Abstract: The objects of the invention are to prevent the backflow of slurry by first enclosing it in a closed space and then using air to force it along a discharge channel, and at the same time to ensure the smooth throughput of the slurry by causing any foreign bodies in the slurry to be broken up en route. To this end, the invention is provided with a casing enclosing a circular cross-section rotor chamber and a rotor which fits inside said rotor chamber and which is caused to rotate by a drive means. The rotor is also fitted with blades en bloc which extend radially from the rotating center section and which form moving chambers that rotate along with the rotor inside the rotor chamber. The casing is also provided with an intake port that connects with the moving chambers at the slurry intake point and a discharge port and air supply port, each of which connects, with the moving chambers at the slurry discharge point.

Abstract: A device to separate muddy water from slurry which is being drained away and a means to use said muddy water to both seal and lubricate a gap between the guide channels and the vanes of the drainage pump, thereby securing the efficient long-term functioning of the pump. The invention presupposes the use of a vane type rotary drainage pump connected to a separation means which is set up to remove muddy water from the slurry discharged from the discharge port. A pressure chamber is incorporated into said rotor and connection with the inner ends of each of said guide channels. The muddy water separated out by the separation means is fed back into said pressure chamber.