Air exchange attenuation apparatus

Abstract

An apparatus for attenuating the exchange of air in a freight container with the surrounding atmosphere comprises a flexible but substantially not resilient membrane which delimits in the container a first air volume from a second air volume in which cargo sensitive to humidity is stored. The first air volume is in communication with the surrounding atmosphere and capable of varying as a result of differences between atmospheric pressure and the pressure in the second air volume. Also disclosed is a freight container provided with the apparatus.

1 . Apparatus for attenuating the exchange of air in a freight container with the surrounding atmosphere, comprising a flexible but substantially not resilient membrane which delimits in the container a first air volume from a second air volume in which cargo sensitive to humidity is stored, said first air volume being in communication with the surrounding atmosphere and capable of varying as a result of differences between atmospheric pressure and the pressure in said second air volume.  
   
   
       2 . The apparatus according to  claim 1 , wherein the membrane comprises a sealing means extending along its circumference.  
   
   
       3 . The apparatus according to  claim 2 , wherein the sealing means comprises a rectangular frame capable of being mounted so as to make the membrane cover a door opening of the container.  
   
   
       4 . The apparatus according to  claim 3 , wherein the frame comprises an adhesive for gluing the frame to the rebate of the container door.  
   
   
       5 . The apparatus according to  claim 1 , wherein the membrane or a portion thereof is transparent.  
   
   
       6 . The apparatus according to  claim 2 , wherein the sealing means comprises an assembly for mounting the membrane to a container wall having a first through opening which is not a door opening to provide substantially unrestricted communication between said first volume and the surrounding atmosphere through said first through opening.  
   
   
       7 . The apparatus according to  claim 6 , wherein the mounting assembly comprises an element for interposition between said first through opening and the remainder of said assembly, the interposition element comprising means for its fixation to the container wall in a manner so as to make it cover the first through opening and comprising a first through bore for its fixation to the remainder of the mounting assembly and a second through bore for providing communication of atmospheric air to the first air volume.  
   
   
       8 . The apparatus according to  claim 6 , wherein the mounting assembly comprises a means for its fixation to a second trough bore in the container wall disposed adjacent to said first through bore.  
   
   
       9 . The apparatus according to  claim 6 , wherein the mounting assembly comprises a mounting stud, a first tube extending from the mounting stud generally perpendicularly to the stud axis, a second tube slidingly and sealingly disposed on the first tube or in the first tube having, in respect of the stud, a an open proximal end and a closed distal end, the second tube comprising a neck extending from its closed end for air-tight fixation of said membrane.  
   
   
       10 . The apparatus according to  claim 9 , wherein the mounting assembly further comprises a means for suspending the first or the second tube on a lashing eye fixed at the container wall.  
   
   
       11 . The apparatus according to  claim 9 , wherein the second tube is a corrugated tube slidingly and sealingly disposed on said first tube.  
   
   
       12 . The apparatus according to  claim 10 , wherein said suspension means is arranged for clamping fixation on said second tube.  
   
   
       13 . The apparatus according to  claim 6 , wherein said membrane has the general form of a bag.  
   
   
       14 . The apparatus according to  claim 1 , wherein said first volume is up to ten percent of said second volume.  
   
   
       15 . The apparatus according to  claim 1 , wherein said first volume is up to six percent of said second volume.  
   
   
       16 . The apparatus according to  claim 1 , wherein said first volume is comprised by two or more apparatus according to the invention.  
   
   
       17 . The apparatus according to  claim 1 , wherein the flow resistance of the communication between the atmosphere and said first volume is ten percent or less of the flow resistance of the combined leaks from said second volume to the atmosphere.  
   
   
       18 . The apparatus according to  claim 8 , wherein the mounting assembly comprises a mounting stud and a tube element extending from the mounting stud perpendicularly or obliquely to the stud axis and being in fluid communication with the stud, the tube element comprising, at its free end, means for sealing fixation of the membrane.  
   
   
       19 . The apparatus according to  claim 18 , wherein the membrane has the general form of a bag.  
   
   
       20 . The apparatus according to  claim 18 , wherein the fixation means comprises screw means.  
   
   
       21 . The apparatus according to  claim 18 , wherein the fixation means comprises hook means.  
   
   
       22 . A freight container provided with the apparatus according to  claim 1 .  
   
   
       23 . The apparatus according to  claim 19 , wherein the fixation means comprises screw means.