Experimental Study On Activity Of Quicklime And Performance Of Dry Slaking In Circulating And Suspension Semi-dry Flue Gas Desulfurization

Circulating and suspension semi-dry flue gas desulfurization has advantages in simple structure, lower investment, higher efficiency of desulfurization and utilization of absorbent, so it is a kind of flue gas purification which fit to the situation of our country. In the dry and semi-dry flue gas desulfurization system, the reaction performance of absorbent is very important and it has direct influence on the efficiency of desulfurization. Now, hydrated lime is used as the main absorbent in most dry and semi-dry flue gas desulfurization technic. Because the lime is cheaper than the hydrated lime, not only can it save money but also can produce the high-effect absorbent by change the lime to the hydrated lime. The reduction of activity of lime and the performance of dry slaking were studied in this paper.In the practical process, the reduction of activity of lime has important influence on lime's quality. This paper noted everyday temperature and relative humidity, then studied the reduction of activity of lime from vertical direction, finally the influence of stack time on the thickness of the reduction of activity of lime was concluded.Hydrated production's properties mainly include lime slaking rate, particle size, specific surface and so on, which have important significance on the deposition, transportation and desulfurization effectively of the absorbent. The lime slaking rate is the important factor of the quality of the hydrated production. The smaller of the particle size of hydrated lime, the larger of the specific surface and the higher of the efficiency of utilization. The hydration process of lime has important influence on lime slaking rate, particle size and specific surface, so it is significant to research the hydration process. In the operational parameters of hydration process, water/solid ratio is a crucial factor and has important influence on hydrated production's properties. Some scholars have studied the water/solid ratio by mixing the lime and ash to hydrate, but very few persons have studied the single hydration and dry hydration. In this paper, the mechanism research of lime dry hydration was studied using small equipment. Then the effect tendencies of operational parameter of hydration process(water/solid) on lime slaking rate, particle size and specific surface was put forward.On the base of mechanism research, two dry slaking pilot-scale equipments were debugged and compared. It has important meaning on the optimization of operational parameters, improvement of efficiency of desulfurization and utilization of absorbent and economy of investment and function.Circulating and suspension semi-dry flue gas desulfurization technique was introduced and the relation of temperature of outlet flue gas, quality of water and the outlet concentration of SO2 was concluded by testing a circulating and suspension semi-dry flue gas desulfurization system.