Through the test of fines deposition on the exit-tube external wall of cyclone in disengager, it was found that the coking was caused by the low-velocity stagnation layer formed on the wall.

• 通过旋风分离器升气管外壁表面的粉灰沉积试验,进一步说明催化裂化装置沉降器顶旋升气管外壁结焦的原因是管壁表面存在着低速的"滞流区"。