Leak Preventing Device and Tank for Transporting Liquid With such a Device

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.

1 . A leak preventing device for preventing liquid from leaking out of a damaged tank ( 2 ), wherein 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 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 ( 2 ); and   a flexible hose ( 5 ) with a first end ( 6   a ) and an opposite second end ( 6   b ), the first end ( 6   a ) of the hose being fixed to the floating body ( 4 ) and the hose ( 5 ) being fixed to a wall ( 7 ) of the tank ( 2 ) at a point of attachment ( 8 ) at a distance from said first end ( 6   a ), wherein   the hose ( 5 ) extends freely inside the tank ( 2 ) between the floating body ( 4 ) and said point of attachment ( 8 ) and   the second end ( 6   b ) of the hose is connected or connectable to a suction side of a vacuum pump ( 9 ) to allow gas to be drawn off via the hose ( 5 ) from a gas-filled space ( 10 ) in the tank ( 2 ) above the surface ( 3 ) of the liquid in the tank ( 2 ) to produce an underpressure in said space ( 10 ).   
     
     
         2 . A leak preventing device according to  claim 1 , wherein said first end ( 6   a ) of the hose is fixed to the floating body ( 4 ) in such a manner that the hose ( 5 ) projects from the underside ( 17   a ) of the floating body at the centre thereof. 
     
     
         3 . A leak preventing device according to  claim 1 , wherein
 a suction channel ( 18 ) is arranged in the floating body ( 4 );   the suction channel ( 18 ) has an inlet opening ( 20 ) at its upper end, this 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 liquid in the tank ( 2 ) when the floating body ( 4 ) is floating at the surface ( 3 ) of the liquid in the tank ( 2 ); and   the first end ( 6   a ) of the hose is connected to a lower end ( 19   a ) of the suction channel ( 18 ).   
     
     
         4 . A leak preventing device according to  claim 3 , wherein a check valve ( 25 ) is arranged at the inlet opening ( 20 ) of the suction channel ( 18 ) 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 ). 
     
     
         5 . A leak preventing device according to  claim 3 , wherein
 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 ( 17   b ) of the floating body ( 4 ); and   the upper end of said 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 ).   
     
     
         6 . A leak preventing device according to  claim 3 , wherein the suction channel ( 18 ) extends across the floating body ( 4 ) from the underside ( 17   a ) of the floating body to the upper side ( 17   b ) thereof. 
     
     
         7 . A leak preventing device according to  claim 1 , wherein said second end ( 6   b ) of the hose is connected to a shut-off valve ( 11 ), which is fixed to the tank ( 2 ) and accessible from the outside of the tank ( 2 ). 
     
     
         8 . A leak preventing device according to  claim 7 , wherein said shut-off valve ( 11 ) is connected to a coupling 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 , wherein
 the flexible hose ( 5 ) is connected to one or more further shut-off valves ( 11 ), which are fixed to the tank ( 2 ) at a distance from each other and accessible from the outside of the tank ( 2 ); and   each such further shut-off valve ( 11 ) is connected to a coupling 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 ).   
     
     
         10 . A leak preventing device according to  claim 9 , wherein the shut-off valves ( 11 ) are connected to each other by connecting pipes ( 16 ) mounted to the tank ( 2 ) on the outside or on the inside thereof. 
     
     
         11 . A tank for transporting liquid, wherein the tank ( 2 ) is provided with a leak preventing device ( 1 ) according to  claim 1 . 
     
     
         12 . A leak preventing device according to  claim 2 , wherein
 a suction channel ( 18 ) is arranged in the floating body ( 4 );   the suction channel ( 18 ) has an inlet opening ( 20 ) at its upper end;   this 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 liquid in the tank ( 2 ) when the floating body ( 4 ) is floating at the surface ( 3 ) of the liquid in the tank ( 2 ); and   the first end ( 6   a ) of the hose is connected to a lower end ( 19   a ) of the suction channel ( 18 ).   
     
     
         13 . A leak preventing device according to  claim 12 , wherein a check valve ( 25 ) is arranged at the inlet opening ( 20 ) of the suction channel ( 18 ) 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 ). 
     
     
         14 . A leak preventing device according to  claim 12 , wherein
 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 ( 17   b ) of the floating body ( 4 ); and   the upper end of said 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 ).   
     
     
         15 . A leak preventing device according to  claim 14 , wherein the suction channel ( 18 ) extends across the floating body ( 4 ) from the underside ( 17   a ) of the floating body to the upper side ( 17   b ) thereof. 
     
     
         16 . A leak preventing device according to  claim 13 , wherein the suction channel ( 18 ) extends across the floating body ( 4 ) from the underside ( 17   a ) of the floating body to the upper side ( 17   b ) thereof. 
     
     
         17 . A leak preventing device according to  claim 12 , wherein the suction channel ( 18 ) extends across the floating body ( 4 ) from the underside ( 17   a ) of the floating body to the upper side ( 17   b ) thereof. 
     
     
         18 . A leak preventing device according to  claim 5 , wherein the suction channel ( 18 ) extends across the floating body ( 4 ) from the underside ( 17   a ) of the floating body to the upper side ( 17   b ) thereof. 
     
     
         19 . A leak preventing device according to  claim 4 , wherein the suction channel ( 18 ) extends across the floating body ( 4 ) from the underside ( 17   a ) of the floating body to the upper side ( 17   b ) thereof. 
     
     
         20 . A leak preventing device according to  claim 15 , wherein said second end ( 6   b ) of the hose is connected to a shut-off valve ( 11 ), which is fixed to the tank ( 2 ) and accessible from the outside of the tank ( 2 ).