With the increase in production load , there is heavy liquid entrainment from the rectification column , resulting in a rise in urea content in the low - pressure ammonium carbamate solution , bringing about the cold crystallization of the low - pressure carbamate , cavitation erosion of the carbamate pump , and a decrease in decomposition of the carbamate in the rectification column , thereby impairing safety in production 摘要生產負荷提高后,精餾塔帶液嚴重,使低壓甲銨液中的尿素含量增加,引起低壓甲按冷凝器結晶、甲銨泵氣性、精餾塔甲按分解率下降等現象,嚴重影響安全生產。