EP1521704B1

EP1521704B1 - Flushing device

Info

Publication number: EP1521704B1
Application number: EP03738855A
Authority: EP
Inventors: Lars JINBÄCK
Original assignee: Scanjet Marine AB
Current assignee: Scanjet Marine AB
Priority date: 2002-07-11
Filing date: 2003-07-10
Publication date: 2009-08-26
Anticipated expiration: 2023-07-10
Also published as: SE0202173D0; SE0202173L; CN100335364C; CN1668502A; SE524722C2; EP1521704A1; DK1521704T3; DE60328991D1; ATE440770T1; AU2003246228A1; WO2004007274A1

Abstract

The present invention relates to a flushing device for internal flushing of tanks, preferably ship's tanks, wherein at least one pipe (9) for flushing liquid is rotatably mounted in the tank (2). The flushing-liquid pipe (9) has at least one flushing nozzle (10) which is pivotally mounted relative to the flushing-liquid pipe (9). A supply conduit (3) is provided to feed flushing liquid (S) to the flushing-liquid pipe (9) and through said pipe (9) to the flushing nozzle (10), which is adapted to direct jets (SS) of flushing liquid (S) towards the inner sides of the tank (2). The supply conduit (3) comprises a through-flow member (11), in which a through-flow passage (13) is provided for flowing through of flushing liquid (S). At least one by-pass passage (34) of a by-pass device (33) and a turbine wheel (14) are provided in said through-flow member (11). The flushing device (1) may also include a flow control device (36) for controlling the flow of flushing liquid therein.

Description

The present invention relates to a flushing device for internal flushing of tanks, preferably ship's tanks, wherein at least one pipe for flushing liquid is rotatably mounted in the tank. The flushing-liquid pipe has at least one flushing nozzle which is pivotally mounted relative to the flushing-liquid pipe. A supply conduit is provided to feed flushing liquid to the flushing-liquid pipe and through said pipe to the flushing nozzle, which is adapted to direct jets of flushing liquid towards the inner sides of the tank.
The supply conduit comprises a through-flow member, in which a through-flow passage is provided for flowing through of flushing liquid. A turbine wheel is rotatably mounted in said through-flow passage such that said turbine wheel is brought to rotate by means of flushing liquid flowing through the through-flow passage. At least one by-pass device is provided to feed flushing liquid past the through-flow passage such that only a portion of the flow of flushing liquid flows therethrough. The turbine wheel is provided to operate a driving device located outside the supply conduit, said driving device being provided to bring the flushing-liquid pipe to rotate and simultaneously the flushing nozzle to pivot.
Flushing devices for flushing ship's tanks according to the preamble of claim 1 are already known from EP 0 723 909 and WO 95/22415 . It is also known to provide flushing devices with by-pass devices to see to that a part of the flushing water flows past the through-flow passage in which the turbine wheel is located. The purpose of these by-pass devices is to reduce the flow of flushing liquid through the through-flow passage and thus, the rotation of the turbine wheel. Prior art by-pass devices are however complex, ineffective and voluminous, which means that the costs for manufacturing the flushing device are high. Furthermore, they do not permit setting of the rotary speed of the flushing-liquid pipe within a sufficient wide setting range when the flow of flushing liquid through the flushing device lies within a wide flow range. It is therefore necessary to supply several various flushing devices in order to cover a wide flow range, which for many reasons is disadvantageous.
The object of the present invention is to provide a flushing device at which said drawbacks are eliminated and this is arrived at according to the invention by providing the flushing device with the characterizing features of subsequent claim 1.
By providing the flushing device with said characterizing features, said device will have a functional and cost efficient by-pass device which also permits use of the flushing device within a substantially wider flow range for the flushing-liquid flow.
The invention will be further described below with reference to the accompanying drawings, in which

figure 1 is a schematic side view of a flushing device according to the invention mounted on a tank for internal flushing of said tank;
figure 2 is a section through a part of the flushing device of figure 1, wherein a turbine wheel is set in a lower position;
figure 3 is a section through a part of figure 2, wherein the turbine wheel is located in an upper position;
figure 4 is a section through members in the flushing device along the line IV-IV in figure 2;
figure 5 is a perspective view of a section through parts of the flushing device;
figure 6 illustrates with another perspective view the same section as figure 5;
figure 7 is a perspective view of a section through parts of the flushing device having as a first alternative designed members;
figure 8 illustrates with another perspective view the same section as figure 7;
figure 9 is a perspective view of a section through parts of the flushing device having as a second alternative designed members;
figure 10 illustrates with another perspective view the same section as figure 9;
figure 11 is a diagram of a setting range for setting the rotary speed of a flushing-liquid pipe, forming part of a prior art flushing device, in dependence of the flow of flushing liquid therethrough;
figure 12 is a diagram of a setting range for setting the rotary speed of a flushing-liquid pipe forming part of a flushing device according to the invention; and
figure 13 is a diagram of another setting range for setting the rotary speed of a flushing-liquid pipe forming part of a flushing device according to the invention.

Figure 1 schematically illustrates a flushing device 1 for internal flushing of tanks 2, preferably ship's tanks, with a suitable flushing liquid S. The flushing device 1 includes a supply conduit 3 which is connected to a vertically directed pipe 4. This pipe 4 is located above the upper side 5 of the tank 2 and includes a mounting plate.6 through which it is mounted on said upper side 5. The pipe 4 has a bearing member 7 in which upper parts 8 of a vertically directed flushing-liquid pipe 9 are rotatably journalled about a vertical geometric axis. The flushing--liquid pipe 9 extends a suitable distance down into the tank 2 and it includes at least one flushing nozzle 10 which is mounted in the tank 2 such that it can direct jets SS of flushing liquid towards the inner sides, top and bottom of the tank 2. The flushing liquid S is fed from the supply conduit 3, the pipe 4 and the flushing--liquid pipe 9 to the flushing nozzle 10.
A through-flow member 11 of the supply conduit 3 includes a pipe member 12 defining a through-flow passage 13 for flushing liquid S and in this through-flow passage 13 there is mounted a turbine wheel 14 which is provided to be rotated by the flow F of flushing liquid through the through-flow passage 13. The rotary movement of the turbine wheel 14 is transmitted out of the supply conduit 3, preferably be means of a magnetic coupling 16, through a closed and eventually openable portion 15 of the wall of the supply conduit 3. The magnetic coupling 16 may e.g. be designed as described and illustrated in EP 0 723 909 . The rotary movement R of the turbine wheel 14, which has been transmitted from the interior of the supply conduit 3 by means of the magnetic coupling 16, is transmitted further to a driving device 17 which is adapted to rotate the flushing-liquid pipe 9 in the direction of rotation R1 about a vertical geometric axis and the flushing nozzle 10 in the direction of rotation R2 about a horizontal geometric axis relative to the flushing-liquid pipe 9 while said pipe also rotates.
The driving device 17 may e.g. be designed as defined in EP 0 723 909 and thus comprise a gear box 18 for reducing the speed of the rotary movement coming from the turbine wheel 14. The reduced rotary movement is transmitted from the gear box 18 to a rotary gear mechanism 19, 20 which rotates a vertically directed pipe 21. This pipe 21 cooperates in turn with the flushing-liquid pipe 9 for rotation thereof in the direction of rotation R1. The rotary movement from the gear box 18 is also transmitted to a gear mechanism in which a rotating member 22 transmits its rotary movement to a linearly up- and downwards moving member 23. This member 23 cooperates with a vertically directed and linearly up- and downwards moving rod 24, which extends downwards through the pipe 21 and the flushing-liquid pipe 9 and cooperates through a gear 25 with the flushing nozzle 10 for pivoting said nozzle about the horizontal axis in the direction of rotation R2.
The turbine wheel 14 consists of a hub 26 with a number of outwardly directed turbine blades 27 which are located in the through-flow passage 13 such that the turbine wheel 14 is rotated by the flow of flushing liquid therethrough. The turbine wheel 14 can preferably be set in the longitudinal direction of the through-flow passage 13 such that its rotary speed increases with the distance said turbine wheel 14 is moved into said through--flow passage 13. This controllability or adjustment is arrived at by means of a suitable setting device which may include a pin 28 with outer or external threads, through which it is screwed into a threaded hole 29 in the through-flow member 11 beneath the through-flow passage 13. Lower parts of the hub 26 of the turbine wheel 14 cooperate with the pin 28 through a spherical bearing 30, which permits rotation of the turbine wheel 14 relative to said pin 28. Upper parts of the hub 26 of the turbine wheel 14 intervene displaceably in a sleeve 31 with an inner screw spring 32 and the hub 26 transmits or transfers its rotary movement to the sleeve 31. The sleeve 31 cooperates with an inner member 16a of the magnetic coupling 16 located within the closed portion 15 of the supply conduit 3 and said inner member 16a cooperates with an outer member 16b of the magnetic coupling 16.
The turbine wheel 14 can be moved or displaced between a lower and an upper position relative to the pipe member 12 and can be set in these and other positions therebetween such that the distance between those parts of the turbine wheel 14 defining the through-flow passage 13 and the pipe member 12 can be varied. The closer to the pipe member 12 the turbine wheel 14 is located, the faster is the turbine wheel 14 rotated by a flow F1 of flushing liquid through the through-flow passage 13 and vice versa.
In figure 2, the turbine wheel 14 is set in a lower position in which it is entirely or to the greater part located in the through-flow passage 13. In order to move the turbine wheel 14 upwards from its lower to an upper position in which it is partly situated outside the through-flow passage 13 - see figure 3 - or any position between the lower and upper positions, the pin 28 is screwed into the through-flow member 11 until the desired position of the turbine wheel 14 has been reached relative to the through-flow passage 13.
At the embodiment illustrated in the drawings, the hub 26 and turbine blades 27 of the turbine wheel 14 taper, preferably conically, in the direction of flow of the flow F1 of flushing liquid through the through-flow passage 13. The pipe member 12 or at least the inner side thereof has a corresponding tapering shape, preferably conically tapering shape in said direction of flow.
The flushing device 1 includes a by-pass device 33 for feeding flushing liquid S past the through-flow passage 13, such that only a portion F1 of the flow F of flushing liquid flows through the through-flow passage 13, while the remaining portion F2 of the flow F of flushing liquid flows through the by-pass device 33.
The by-pass device 33 includes at least one by-pass passage 34 which is provided in the same through-flow member 11 as the turbine wheel 14, i.e. inside the through--flow member 11 forming part of the supply conduit 3 and in which the pipe member 12 is found. By providing the by-pass passage 34 inside the through-flow member 11, the by-pass device 33 becomes functional and cost efficient inter alia because it is built into a part of the supply conduit 3 close to the turbine wheel 14.
At the embodiment illustrated in the drawings, the pipe member 12 and the through-flow member 11 define the by-pass device 33. Thus, the outer diameter of the pipe member 12 is e.g. less or smaller than the diameter of the parts of the through-flow member 11 surrounding the pipe member 12 and the pipe member 12 has a number of, e.g. four, outwardly directed flanges 35, which can be uniformly distributed around the pipe member 12. The flanges 35 are dimensioned such that they with outer edges engage the inner side of the through-flow member 11 and they are adapted for locating the pipe member 12 relative to the through-flow member 11 such that the by-pass passage 34 is defined therebetween. Thus, the outer side of the pipe member 12, the sides of the flanges 35 and the inner side of the through-flow member 11 together define the by-pass passage 34 (in this embodiment divided into four members) through which the portion F2 of the flow F of flushing liquid can flow.
The flanges 35 and thereby, the pipe member 12 can preferably be released from the through-flow member 11 for demounting the pipe member 12 therefrom and they can be as long or substantially as long as the pipe member 12.
The by-pass passage 34 may e.g. be designed such that it permits the portion F2 of the flow F of flushing liquid flowing therethrough to be larger than the portion F1 of the flow F of flushing liquid flowing through the through-flow passage 13.
A flow controlling or regulating device 36 can be provided on the turbine wheel 14 or on members connected thereto. This flow control device 36 is adapted to define a through-flow gap 37 with the pipe member 12 for flushing liquid S.
The flow control device 36 is displaceable relative to the pipe member 12 by moving or displacing the turbine wheel 14 in an axial direction relative to the pipe member 12 for varying the size of the through-flow gap 37 and thereby, the volume of flow of flushing liquid through the through-flow gap 37.
The flow control device 36 is preferably provided downstream of the pipe member 12 such that it defines the through-flow gap 37 with a lower edge of the pipe member 12 and such that the through-flow gap 37 is larger when the turbine wheel 14 is set close to the pipe member 12 - as is shown in figure 1 - than if the turbine wheel 14 is set farther away from the pipe member 12 - as is shown in figure 2.
When the turbine wheel 14 has been set close to the pipe member 12 - e.g. in a lower position - in order to attain a certain speed on the flow F1 of flushing liquid through the through-flow passage 13 and thereby, a certain rotary speed on the turbine wheel 14, then the flow control device 36 is situated at a certain distance from the pipe member 12 - e.g. also in a lower position - while when the turbine wheel 14 is set farther away from the pipe member 12 - e.g. in a position above said lower position - for attaining a lower speed on the flow F1 of flushing liquid through the through-flow passage 13 and thereby, a lower rotary speed on the turbine wheel 14, then the flow control device 36 is situated at a less or smaller distance from the pipe member 12 - e.g. also in a position above the lower position - in order to throttle the flow F1 of flushing liquid in the through--flow passage 13.
The flow control device 36 can be provided transverse relative to the direction of flow of the flushing--liquid flow F1 through the through-flow passage 13 and it can have an outer diameter which corresponds or substantially corresponds with the diameter of the closest parts of the through-flow passage 13.
In a preferred embodiment, the flow control device 36 can be designed as a circular or substantially circular washer 38.
The washer 38 is preferably provided transverse relative to the direction of flow of the flow F1 of flushing liquid through the through-flow passage 13 and it preferably has an outer diameter which substantially corresponds with the diameter of the nearest parts of the through-flow passage 13.
As is apparent from figures 5 and 6, the flow control device 36 may instead be located upstream of the pipe member 12. As is apparent from figures 7 and 8, the pipe member 12 may be cylindrical instead of conical and the flow control device 36 can be located downstream of the pipe member 12. In figures 9 and 10 there is shown an embodiment with the same cylindrical pipe member 12 as in figures 7 and 8, but with the flow control device 36 located upstream of the pipe member 12.
As an example of which difference or variation of the size of the setting range of the flushing-liquid pipe 9 regarding its rotary speed (revolutions per minute, rpm) the flushing device described above permits relative to prior art flushing devices, the following should be mentioned while referring to the diagrams of figures 11 and 12.
A prior art flushing device may e.g. be built for a flushing-liquid pressure of 8 bar (the pressure is generated in a manner known per se by means of a pump device) and a flow volume of flushing liquid of about 30 m³/h. As is apparent from the diagram according to figure 11, the rotary speed of the flushing-liquid pipe 9 may in this embodiment be set within the setting range 0,5 - 1,5 rpm, which is a common range or interval for the rotary speed of flushing-liquid pipes. If however, one tries to operate such a flushing device with a flow volume of the flushing liquid of more than 30 m³/h, the setting range is so narrow that the rotary speed of the flushing-liquid pipe can no longer be set within the common range or interval of about 0,5 - 1,5 rpm. This is illustrated in the diagram of figure 11 by the taper of the setting range from 15 m³/h and by the very narrow setting range at 30 m³/h.
At the flushing device 1 described above, including a by-pass device 33 but without the flow control device 36, the by-pass passage 34 permits bringing a portion F2 of the flow F of flushing liquid to flow through the by-pass passage 34 such that the setting range for setting the rotary speed of the flushing-liquid pipe 9 - as is shown in the diagram of figure 12 - can be varied within the common range or interval of about 0,5 - 1,5 rpm at a flow volume of the flushing liquid S of up to 45 m³/h. Said flushing device 1 with a by-pass device 33 may thus be used for setting the common range or interval of about 0,5 - 1,5 rpm for the rotary speed of the flushing-liquid pipe 9 within a much larger range or interval for the flow volume of the flushing liquid than what previously has been possible with prior art flushing devices.
By equipping the flushing device 1 described above with a by-pass device 33 as well as a flow control device 36, it is e.g. possible to reduce the rotary speed of the turbine wheel 14 substantially more than if the flushing device 1 comprises only a by-pass device 33. If e.g. the turbine wheel 14 is raised from a lower position - as is shown in figure 2 - to an upper position - as in figure 3 - the washer 38 will automatically be displaced or moved closer to the pipe member 12 such that the through-flow gap 37 gets substantially smaller or narrower, e.g. the flow F1 of flushing liquid through the through-flow passage 13 is throttled considerably, which means that the flow F2 of flushing liquid through the by-pass passage 34 increases correspondingly. Hereby, a wide, non-tapering setting range for the rotary speed of the flushing liquid pipe 9 is obtained - as is shown in the diagram of figure 13 - meaning that the rotary speed of the flushing-liquid pipe 9 can be controlled or varied within the common interval of about 0,5 - 1,5 rpm. at flushing-liquid flows up to e.g. 55 m³/h or to the maximum capacity of the flushing device 1 regarding flushing-liquid flows in m³/h.
In summary, said by-pass device 33 together with the flow control device 36 permit setting of the rotary speed of the flushing-liquid pipe within the common interval of about 0,5 - 1,5 rpm, within a substantially larger range or interval for the flow of flushing liquid in m³/h, e.g. within the range from about 10 m³/h to at least about 55 m³/h.
The invention is not limited to the embodiment described above and illustrated in the drawings, but may vary within the scope of the following claims. As examples of alternative embodiments of the flushing device it should be mentioned that the by-pass device 33 can be used not only in combination with the flow control device 36 but also without said flow control device 36, and that the flow control device 36 can be used without the by-pass device 33. In said latter embodiments it might eventually be necessary to design the flow control device 36 and the by-pass device 33 in other ways and/or with other dimensions than described above.
In certain embodiments the pipe member 12 may eventually be dispensed with and the through-flow pipe 13 defined by the through-flow member 11 or by any other member. The by-pass device 33 may have a suitable number of by-pass passages 34 of suitable size and the flow control device 36 may be designed otherwise than described above. The flushing device may also have more than one flushing nozzle 10 and its through-flow member 11 with associated members and driving device 17 with associated members can be located in the tank 2 instead of outside the tank.

Claims

Flushing device or internal flushing of tanks, preferably ship's tanks,
wherein at least one pipe (9) for flushing liquid is rotatably mounted in the tank (2),
wherein the flushing-liquid pipe (9) has at least one flushing nozzle (10) which is pivotally mounted relative to the flushing-liquid pipe (9),
wherein a supply conduit (13) is provided to feed flushing liquid (S) to the flushing-liquid pipe (9) and through said pipe (9) to the flushing nozzle (10), which is adapted to direct jets (SS) of flushing liquid (S) towards the inner sides of the tank (2),
wherein the supply conduit (3) comprises a through--flow member (11), in which a through-flow passage (13) is provided for flowing through of flushing liquid (S),
wherein a turbine wheel (14) is rotatably mounted in said through-flow passage (13) such that said turbine wheel (14) is brought to rotate by means of a flow of flushing liquid through the through-flow passage (13),
wherein at least one by-pass passage (34) is provided to feed flushing liquid (S) past the through-flow passage (13) such that only a portion (F1) of the flow (F) of flushing liquid flows therethrough while other portions (F2) of the flushing-liquid flow (F) flow through the by-pass passage (34), and
wherein the turbine wheel (14) is provided to operate a driving device (17) which is provided to bring the flushing-liquid pipe (9) to rotate and simultaneously the flushing nozzle (10) to pivot,
characterized in
that the through-flow member (11) comprises a pipe member (12) which divides said through-flow member (11) into the through-flow passage (13) and the by-pass passage (34),
that the turbine wheel (14) is displaceable in an axial direction relative to the pipe member (12) for setting of the turbine wheel (14) at different distances from the pipe member (12),
that the turbine wheel (14) or members connected thereto includes/include a flow control device (36) defining together with the pipe member (12) a through-flow gap (37) for flushing liquid (S), and
that the flow control device (36) is displaceable relative to the pipe member (12) by displacing the turbine wheel (14) in an axial direction relative to said pipe member (12) in order to vary the size of the through-flow gap (37) and thereby the flow volume of flushing liquid through the through-flow gap (37).
Flushing device according to claim 1, characterized in that the pipe member (12) has outwardly directed flanges (35) through which said pipe member (12) cooperates with the through-flow member (11).
Flushing device according to claim 2, characterized in that the flanges (35) engage the through-flow member (11) and locate the pipe member (12) in relation thereto for defining the by-pass passage (34).
Flushing device according to any preceding claim,
characterized in that the by-pass passage (34) is designed to permit that the portion (F2) of the flow (F) of flushing liquid which can flow therethrough is larger than the portion (F1) of the flow (F) of flushing liquid which can flow through the through-flow passage (13).
Flushing device according to any preceding claim,
characterized in that the turbine wheel (14) can be set at different distances from a pipe member (12) defining the through-flow passage (13) or a corresponding member.
Flushing device according to claim 5, characterized in that the turbine wheel (14) can be set in a position in which it is completely or almost completely located in a pipe member (12) defining the through-flow passage (13) or in a member corresponding thereto and in another position in which it is partly located outside said pipe member (12) or the member corresponding thereto, and that the turbine wheel (14) can be set in different positions between said positions.
Flushing device according to any preceding claim, characterized in that the turbine wheel (14) and a pipe member (12) defining the through-flow passage (13) or a member corresponding thereto, have a tapering, preferably conically tapering shape in the direction of flow of the flow (F1) of flushing liquid through the through-flow passage (13).
Flushing device according to any preceding claim, characterized in that the flow control device (36) is provided downstream of the pipe member (12) such that the through-flow gap (37) is larger when the turbine wheel (14) is set close to the pipe member (12) than if the turbine wheel (14) is set farther away from the pipe member (12).
Flushing device according to any preceding claim, characterized in that when the turbine wheel (14) is set close to the pipe member (12) for attaining a certain speed of the flow (F) of flushing liquid through the through-flow passage (13) and thereby a certain rotary speed of the turbine wheel (14), then the flow control device (36) is located at a certain distance from the pipe member (12), and when the turbine wheel (14) is set farther away from the pipe member (12) for attaining a lower speed of the flow (F1) of flushing liquid through the through-flow passage (13) and thereby a lower rotary speed of the turbine wheel (14), then the flow control device (36) is located at a smaller distance from the pipe member (12) for throttling the flow (F1) of flushing liquid in the through-flow passage (13).
Flushing device according to any preceding claim, characterized in that the flow control device (36) is provided transverse relative to the direction of flow of the flow (F1) of flushing liquid through the through-flow passage (13).
Flushing device according to any preceding claim, characterized in that the flow control device (36) has an outer diameter which corresponds or substantially corresponds with the diameter of those parts of the through-flow passage (13) lying closest to said flow control device (36).
Flushing device according to any preceding claim, characterized in that the flow control device (36) is designed as a circular or substantially circular washer (38).
Flushing device according to any preceding claim, characterized in that the by-pass passage (34) and the flow control device (36) are provided such that the rotary speed of the flushing-liquid pipe (9) can be set within a range or interval of substantially 0,5-1,5 revolutions per minute (rpm) at a flow volume for the flushing liquid (S) within a range or interval of about 10-55 m³/h or up to the maximum capacity of the flushing device (1). ,
Flushing device according to any preceding claim, characterized in that the turbine wheel (14) and the pipe member (12) have a tapering, preferably conically tapering shape in the flow of direction of the flushing-liquid flow (F1) through the through-flow gap (37) and that the flow control device (36) is provided downstream of the pipe member (12) or a member corresponding therewith such that the through-flow gap (37) is larger when the turbine wheel (14) is set close to the pipe member (12) or the member corresponding therewith than if the turbine wheel (14) is set farther away from the pipe member (12) or the member corresponding therewith.
Flushing device according to any of claims 1-13,
characterized in that the pipe member (12) has a cylindrical shape in the direction of flow of the flushing-liquid flow (F1) through the through-flow passage (13) and the turbine wheel (14) a corresponding shape, and that the flow control device (36) is provided downstream or upstream of the pipe member (12).