RTO with Secondary & Tertiary Heat Recovery
This patent was developed for a Metal Finishing operation to have a Regenerative Thermal Oxidizer, as a pollution control device, and at the same time recycles hot air back into the process. There is a Heat Exchanger, which captures the fugitive emission from the process through the Heat Exchanger rather than having an additional Thermal Oxidizer or added capacity to the original Thermal Oxidizer.
In a first cycle, an effluent gas composition including volatile organic compounds flows into a first vessel having heated ceramic material therein, which then flows into a combustion/retention chamber connected to the first vessel, the combustion/retention chamber comprising a burner, which combusts VOCs in heated effluent composition. The hydrocarbon-depleted heated effluent composition flows into a second vessel with a second ceramic material therein, and heat transferred thereto. A hydrocarbon-depleted first cycle cooled effluent composition is directed into a first indirect heat exchanger, transferring heat to a very low VOC airstream. The heated very low VOC airstream is then directed into a unit designed to employ the heated very VOC airstream for heating. The effluent composition is then directed into a second indirect heat exchanger, transferring heat to a water stream. The direction of flow is reversed in a second cycle, while a third vessel is purged.The fugitive emissions are recycled through the Heat Exchanger and to the Booster Burner through the Oven and then to the Thermal Oxidizer. Epcon has built multiple systems like this, throughout the world.