| Description |
This system layout was initially 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 Secondary Heat Exchanger, which recovers un-used heat from the Regenerative Thermal Oxidizer exhaust to provide pre-heated air to the plant processing equipment. There is also a Tertiary Heat Exchanger that captures the remaining low BTU exhaust from the Secondary Heat Exchanger to be used for heating hot water for other plant processes. In a first cycle, an effluent gas composition including volatile organic compounds flows into a first vessel having heated ceramic material through absorption, which then flows into a combustion/retention chamber connected to the first vessel. The combustion/retention chamber comprising a burner(s) with the appropriate residence time elevates the pre-heated effluent composition containing the VOCs to a higher temperature to allow oxidation of the hydrocarbons to occur. After leaving the combustion/retention chamber the hydrocarbon-depleted heated effluent composition flows into a second vessel with a second ceramic material, and heat transferred thru desorption. A hydrocarbon-depleted first cycle cooled effluent composition is directed into the secondary heat exchanger, transferring heat to a low VOC content airstream or ambient air. The heated low VOC content airstream or ambient air is then directed into a unit designed to employ the heated VOC airstream for pre-heating. The effluent composition is then directed into a tertiary indirect heat exchanger, transferring heat to a water or stream. The direction of flow is reversed in a second cycle, while a third vessel is being purged. |
