Liquid circulating device

A system for treating sewage and the like in a liquid body, comprising a tank for the liquid sewage;

• a substantially vertically extending stackpipe positioned within said tank;
• the stackpipe having a lower inlet opening and an upper discharge opening below a predetermined level within said tank;
• a large-bubble generator means located within the tank adjacent the stackpipe;
• and comprising a gas accumulator chamber having a peripheral wall and a top wall, the bottom of the chamber being substantially open;
• a substantially vertically extending standpipe adjacent the accumulator chamber and the stackpipe within the tank;
• an inverted siphon defining fluid flow connecting means between the upper portion of the accumulator chamber and the standpipe;
• pressure means for delivering gas under pressure into the accumulator chamber;
• transverse gas flow conduit means between the upper end of the standpipe and stackpipe;
• the transverse conduit connecting through the peripheral wall of the stackpipe at one end of the conduit;
• and secondary liquid inlet means into the transverse conduit between the standpipe and the stackpipe, whereby the generation of a large-bubble of gas passes from the accumulator chamber up through the stackpipe, acting as a piston to generate a current flow through a large body of liquid within the tank.