WO2016171606A1

WO2016171606A1 - Leak preventing device and tank for transporting liquid provided with such a device

Info

Publication number: WO2016171606A1
Application number: PCT/SE2016/050330
Authority: WO
Inventors: Christer Lundin
Original assignee: Individual
Current assignee: Individual
Priority date: 2015-04-22
Filing date: 2016-04-15
Publication date: 2016-10-27
Anticipated expiration: 2017-10-22
Also published as: JP2018516813A; KR20180011093A; CN107531409A; SE1550478A1; SE538812C2; EP3286110A4; US20180118454A1; EP3286110A1

Abstract

A leak preventing device (1) for preventing liquid from leaking out of a damaged tank (2), the device comprising: -a floating body (4) capable of floating at the surface (3) of the liquid in the tank; and -a flexible hose (5), the first end of the hose being fixed to the floating body and the hose being fixed to a wall of the tank at a point of attachment (8) at a distance from said first end, wherein the hose extends freely inside the tank between the floating body and said point of attachment and wherein the second end of the hose is connectable to a suction side of a vacuum pump(9) so as to allow gas to be drawn off via the hose from a gas-filled space (10) in the tank above the surface of the liquid in order to produce an under pressure in said space. The invention also relates to a tank for transporting liquid provided with such a device.

Description

Leak preventing device and tank for transporting liquid provided with such a device

FI ELD OF THE I NVENTION AND PRIOR ART

The present invention relates to a leak preventing device accord ing to the preamble of claim 1 for preventing liqu id from leaking out of a damaged tank. The invention also relates to a tank for transporting liquid provided with such a device.

Liquid fuel and other types of liqu ids may be transported and stored in tanks of various types. If such a tank is damaged , for instance due to an accident or wear, the liquid in the tan k may leak to the surrounding environment, which may cause a lot of problem, for instance in the form of material damages, environmental pollution and health and safety hazards for people in the vicinity of the leaking tank. It is previously known , for instance from GB 1 020 581 A and DE 1 525 465 B, that liquid may be prevented from leaking out through a leak below the surface of the liquid in a tan k by producing a sufficient underpressure in a gas-filled space above the surface of the liquid in the tank by means of a vacuum pump.

A leak preventing device is previously known from WO 87/02650 A1 . This previously known device has the form of a leak sealing pad which is to be attached to an outer wall of a tank so as to cover a leak opening in the tan k wall and thereby prevent gas or liquid from flowing out of the tank through the leak opening . The pad is pressed against the tank wall under the effect of an underpressure generated in a vacuum chamber of the pad by means of a vacuum pump. However, th is leak preventing device is only suitable for use when it comes to an easily accessible leak concentrated to a limited area.

OBJECT OF THE I NVENTION

The object of the present invention is to provide a new and favourable leak preventing device for preventing liqu id from leaking out of a damaged tank.

SUMMARY OF THE I NVENTION

According to the present invention , the above-mentioned object is achieved by a leak preventing device having the features defined in claim 1 .

The leak preventing device of the present invention comprises:

- a floating body with a buoyancy which makes it capable of floating at the surface of the liquid in the tank with at least an upper part of the floating body located above the surface of the liquid in the tan k; and

- a flexible hose with a first end and an opposite second end , the first end of the hose being fixed to the floating body and the hose being fixed to a wall of the tank at a point of attachment at a distance from said first end , wherein the hose extends freely inside the tan k between the floating body and said point of attachment and wherein the second end of the hose is connected or connectable to a suction side of a vacuum pump so as to allow gas to be drawn off via the hose from a gas-filled space in the tank above the surface of the liquid in the tank in order to produce an underpressure in said space.

With the leak preventing device of the present invention , a leak- preventing underpressure may be achieved inside a tank in a simple manner. When liqu id leaks out of the tank through a leak below the surface of the liquid in the tank, for instance when the tank has been damaged due to an accident, a vacuum pump is to be connected to the flexible hose inside the tank and the vacuum pump is to be operated in order to draw off gas from the gas- filled space in the tank above the surface of the liquid in the tan k via the flexible hose and thereby produce an underpressure in said space sufficient for preventing liqu id from continuing to leak out of the tank through said leak. The floating body will always float at the surface of the liquid in the tan k irrespective of the prevailing inclination of the tank, and the floating body may thereby ensure that the flexible hose always is maintained in fluid communication with the gas-filled space in the tank above the surface of the liqu id in the tan k. Furthermore, the leak preventing device of the present invention may be used even if the leak opening is inaccessible.

Accord ing to an embod iment of the invention , said first end of the hose is fixed to the floating body in such a manner that the hose projects from the underside of the floating body at the centre thereof. Hereby, the weight of the hose will contribute in keeping the floating body floating in a correct position with its underside facing vertically downwards. Accord ing to another embodiment of the invention , said second end of the hose is connected to a shut-off valve, which is fixed to the tank and accessible from the outside of the tank. The shut-off valve makes it easy to put the flexible hose inside the tank in commun ication with a vacuum pump when so needed and to otherwise keep the flexible hose disconnected from the ambient air.

Accord ing to another embod iment of the invention , said shut-off valve is connected to a cou pling member, which is configured for releasable engagement with a corresponding coupling member arranged at an end of a suction hose from a vacuum pump. Hereby, a vacuum pump may easily and rapidly be connected to the flexible hose inside the tank when so needed .

Accord ing to another embodiment of the invention , the flexible hose is connected to one or more further shut-off valves, which are fixed to the tank at a distance from each other and accessible from the outside of the tank, wherein each such further shut-off valve is connected to a coupling member which is configured for releasable engagement with a corresponding coupling member arranged at an end of a suction hose from a vacuum pump. Each shut-off valve with its associated cou pling member constitutes an access point through wh ich a vacuum pump may be connected to the flexible hose inside the tan k. By providing several such access points, the risk that the tan k, in connection with an accident, wou ld end up in a position in which no access to the flexible hose inside the tank is possible is reduced . Further advantageous features of the leak preventing device of the present invention will appear from the following description and the dependent claims. The invention also relates to a tank for transporting liquid having the features defined in claim 1 1 .

Further advantageous features of the tank of the present invention will appear from the following description .

BRI EF DESCRI PTION OF THE DRAWI NGS

With reference to the appended drawings, a specific description of embod iments of the invention cited as examples follows below. In the drawings:

Fig 1 is a schematic longitud inal section through a tank provided with a leak preventing device according to embod iment of the present invention ,

Fig 2 schematic longitud inal section through the tan k of

1 , as seen with a vacuum pump connected to the flexible hose inside the tank Fig 3 detail enlargement of the encircled area III in Fig

Fig 4 detail enlargement of the encircled area IV in Fig

2 Fig 5 is a schematic perspective view from below of a floating body included in the leak preventing device of Fig 1 , Fig 6 is a schematic perspective view from above of the floating body of Fig 5,

Fig 7 is a schematic vertical section through the floating body of Figs 5 and 6,

Fig 8 is a schematic planar view from above of the floating body of Figs 5 and 6, and

Fig 9 is a schematic vertical section through a floating body accord ing to an alternative variant.

DETAI LED DESCRI PTION OF EMBODI MENTS OF THE I NVENTION A leak preventing device 1 according to an embodiment of the present invention is schematically illustrated in Figs 1 -4. The leak preventing device 1 is to be used with a tank 2 for transporting and/or storing liquid in order to prevent liqu id from leaking out of the tank through a hole or crack in a wall of the tank below the surface 3 of the liquid in the tank if the tank is damaged due to an accident or wear. Thus, the leak preventing device 1 is to be pre-mounted to the tank 2 so as to be ready for use in a possible situation when the tank is damaged and liquid starts to leak out of the tank. The leak preventing device 1 comprises a floating body 4 which is configured to have such a buoyancy that it is capable of floating at the surface 3 of the liquid in the tank 2 with at least an upper part of the floating body 4 located above the surface 3 of the liquid in the tank. The leak preventing device 1 also comprises a flexible hose 5 with a first end 6a and an opposite second end 6b. The first end 6a of the hose is fixed to the floating body 4 and the hose 5 is fixed to a wall 7 of the tan k 2 at a point of attachment 8 at a distance from said first end 6a, wherein the hose 5 extends freely inside the tank 2 between the floating body 4 and said point of attachment 8. The second end 6b of the hose is connected or connectable to a suction side of a vacuum pump 9 (see Fig 2) so as to allow the vacuum pump to draw off gas via the hose 5 from a gas-filled space 10 in the tan k 2 above the floating body 4 and above the surface 3 of the liqu id in the tank in order to reduce the pressure in said space 10 to such a low value that leakage of liquid from the tank 2 through a possible leak below the surface 3 of the liquid is prevented . In the illustrated embodiment, the second end 6b of the hose is connected to a shut-off valve 1 1 , which is fixed to the tank 2 and accessible from the outside of the tank. The shut-off valve 1 1 is connected to a cou pling member 13 which is configured for releasable engagement with a corresponding coupling member 14 (see Fig 4) arranged at an end of a suction hose 15 from a vacuum pump 9.

The flexible hose 5 is with advantage connected to two or more shut-off valves 1 1 which are fixed to the tank 2 at a distance from each other and accessible from the outside of the tank 2, as illustrated in Figs 1 -4, wherein each shut-off valve 1 1 is connected to a coupling member 13 configured for releasable engagement with a corresponding coupling member 14 arranged at an end of a suction hose 15 from a vacuum pump 9. In the illustrated example, the leak preventing device 1 comprises three shut-off valves 1 1 with associated coupling members 13. The shut-off valves 1 1 are connected to each other by means of connecting pipes 16 which are mounted to the tank 2 on the outside thereof. The connecting pipes 16 may as an alternative be mounted inside the tank 2.

Each shut-off valve 1 1 comprises a valve member (not shown) which is moveable by means of a maneuvering member 12 between a closed position and an open position . The maneuvering member 12 may for instance have the form of a lever or knob.

In the illustrated embod iment, the suction hose 15 of the vacuum pump 9 is to be connected to one of the shut-off valves 1 1 when need arises. However, the leak preventing device of the present invention may as an alternative comprise a vacuum pump which is permanently connected to the flexible hose 5 inside the tank 2 via a shut-off valve 1 1 . The first end 6a of the flexible hose 5 is with advantage fixed to the floating body 4 in such a manner that the hose 5 projects from the underside 1 7a of the floating body at the centre thereof, as illustrated in Figs 5 and 7. In the embod iments illustrated in Figs 5-9, the floating body 4 is provided with a suction channel 18 , wherein the first end 6a of the flexible hose 5 is connected to a lower end 19a of the suction channel 18 and an inlet opening 20 is arranged at an upper end 19b of the suction channel 18. The inlet opening 20 is provided in a part of the floating body 4 which is configured to be located above the surface 3 of the liquid in the tank 4 when the floating body 4 is floating at the surface 3 of the liquid in the tank. In the illustrated examples, the suction channel 1 8 extends across the floating body 4 from the underside 1 7a of the floating body to the upper side 1 7b thereof along the centre axis of the floating body 4.

In the embodiment illustrated in Figs 5-8, the inlet opening 20 of the suction channel 18 is arranged at the upper end of a pipe 21 which projects from the upper side 1 7b of the floating body 4, wherein the upper end of the pipe 21 is received in a cover 22 which is configured to prevent liquid from splashing into the suction channel 18 through the inlet opening 20. The cover 22 is fixed to the pipe 21 by means of a supporting member 23 in the form of a plate or the similar, wherein gas is allowed to flow into the cover 22 towards the inlet opening 20 of the suction channel 18 through gaps 24 between the supporting member 23 and an inner wall of the cover 22, as illustrated in Figs 7 and 8, or through gaps in the supporting member 23.

In the embodiment illustrated in Fig 9, a check valve 25 is arranged at the inlet opening 20 of the suction channel 18 in order to keep the inlet opening closed when no gas to is drawn off via the flexible hose 5 from the gas-filled space 10 above the surface 3 of the liquid in the tank 2. The check valve 25 comprises a valve member 26, for instance in the form of a disc, which is moveably mounted to the float 4 at the upper end 19b of the suction channel 18. Under the effect of a suction effect in the suction channel 18 produced by a vacuum pump 9, the valve member 26 is moveable from a closed position , in which the valve member 26 covers the inlet opening 20 of the suction channel 18 and thereby prevents liquid from splashing into the suction channel 18 through the inlet opening 20, to an open position , in which the valve member 26 is swung away from the inlet opening 20. A stop member 27 is with advantage arranged at the inlet open ing 20 of the suction channel 18 in order to define the closed position of the valve member 26, wherein the valve member 26 is configured to abut against this stop member 27 in its closed position . The valve member 26 is preferably spring-loaded so as to assume its closed position under the effect of the spring force from a spring member (not shown) acting on the valve member 26.

The invention is of course not in any way restricted to the embodiments described above. On the contrary, many possibilities to modifications thereof will be apparent to a person with ord inary skill in the art without departing from the basic idea of the invention such as defined in the appended claims.

Claims

CLAI MS

1 . A leak preventing device for preventing liqu id from leaking out of a damaged tank (2), characterized in that the leak preventing device (1 ) comprises:

- a floating body (4) with a buoyancy which makes it capable of floating at the surface (3) of the liqu id in the tank (2) with at least an upper part of the floating body (4) located above the surface (3) of the liquid in the tank (2); and

- a flexible hose (5) with a first end (6a) and an opposite second end (6b), the first end (6a) of the hose being fixed to the floating body (4) and the hose (5) being fixed to a wall (7) of the tan k (2) at a point of attachment (8) at a distance from said first end (6a), wherein the hose (5) extends freely inside the tank (2) between the floating body (4) and said point of attachment (8) and wherein the second end (6b) of the hose is connected or connectable to a suction side of a vacuum pump (9) so as to allow gas to be drawn off via the hose (5) from a gas-filled space (10) in the tan k (2) above the surface (3) of the liqu id in the tank (2) in order to produce an underpressure in said space ( 10).

2. A leak preventing device according to claim 1 , characterized in that said first end (6a) of the hose is fixed to the floating body (4) in such a manner that the hose (5) projects from the underside (1 7a) of the floating body at the centre thereof.

3. A leak preventing device according to claim 1 or 2, characterized in : - that a suction channel (18) is arranged in the floating body

(4);

- that the suction channel (18) has an inlet opening (20) at its upper end , wherein th is inlet opening (20) is arranged in a part of the floating body (4) which is configured to be located above the surface (3) of the liqu id in the tank (2) when the floating body (4) is floating at the surface (3) of the liqu id in the tank (2); and

- that the first end (6a) of the hose is connected to a lower end ( 19a) of the suction channel (18).

A leak preventing device according to claim 3, characterized in that a check valve (25) is arranged at the inlet opening (20) of the suction channel ( 18) in order to keep the inlet opening closed when no gas to is drawn off via the hose (5) from said gas-filled space ( 10) in the tank (2) .

A leak preventing device according to claim 3, characterized in :

- that the inlet opening (20) of the suction channel (18) is provided at an upper end of a pipe (21 ) which projects from the upper side (1 7b) of the floating body (4); and

- that the upper end of said pipe (21 ) is received in a cover (22), which is configured to prevent liquid from splash ing into the suction channel ( 18) through the inlet opening (20) .

A leak preventing device according to any of claims 3-5, characterized in that the suction channel (18) extends across the floating body (4) from the underside (1 7a) of the floating body to the upper side ( 1 7b) thereof.

7. A leak preventing device according to any of claims 1 -6, characterized in that said second end (6b) of the hose is connected to a shut-off valve (1 1 ), which is fixed to the tank (2) and accessible from the outside of the tan k (2) .

8. A leak preventing device according to claim 7, characterized in that said shut-off valve (1 1 ) is connected to a cou pling member (13), which is configured for releasable engagement with a corresponding coupling member ( 14) arranged at an end of a suction hose ( 15) from a vacuum pump (9).

9. A leak preventing device according to claim 7 or 8, characterized in :

- that the flexible hose (5) is connected to one or more further shut-off valves (1 1 ), which are fixed to the tank (2) at a distance from each other and accessible from the outside of the tank (2); and

- that each such further shut-off valve (1 1 ) is connected to a cou pling member (13), which is configured for releasable engagement with a correspond ing cou pling member (14) arranged at an end of a suction hose (15) from a vacuum pump (9).

10. A leak preventing device according to claim 9, characterized in that the shut-off valves (1 1 ) are connected to each other by means of connecting pipes (16) mounted to the tank (2) on the outside or on the inside thereof.

11. A tank for transporting liquid, characterized in that the tank (2) is provided with a leak preventing device (1) according to any of claims 1-10.