Apparatus and method for extracting heat from contaminated waste steam

An apparatus for removing heat, oil and pollutants from the waste gas of food fryers, which comprises:

• saturation means for receiving the waste gas from the fryer and for reducing the temperature of the gas to its corresponding saturation temperature;
• a downwardly disposed gas to liquid heat exchanger, having an upper end operatively connected to the saturation means, and a lower end, for transferring heat from the gas to a liquid in the heat exchanger and causing portions of waste gas to condense and agglomerate by passing the waste gas through the heat exchanger from its upper end to its lower end;
• collection means being held below the lower end of the gas to liquid heat exchanger for receiving, collecting and separating the mixture of oil, condensate water and pollutants, said collection means further comprising a plurality of condensate trays being held below the lower end of the air to liquid heat exchanger and disposed in a cascading fashion to collect and hold a condensate mixture of oil, water and pollutants in the path of the waste gas, resulting in the heating of the mixture to a temperature at which the viscosity of the oil promotes separation from the mixture, said collection means further comprising a collection basin positioned below the condensate trays for collecting and holding condensate passed from the condensate trays;
• oil extraction means for removing separated oil from the mixture held in the collection means;
• water washing means operatively connected to the lower end of the gas to liquid heat exchanger for receiving the remaining non-condensed waste gas for washing additional condensate, oil and pollutants from the waste gas;
• and
• forced air venting means for venting from the water washing means the remaining waste gas.

An apparatus for removing heat, oil and pollutants from the waste gas of a food fryer, which comprises:

• a saturation means for receiving the waste gas from the food fryer and for reducing the temperature of the waste gas to its corresponding saturation temperature;
• a downwardly disposed gas to liquid heat exchanger, having an upper end operatively connected to the saturation means, and a lower end, said heat exchanger for transferring heat from the gas to a liquid and causing portions of waste gas to condense and agglomerate by passing the waste gas through the heat exchanger from its upper end to its lower end;
• a first collection means being held below the lower end of the gas to liquid heat exchanger for receiving, collecting and separating the mixture of oil, condensate water and pollutants, said first collection means further comprising a plurality of condensing trays being held below the lower end of the air to liquid heat exchanger and disposed in a cascading fashion to collect and hold a condensate mixture of oil, water and pollutants in the path of the waste gas, resulting in the heating of the mixture to a temperature at which the viscosity of the oil promotes the separation from the mixture, said first collection means further comprising a collection basin positioned below the condensing trays for collecting and holding condensate passed from the condensing trays;
• an oil extraction means for removing separated oil from the mixture held in the collection means;
• a water washing means operatively connected to the lower end of the gas to liquid heat exchanger for receiving the remaining non-condensed waste gas for washing additional condensate, oil and pollutants from the waste gas;
• a second collection means being held below the lower end of the water washing means for receiving, collecting and separating the additional condensate, oil, and pollutants washed from the waste gas, wherein concentrated, separated additional condensate, oil, and pollutants are returned to the first collection means for further oil extraction, wherein diluted, separated additional condensate, oil, and pollutants are supplied to the saturation means;
• and
• a forced air venting means for venting from the water washing means the remaining waste gas.