Experimental scheme and procedure

Commonly, flue gas consists of N2, NOx, C02, S02 and air. In the process of wet desulfurization with hydrated lime as the absorbent, N2 is inert, and the amount of Ca(OH)2 consumed in its reaction with NOx can be neglected while both C02 and S02 react significantly with Ca(OH)2. However, what we are mostly concerned with is the 

The Ca(OH)2 suspension is prepared just before each run with commercial lime, with CaO content 95%, and water, and the concentration of Ca in the form of Ca(OH)2 in the prepared suspension for each run is chemically analyzed. 

Air and gaseous S02 in the required ratio enter Mixer 6 to mix fully with each other, and the resulting pseudo flue gas is divided into two equal streams to enter Absorber 7. The air flow rate is adjusted by a butterfly valve in the pipeline and measured with a Pitot tube-pressure difference meter and that of S02 by the rotameter 5. The total gas flow rate is also monitored by a wind velocity meter of DF-3 type at the gas outlet of the reactor. For each run, gas-samplings are made at both inlet and outlet of the reactor, and the S02 concentrations in the samples are measured with the Iodine-quantitative method, a standard and authentic method of determining the integral amount of S02 absorbed in the reactor. 

The system s hydraulic resistance, mainly the absorption device, is a very important parameter affecting the economic index of the technology because a huge amount of flue gas is emitted from the power plant. To evaluate the hydraulic resistance of the equipment, the pressure drop Ap, between Points A and B shown in Fig. 7.11, is measured in each run. 

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