Embodiments described herein include systems and methods for safely and efficiently transferring granular material from a container. An example system can include a container for transporting granular material that includes a valve positioned to discharge the granular material from the container. The system can also include a frame shaped to receive and support the container. The system can further include an actuator mounted to the frame and oriented such that actuation of the actuator causes the valve of the container to be opened. Finally, the system can include a conveyor positioned to receive granular material from the container when the valve of the container is opened.

An apparatus for sealing a vacuum tank door. The apparatus comprises a circular flange attached to a door panel of a vacuum tank, a horizontal crossbar connected to the center of the door panel and a lifting assembly. The lifting assembly comprises an upper linkage arm, a lower linkage arm, and a hydraulic cylinder. Activation of the hydraulic cylinder causes the linkage assembly to move downwards pulling on the horizontal crossbar and pulling the vacuum tank door towards the tank. Activation of the hydraulic cylinder also causes a connection point of the lower linkage arm and the upper linkage arm to move over-center of the connection between the lower linkage arm to the to the tank creating a tight seal between the vacuum tank door and the tank.

An apparatus for moving proppant from a container has a frame with a surface for suitable for receiving a container thereon, a hopper affixed to the frame, and a conveyor having a surface positioned below the hopper. The hopper has an opening at or adjacent to a lower end thereof. The hopper is suitable for receiving proppant from the container. The surface of the conveyor is suitable for receiving the proppant a discharged through the opening of the hopper. A receptacle is translatably positioned at the surface of the frame. A metering gate is translatably positioned adjacent to the opening of the hopper.

An apparatus for moving proppant from a container has a frame with a surface for suitable for receiving a container thereon, a hopper affixed to the frame, and a conveyor having a surface positioned below the hopper. The hopper has an opening at or adjacent to a lower end thereof. The hopper is suitable for receiving proppant from the container. The surface of the conveyor is suitable for receiving the proppant a discharged through the opening of the hopper. A receptacle is translatably positioned at the surface of the frame. A metering gate is translatably positioned adjacent to the opening of the hopper.

A proppant discharge system includes a container having an outlet formed at a bottom thereof, a gate affixed at the outlet and positioned on the floor of the container so as to be movable between a first position covering the outlet to a second position opening the outlet, a support structure having the container positioned on the top surface thereof. The support structure has at least one actuator affixed thereto. The actuator is positioned so as to move the gate between the first position and the second position. The container has a cage affixed on the floor thereof in a position over the outlet. The gate is positioned within the cage and is movable by the actuator so as to open the gate so as to allow proppant to be discharged therefrom.

A doser apparatus includes a throttle device on a doser mechanism. The throttle device includes a vibratory hopper and a vibration device. The vibratory hopper is configured to hold a granular material within a vibratory hopper conduit that tapers towards a bottom opening and is configured to induce bridging of the granular material at the bottom opening. The vibration device is configured to break the bridging of the granular material at the bottom opening to induce flow of the granular material through the bottom opening to a doser reservoir of the doser mechanism, based on inducing vibration of the vibratory hopper. The throttle device is configured to control a head pressure of the granular material at a portion of a conveyor device of the doser mechanism extending into the doser reservoir based on operating the vibration device to adjustably control the flow of granular material through the bottom opening.

Closure unit (24) for a bulk material container (12), comprising a closure element (26) and a carrier unit (28) with a carrier element (30) and a emptying opening 34 arranged in the carrier element (30) and having a longitudinal axis of the opening (32).
wherein the closure element (26) can be moved between a closed position, in which the closure element (26) closes the emptying opening (34), and an open position, in which the closure element (26) at least partially opens the emptying opening (34).
wherein the carrier unit (28) has container connecting means (36) for non-destructively detachable arrangement of the closure unit (24) on the bulk material container (12),
and container system (10) with such a closure unit,
and emptying station (64) for a container system (10),
and container emptying system with a container system (10) and an emptying station (64).