Patent ID: 8347912

Claim:
A waste water pumping device comprising: i) a gravity flow channel having a cross-section calculated based on the amount of waste water to be transferred, and comprising an external retention tank in line with the flow of waste water positioned at a downstream portion of the gravity flow channel, wherein the external retention tank has a cross-section greater than the cross-section of an upstream portion of the gravity flow channel; and ii) a dry tank having a gravity flow inlet pipe, which is connected to an outlet of the gravity flow channel, and a pressure flow outlet pipe, wherein the dry tank contains: (a) a retention tank disposed on a bed of the dry tank and connected to the gravity flow inlet pipe, wherein the retention tank constitutes a distributing chamber for the external retention tank, and wherein the capacity of the retention tank is at least two times smaller than the capacity of the external retention tank; (b) at least one pump connected to the pressure flow outlet pipe, wherein the pump is a pneumatic positive-displacement pump or an impeller pump; and (c) at least one suction channel connecting the retention tank and the at least one pump; wherein waste water flows from the external retention tank portion of the gravity flow channel to the retention tank, and, by way of the at least one suction channel, the at least one pump transfers waste water from the retention tank to the pressure flow outlet pipe.