CA3041179C - Nozzle of a ship propeller - Google Patents
Nozzle of a ship propeller Download PDFInfo
- Publication number
- CA3041179C CA3041179C CA3041179A CA3041179A CA3041179C CA 3041179 C CA3041179 C CA 3041179C CA 3041179 A CA3041179 A CA 3041179A CA 3041179 A CA3041179 A CA 3041179A CA 3041179 C CA3041179 C CA 3041179C
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- Canada
- Prior art keywords
- nozzle
- recess
- ship propeller
- sacrificial anode
- nozzle casing
- Prior art date
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING
- B63B59/00—Hull protection specially adapted for vessels; Cleaning devices specially adapted for vessels
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63H—MARINE PROPULSION OR STEERING
- B63H5/00—Arrangements on vessels of propulsion elements directly acting on water
- B63H5/07—Arrangements on vessels of propulsion elements directly acting on water of propellers
- B63H5/14—Arrangements on vessels of propulsion elements directly acting on water of propellers characterised by being mounted in non-rotating ducts or rings, e.g. adjustable for steering purpose
- B63H5/15—Nozzles, e.g. Kort-type
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
- C23F13/00—Inhibiting corrosion of metals by anodic or cathodic protection
- C23F13/02—Inhibiting corrosion of metals by anodic or cathodic protection cathodic; Selection of conditions, parameters or procedures for cathodic protection, e.g. of electrical conditions
- C23F13/06—Constructional parts, or assemblies of cathodic-protection apparatus
- C23F13/08—Electrodes specially adapted for inhibiting corrosion by cathodic protection; Manufacture thereof; Conducting electric current thereto
- C23F13/10—Electrodes characterised by the structure
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
- C23F13/00—Inhibiting corrosion of metals by anodic or cathodic protection
- C23F13/02—Inhibiting corrosion of metals by anodic or cathodic protection cathodic; Selection of conditions, parameters or procedures for cathodic protection, e.g. of electrical conditions
- C23F13/06—Constructional parts, or assemblies of cathodic-protection apparatus
- C23F13/08—Electrodes specially adapted for inhibiting corrosion by cathodic protection; Manufacture thereof; Conducting electric current thereto
- C23F13/18—Means for supporting electrodes
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
- C23F13/00—Inhibiting corrosion of metals by anodic or cathodic protection
- C23F13/02—Inhibiting corrosion of metals by anodic or cathodic protection cathodic; Selection of conditions, parameters or procedures for cathodic protection, e.g. of electrical conditions
- C23F13/06—Constructional parts, or assemblies of cathodic-protection apparatus
- C23F13/08—Electrodes specially adapted for inhibiting corrosion by cathodic protection; Manufacture thereof; Conducting electric current thereto
- C23F13/20—Conducting electric current to electrodes
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Combustion & Propulsion (AREA)
- Ocean & Marine Engineering (AREA)
- Prevention Of Electric Corrosion (AREA)
Abstract
The invention relates to a nozzle (1) of a ship propeller (19) that can rotate about an axis of rotation (A), comprising a nozzle casing (10) extending along the axis of rotation (A) and surrounding the ship propeller (19), and having inner and outer surfaces (11, 12), which together form a flow profile, and having at least one sacrificial anode (2) arranged on the outer surface (12) of the nozzle casing (10), wherein the outer surface (12) of the nozzle casing (10) has at least one recess (13) that is deepened in relation to the flow profile and the at least one sacrificial anode (2) is correspondingly designed such that it can be introduced into the recess (13) such that it substantially fills the recess (13).
Description
, '' 1 -Nozzle of a Ship Propeller Description:
The invention relates to a nozzle of a ship propeller that can rotate about an axis of rotation, comprising a nozzle casing extending along the axis of rotation and surrounding the ship propeller, and having inner and outer surfaces, which together form a flow profile, and having at least one sacrificial anode arranged on the outer surface of the nozzle casing.
Arrangement of a nozzle as a casing around a ship propeller has been known for many years, and is also known as a Kort nozzle. The nozzle casing comprises a flow profile similar to a wing, and serves to reduce losses of flow on the ends of the propeller blades, and to generate a higher mass flow. This leads to an increase of the efficiency of such a ship propeller. But like the ship propeller itself, the nozzle casing is usually made of metal, and must be protected against electrolytic corrosion, In particular, when using the ship propeller in seawater, there is otherwise, due to high conductivity of the seawater and its suitability as an electrolyte and galvanic element, the risk of a heavy electrolytic corrosion and premature wear and tear as a result, of component parts of the propulsion system comprising the ship propeller including the associated nozzle.
Therefore it is usual for the purpose of corrosion protection to attach a determined number of sacrificial anodes projecting from the outer surface of the nozzle casing. But the sacrificial anodes are interference members in the fluid flow occurring along the outer surface increasing the nozzle resistance during travel. As a consequence, nozzle thrust decreases and thus the ship propeller as a whole becomes less efficient.
It is the objective of the invention to suggest a nozzle of a ship propeller, which overcomes the disadvantages of the State of the Art, is easy to manufacture, and for which a replacement of the sacrificial anodes after their consumption is easy to handle.
The invention relates to a nozzle of a ship propeller that can rotate about an axis of rotation, comprising a nozzle casing extending along the axis of rotation and surrounding the ship propeller, and having inner and outer surfaces, which together form a flow profile, and having at least one sacrificial anode arranged on the outer surface of the nozzle casing.
Arrangement of a nozzle as a casing around a ship propeller has been known for many years, and is also known as a Kort nozzle. The nozzle casing comprises a flow profile similar to a wing, and serves to reduce losses of flow on the ends of the propeller blades, and to generate a higher mass flow. This leads to an increase of the efficiency of such a ship propeller. But like the ship propeller itself, the nozzle casing is usually made of metal, and must be protected against electrolytic corrosion, In particular, when using the ship propeller in seawater, there is otherwise, due to high conductivity of the seawater and its suitability as an electrolyte and galvanic element, the risk of a heavy electrolytic corrosion and premature wear and tear as a result, of component parts of the propulsion system comprising the ship propeller including the associated nozzle.
Therefore it is usual for the purpose of corrosion protection to attach a determined number of sacrificial anodes projecting from the outer surface of the nozzle casing. But the sacrificial anodes are interference members in the fluid flow occurring along the outer surface increasing the nozzle resistance during travel. As a consequence, nozzle thrust decreases and thus the ship propeller as a whole becomes less efficient.
It is the objective of the invention to suggest a nozzle of a ship propeller, which overcomes the disadvantages of the State of the Art, is easy to manufacture, and for which a replacement of the sacrificial anodes after their consumption is easy to handle.
- 2 -Said objective is achieved in accordance with the invention with a nozzle according to the features of the present disclosure.
Advantageous embodiments and developments of the nozzle according to the invention are the subject matter of the present disclosure.
For achieving the objective, it is suggested that the outer surface of the nozzle casing has at least one recess that is deepened in relation to the flow profile, and the at least one sacrificial anode is designed correspondingly to the recess so that it can be introduced into the recess such that it substantially fills the recess. In this manner it is possible to arrange a sufficient number and/or a sufficient volume of sacrificial anodes in the area of the outer surface of the nozzle casing which due to their arrangement in the deepened recess do not project from the flow profile or at most slightly project from the flow profile. The at least one sacrificial anode is not subject to any further restrictions, therefore they can be anodes of almost any contour, in particular also standard designs as long as they substantially fill the deepened recess. By "substantially fill the deepened recess" is meant a filling of the space in the area of the deepened recess, wherein the received anode does not or only slightly project from the adjacent flow profile.
According to one suggestion of the invention, the at least one sacrificial anode is configured such that after introduction into the recess it smoothly continues the contour of the flow profile of the inventive nozzle adjacent to the recess, and thus, due to a design corresponding to the flow profile, forms part of the flow profile itself. According to the invention, interference of the fluid flow around the nozzle casing due to the sacrificial anodes is reduced according to the invention to a minimum in this way, and nozzle thrust during travel is not impaired despite the existence of the sacrificial anodes.
In principle, there is no restriction regarding the arrangement and positioning of the recess and the sacrificial anodes positioned therein, and it can be selected by the person skilled in the art depending on the conditions on the nozzle.
Not Date Recue/Date Received 2022-07-14
Advantageous embodiments and developments of the nozzle according to the invention are the subject matter of the present disclosure.
For achieving the objective, it is suggested that the outer surface of the nozzle casing has at least one recess that is deepened in relation to the flow profile, and the at least one sacrificial anode is designed correspondingly to the recess so that it can be introduced into the recess such that it substantially fills the recess. In this manner it is possible to arrange a sufficient number and/or a sufficient volume of sacrificial anodes in the area of the outer surface of the nozzle casing which due to their arrangement in the deepened recess do not project from the flow profile or at most slightly project from the flow profile. The at least one sacrificial anode is not subject to any further restrictions, therefore they can be anodes of almost any contour, in particular also standard designs as long as they substantially fill the deepened recess. By "substantially fill the deepened recess" is meant a filling of the space in the area of the deepened recess, wherein the received anode does not or only slightly project from the adjacent flow profile.
According to one suggestion of the invention, the at least one sacrificial anode is configured such that after introduction into the recess it smoothly continues the contour of the flow profile of the inventive nozzle adjacent to the recess, and thus, due to a design corresponding to the flow profile, forms part of the flow profile itself. According to the invention, interference of the fluid flow around the nozzle casing due to the sacrificial anodes is reduced according to the invention to a minimum in this way, and nozzle thrust during travel is not impaired despite the existence of the sacrificial anodes.
In principle, there is no restriction regarding the arrangement and positioning of the recess and the sacrificial anodes positioned therein, and it can be selected by the person skilled in the art depending on the conditions on the nozzle.
Not Date Recue/Date Received 2022-07-14
- 3 -only an arrangement of the recess, extending entirely around the nozzle circumference, and the sacrificial anodes positioned in the recess but also an arrangement only in partial segments, for example, a circumferential section of 1800 around the outer nozzle casing, can be provided.
According to a suggestion of the invention, the recess is formed in the nozzle back area seen in flow direction of the fluid through the nozzle, preferably close to the outlet opening of the nozzle casing behind the ship propeller.
According to a suggestion of the invention, the recess can be formed as an annularly extending stepped shoulder in the outer surface of the nozzle casing, and a plurality of sacrificial anodes is introduced into the stepped shoulder in an annularly extending manner so that a requested volume fraction of the stepped shoulder is filled by the sacrificial anodes, and the flow profile of the nozzle casing is smoothly continued by bridging the stepped shoulder. Here, it is not necessary to fill the entire volume fraction of the stepped shoulder with sacrificial anodes, although such an entire filling is particularly efficient in terms of flow. But it can also be provided to fill the recess only partly with anodes which is surprisingly without considerable loss of efficiency. It is only essential that the anodes within the recess can be overflown along the flow profile without considerable resistance.
Alternatively, it can also be provided that a plurality of discrete recesses introduced annularly into the outer surface is provided into which one corresponding sacrificial anode each is introduced. Between adjacent sacrificial anodes and associated recesses, webs are maintained in this embodiment extending along the flow profile in the area of the outer surface and stiffening the outer surface of the nozzle casing in the manner of reinforcing ribs.
According to another suggestion of the invention it is provided that the at least one sacrificial anode is releasably introduced into the recess, for example, is fixed in the same in an appropriate manner by means of screws. By this, not only assembly is simplified but the sacrificial anode after its consumption can be easily replaced by a new sacrificial anode.
According to a suggestion of the invention, the recess is formed in the nozzle back area seen in flow direction of the fluid through the nozzle, preferably close to the outlet opening of the nozzle casing behind the ship propeller.
According to a suggestion of the invention, the recess can be formed as an annularly extending stepped shoulder in the outer surface of the nozzle casing, and a plurality of sacrificial anodes is introduced into the stepped shoulder in an annularly extending manner so that a requested volume fraction of the stepped shoulder is filled by the sacrificial anodes, and the flow profile of the nozzle casing is smoothly continued by bridging the stepped shoulder. Here, it is not necessary to fill the entire volume fraction of the stepped shoulder with sacrificial anodes, although such an entire filling is particularly efficient in terms of flow. But it can also be provided to fill the recess only partly with anodes which is surprisingly without considerable loss of efficiency. It is only essential that the anodes within the recess can be overflown along the flow profile without considerable resistance.
Alternatively, it can also be provided that a plurality of discrete recesses introduced annularly into the outer surface is provided into which one corresponding sacrificial anode each is introduced. Between adjacent sacrificial anodes and associated recesses, webs are maintained in this embodiment extending along the flow profile in the area of the outer surface and stiffening the outer surface of the nozzle casing in the manner of reinforcing ribs.
According to another suggestion of the invention it is provided that the at least one sacrificial anode is releasably introduced into the recess, for example, is fixed in the same in an appropriate manner by means of screws. By this, not only assembly is simplified but the sacrificial anode after its consumption can be easily replaced by a new sacrificial anode.
- 4 -For functioning of the sacrificial anode it is necessary that it is connected with the component parts to be protected, in particular the nozzle casing, in an electrically conductive manner. For this purpose, it is suggested according to the invention that the at least one sacrificial anode comprises an electrically conductive support plate with protruding fastening straps for fastening on the nozzle casing. For example, the sacrificial anodes can be cast from a suitable metal, wherein the support plate can be directly included in the casting when manufacturing the sacrificial anodes, permitting an efficient production and a good electrical connection.
For example, the at least one sacrificial anode can be produced based on zinc, magnesium or aluminium or combinations thereof, whereas the support plate, for example, can be produced from a commercial steel or any other suitable, electrically conductive material.
According to another suggestion of the invention, the at least one sacrificial anode is fixed in the recess such that a gap remains between the sacrificial anode and the nozzle casing. Through said gap, an advantageous flow around the sacrificial anode also on its underside by a recirculation, which develops, can be achieved which is also accompanied by a cleaning effect for the surface of the sacrificial anode. For further increase of said effect, the gap can be formed in such a way that it becomes larger in the direction of the inlet opening of the nozzle.
According to another aspect of the invention, there is provided a ship propeller having a nozzle, rotatable about an axis of rotation comprising a nozzle casing extending along the axis of rotation and surrounding the ship propeller, and having inner and outer surfaces, which together form a flow profile, and Date Recue/Date Received 2022-07-14 - 4a -having at least one sacrificial anode arranged on the outer surface of the nozzle casing, wherein the outer surface of the nozzle casing has at least one recess that is deepened in relation to the flow profile, the at least one recess is formed in a downstream area of the nozzle seen in a flow direction of the nozzle, and the at least one sacrificial anode is correspondingly configured to be introduced into the at least one recess so that it substantially fills the at least one recess.
The nozzle according to the invention can be used not only in conventional propeller systems with fixed ship propellers for watercrafts of any type but also in rudder propellers, wherein the ship propeller is rotatably mounted around its vertical axis, and directly permits control of a ship propelled in such a manner, including different types of water jet propulsion, for example, the linear jet developed by the Voith company.
Further embodiments and details of the invention will be explained below by means of the drawing representing an embodiment.
Date Recue/Date Received 2022-07-14
For example, the at least one sacrificial anode can be produced based on zinc, magnesium or aluminium or combinations thereof, whereas the support plate, for example, can be produced from a commercial steel or any other suitable, electrically conductive material.
According to another suggestion of the invention, the at least one sacrificial anode is fixed in the recess such that a gap remains between the sacrificial anode and the nozzle casing. Through said gap, an advantageous flow around the sacrificial anode also on its underside by a recirculation, which develops, can be achieved which is also accompanied by a cleaning effect for the surface of the sacrificial anode. For further increase of said effect, the gap can be formed in such a way that it becomes larger in the direction of the inlet opening of the nozzle.
According to another aspect of the invention, there is provided a ship propeller having a nozzle, rotatable about an axis of rotation comprising a nozzle casing extending along the axis of rotation and surrounding the ship propeller, and having inner and outer surfaces, which together form a flow profile, and Date Recue/Date Received 2022-07-14 - 4a -having at least one sacrificial anode arranged on the outer surface of the nozzle casing, wherein the outer surface of the nozzle casing has at least one recess that is deepened in relation to the flow profile, the at least one recess is formed in a downstream area of the nozzle seen in a flow direction of the nozzle, and the at least one sacrificial anode is correspondingly configured to be introduced into the at least one recess so that it substantially fills the at least one recess.
The nozzle according to the invention can be used not only in conventional propeller systems with fixed ship propellers for watercrafts of any type but also in rudder propellers, wherein the ship propeller is rotatably mounted around its vertical axis, and directly permits control of a ship propelled in such a manner, including different types of water jet propulsion, for example, the linear jet developed by the Voith company.
Further embodiments and details of the invention will be explained below by means of the drawing representing an embodiment.
Date Recue/Date Received 2022-07-14
- 5 -Figure 1 shows in perspective view a rudder propeller with a nozzle according to the invention, Figure 2 shows the nozzle according to Figure 1 with representation of individual components, Figure 3 shows a section through the nozzle according to Figure 2 in an enlarged scale.
Figure 1 shows in perspective view a rudder propeller known per se which comprises a ship propeller 19 rotatable about an axis of rotation A by means of a propulsion not shown. For the purpose of control of a watercraft, which is equipped by it, the rudder propeller is rotatable about its vertical axis H.
The propeller blades 190 of the ship propeller 19 are surrounded by a nozzle 1 extending along the axis of rotation A and comprising a nozzle casing 10, conically tapering in flow direction S through the nozzle 1, with inlet opening 100 and outlet opening 101 for the fluid accelerated by the ship propeller 19, i.e.
water.
As can be seen from the sectional view according to Figure 3, the nozzle casing 10 surrounding the ship propeller 19, comprises an inner surface 11 and an outer surface 12 which together form a flow profile similar to a wing. The water flowing in in flow direction S divides into a partial flow S1 within the nozzle 10 and a partial flow S2 outside the nozzle 10, wherein the boundary layers to the nozzle 10 are lead along the inner surface 11 and/or the outer surface. The flow profile is formed as smooth as possible along the nozzle inner and outer surface 10, 11 in order to avoid flow losses.
Adjacent to the outlet opening 101, a recess 13, deepened in relation to the flow profile along the outer surface 12, in the form of an annularly extending stepped shoulder is formed in the area of the outer surface 12 of the nozzle casing 10.
Figure 1 shows in perspective view a rudder propeller known per se which comprises a ship propeller 19 rotatable about an axis of rotation A by means of a propulsion not shown. For the purpose of control of a watercraft, which is equipped by it, the rudder propeller is rotatable about its vertical axis H.
The propeller blades 190 of the ship propeller 19 are surrounded by a nozzle 1 extending along the axis of rotation A and comprising a nozzle casing 10, conically tapering in flow direction S through the nozzle 1, with inlet opening 100 and outlet opening 101 for the fluid accelerated by the ship propeller 19, i.e.
water.
As can be seen from the sectional view according to Figure 3, the nozzle casing 10 surrounding the ship propeller 19, comprises an inner surface 11 and an outer surface 12 which together form a flow profile similar to a wing. The water flowing in in flow direction S divides into a partial flow S1 within the nozzle 10 and a partial flow S2 outside the nozzle 10, wherein the boundary layers to the nozzle 10 are lead along the inner surface 11 and/or the outer surface. The flow profile is formed as smooth as possible along the nozzle inner and outer surface 10, 11 in order to avoid flow losses.
Adjacent to the outlet opening 101, a recess 13, deepened in relation to the flow profile along the outer surface 12, in the form of an annularly extending stepped shoulder is formed in the area of the outer surface 12 of the nozzle casing 10.
- 6 -Said recess 13 formed by the stepped shoulder is occupied by a plurality of sacrificial anodes 2 designed correspondingly to the recess 13 and substantially filling the recess 13 which sacrificial anodes 2 are formed such that they do not only substantially fill the recess 13 but also smoothly continue the flow profile along the outer surface 12. In this way, a flow profile along the outer surface 12 is maintained which despite arrangement of the sacrificial anodes 2 is only minimally impaired. Hence, the sacrificial anodes 2 are part of the flow profile in the area of the outer surface 12 of the nozzle casing 10.
The sacrificial anodes 2 themselves exist in such a number that there is a volume and/or mass which for corrosion protection of the propulsion system comprising the ship propeller 19 including the nozzle 1 has been calculated as being sufficient.
The individual sacrificial anodes 2 are connected with the nozzle casing 10 by means of fastening straps 21 protruding from the nozzle casing 10, for example, by means of a screw or weld connection, and therefore can be easily mounted and replaced after consumption. As is shown, each sacrificial anode 2 can, for example, be fastened on the recess 13 on both sides each via two fastening straps 21 positioned at an angle of 90 , and associated screws.
Moreover, each sacrificial anode 2 can be arranged via the fastening straps 21 by leaving a gap to the nozzle casing 10 through which recirculation of the flowing water occurs which does not only increase flushing of the surface of the sacrificial anode 2 but also exercises a cleaning effect on the surface of the sacrificial anode 2. In order to increase said effect, the gap between the sacrificial anode 2 and the nozzle casing 10 can be optimised regarding its gap width by increasing the same towards the inlet opening 100 of the nozzle 1.
The sacrificial anodes 2 are manufactured from a suitable metal, for example, zinc, magnesium or aluminium or combinations thereof, in a casting process, wherein during casting an electrically conductive support plate 20 is cast into the body of the sacrificial anodes 2, and thus integrally connected with the sacrificial anodes 2. It is understood that the sacrificial anodes can be of any
The sacrificial anodes 2 themselves exist in such a number that there is a volume and/or mass which for corrosion protection of the propulsion system comprising the ship propeller 19 including the nozzle 1 has been calculated as being sufficient.
The individual sacrificial anodes 2 are connected with the nozzle casing 10 by means of fastening straps 21 protruding from the nozzle casing 10, for example, by means of a screw or weld connection, and therefore can be easily mounted and replaced after consumption. As is shown, each sacrificial anode 2 can, for example, be fastened on the recess 13 on both sides each via two fastening straps 21 positioned at an angle of 90 , and associated screws.
Moreover, each sacrificial anode 2 can be arranged via the fastening straps 21 by leaving a gap to the nozzle casing 10 through which recirculation of the flowing water occurs which does not only increase flushing of the surface of the sacrificial anode 2 but also exercises a cleaning effect on the surface of the sacrificial anode 2. In order to increase said effect, the gap between the sacrificial anode 2 and the nozzle casing 10 can be optimised regarding its gap width by increasing the same towards the inlet opening 100 of the nozzle 1.
The sacrificial anodes 2 are manufactured from a suitable metal, for example, zinc, magnesium or aluminium or combinations thereof, in a casting process, wherein during casting an electrically conductive support plate 20 is cast into the body of the sacrificial anodes 2, and thus integrally connected with the sacrificial anodes 2. It is understood that the sacrificial anodes can be of any
- 7 -shape and that it depends on the respective contour of the flow profile of the nozzle casing 10 and the installation position in the nozzle casing 10. Also, standard anodes in a size matching the recess 13 can be used.
It is also possible to arrange the sacrificial anodes 2 in a position further in the direction of the inlet opening 100. Moreover, if necessary, the clearances between adjacent sacrificial anodes 2 can be closed with covers in accordance with the desired flow profile or a plurality of discrete deepened recesses 13 are provided into which one sacrificial anode 2 each is introduced to fill the recess and substantially continue the flow profile smoothly. The recesses 13 are then similar to recess pockets and are delimited to adjacent recesses 13 each by webs of the nozzle casing 10, whereby a higher stability can be achieved.
Generally it would also be imaginable to attach the sacrificial anodes in the area of the inner surface but in that case a major interference of the fluid flow accelerated by the propeller blades along the inner surface has to be expected, and moreover modifications of the flow profile occur during consumption of the sacrificial anodes 2 which have an adverse effect on efficiency of the ship propeller 19.
The nozzle according to the invention explained above is suitable not only for new manufacture of a ship propulsion system but also for retrofit of already existing ship propellers, and replacement of existing nozzles on such a ship propeller.
It is also possible to arrange the sacrificial anodes 2 in a position further in the direction of the inlet opening 100. Moreover, if necessary, the clearances between adjacent sacrificial anodes 2 can be closed with covers in accordance with the desired flow profile or a plurality of discrete deepened recesses 13 are provided into which one sacrificial anode 2 each is introduced to fill the recess and substantially continue the flow profile smoothly. The recesses 13 are then similar to recess pockets and are delimited to adjacent recesses 13 each by webs of the nozzle casing 10, whereby a higher stability can be achieved.
Generally it would also be imaginable to attach the sacrificial anodes in the area of the inner surface but in that case a major interference of the fluid flow accelerated by the propeller blades along the inner surface has to be expected, and moreover modifications of the flow profile occur during consumption of the sacrificial anodes 2 which have an adverse effect on efficiency of the ship propeller 19.
The nozzle according to the invention explained above is suitable not only for new manufacture of a ship propulsion system but also for retrofit of already existing ship propellers, and replacement of existing nozzles on such a ship propeller.
Claims (10)
1. A ship propeller having a nozzle, rotatable about an axis of rotation comprising a nozzle casing extending along the axis of rotation and surrounding the ship propeller, and having inner and outer surfaces, which together form a flow profile, and having at least one sacrificial anode arranged on the outer surface of the nozzle casing, wherein the outer surface of the nozzle casing has at least one recess that is deepened in relation to the flow profile, the at least one recess being formed in a downstream area of the nozzle seen in a flow direction of the nozzle, and the at least one sacrificial anode is correspondingly configured to be introdu d into the at least one re ss so that it substantially fills the at least one recess.
2. The ship propeller according to claim 1, wherein the at least one sacrificial anode is configured to be introduced into the at least one recess smoothly continuing the flow profile.
3. The ship propeller according to claim 1 or 2, wherein the at least one recess is formed as an annularly extending stepped shoulder in the outer surface of the nozzle casing, and the at least one sacrificial anode is a plurality of sacrificial anodes introduced into the stepped shoulder in an annularly extending manner.
4. The ship propeller according to claim 1 or 2, wherein the at least one recess is a plurality of discrete recesses introduced annularly into the outer surface, and one corresponding sacrificial anode is introduced into each one of the plurality of discrete recesses.
5. The ship propeller according to any one of claims 1 to 4, wherein the at least one sacrificial anode is releasably introdu d into the at least one recess.
6. The ship propeller according to any one of claims 1 to 5, wherein the at least one sacrificial anode comprises an electrically conductive support plate with protruding fastening straps for fastening on the nozzle casing.
7. The ship propeller according to any one of claims 1 to 6, wherein the at least one sacrificial anode forms a partial segment of the flow profile.
8. The ship propeller according to any one of claims 1 to 7, wherein the at least one sacrificial anode is produced based on zinc, magnesium, aluminium or combinations thereof.
9. The ship propeller according to any one of claims 1 to 8, wherein the at least one sacrificial anode is arranged in the at least one recess by leaving a gap to the nozzle casing.
10. The ship propeller according to any one of claims 1 to 9, wherein the ship propeller has the form of a rudder propeller.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/EP2016/078956 WO2018095548A1 (en) | 2016-11-28 | 2016-11-28 | Nozzle of a ship propeller |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA3041179A1 CA3041179A1 (en) | 2018-05-31 |
| CA3041179C true CA3041179C (en) | 2023-05-09 |
Family
ID=57406243
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA3041179A Active CA3041179C (en) | 2016-11-28 | 2016-11-28 | Nozzle of a ship propeller |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP3544887B1 (en) |
| CN (1) | CN110023187B (en) |
| BR (1) | BR112019006498B1 (en) |
| CA (1) | CA3041179C (en) |
| RU (1) | RU2722082C1 (en) |
| WO (1) | WO2018095548A1 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111645838B (en) * | 2020-06-15 | 2021-04-06 | 中国船舶科学研究中心 | Pipe oar supports subregion guiding device that prerevolves |
| CN115386883B (en) * | 2022-09-21 | 2024-03-01 | 广州船舶及海洋工程设计研究院(中国船舶集团有限公司第六〇五研究院) | Mounting structure of flow passage type ship body sacrificial anode |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SU1689213A1 (en) * | 1988-08-29 | 1991-11-07 | Ленинградское высшее инженерное морское училище им.адм.С.О.Макарова | Propeller nozzle |
| US5052962A (en) * | 1990-05-21 | 1991-10-01 | The United States Of America As Represented By The Secretary Of The Navy | Naval electrochemical corrosion reducer |
| US5342228A (en) * | 1992-05-27 | 1994-08-30 | Brunswick Corporation | Marine drive anode |
| DK1904365T3 (en) * | 2005-07-05 | 2012-04-16 | Marine propulsion technologies inc | VENTURY SYSTEM WITH MULTIPLE NOZZES FOR WATER VESSELS |
| US7641526B1 (en) * | 2008-09-09 | 2010-01-05 | Thrustmaster of Texas, Inc. | Vessel and underwater mountable azimuthing thruster |
| GB201119446D0 (en) * | 2011-11-11 | 2011-12-21 | Rolls Royce Plc | A sacrificial anode |
| KR101487668B1 (en) * | 2012-12-03 | 2015-01-30 | 삼성중공업 주식회사 | Propulsion apparatus for ship, and ship having the same |
| CN104032308B (en) * | 2014-06-24 | 2016-06-01 | 中国船舶重工集团公司第七二五研究所 | A kind of water-jet propulsor flow passage system anticorrosion and antifouling integrated control method |
| GB201420357D0 (en) * | 2014-11-17 | 2014-12-31 | Rolls Royce Plc | A marine cathodic protection system |
| CN104648638B (en) * | 2015-02-11 | 2016-11-02 | 江苏科技大学 | The bionical pressure hull in a kind of deep-sea |
-
2016
- 2016-11-28 WO PCT/EP2016/078956 patent/WO2018095548A1/en active Application Filing
- 2016-11-28 CA CA3041179A patent/CA3041179C/en active Active
- 2016-11-28 BR BR112019006498-2A patent/BR112019006498B1/en active IP Right Grant
- 2016-11-28 RU RU2019120005A patent/RU2722082C1/en active
- 2016-11-28 CN CN201680091203.3A patent/CN110023187B/en active Active
- 2016-11-28 EP EP16801780.4A patent/EP3544887B1/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| EP3544887B1 (en) | 2021-05-05 |
| EP3544887A1 (en) | 2019-10-02 |
| CA3041179A1 (en) | 2018-05-31 |
| CN110023187A (en) | 2019-07-16 |
| BR112019006498B1 (en) | 2023-05-09 |
| WO2018095548A1 (en) | 2018-05-31 |
| CN110023187B (en) | 2021-06-15 |
| BR112019006498A2 (en) | 2019-06-25 |
| RU2722082C1 (en) | 2020-05-26 |
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