Conveying device for conveying a flowable medium

A delivery device (1) for delivering a liquid medium, comprising a delivery drive (2), a pump device (3), and a scoop device (4), the delivery drive (2) is arranged at a first end (6) of a pipe (5), the pump device (3) and the scoop device (4) are arranged inside the pipe (5), and the scoop device (4) comprises a foot valve (8), which is arranged at a second end (7) of the pipe (5) and said foot valve (8) serves to control an inlet (9) for an inflow of liquid medium into a piston chamber (10) of the scoop device, a piston (11) of the scoop device arranged in the piston chamber (10), the piston sub-divides the piston chamber (10) into an inflow area (12) and a discharge area (13), the inflow area (12) and the discharge area (13) are connectable via the piston (11), the piston (11) is movable via a piston rod (14) between a retracted position and an extended position inside the piston chamber (10) by the delivery drive (2) such that the liquid medium is adapted to be sucked into the piston chamber (10) by a movement of the piston (11) into the retracted position while the liquid medium in the discharge area (13) is displaced into a pump chamber (19) of the pump device (3), and the liquid medium is adapted to be displaced into the discharge area (13) of the piston chamber for delivery to the pump device (3) as the piston (11) moves into the extended position, the scoop device (4) is connected upstream of the pump device (3) in an inflow direction of the liquid medium, and the pump device (3) comprises the pump chamber (19), in which a pump piston (20) is arranged, which by the delivery drive (2) is movable between an extended position and a retracted position inside the pump chamber (19), the pump chamber (19) comprises an inlet valve (21) and an outlet valve (22), and the liquid medium contained in the pump chamber (19) is displaceable by the pump piston (20) through the outlet valve (22) into a delivery line (24) via a delivery duct (23) when the pump piston (20) moves from the retracted position to the extended position, a delivery capacity of the scoop device (4) is greater than a delivery capacity of the pump device (3), and the delivery device allows the liquid medium to flow back to the inflow area when the piston (11) moves from the extended position to the retracted position by allowing a backflow of liquid medium via at least one relief opening (17) on the piston valve (15), and the piston (11), the piston rod (14), the pump piston (20), the inlet valve (21), the outlet valve (22), and the foot valve (8) are arranged coaxially in the pipe (5).