Study On Blocking-up Malfunction Of AN Recovery Column With Improvement Means

In recent years, the cycle of normal operation of Qilu AN Factory decreased greatly because the trays were blocked up with polymer in the recovery column unit during the course of increasing the purification yield of AN. In view of such a situation, the polymer composition was physical-chemical analyzed first and a conclusion was reached that the above-mentioned polymer was the thermosetting polymer of acraldehyde. According to the multiphase vapor-liquid balance theory and the recovery column model, the simulated calculation of the material flow system and the acraldehyde distribution was made using the Aspen Plus software, the calculation tallied with the measured result of the main composition of the material flow. Under different tower tray efficiency, the location of the zone of enrichment of acraldehyde didn't change and was identical with the actual area that was blocked up with the polymer, thus the reason that why the tower was blocked up with polymer was found out, which has great reference value and directive significance for the reformation of AN factory in the future.