Patent ID: 8852394

Claim:
A method for evaporating waste water having chemicals therein which cause foaming, the method comprising: providing a holding tank having an inlet for receiving waste water and one or more submerged combustion chambers with one or more burners suspended within the holding tank; burning fuel with the one or more burners to generate hot combustion gasses in the one or more combustion chambers to evaporate the waste water; skimming foam off of a surface of liquid in the holding tank with one or more foam skimming weirs located in an upper portion of the holding tank, wherein the foam spills over into the weirs and is collected therein, the one or more foam skimming weirs defining one or more foam collection zones, wherein the holding tank is generally rectangular, and wherein skimming foam comprises skimming foam with four foam skimming weirs configured to define foam collection zones in each of the four corners of the holding tank; and removing liquids from each of the foam collection zones through a liquid outlet in fluid communication with an upper portion of the associated foam collection zone; and removing solids from each of the foam collection zones through a solids outlet located at the bottom of the associated foam collection zone.