Containment system for particulate materials

Abstract

A containment system for particulate materials comprises a substantially vertical annular wall defining a substantially cylindrical storage area. A plurality of membrane supports are each attached near an outer end thereof to an upper edge of the wall and extend inwardly and upwardly to a central location above a central portion of the storage area where inner ends of each membrane support are secured to each other. An impermeable flexible membrane is attached at an outer edge thereof to the wall and extends over the membrane supports to enclose the storage area. Curved membrane supports are provided that reduce flapping of the membrane in the wind, and the supports may also be provided with a lower tensioner, thereby increasing strength.

We claim:  
     
         1 . A containment system for particulate materials, said system comprising: 
 a substantially vertical annular wall defining a substantially cylindrical storage area, the wall having an upper edge;    a plurality of membrane supports, each attached near an outer end thereof to the upper edge of the wall and extending inwardly and upwardly to a central location above a central portion of the storage area where inner ends of each membrane support are secured to each other; and    an impermeable flexible membrane attached at an outer edge thereof to the wall and extending over the membrane supports to enclose the storage area.    
     
     
         2 . The containment system of  claim 1  further comprising a plurality of substantially vertical members located between the wall and the central location and having a lower end resting on a bottom of the storage area and a top end supporting a mid-point of the membrane supports.  
     
     
         3 . The containment system of  claim 2  further comprising a substantially horizontal annular member supported by the vertical members and supporting a mid-point of the membrane supports.  
     
     
         4 . The containment system of  claim 1  further comprising a hatch member, and wherein the inner end of each membrane support is attached to the hatch member.  
     
     
         5 . The containment system of  claim 4  wherein the hatch member defines a hatch opening and wherein the membrane defines an aperture coincidental with the hatch opening.  
     
     
         6 . The containment system of  claim 1  wherein the outer edge of the membrane is attached to at least one of an outside of the wall or the ground.  
     
     
         7 . The containment system of  claim 6  further comprising means to exert a downward force on the outer edge of the membrane.  
     
     
         8 . The containment system of  claim 7  wherein the downward force is exerted by a cord around the outside edge of the membrane, the cord exerting a circumferential force such that the outer edge of the membrane moves down a slope defined by the wall.  
     
     
         9 . The containment system of  claim 1  wherein the membrane supports are curved from the inner end to the outer end, and wherein a concave side of the membrane support is facing generally downward.  
     
     
         10 . The containment system of  claim 9  wherein the outer edge of the membrane is attached to at least one of an outside of the wall or the ground.  
     
     
         11 . The containment system of  claim 10  further comprising means to exert a downward force on the outer edge of the membrane.  
     
     
         12 . The containment system of  claim 11  wherein the downward force is exerted by a cord around the outside edge of the membrane, the cord exerting a circumferential force such that the outer edge of the membrane moves down a slope defined by the wall.  
     
     
         13 . The containment system of  claim 9  further comprising a tensioner attached at an inner end thereof near the inner end of a membrane support, and attached at an outer end thereof near an outer end of the membrane support, the tensioner extending across the concave side of the membrane support and exerting a tension holding the membrane support in a curved position.  
     
     
         14 . The containment system of  claim 13  further comprising a spacer mounted between the membrane support and the tensioner in proximity to a mid-point of the tensioner and arranged to maintain a constant distance between the membrane support and the tensioner.  
     
     
         15 . The containment system of  claim 13  wherein the tensioner is attached to the membrane support when the membrane support is substantially straight, and wherein the tensioner is tightened to force the membrane support into the curved position.  
     
     
         16 . The containment system of  claim 15  wherein the tensioner can be tightened after the membrane is installed.  
     
     
         17 . The containment system of  claim 16  wherein the tensioner can be tightened from outside the wall.  
     
     
         18 . The containment system of  claim 15  wherein the tensioner further comprises a turnbuckle.  
     
     
         19 . The containment system of  claim 15  wherein the tensioner further comprises a winch.  
     
     
         20 . The containment system of  claim 15  wherein the tensioner comprises a threaded rod.