for VOC reduction, for NOx reduction
TYPE OF EQUIPMENT:
VOC (volatile organic compound) Regenerative Thermal combustion plant.
The plant basically consists of three vertical chambers filled of high thermal capacity ceramic material (a preheating inlet gas chamber, a heat recovery of purified gas from combustion chamber and a cleaning chamber with fresh air) and a combustion chamber with modulating burner that connect up the 3 chambers. The gas with V.O.C. undergoes a preheating phase crossing from the lower part to the upper of the ceramic bed in the first chamber until a temperature near 750 – 800°C.
Then the gas goes through the chamber where the modulating burner, usually fuelled by methane, gives necessary energy to reach and/or maintain complete oxidation temperature of V.O.C. and finally looses the accumulated heat, by crossing to the upper from the lower part of the ceramic bed in a second chamber and is released, cleaned, into atmosphere. In the third chamber ceramic bed a fresh air flow goes bottom up with the purpose to convey in the combustion chamber the rest of polluted air. The particular ceramic beds with high thermal capacity permit to achieve a thermal recovery efficiency from 92 up to 95%.
This efficiency, added to the heat produced from the V.O.C. oxidation, is sufficient to maintain the process without any supporting fuel starting from a V.O.C. concentration value higher than 1,2 -2 g/Nm3. The 3 chambers, at regular intervals, exchange the function of preheating, recovering and washing with special automatic valves to guarantee a constant C.O.T. (Carbon Organic Total) emission according to the environmental legal limits.