Wastewater heat recovery device and method

A method of recovering heat energy from a first liquid delivered to a chamber, wherein the chamber has a bottom floor and an upper opening through which the first liquid can be delivered to the chamber, the chamber has a discharge conduit with an outlet end located outside the chamber and an inlet end located inside the chamber, the inlet end is lower than the upper opening of the chamber, the inlet end terminates at a weir over which the first liquid in the chamber must flow to be discharged from the chamber through the discharge conduit, the chamber has a baffle wall which extends upward from above the chamber floor to above the inlet end of the discharge conduit, the baffle wall substantially surrounds the inlet end of the discharge conduit, and the upper opening of the chamber and the inlet end of the discharge conduit are on opposite sides of the baffle wall;

• the method comprising the steps of:
• (a) delivering the first liquid through the upper opening and into the chamber,
• (b) passing the first liquid delivered into the chamber downward, under the baffle wall, and then upward and over the weir,
• (c) discharging the first liquid passing over the weir from the chamber through the discharge conduit, and
• (d) passing a second liquid through a heat exchange conduit located in the chamber and lower than the weir.