The toilet bowl (1) is connected to a rotary 3-way valve (7) with a connection to a suction line (2). It may connect the suction to the bottom of the toilet bowl or the rim. The line leads into a vertical 500 mm long large-diameter piece of pipe made of polypropylene, which can act as a reservoir. It has a flap valve (4) at the bottom which allows liquid and solid materials to flow downward into a drainpipe while resisting reverse flow. The suction is provided by a turbine pump (5) at the top of the polypropylene pipe. The air drawn off from the reservoir passes through a small-diameter pipe to a point (6) in the drainpipe just under the flap valve. the suction may be turned off and air let into the pile to allow the liquid and solid matter to drop though the flap valve.
