Material handling system

A material handling system for effecting the transfer of powdered or granular fluent material with respect to a container while preventing the escape of such material to a surrounding work environment, said system comprising

• a container defining a volume for containing a load of said material and having an opening in the top of the container in communication with said volume,
• a lower closure device secured to the container at the top thereof, said closure device being movable between a closed position closing said opening and an open position for permitting access to said volume via said container opening,
• an upper closure device on the container above the lower closure device, at least part of said upper closure device being adapted for removal from the container to permit access to the container opening when said lower closure device is in its open position,
• a tubular head comprising an outer sleeve, and inner tube means inside the outer sleeve and generally coaxial therewith,
• the container being adapted to be sealingly connected to said tubular head with the outer sleeve in sealing engagement with respect to the container when at least part of said upper closure device is removed from the container,
• said inner tube means being movable axially relative to the outer sleeve between a raised position and a lowered position in which said inner tube means extends endwise down beyond the outer sleeve,
• said inner tube means being movable from its raised position to its lowered position after said container has been connected to said tubular head with the outer sleeve in sealing engagement with respect to the container and with at least part of said upper closure device removed from the container, and after said lower closure device has been opened to permit passage of said inner tube means down through said container opening, and
• said lower closure device being movable from its open position into sealing engagement around said inner tube means when said inner tube means is in its lowered position.

A method of releasably connecting a container to a tubular head prior to transfer of a powdered fluent material with respect to the container, said method being adapted to reduce exposure of a person to such material during connection of the container to the tubular head, said tubular head comprising an outer sleeve and inner tube means inside said outer sleeve and generally coaxial therewith, said method comprising

• providing a container defining a volume for containing a load of said material and having an opening in the top thereof in communication with said volume, a lower closure device secured to the container at the top thereof movable between a closed position closing said opening and an open position for permitting access to said volume via said container opening, and an upper closure device on the container above the lower closure device, at least part of said upper closure device being adapted for removal from the container to permit access to the container opening when said lower closure device is in its open position,
• releasably connecting the container to the tubular head with the outer sleeve in sealing engagement with respect to the container when at least part of the upper closure device is removed from the container and when said lower closure device is in its closed position,
• moving said lower closure device from its closed position to its open position,
• moving said inner tube means of the tubular head relative to the outer sleeve from a raised position to a lowered position in which the inner tube means extends down through said opening in the top of the container, and
• moving said lower closure device from its open position into sealing engagement with said inner tube means prior to transfer of material to or from the container.