Septic tank pump arrangement including a self-cleaning rotary strainer

A system for pumping effluent from a septic tank comprising:

• a tube having an open end adapted to be disposed upright within a septic tank so that effluent can enter the tube;
• a strainer for straining effluent entering the tube, including a cylindrical filter screen disposed coaxial with the tube to separate a cylindrical interior of the strainer circumscribed by the filter screen from an exterior surrounding the interior and constrain flow of effluent through the strainer to pass radially through the filter screen;
• an electric pump unit disposed coaxially within the tube and comprising an inlet port which, along the direction of effluent flow through the system, is disposed downstream of the strainer and through which effluent enters the pump unit, and an outlet port at which effluent pumped by the pump unit exits the pump unit;
• an outlet pipe which is communicated to the pump unit outlet port and through which effluent pumped by the pump unit is conveyed out of the septic tank;
• a nozzle communicated to the pump unit outlet port and arranged to emit effluent pumped by the pump unit in a direction toward the cylindrical filter screen opposite the effluent flow through the filter screen so as to cause the filter screen to be acted upon by both radial and circumferential flow components of effluent emitted from the nozzle;
• and
• a journal mounting one of the screen and the nozzle for rotation relative to the other such that effluent emitted from the nozzle is effective both to turn the screen and nozzle relative to each other and to dislodge debris from the filter screen.