Portable double-walled fuel tank

Abstract

A double-walled tank for the transport of fluid, the tank includes a rigid fluid impervious substantially cylindrical inner container concentrically nested within a rigid correspondingly substantially cylindrical outer container, the inner and outer containers having end walls sealing the containers. A grapple mount is mounted to an upper side of an outer surface of the outer container at a substantially medial position substantially medially along the outer container. A lower side of the outer container, opposite the upper side, is reinforced. The grapple mount may include a rigid plate mounted atop the upper side of the outer container at the medial position. An anti-surge baffle is mounted across, so as to extend between and into engagement with, an upper side of the inner container adjacent the baffle mount and a lower side of the inner container adjacent the reinforced lower side of the outer container.

1 . A double-walled tank for the transport of fluid comprising: 
 a rigid fluid impervious substantially cylindrical inner container concentrically nested within a rigid correspondingly substantially cylindrical outer container,    said inner and outer containers having end walls sealing said containers,    a grapple mount mounted to an upper side of an outer surface of said outer container at a substantially medial position substantially medially along said outer container, a reinforced lower side of said outer container opposite said upper side,    an anti-surge baffle mounted across, so as to extend between and into engagement with, an upper side of said inner container adjacent said baffle mount and a lower side of said inner container adjacent said reinforced lower side of said outer container,    wherein said baffle has an upper aperture in an upper side of said baffle adjacent said upper side of said inner container, and wherein said baffle has a lower aperture in a lower side of said baffle adjacent said lower side of said inner container, said lower aperture defined between lower extremities of said baffle mounted to said lower side of said inner container, wherein said lower extremities extend along in supporting contact with an inner surface of said lower side of said inner container so as to be coextensive with distal ends of grapple arms of a grapple engaging said grapple mount so as to extend the grapple arms of the grapple around a grapple line extending substantially from said substantially medial position and extending around said outer container from said upper side to said lower side of said outer container,    a radially spaced apart array of rigid stringers extending along said inner and outer containers in a substantially cylindrical gap between said inner and outer containers, said array of rigid stringers mounted to, so as to extend between, into engagement with, said inner and outer containers so as to rigidly space apart said inner and outer containers, at least one stringer of said array of rigid stringers sandwiched on opposite lateral sides of said inner and outer containers between said inner container and said reinforced lower side of said outer container.    
   
   
       2 . The device of  claim 1  wherein said end walls are single-walled end walls providing a common end wall on each end of said inner and outer containers.  
   
   
       3 . The device of  claim 1  wherein said reinforced lower side of said outer container includes a rigid reinforcing collar mounted to and around said lower side of said outer container.  
   
   
       4 . The device of  claim 3  wherein said reinforcing collar extends partially along the length of said outer container so as distribute compression loads from the grapple arms along said stringers sandwiched between said inner container and said lower side of said outer container.  
   
   
       5 . The device of  claim 4  wherein said grapple mount includes a rigid plate mounted atop said upper side of said outer container at said medial position.  
   
   
       6 . The device of  claim 1  wherein said baffle is a rigid circular plate having a first cutout at an upper end thereof forming said upper aperture, and having a second cutout at a lower end thereof forming said lower aperture.  
   
   
       7 . The device of  claim 6  wherein said first and second cutouts are substantially semi-circular and symmetrical about a vertical plane bisecting said inner and outer containers.  
   
   
       8 . The device of  claim 6  wherein said second cutout is larger in cutout area than said first cutout.  
   
   
       9 . The device of  claim 8  wherein said second cutout extends substantially ¼ of the vertical diameter of said inner container.  
   
   
       10 . The device of  claim 8  wherein said first cutout is an air passage and wherein said second cutout is a fluid passage in fluid communication between opposite ends of said inner container on corresponding opposite sides of said baffle.  
   
   
       11 . The device of  claim 1  wherein said array of rigid stringers includes eight elongate rigid members in radially spaced apart array about a longitudinally extending substantially centroidal axis through said inner and outer containers.  
   
   
       12 . The device of  claim 11  wherein said radially spaced apart array are substantially equally radially spaced apart and wherein five of said eight rigid members are sandwiched between said lower side of said inner container and said reinforced lower side of said outer container.