Ecopure® RTO: for the efficient purification of exhaust gas
The Ecopure® RTO plant consists of the following main components
- the regenerator columns,
- the combustion chambers with burner system and
- the required air-directing system with valves and fan.
The regenerator columns are filled with ceramic packing material and are lined inside with an insulation layer to suit the high reaction temperatures.
The combustion chambers are also lined with fiber material, and they connect the individual regenerator columns with each other. The burner is located at the side to allow easy access. It has a separate combustion air connection. The required valve and instrument mountings, and monitoring devices are pre-assembled in the factory, and are connected to the burner via flexible connecting conduits.
The raw and clean gas ducts with integrated tight-closing valves for exhaust air inlet and clean gas outlet and the dampers for purge air inlet - if a purge cycle is planned (see below) - are part of the air-directing system. All valves and dampers are located at the bottom of the regenerator column to allow easy access.
The exhaust air stream is transferred through the Ecopure® RTO plant by a fan, and is directed through the valves by a timer system alternately into one of the regenerator columns. The exhaust air flows through the hot packed beds from bottom to top, and is pre-heated in the process. A large portion of the hydrocarbons already oxidize here.
If necessary, a burner heats up the raw gas to the final combustion and/or final reaction temperature of approx. 820°C. Complete oxidation of the contaminants takes place in this process. The purified hot exhaust air then flows through the heat exchanger in column 2 from top to bottom, transmitting its heat to the packed bed while doing so.
Due to the regenerative heat exchange, the direction of flow through the columns is changed. Now the raw gas flows from bottom to top through column 2, is oxidized in the combustion chamber, and leaves the system as clean gas via column 1.
The system is constantly switched over to ensure optimum heat exchanger performance and raw gas cleaning efficiency.
The temperature of the clean gas is, depending on the application, 40°C higher than the raw gas temperature.
In Ecopure® RTO plants with an uneven number of columns, one column is purged before purified exhaust air flows through in the next cycle. The advantage of this operation mode, where one column is always in the purge phase, is that contaminant peaks in the exhaust air are avoided when the poppet valves are switched over, which means that low emission limits can also be met.