiments, the first set of spray holes provided on the front wall of the sleeve-shaped body are arranged in one or more separate front clusters of spray holes, wherein each hole of the separate front clusters is located within a sector having a central angle of no more than 90 degrees, in particular wherein the sector has a central angle of no more than 45 degrees. This provides a maintained liquid spray pressure at reduced supply pressure or an increased liquid spray pressure at maintained supply pressure.

[0043] In some exemplary embodiments, which can be combined with any one or more of the above-described embodiments, the front surface of the first plug has a substantially flat surface arranged in a plane perpendicular to the axial direction, and the first set of spray holes are arranged in said substantially flat surface. This provides a flush surface of the cleaning nozzle.

[0044] In some exemplary embodiments, which can be combined with any one or more of the above-described embodiments, the first set of spray holes provided on the front wall of the sleeve-shaped body are arranged in two oppositely positioned front clusters of spray holes, wherein each front cluster comprises about 5-15 holes. This provides a maintained liquid spray pressure at reduced supply pressure or an increased liquid spray pressure at maintained supply pressure.

[0045] In some exemplary embodiments, which can be combined with any one or more of the above-described embodiments, the first set of spray holes provided on the front wall of the sleeve-shaped body are arranged to spray cleaning liquid within an angular range of at least 0-30 degrees relative to the axial direction, and the second set of spray holes provided in the sleeve-shaped body are arranged to spray cleaning liquid within an angular range of about 45-135 degrees relative to the axial direction. This allows the cleaning nozzle to have a very good coverage of adjacent inner surfaces of a tank or tube.

[0046] The present disclosure also relates to an assembly comprising a tank or pipe and a retractable cleaning nozzle as described above, wherein the nozzle housing of the retractable cleaning nozzle is fixedly mounted in a bore of a side wall of the pipe or tank, wherein the front side is arranged to face the interior of the tank or pipe.

[0047] In some exemplary embodiments, which can be combined with any one or more of the above-described embodiments, the retractable cleaning nozzle further comprises a rotation mechanism arranged to cause the first plug to angularly displace a predetermined angle about its central longitudinal axis during each activation event involving moving the first plug from the retracted position to the extended position and back again to the retracted position, the method comprising repeating the step of activating the control linear actuator to move the first plug from the retracted position to the extended position and subsequently move the first plug from the extended position back to the retracted position during a cleaning event at least four times, in particular at least eight times, for providing at least one full rotation of the first plug during the cleaning event.

[0048] Additional features and advantages of the present application will be apparent from the detailed description that follows, taken in conjunction with the accompanying drawings. Those skilled in the art will recognize that the various features of the present disclosure can be combined in different embodiments without departing from the scope of the present disclosure. BRIEF DESCRIPTION OF DRAWINGS

[0049] In the following, a retractable cleaning nozzle and associated method of use according to the present disclosure will be described in detail with reference to the accompanying drawings, in which

[0050] Figure 1 a perspective view schematically illustrating an exemplary embodiment of a cleaning nozzle,

[0051] Figures 2A-2D a cross-section of an exemplary embodiment of a cleaning nozzle in a retracted state,

[0052] Figures 3A-3B a cross-section of an exemplary embodiment of a cleaning nozzle in an extended state, Figures 2A-2D

[0053] Figures 4A-4C various views of a first plug of the cleaning nozzle of Figs. 1A-1B and 3A-3B, Figures 2A-2D

[0054] Figure 4D illustrating an exemplary spray angle of a first plug,

[0055] Figures 5A-5C various views of a second plug of the cleaning nozzle of Figs. 1A-1B and 3A-3B, Figures 2A-2D

[0056] Figures 6A-6C Figures 2A-2D ​​​​Various views of the cam part of the cleaning nozzle of 3A-3B,

[0057] Figures 7A-7C showing Figures 2A-2D Various views of the piston of the cleaning nozzle of 3A-3B,

[0058] Figures 8A-8B showing a cross section of a further exemplary embodiment of a cleaning nozzle in a retracted state and an extended state,

[0059] Figures 9A-9B showing a cross section of a still further exemplary embodiment of a cleaning nozzle in a retracted state and an extended state,

[0060] Figures 10A-10B showing a cross section of a still another exemplary embodiment of a cleaning nozzle in a retracted state and an extended state,

[0061] Figures 11-12 showing an assembly of a cleaning nozzle mounted in a pipe or tank,

[0062] Figure 13 showing an example of an asymmetric spray pattern,

[0063] Figure 14 showing a nozzle housing attached to a side wall,

[0064] Figures 15-16 showing the main steps of some exemplary methods of use of a cleaning nozzle. DETAILED DESCRIPTION

[0065] Various aspects of the present disclosure will be described below with reference to the accompanying drawings, in which like names represent like elements, and variations of the described aspects are not limited to particularly shown embodiments, but are applicable to other variations of the present disclosure.

[0066] Figure 1 schematically showing a perspective view of a first exemplary embodiment of a retractable cleaning nozzle 1 for spraying the inner surface of a cleaning pipe or tank according to the present disclosure. As discussed in more detail below, the cleaning nozzle 1 has a first plug 2 movably arranged in an axial direction AD between a retracted position and an extended position, and in Figure 1 the first plug 2 is in the retracted position in

[0067] Figure 2A showing Figure 1 a cross section of the cleaning nozzle 1 of Figure 2B , 2C and 2D are Figure 2A enlargements of certain parts of the cleaning nozzle of

[0068] Figure 3A Show Figure 1 The cross-section of the cleaning nozzle 1, wherein the first plug is in the extended position, and Figure 3B yes Figure 3A An enlarged portion of the cleaning nozzle.

[0069] Reference Figure 1 , 2A -2D and 3A-3B, the retractable cleaning nozzle 1 includes a nozzle housing 3 configured to be fixedly mounted in a hole in the side wall of a pipe or tank, and having a front side 4 arranged facing the interior of the pipe or tank and a rear side 5 arranged away from the interior of the pipe or tank, an inlet port 6 configured to receive cleaning fluid, and a cylindrical internal opening 7 having a central axis 8 defining an axial direction AD, wherein the internal opening 7 opens toward the front side 4 of the nozzle housing 3.

[0070] The retractable cleaning nozzle 1 also includes a first plug 2, which is movably arranged in the axial direction AD between a retracted position and an extended position within an opening 7 in the nozzle housing 3. The first plug 2 has a sleeve-shaped body 9, which has a front wall 10 that closes the front portion of the sleeve-shaped body 9.

[0071] The front wall 10 of the sleeve-shaped body 9 includes a first set of spray holes 11 configured to spray cleaning fluid substantially in the axial direction AD. The sleeve-shaped body of the first plug also includes a second set of spray holes 12 configured to spray cleaning fluid substantially in the radial direction RD perpendicular to the axial direction AD.

[0072] The cleaning fluid located inside the sleeve-shaped body 9 can therefore only escape from the inside of the sleeve-shaped body 9 either forward through the first set of spray holes 11 and radially outward through the second set of spray holes 12, or backward.

[0073] In the retracted position of the first plug 2, the front surface 13 of the first plug 2 is substantially flush with the front surface 14 of the nozzle housing 3, and in the extended position of the first plug 2, the front portion of the first plug 2, including the first set of spray holes 11 and the second set of spray holes 12, extends beyond the front surface 14 of the nozzle housing 3 to allow spraying of the inner surface of the cleaning tube or tank.

[0074] The retractable cleaning nozzle 1 also includes a second plug 15, which is arranged within the space defined by the sleeve-shaped body 9 of the first plug 2 and configured to close the flow path from the inlet port to the first set of spray holes 11 of the first plug 2 when the first plug 2 is in the retracted position.

[0075] Thereby, a retractable cleaning nozzle 1 is provided which not only lies flush substantially over the entire surface facing the inner surface of a tank or pipe for ensuring a high hygienic standard, but which is also capable of spraying cleaning fluid substantially in axial direction AD and substantially in radial direction RD for ensuring an improved cleaning efficiency.

[0076] In some exemplary embodiments, the retractable cleaning nozzle further comprises a first sealing arrangement 16 for sealing the first plug 2 against the nozzle housing 3 and a second sealing arrangement 17 for sealing the second plug 15 against the first plug 2.

[0077] In particular, in exemplary embodiments of the Figures 2A-3B first sealing arrangement 16 is configured for sealingly closing the passage between the first plug 2 and the nozzle housing 3, i.e. for sealing the annular space between the first plug 2 and the nozzle housing 3.

[0078] In more detail, the first sealing arrangement can be arranged for sealing an annular space between a radially outer surface of the first plug 2 and a radially inner surface of the nozzle housing 3, in particular an annular space between a radially outer surface of the first plug 2 and a radially inner surface of the inner opening 7 of the nozzle housing 3. Thereby, when the first plug 2 is in the retracted position, leakage of cleaning fluid out of the cleaning nozzle through the annular space defined by the radially outer surface of the first plug 2 and the radially inner surface of the inner opening 7 of the nozzle housing 3 is prevented.

[0079] In fact, in exemplary embodiments of the cleaning nozzle according to the Figures 1-3B first sealing arrangement 16 seals the first plug 2 against the nozzle housing 3 only in the retracted position of the first plug 2, because the first sealing arrangement 16 protrudes from the nozzle housing 3 when the first plug 2 is in the extended position, i.e. is not in contact with the nozzle housing 3 when the first plug 2 is in the extended position.

[0080] Thus, the portion of the sleeve-shaped body 9 having the second set of spray holes 12 protrudes and exceeds the front surface 14 of the nozzle housing 3 in the extended position of the first plug 2, and the portion of the sleeve-shaped body 9 having the second set of spray holes 12 is located within the nozzle housing 3 and is sealed from the interior of the pipe or tank by means of the first sealing arrangement 16 in the retracted position of the first plug 2.

[0081] With reference to Figure 3B , the first plug 2 can protrude from the front surface 14 of the housing 3 in the extended position by a distance 72 of about 5-100 mm, and is substantially flush with the front surface 14 in the retracted position.

[0082] Figure 4A a perspective view of the first plug 2 is shown in a disassembled state, i.e. detached from the nozzle housing 3, and Figure 4B a rear view of the first plug 2 is shown, and Figure 4C a side view of the first plug 2 is shown along Figure 4Bcross-sectional view of the cut A-A.

[0083] With reference to Figures 1-4C The first sealing arrangement 16 is mounted in an annular recess 18 in the radially outer surface of the front portion 19 of the sleeve-shaped body 9 of the first plug 2. Thereby, the first sealing arrangement 16 is located relatively close to the front surface of the first plug 2, such that only a small amount of fluid product can enter the cleaning nozzle 1 when the first plug 2 is in the retracted position.

[0084] The front surface 13 of the first plug 2 has a substantially flat surface arranged in a plane perpendicular to the axial direction AD, and the first set of spray holes 11 is arranged in said substantially flat front surface 13. This feature contributes to a flush front surface of the cleaning nozzle, thereby reducing the risk of contamination caused by possible dirt or bacteria breeding stuck in recesses of the cleaning nozzle. Furthermore, by arranging the first set of spray holes 11 in said substantially flat front surface 13, it is allowed to spray cleaning fluid in, or at least substantially in, the axial direction AD.

[0085] The substantially flat front surface 13 of the first plug 2 defines an angle of about 90 degrees with the elongation direction of the sleeve-shaped body 9 of the first plug 2 in a plane perpendicular to the axial direction AD. In other words, the front wall 10 of the first plug 2 together with the sleeve-shaped body 9 of the first plug 2 defines a piston-shaped hollow structure similar to those typically found in combustion engines, where the piston crown corresponds to the front wall 10 of the first plug 2, and the piston skirt corresponds to the sleeve-shaped body 9 of the first plug 2.

[0086] The annular recess 18 for holding the first sealing arrangement 16 is located in the front portion 19 of the sleeve-shaped body 9, in particular in the corner region of the first plug 2 where the front wall 10 and the sleeve-shaped body 9 meet.

[0087] Thus, the substantially flat front surface 13 of the first plug 2 extends mainly in the radial direction RD to the first sealing arrangement 16.

[0088] In Figures 2A-3B In the exemplary embodiment of the cleaning nozzle 1, the second sealing arrangement 17 is arranged in the annular recess 18 in the radially outer surface of the front portion 19 of the sleeve-shaped body 9 of the first plug 2. Thereby, the second sealing arrangement 17 is located relatively close to the front surface of the first plug 2, such that only a small amount of fluid product can enter the cleaning nozzle 1 when the first plug 2 is in the retracted position.

[0089] Thus, in this exemplary embodiment of the cleaning nozzle, the second sealing arrangement 17 only seals the second plug 15 against the first plug 2 in the retracted position of the first plug 2. In the extended position of the first plug 2, the second sealing arrangement 17 does not seal the second plug 15 against the first plug 2.

[0090] As a result, in particular with reference toFigure 2A and 3B The nozzle housing 3 has an inlet port 6 for receiving a cleaning fluid, and the cleaning fluid is configured to flow, in the extended position of the first plug 2, from the inlet port 6 to the first set of spray holes 11 and the second set of spray holes 12 via an annular passage defined by the second sealing arrangement 17 and the radially inner surface of the sleeve-shaped portion 9 of the first plug 3.

[0091] For the same reasons, in particular because the first sealing arrangement 16 seals and closes the annular space between the radially outer surface of the first plug 2 and the radially inner surface of the inner bore 7 of the nozzle housing 3, and the second sealing arrangement 17 seals and closes the annular passage between the radially inner surface 33 of the sleeve-shaped portion 9 of the first plug 3 and the radially outer surface of the second plug 15, the cleaning fluid is configured to stop the first set of spray holes 11 and the second set of spray holes 12 from spraying by means of the first sealing arrangement 16 and the second sealing arrangement 17 in the retracted position of the first plug 2.

[0092] Thus, the retractable cleaning nozzle can be free of a closing member located in all of the first set of spray holes 11, i.e. in the front portion of the first plug and configured for stopping the flow of cleaning liquid through the first set of spray holes 11 when the first plug 2 is transferred from the extended position to the retracted position. As a result, the cleaning nozzle can have a very flat and flush front surface.

[0093] Figure 5A a perspective view of the second plug 15 in a disassembled state, i.e. detached from the nozzle housing 3, and Figure 5B a rear view of the second plug 2, and Figure 5C a cross-sectional view along the cut A-A. Figure 5B a cross-sectional view along the cut A-A.

[0094] In this exemplary embodiment of the cleaning nozzle, the second sealing arrangement 16 is mounted in an annular recess 21 in the radially outer surface of the flange 20 of the second plug 15.

[0095] When the first plug 2 is located in the retracted position, the first set of spray holes 11 is closed by means of the second plug 15. In particular, the second plug 15 can comprise a central cylindrical shaft 24 having a radially outwardly extending flange 20 at its front end, and a front-facing, preferably flat surface 25 of the flange 20 abuts against a corresponding rear-facing surface 26 of the front wall 10 of the first plug 2. Furthermore, the second sealing arrangement 17 ensures that the cleaning fluid cannot reach the first set of spray holes 11, and that the fluid product within the tank or tube cannot enter the cleaning nozzle 1.

[0096] The outer diameter D1 of the radially outwardly extending flange 20 at the front end of the second plug 15 can be at least 50% of the outer diameter D2 of the front surface 13 of the first plug 2 for allowing the first set of spray holes 11 to be positioned on a relatively large useful area of the front surface 13 of the first plug 2.

[0097] The actuation of the first plug 2 between the retracted position and the extended position can be implemented in various ways. For example, the retractable cleaning nozzle 1 can comprise a linear actuator 27 operatively connected to the movable first plug 2 for controlling the movement of the first plug 2 between the retracted position and the extended position.

[0098] The linear actuator 27 can for example be a pneumatically, hydraulically or electrically operated linear actuator.

[0099] In some example embodiments, the first plug 2 can comprise a central cylindrical operating rod 28 extending in axial direction and operatively connected to the linear actuator 27. The operating rod 28 can for example be connected to or integrally formed with the front wall 10 of the first plug 2.

[0100] In this arrangement, the second plug 15 can have a central cylindrical bore 29 extending in axial direction AD and configured to receive the operating rod 28 of the first plug 2 and to allow relative movement between the first plug 2 and the second plug 15.

[0101] In other words, the operating rod 28 of the first plug 2 can extend through the second plug 15 and be operatively connected to the linear actuator 27 on the rear side of the second plug 15. The second plug 15 can thus be telescoped over the operating rod 28 of the first plug 2.

[0102] Further, a forward movement of the operating rod 28 will result in a forward movement of the first plug 2, while the second plug 15 can remain more or less stationary, thereby moving the cleaning nozzle from a passive state in which the first plug 2 is in the retracted position to an active cleaning state in which the first plug 2 is in the extended position.

[0103] In addition, in this example embodiment of the cleaning nozzle, the third sealing arrangement 22 can be mounted in an annular recess 23 in the radially inner surface of the flange 20 of the second plug 15 for sealing the passage between the radially inner surface of the second plug 15 and the radially outer surface of the first plug 2 or the operating rod 28 of the first plug 2.

[0104] In some example embodiments, the first sealing arrangement 16 and the second sealing arrangement 17 are substantially located in the same radial plane when the first plug 2 is in the retracted position. Substantially located in the same radial plane means herein that the seals are displaced from each other in the axial direction AD by no more than 5 mm. This allows a reduced space for the liquid product from the tank or tube to enter the cleaning nozzle in the retracted position of the first plug 2, and an effective and reliable radial compression of the sealing arrangements between the opening 7 of the housing 3 and the operating rod 28 of the first plug 2.

[0105] Similarly, in some example embodiments, the first sealing arrangement, the second sealing arrangement and the third sealing arrangement can be substantially located in the same radial plane when the first plug is in the retracted position. This allows a further reduced space for the liquid product from the tank or tube to enter the cleaning nozzle in the retracted position of the first plug 2, and a further improved radial compression of the sealing arrangements between the opening 7 of the housing 3 and the operating rod 28 of the first plug 2.

[0106] In some example embodiments, the cleaning nozzle 1 can comprise a fourth sealing arrangement 30 for sealing the first plug 2 against the nozzle housing 3 in the extended position of the first plug 2. In particular, the fourth sealing arrangement 30 is arranged for sealing an annular space between the sleeve-shaped body 9 of the first plug 2 and a radially inner surface of the internal opening 7 of the nozzle housing 3. Thereby, in the extended position of the first plug 2 a leakage flow of the cleaning fluid between the first plug 2 and the nozzle housing 3 can be reduced, thereby increasing the spray flow out through the first and second set of spray holes 11, 12.

[0107] Indeed, the fourth sealing arrangement 30 can be seated in a radially outward facing annular recess 31 at the rear portion 32 of the sleeve-shaped body 9, and can be arranged for sliding contact with the radially inner surface of the internal opening 7 during displacement of the first plug 2 between the retracted and the extended position, thereby reducing the risk of accidental and unintentional escape of the fourth sealing arrangement 30 from the annular recess 31.

[0108] Hence, the first sealing arrangement 16 is mounted in an annular recess 18 in the radially outer surface of the front portion 19 of the sleeve-shaped body 9 of the first plug 2, and the fourth sealing arrangement 30 is mounted in an annular recess 31 in the radially outer surface of the rear portion 32 of the sleeve-shaped body 9 of the first plug 2.

[0109] In some example embodiments, the second sealing arrangement 17 and the fourth sealing arrangement 30, and in particular the second sealing arrangement 17, the third sealing arrangement 22 and the fourth sealing arrangement 30, are located substantially in the same radial plane when the first plug 2 is in the extended position. Substantially in the same radial plane means herein that the sealing members are displaced from each other in the axial direction AD not more than 5 mm. This allows an efficient and reliable radial compression of said sealing arrangements between the operating rod 28 of the first plug 2 in the extended position and the opening 7 of the housing 3.

[0110] Various types of annular sealing members, such as O-rings, can be used to implement the various sealing arrangements described above. Thus, the first sealing arrangement can be implemented as a sealing ring, in particular an O-ring. The second sealing arrangement can also be implemented as a sealing ring, in particular an O-ring. The third sealing arrangement can be implemented as a sealing ring, in particular an O-ring. The fourth sealing arrangement can also be implemented as a sealing ring, in particular an O-ring.

[0111] The cleaning nozzle is generally made of a metallic material, such as stainless steel or a similar type of hygienic material. Thus, the nozzle housing, as well as each of the first and second plugs, can be made of stainless steel or the like.

[0112] As Figure 2A and 3A As schematically shown in Figs. 1 and 2, the linear actuator 27 can be implemented as a pneumatic cylinder having a fixed actuator housing 34 and a driving member in the form of a piston 36 operatively connected with a central actuation member 35. The piston 36 can be operated by supplying pressurized air into a pressure chamber 58 of the cylinder via an air supply connector 59. The fixed actuator 34 housing can be rigidly attached to the fixed nozzle housing 3, and the actuation member 35 can be operatively connected with the operating rod 28 of the first plug 2 for controlling the movement position of the movable first plug 2 between the retracted position and the extended position.

[0113] However, the linear actuator 27 can alternatively be implemented as a hydraulic cylinder, or as an electric linear actuator having a driving member in the form of a screw nut, for example, which is engaged with a linearly movable screw rod acting as the actuation member.

[0114] If the first set of spray holes 11 and / or the second set of spray holes 12 of the first plug 2 are substantially evenly distributed and reach a sufficient high spray pressure of the cleaning liquid, the cleaning nozzle can produce a satisfactory cleaning performance of the inner surface of the tank or pipe without a rotation mechanism arranged to cause rotation of the first plug.

[0115] However, in certain situations, such as when the fluid pressure of the supplied cleaning fluid is relatively low for the same reasons, the injection pressure of the cleaning liquid can be too low when there is a relatively large number of spray holes. Such situations can occur, for example, when the cleaning liquid pump for supplying cleaning liquid to the cleaning nozzle 1 has a relatively small capacity for allowing a cost-efficient and energy-efficient design of the cleaning system.

[0116] Thus, in order to achieve a relatively long operating distance of the cleaning nozzle, while avoiding the use of large, expensive and powerful pumps, the cleaning nozzle 1 can be provided with a relatively small number of spray holes. Thereby, the injection pressure of the cleaning liquid at the spray holes can be maintained even with a smaller pump capacity. Furthermore, in order to achieve a satisfactory cleaning result even with fewer spray holes, the retractable cleaning nozzle can comprise a rotation mechanism for rotating the first plug during use of the cleaning nozzle 1. Thereby, a satisfactory cleaning performance is achieved in combination with a cost-efficient and energy-efficient pump design.

[0117] In other words, according to some example embodiments, the retractable cleaning nozzle 1 can comprise a rotation mechanism 37 arranged to cause the first plug 2 to become angularly displaced by a predetermined angle, such as, for example, in the range of 5-175 degrees, particularly in the range of 20-110 degrees, about its central longitudinal axis during each activation event involving moving the first plug 2 from the retracted position to the extended position and back again to the retracted position.

[0118] With reference to Figure 2A , 2C , 3A, 6A-C and 7A-C, according to some example embodiments, the rotation mechanism 37 comprises at least one radially extending guide member 38 rotatably connected with the first plug 2, and a cam member 39 rotatably connected with the fixed actuator housing 34, wherein the cam member 39 comprises at least one cam surface 40 inclined with respect to the axial direction AD and configured for interacting with the at least one radially extending guide member 38 upon movement of the first plug 2 from the retracted position to the extended position and back again to the retracted position for causing a controlled rotation of the first plug 2.

[0119] In Figure 2A , 2C , 3A, 6A-C and 7A-C, the rotation mechanism 37 comprises four radially extending guide members 38 distributed around a periphery of a sleeve member 41 associated with the piston 36, which is rotatably connected with the first plug 2 via the actuation member 25 and the operating lever 28.

[0120] In some example embodiments, the rotation mechanism 37 can be arranged to cause the first plug 2 to become angularly displaced by a first predetermined angle around its central longitudinal axis during movement of the first plug 2 from the retracted position to the extended position. The rotation mechanism 37 can also be arranged to cause the first plug 2 to become angularly displaced by a second predetermined angle around its central longitudinal axis during movement of the first plug 2 from the extended position to the retracted position.

[0121] Thus, during each activation event involving moving the first plug 2 from the retracted position to the extended position and back again to the retracted position, the piston 36 and the first plug 2 connected thereto will perform two separate rotational movements, one when the piston 36 is moved forward and the first plug 3 is moved from the retracted position to the extended position, and one when the piston 36 is moved backward and the first plug 2 is moved from the extended position to the retracted position.

[0122] This two-step movement of the piston 36 is caused by the design of the sleeve part 41 of the fixed actuator housing 34, which involves two cam surfaces for each guide part 38 and activation event. In detail, a first cam surface 40 interacts with the extended guide part 38 during forward movement of the piston, and a further cam surface 43 interacts with the extended guide part 38 during backward movement of the piston.

[0123] Figure 6A The cam part 39 of -C has eight cam surfaces 40 distributed around the circumference of the cam part 39 for providing the first rotational step, and eight further cam surfaces 43 distributed around the circumference of the cam part 39 for providing the second rotational step. Thus, the cleaning nozzle according to this example embodiment requires eight activation events to perform a full 360-degree rotation of the first plug 2. However, the number of cam surfaces can of course vary depending on the specific situation and needs.

[0124] Furthermore, this two-step design of the cam part 39 is optional, and the cam part 39 can be implemented with a single cam surface for each activation event.

[0125] The radially extending guide parts 38 can for example be radially extending pins, sliders or rollers. As Figure 2C As depicted in Fig. 4, the guide parts 38 can even be rollers with roller bearings 44 for further reducing friction losses.

[0126] According to some example embodiments, the rotation mechanism 37 can comprise a set of at least two radially extending guide members 38 rotatably connected with the piston 36 of the pneumatic linear actuator 27, and a cam member 39 torsionally fixed to the stationary actuator housing 34, wherein the piston 36 is rigidly connected and torsionally fixed to the first plug 2, and wherein the cam member 39 has at least two cam surfaces inclined with respect to the axial direction and configured for interacting with the radially extending guide members 38 upon axial movement of the piston 36 and the first plug 2 from the retracted position to the extended position and back again to the retracted position for causing a controlled rotation of the piston 36 and the first plug 2.

[0127] With reference to Figures 6A-6C , according to some example embodiments, the cam member 39 of the rotation mechanism 37 can comprise a first annular sleeve 39a and a second annular sleeve 39b joined to each other and axially overlapping, wherein each of the first annular sleeve 39a and the second annular sleeve 39b comprises at least one cam surface 40, 43 inclined with respect to the axial direction AD, wherein the at least one radially extending guide member 38 is configured for interacting with the at least one cam surface 40 of the first annular sleeve 39a when the first plug 2 is moved from the retracted position to the extended position, and wherein the at least one radially extending guide member 38 is configured for interacting with the at least one cam surface 43 of the second annular sleeve 39b when the first plug 2 is moved from the extended position to the retracted position.

[0128] The exact number of radially extending guide members 38 can depend on the specific case and can for example be in the range of 2-16 individual guide members 38.

[0129] Similarly, depending on the case, the rotation mechanism can be arranged to perform a suitably large angular rotation for each activation event. For example, the rotation mechanism can be arranged such that 4-24 consecutive activation events, in particular 6-12 consecutive activation events, will cause the first plug to perform a full rotation, i.e. to rotate at least 360 degrees around the central axis 8.

[0130] The cleaning nozzle 1 is not limited to Figure 2A , 2C , the example embodiments of 3A, 6A-C and 7A-C, and various changes can be made to the cleaning nozzle 1 and / or the rotation mechanism 37. For example, with regard to the rotation mechanism, the cam member 39 can be rotatably connected with the piston 36 and / or the first plug 2, and the radially extending guide members 38 can be torsionally fixed to the stationary actuator housing 34. Furthermore, the rotation mechanism 37 comprising the radially extending guide members 38 and the cam member 39 can even be implemented in the nozzle housing 3, thereby allowing the use of a more conventional linear actuator.

[0131] The linear actuator 27 can have a housing 34 for enclosing the piston and the rotary mechanism 37, wherein the housing 34 comprises a rear wall 46, a front wall 42 and a cylindrical wall 47 extending between the front wall 42 and the rear wall 46.

[0132] In Figure 2A and 3A exemplary embodiments, the actuation member 35 extends rearwardly through the rear wall 46 of the linear actuator 27 for allowing position detection of the linear actuator 27, e.g. using suitable sensor means. However, this is optional and the actuation member 35 can alternatively not extend through the rear wall 46, which can then be closed instead.

[0133] Depending on the overall design of the retractable cleaning nozzle 1, a spacer 57 can be provided between the linear actuator 27 and the nozzle housing 3. In Figure 2A and 3A exemplary embodiments, the spacer 57 is integrated in the front wall 42 of the actuator 27.

[0134] For example, the linear actuator 37 is a pneumatic or hydraulic operated single-acting cylinder-piston actuator with a mechanical return spring 45 for biasing the piston 36 towards a rear position of the piston 36. The return spring 45 can thus be mounted between the front wall 42 of the actuator housing 34 and the front side of the piston 36.

[0135] Further, as shown in Figure 2D , if the linear actuator 27 has the rotary mechanism 37 integrated therein, the cylinder-piston actuator 27 can additionally comprise a roller bearing 70 arranged between the mechanical spring 45 of the first plug 2 and the piston 36 for simplifying the relative rotation between the mechanical spring 45 and the piston 36.

[0136] With reference to Figure 1 and 4B , the first set of spray holes 11 provided in the front wall 10 of the sleeve-shaped body 9 can be arranged in one, two, three, four or more separate front clusters 48 of spray holes 11, wherein each spray hole 11 of the separate front clusters 48 can be located within a sector 49 having a central angle 50 of no more than 90 degrees, in particular wherein the sector has a central angle of no more than 45 degrees.

[0137] For example, the first set of spray holes 11 provided in the front wall 10 of the sleeve-shaped body 9 can be arranged in two separate and oppositely located front clusters 48 of spray holes 11, wherein each spray hole 11 of the separate front clusters 48 can be located within a sector 49 having a central angle 50 of no more than 45 degrees. According to some exemplary embodiments, each front cluster 48 comprises about 5-15 spray holes.

[0138] Thus, as Figure 13As is schematically illustrated, the resulting spray pattern of the first set of spray holes 11 can be relatively narrow in a first radial direction RD1 and relatively wide in a second radial direction RD2 positioned substantially perpendicular to the first radial direction. This type of spray pattern can be particularly suitable for the rotatable first plug 2, because the relatively narrow spray pattern allows for a stronger spray pressure without the need for a higher pump capacity and still a satisfactory cleaning performance is obtained due to the rotatable first plug 2, i.e. the rotatable spray pattern.

[0139] In other words, the non-uniformly distributed cluster-shaped first set of spray holes 11 allows to maintain the cleaning liquid spray pressure at a reduced pump supply pressure or to increase the liquid spray pressure at a maintained pump supply pressure.

[0140] Figure 4D An exemplary embodiment of the first plug 2 with the first set of spray holes 11 and the second set of spray holes 12 is schematically illustrated, wherein the first set of spray holes 11 provided in the front wall 10 of the sleeve-shaped body 9 are arranged to spray cleaning liquid in an angular range of at least 0-30 degrees with respect to the axial direction AD, as depicted by the first angle 51. Further, the second set of spray holes 12 provided in the sleeve-shaped body 9 are arranged to spray cleaning liquid in an angular range of about 45-135 degrees with respect to the axial direction AD, as depicted by the second angle 52 and the third angle 53.

[0141] In order to increase the likelihood that the spray pressure of the cleaning liquid at the first set of spray holes and the second set of spray holes is strong enough, the flow area of the inlet port 6 can be selected to be larger than the cumulative flow area of the first set of spray holes 11 and the second set of spray holes 12 taken together. In particular, the flow area of the inlet port 6 can be selected to be at least twice the cumulative flow area of the first set of spray holes 11 and the second set of spray holes 12.

[0142] Thus, for example, when the flow area of the inlet port 6 is about 400 mm 2 , the cumulative flow area of the first set of spray holes 11 and the second set of spray holes 12 can be selected to be not larger than 400 mm 2 , in particular less than 200 mm 2 . The flow area of the inlet port and / or the spray holes corresponds to the flow area, i.e. the effective flow area, of the tube port or the spray opening.

[0143] Reference is made to Figure 2A and 3AThe second plug 15 is movably arranged in axial direction AD relative to the first plug 2 and spring loaded towards the front side 14 of the nozzle housing 3 for providing an improved sealing contact between the first plug 2 and the second plug 15 in the retracted position of the first plug 2. The spring loaded second plug 15 guarantees a particularly good sealing performance between the front flange 20 of the second plug 15 and the front wall 10 and / or the sleeve-shaped body 9 of the first plug 2.

[0144] The spring loaded second plug 15 can be realized in various ways. For example, as Figure 2A and 3A schematically shown, the linear actuator 27 can be a cylinder-piston actuator 27 which is operated pneumatically or hydraulically, wherein the second plug 15 extends via a connection arrangement 55 into the actuator housing 34 and wherein the mechanical spring 54 of the second plug 15 is located in the actuator housing 34 and abuts the rear side of the second plug 15, in particular of the components of the connection arrangement 55, and the front side of the piston 36.

[0145] Thereby, in the retracted position of the first plug 2, the second plug 15 is always pushed forward against the valve seat on the rear side of the first plug 2. In the extended position of the first plug 2, the second plug 15 has to have some kind of forward movement limiting arrangement for avoiding that the second sealing arrangement remains in sealing contact with the first plug 2, because this would prevent the cleaning liquid from reaching the first group of spray holes. In the exemplary embodiment shown in Figure 3A , the forward movement limiting arrangement 56 is implemented by means of a flange component of the connection arrangement 55 of the second plug 15 which is configured to abut the rear side 5 of the nozzle housing 3 when the first plug 2 is in the extended position.

[0146] As shown in Figure 2D , if the linear actuator 27 has a rotation mechanism 37 integrated therein, the cylinder-piston actuator 27 can additionally comprise a roller bearing 71 arranged between the mechanical spring 54 of the second plug 15 and the piston 36 for simplifying the relative rotation between the mechanical spring 54 and the piston 36.

[0147] Within the scope of the appended claims, many alternative embodiments of the retractable cleaning nozzle are possible. For example, a further exemplary embodiment of the cleaning nozzle 1 is schematically shown in the retracted state in Figure 8A and in the extended state in Figure 8B . This exemplary embodiment of the cleaning nozzle mainly corresponds to the previously described exemplary embodiment, but without the previously described rotation mechanism 37. However, if desired, the rotation mechanism 37 can be implemented in the cleaning nozzle 1 of Figure 8A -B. The various parts and functions are not repeated here and for a detailed description of the parts, reference is made instead to the above description and Figures 1-7C .

[0148] Another exemplary embodiment of the cleaning nozzle 1 is shown in Figure 9A In the middle of the retracted state and in Figure 9B The nozzle is schematically shown in an extended state. This exemplary embodiment of the cleaning nozzle largely corresponds to the previously described exemplary embodiment, but with a fixedly mounted second plug 15. This type of simplified mounting of the second plug 15 provides a more cost-effective design that may be suitable in some embodiments. The cleaning nozzle also lacks the previously described rotating mechanism 37. However, if desired, it can be... Figure 9A The rotating mechanism 37 is implemented in the cleaning nozzle 1 of -B. The various parts and functions are not repeated here, and for detailed descriptions of the parts, please refer to the description above. Figures 1-7C .

[0149] Another exemplary embodiment of the cleaning nozzle 1 is shown in Figure 10A In the middle of the retracted state and in Figure 10B The nozzle is schematically shown in its extended state. This exemplary embodiment of the cleaning nozzle largely corresponds to the previously described exemplary embodiment, except that the spring 54 of the second plug 15 and the forward movement limiting arrangement 56 are instead mounted within the nozzle housing 3. This allows for the use of a simplified linear actuator design. The cleaning nozzle also lacks the previously described rotating mechanism 37. However, if desired, a rotating mechanism 37 can be added. Figure 10A The rotating mechanism 37 is implemented in the cleaning nozzle 1 of -B. The various parts and functions are not repeated here, and for detailed descriptions of the parts, please refer to the description above. Figures 1-7C .

[0150] Reference Figure 11 and 12 This disclosure also relates to assemblies including a tank or pipe and a retractable cleaning nozzle as described above. For example, Figure 11 A portion of a tube 60 is shown, having a plurality of retractable cleaning nozzles mounted in the tube wall at regularly spaced intervals. The cleaning nozzles 1 are thus used to clean the inner surface 61 of the tube 60. The tube may, for example, have a diameter 62 in the range of about 0.1-3 meters (particularly about 0.3-1.5 meters). Adjacent cleaning nozzles may, for example, be positioned at a distance 63 of about 0.5-3 meters from each other. Each cleaning nozzle 1 receives cleaning fluid via a supply tube 64 connected to it.

[0151] Figure 12A tank 65 for a working product, such as a fluid, is schematically shown with an inlet opening, an outlet opening and a retractable cleaning nozzle 1 mounted in a wall of the tank 65. The cleaning nozzle 1 is thus usable for cleaning the inner surface 61 of the tank 65. The tank may, for example, have a diameter 62 in the range of about 1-3 meters, and the cleaning nozzle may thus be configured to have an operational range of at least 3 meters. The cleaning nozzle may be configured to have a relatively large spray angle 66, i.e. at least 180 degrees, for allowing efficient and reliable cleaning of the inner surface 61 of the tank 65.

[0152] As Figure 13 schematically shown in Fig. 1, the first set of spray holes 11 can be configured to provide an asymmetric spray pattern 67, Figure 13 An example of a cross section of the spray pattern 67 of the first set of spray holes 11 of the cleaning nozzle 1 for a certain rotational position is shown. However, due to the rotational properties of the cleaning nozzle according to certain embodiments, even the asymmetric spray pattern, the cleaning nozzle 1 will still provide full coverage of the adjacent inner surface of the tank 65 or pipe 60.

[0153] The second set of spray holes 12 arranged within the sleeve-shaped body 9 can also be asymmetrically provided, i.e. have an asymmetric spray pattern, which requires the rotational mechanism 37 for providing full coverage of the adjacent inner surface of the tank or pipe, and thereby further contribute to the improved cost-effective and energy-efficient design of the cleaning nozzle 1.

[0154] Figure 14 The nozzle housing 3 of the retractable cleaning nozzle 1 fixedly mounted in a hole of the side wall 68 of the pipe 60 or tank 65 is only schematically shown. The nozzle housing 3 may, for example, have a mounting flange 69 welded to the side wall 68 at the opening. The front side 4 of the nozzle housing is arranged to face towards the interior of the tank or pipe, and the front surface 4 of the housing 3 is preferably arranged substantially flush with the inner surface 61 of the side wall 68 of the tank 65 or pipe 60.

[0155] The present disclosure also relates to a method for spraying cleaning of an inner surface of a pipe 60 or tank 65 using a retractable cleaning nozzle 1 having a nozzle housing 3 fixedly mounted in a hole of the side wall 68 of the pipe 60 or tank 65. The nozzle housing 3 can have a front side 4 facing towards the interior of the pipe 60 or tank 65 and a rear side 5 facing away from the interior of the pipe or tank. The nozzle housing 3 can also have an inlet port 6 for receiving a cleaning liquid, a cylindrical inner bore 7 having a central axis 8 defining an axial direction AD, a first plug 2 movably arranged within the bore 7 in the axial direction, and a second plug 15.

[0156] Figure 15The main steps are schematically illustrated. In particular, the method comprises a first step S1 of controlling the linear actuator 27 operatively connected to the movable first plug 2 for moving the first plug 2 from a retracted position to an extended position in which a front portion of the first plug 2 comprising the first set of spray holes 11 and the second set of spray holes 12 is extended into the tank or pipe, thereby starting the spraying of the cleaning fluid via the first set of spray holes 11 of the first plug 2 substantially in the axial direction AD and starting the spraying of the cleaning fluid via the second set of spray holes 12 of the first plug 2 substantially in the radial direction RD perpendicular to the axial direction AD.

[0157] The method comprises a second step S2 of controlling the linear actuator 27 for moving the first plug 2 from the extended position to the retracted position in which the front surface 13 of the first plug 2 is substantially flush with the front surface 14 of the nozzle housing 3 and in which the second plug 15 closes the flow path from the inlet port 6 to the first set of spray holes 11 of the first plug 2.

[0158] According to some exemplary embodiments, the retractable cleaning nozzle 1 can further comprise a rotation mechanism 37 arranged to cause the first plug 2 to become angularly displaced by a predetermined angle around its central longitudinal axis during each activation event involving moving the first plug 2 from the retracted position to the extended position and back again to the retracted position. In such cases, the above described method for spraying the inner surface of the cleaning pipe 60 or tank 65 using the retractable cleaning nozzle 1 can involve repeating the first and second steps S1, S2 of controlling the linear actuator to move the first plug from the retracted position to the extended position and subsequently from the extended position back to the retracted position at least four times (as schematically illustrated by the method steps of Figure 16 ).

[0159] It will be appreciated that the foregoing description is only exemplary of the application and intended to be illustrative only, and not limiting of the disclosure, its application or uses. Numerous changes and modifications can be made to the specific example described and illustrated in the specification without departing from the scope of the disclosure as defined by the claims. Further, modifications can be made to adapt a particular situation or material to the teachings of the disclosure without departing from the essential scope thereof.

[0160] Accordingly, it is intended to be encompassed within the scope of the present disclosure that the present disclosure is not limited to the particular examples of specific elements that are illustrated by the figures and described in the specification as presently contemplated for carrying out the teachings of the present disclosure, but that the scope of the present disclosure will include any embodiments falling within the pre- scribed description and the appended claims. Reference signs mentioned in the claims should not be considered as limiting the scope of the subject-matter of the claims and their sole purpose is to make the claims easier to understand.

[0161] Reference signs

[0162] 1. retractable cleaning nozzle

[0163] 2. first plug

[0164] 3. nozzle housing

[0165] 4. front side of the housing

[0166] 5. rear side of the housing

[0167] 6. inlet port

[0168] 7. internal bore of the housing

[0169] 8. central axis of the bore

[0170] 9. sleeve-shaped body

[0171] 10. front wall

[0172] 11. first set of spray holes

[0173] 12. second set of spray holes

[0174] 13. front surface of the first plug

[0175] 14. front surface of the housing

[0176] 15. second plug

[0177] 16. first sealing arrangement

[0178] 17. second sealing arrangement

[0179] 18. annular recess for retaining the first sealing arrangement

[0180] 19. front portion of the sleeve-shaped body

[0181] 20. flange of the second plug

[0182] 21. annular recess for retaining the second sealing arrangement

[0183] 22. third sealing arrangement

[0184] 23. annular recess for holding the third sealing arrangement

[0185] 24. central axis of the second plug

[0186] 25. forward facing surface of the second plug

[0187] 26. rearward facing surface of the front wall

[0188] 27. linear actuator

[0189] 28. operating lever of the first plug

[0190] 29. central bore of the second plug

[0191] 30. fourth sealing arrangement

[0192] 31. annular recess for holding the fourth sealing arrangement

[0193] 32. rear portion of the sleeve shaped body

[0194] 33. inner surface of the first plug

[0195] 34. actuator housing

[0196] 35. actuating member

[0197] 36. piston

[0198] 37. rotation mechanism

[0199] 38. radially extending guide member

[0200] 39. cam member

[0201] 40. cam surface

[0202] 41. sleeve member of the piston

[0203] 42. front wall of the actuator housing

[0204] 43. further cam surface

[0205] 44. roller bearing of the guide member

[0206] 45. spring of the first plug

[0207] 46. rear wall of the actuator housing

[0208] 47. cylindrical wall of the actuator housing

[0209] 48. separate front cluster

[0210] 49. sector

[0211] 50. circle center angle

[0212] 51. first angle

[0213] 52. second angle

[0214] 53. third angle

[0215] 54. spring of second plug

[0216] 55. connection arrangement of second plug

[0217] 56. forward movement limiting arrangement

[0218] 57. spacer

[0219] 58. pressure chamber

[0220] 59. air supply connector

[0221] 60. tube

[0222] 61. inner surface

[0223] 62. diameter of tube

[0224] 63. distance between nozzles

[0225] 64. supply tube

[0226] 65. tank

[0227] 66. spray angle

[0228] 67. spray pattern

[0229] 68. side wall

[0230] 69. mounting flange

[0231] 70. roller bearing of spring of first plug

[0232] 71. roller bearing of spring of second plug

[0233] 72. overhang distance.

Claims

1. A retractable cleaning nozzle (1) for spraying the inner surface of a pipe or tank, the cleaning nozzle (1) comprising: a nozzle housing (3) configured to be fixedly mounted in a bore of a side wall of the pipe or tank and having a front side (4) arranged to face the interior of the pipe or tank and a rear side (5) arranged to face away from the interior of the pipe or tank, an inlet port (6) configured for receiving a cleaning fluid, and a cylindrical inner bore (7) with a central axis defining an axial direction, wherein the inner bore (7) is open towards the front side (4) of the nozzle housing (3), a first plug (2) movably arranged within the bore (7) of the nozzle housing (3) between a retracted position and an extended position in the axial direction (AD), wherein the first plug (2) has a sleeve-shaped body (9) with a front wall (10) closing a front portion (19) of the sleeve-shaped body (9), wherein the front wall (10) of the sleeve-shaped body (9) comprises a first set of spray holes (11) configured to spray cleaning fluid substantially in the axial direction (AD), wherein the sleeve-shaped body (9) of the first plug (2) comprises a second set of spray holes (12) configured to spray cleaning fluid substantially in a radial direction (RD) perpendicular to the axial direction (AD), wherein in the retracted position of the first plug (2) a front surface (13) of the first plug (2) is substantially flush with a front surface (14) of the nozzle housing (3), and wherein in the extended position of the first plug (2) a front portion of the first plug (2) comprising the first set of spray holes (11) and the second set of spray holes (12) extends beyond the front surface (14) of the nozzle housing (3) for allowing to spray clean the inner surface of the pipe or tank, a second plug (15) arranged within a space defined by the sleeve-shaped body (9) of the first plug (2) and configured to close a flow path from the inlet port (6) to the first set of spray holes (11) of the first plug (2) when the first plug (2) is in the retracted position.

2. The retractable cleaning nozzle (1) according to claim 1, further comprising a first sealing arrangement (16) for sealing the first plug (2) against the nozzle housing (3), and a second sealing arrangement (17) for sealing the second plug (15) against the first plug (2).

3. A retractable cleaning nozzle (1) according to claim 2, wherein, The first sealing arrangement (16) is for sealing an annular space between the first plug (2) and the nozzle housing (3).

4. The retractable cleaning nozzle (1) according to claim 2, wherein, The second sealing arrangement (17) is for sealing an annular space between the second plug (15) and the first plug (2).

5. The retractable cleaning nozzle (1) according to any one of claims 1 to 4, wherein, The first plug (2) further has a central cylindrical operating rod (28) extending in the axial direction (AD), and wherein the second plug (15) has a central cylindrical bore (29) extending in the axial direction (AD) and configured to receive the operating rod (28) of the first plug (2).

6. The retractable cleaning nozzle (1) according to any one of claims 1 to 4, further comprising a linear actuator (27) operably connected to the movable first plug (2) for controlling movement of the first plug (2) between the retracted position and the extended position.

7. The retractable cleaning nozzle (1) according to any one of claims 1 to 4, further comprising a rotation mechanism (37) arranged to cause the first plug (2) to become angularly displaced by a predetermined angle about its central longitudinal axis during each activation event involving moving the first plug (2) from the retracted position to the extended position and back again to the retracted position.

8. A retractable cleaning nozzle (1) according to claim 7, wherein, The predetermined angle is in the range of 5-175 degrees.

9. A retractable cleaning nozzle (1) according to claim 8, wherein, The predetermined angle is in the range of 20-110 degrees.

10. A retractable cleaning nozzle (1) according to claim 7, wherein, The rotation mechanism (37) comprises: at least one radially protruding guide member (38) rotatably connected with the first plug (2), and a cam member (39) rotatably connected with the fixed nozzle housing (3) or actuator housing (34), or at least one radially protruding guide member (38) rotatably connected with the fixed nozzle housing (3) or actuator housing (34), and a cam member (39) rotatably connected with the first plug (2), wherein the cam member (39) has at least one cam surface (40, 43) inclined relative to the axial direction and configured for interacting with the at least one radially protruding guide member (38) for causing a controlled rotation of the first plug (2) upon movement of the first plug (2) from the retracted position to the extended position and back again to the retracted position.

11. A retractable cleaning nozzle (1) according to claim 10, wherein, The cam member (39) of the rotation mechanism (37) comprises a first annular sleeve and a second annular sleeve which are interconnected and axially overlapping, wherein each of the first annular sleeve and the second annular sleeve comprises at least one cam surface (40, 43) inclined relative to the axial direction, wherein the at least one radially protruding guide member (38) is configured for interacting with the at least one cam surface (40) of the first annular sleeve when the first plug (2) is moved from the retracted position to the extended position, and wherein the at least one radially protruding guide member (38) is configured for interacting with the at least one cam surface (43) of the second annular sleeve when the first plug (2) is moved from the extended position to the retracted position.

12. The retractable cleaning nozzle (1) according to any one of claims 1 to 4, wherein The second plug (15) is movably arranged in the axial direction relative to the first plug (2) and spring loaded towards the front side of the nozzle housing (3) for providing an improved sealing contact with the first plug (2).

13. A retractable cleaning nozzle (1) according to claim 12, wherein, The second plug (15) is arranged for providing an improved sealing contact with the front wall (10) and / or the sleeve-shaped body (9) of the first plug (2).

14. A retractable cleaning nozzle (1) according to claim 6, wherein, The linear actuator (27) is a pneumatic or hydraulic operated cylinder-piston actuator, wherein the second plug (15) extends into the actuator housing, and wherein a mechanical spring (54) of the second plug (15) is located in the actuator housing (34) and abuts a rear side of the second plug (15) and a front side of the piston (36).

15. A retractable cleaning nozzle (1) according to any one of claims 1 to 4, wherein, The first set of spray holes (11) provided on the front wall (10) of the sleeve-shaped body (9) are arranged in one or more separate front clusters (48) of spray holes, wherein each spray hole of a separate front cluster (48) is located within a sector (49) having a central angle of no more than 90 degrees.

16. A retractable cleaning nozzle (1) according to claim 15, wherein, Each spray hole of a separate front cluster (48) is located within a sector (49) having a central angle of no more than 45 degrees.

17. A retractable cleaning nozzle (1) according to any one of claims 1 to 4, wherein, The front surface (13) of the first plug (2) has a substantially flat surface arranged in a plane perpendicular to the axial direction (AD) and the first set of spray holes (11) are arranged in the substantially flat surface.

18. The retractable cleaning nozzle (1) according to any one of claims 1 to 4, wherein, The first set of spray holes (11) provided on the front wall (10) of the sleeve-shaped body (9) are arranged to spray cleaning liquid within an angular range of 0-30 degrees relative to the axial direction (AD) and the second set of spray holes (12) provided in the sleeve-shaped body (9) are arranged to spray cleaning liquid within an angular range of 45-135 degrees relative to the axial direction (AD).

19. An assembly for performing spray cleaning using a cleaning nozzle, the assembly comprising: a tank (65) or a tube (60), and a retractable cleaning nozzle (1) according to any one of claims 1 to 18, wherein the nozzle housing (3) of the retractable cleaning nozzle (1) is fixedly mounted in a hole of a side wall (68) of the tube (60) or the tank (65), wherein the front side (4) is arranged to face towards the interior of the tank (65) or the tube (60).

20. A method for spraying the inner surface of a cleaning pipe or tank using a retractable cleaning nozzle (1) having a nozzle housing (3) fixedly mounted in a hole of a side wall of the pipe or the tank, wherein, The nozzle housing (3) has a front side (4) facing towards the interior of the tube or the tank and a rear side (5) facing away from the interior of the tube or the tank, wherein the nozzle housing (3) further has an inlet port (6) for receiving cleaning liquid, a cylindrical inner bore (7) having a central axis defining an axial direction (AD), a first plug (2) movably arranged within the bore (7) in the axial direction (AD), and a second plug (15), the method comprising: a linear actuator (27) operatively connected to the movable first plug (2) for moving said first plug (2) from a retracted position to an extended position in which a front portion of said first plug (2) comprising a first set of spray holes (11) and a second set of spray holes (12) is extended into said tank or said tube, thereby starting the spraying of cleaning fluid via said first set of spray holes (11) of said first plug (2) essentially in said axial direction (AD) and starting the spraying of cleaning fluid via said second set of spray holes (12) of said first plug (2) essentially in a radial direction (RD) perpendicular to said axial direction (AD), controlling said linear actuator (27) for moving said first plug (2) from said extended position to said retracted position in which a front surface (13) of said first plug (2) is essentially flush with a front surface (14) of said nozzle housing (3) and in which said second plug (15) closes the flow path from said inlet port (6) to said first set of spray holes (11) of said first plug (2).

21. The method of claim 20, wherein, said retractable cleaning nozzle (1) further comprising a rotation mechanism (37) arranged to cause said first plug (2) to become angularly displaced by a predetermined angle around its central longitudinal axis during each activation event involving moving said first plug (2) from said retracted position to said extended position and back again to said retracted position, said method comprising repeating the step of controlling said linear actuator (27) to move said first plug (2) from said retracted position to an extended position and subsequently to move said first plug (2) from said extended position back to said retracted position during a cleaning event at least four times for providing at least one full rotation of said first plug (2) during a cleaning event.

22. The method of claim 21, wherein, said method comprising repeating the step of controlling said linear actuator (27) to move said first plug (2) from said retracted position to an extended position and subsequently to move said first plug (2) from said extended position back to said retracted position during a cleaning event at least eight times for providing at least one full rotation of said first plug (2) during a cleaning event.

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