In the experiments, CaCO3 were used as SO2 absorbent to simulate the limestone-based processes in the spray scrubber. In order to be closer to the actual conditions, desulfurization liquid was circulated with a recycle ratio of near 100%. The flue gas temperature at the inlet of desulfurization tower was in the range of 90–150 C.
A supersaturated vapor phase was achieved by injecting steam into the scrubbed flue gas in the particle growth region. The steam was generated simultaneously by electric boiler and oil-fired boiler and mixed in the cylinder, in which the pressure and temperature of steam remained stable.