喷淋塔脱氨传质特性的实验研究

在自行设计的喷淋塔中,以空气/氨/稀硝酸为实验体系,考察了喷淋密度、空塔气速、吸收液pH、入口氨浓度及入口气体温度对喷淋塔体积传质系数（Kga）的影响。结果表明,Kga随喷淋密度的提高而增大,优选喷淋密度约0.039 m3/（m2·s）;Kga随空塔气速的增大呈现增大后减小的趋势,控制空塔气速在2-2.4 m/s具有较好的经济性;Kga随吸收液pH的增大而减小,入口氨浓度对Kga的影响不显著,提高气体温度于吸收不利;拟合得到Kga的经验关联式Kga=7.45Re0.32pH-0.12β/H,其计算值与实验值相对偏差在15%以内;操作参数对Kga的影响大小顺序为：喷淋密度,空塔气速,吸收液pH值。

Experimental Investigation on Mass-transfer Characteristics of Spray Tower in Ammonia Absorption Process

An experimental spray tower was designed in this paper. The effects of operating parameters, such as spray density, superficial gas velocity, pH value of absorbent, inlet ammonia concentration and gas temperature, to the volumetric mass transfer coefficient（Kga） were investigated with the experimental system of air/ammonia/water. The results show that Kga increases with the increasing of spray density, and the optimal spray density is approximately 0.039 m3/（m2.s）. Kga first increases and then decreases with the increasing of superficial gas velocity, and obvious economic benefit is achieved when superficial gas velocity between 2-2.4m/s. Kga decreases with the increasing of pH value of absorbent. The influence of inlet ammonia concentration to Kga is not remarkable, and high gas temperature is unfavorable for absorbing. Furthermore, the empirical correlation equation for Kga is expressed as Kga=7.45Re0.32pH-0.1213/H, and the deviations between experimental data and calculated values are less than 15%. Effects of operating parameters to Kga are successive as follows： spray density, superficial gas velocity, pH value of absorbent.