Abstract: A pump assembly includes a rotating component and a stationary component coupled to the rotating component such that the stationary component substantially circumscribes at least a portion of the rotating component. A high pressure outlet extends at least partially through the rotating and stationary components. An inlet is positioned a predefined distance from the high pressure outlet. The inlet extends at least partially through the rotating and stationary components. A solid fuel flow is channeled from the inlet to the outlet as the rotating component rotates. A flow control member is coupled to the rotating and stationary components in a first predefined position. The flow control member is selectively moveable from the first predefined position to a second predefined position to form a seal within the pump assembly such that the solid fuel flow and a fluid flow are substantially restricted from being channeled back into the inlet.

Abstract: A system includes a solid feed pump configured to transport a solid feedstock. The solid feed pump includes at least one passage for the transport of the solid feedstock. The solid feed pump also includes at least one movable wall configured to move along the passage. The solid feed pump further includes a retractable gripping element configured to extend from the at least one movable wall into the at least one passage to grip a portion of the solid feedstock. In addition, the retractable gripping element is configured to retract away from the at least one passage.

Abstract: A pump assembly includes a rotating component and a stationary component coupled to the rotating component such that the stationary component substantially circumscribes at least a portion of the rotating component. A high pressure outlet extends at least partially through the rotating and stationary components. An inlet is positioned a predefined distance from the high pressure outlet. The inlet extends at least partially through the rotating and stationary components. A solid fuel flow is channeled from the inlet to the outlet as the rotating component rotates. A flow control member is coupled to the rotating and stationary components in a first predefined position. The flow control member is selectively moveable from the first predefined position to a second predefined position to form a seal within the pump assembly such that the solid fuel flow and a fluid flow are substantially restricted from being channeled back into the inlet.

Abstract: A system includes a solid feed pump configured to transport a solid feedstock. The solid feed pump includes at least one passage for the transport of the solid feedstock. The solid feed pump also includes at least one movable wall configured to move along the passage. The solid feed pump further includes a retractable gripping element configured to extend from the at least one movable wall into the at least one passage to grip a portion of the solid feedstock. In addition, the retractable gripping element is configured to retract away from the at least one passage.