Study On The Calcium Sulfate Scale And Blocked Of GGH In The WFGD Technology

China is a developing country,and it has become the world’s largest producer and user of coal. Also she is one of the countries using coal as the most energy sources, Most of our county’s electricity comes from coal-fired thermal power plant. SO2brought by a lot of coal’s burning has been working grievous atmosphere pollution.Now, the amount of sulfur dioxide emission of our country has became the largest in the world, and the flue gas desulfurization need to be widely used urgently. But here are lots of problems which affect the stable operation of the equipment,one of it is scale. At present,the research on the formation of scale and the influences of every factor is incomplete.So this article studied on the influences of several important factors, the scale component, sulfurous acid calcium oxidated, mist eliminator performance, the heat exchange component chemical cleaning, operation adjustment and so on to the scale of the wet FGD equipment.In this paper,we firstly analyse the formation mechanism of the scale in wet FGD equipment and the control measures. We studied on the reaction mechanism of oxidating sulfurous acid calcium to gypsum. Through the analysis of GGH scale composition in BAQIAO power plant,it had been found that GGH scale was derived from the gypsum slurry carried by the net flue gas.This paper study on the mist eliminator performance.it has been found that droplets on the particle size of20microns or less are low efficiency even no efficiency of removal. The second brought in demister accurs when the flue gas flow rate is higher than critical velocity,leading the efficiency to a rapid decline.On the basis of the mechanism, FGD plug of solution has been put forward through a technology of daily operation process analysis, sulfurous acid calcium oxidated, performance test on mist eliminator,GGH heat exchanger cleaning and other key technology.Baqiao thermal power plant engineering has got good results.