Abstract: The cracking of the Johnson inner screen in the regenerator of a 1M/a continuous catalytic reforming unit of SINOPEC Tianjin Refinery Company was caused by the stress existing on the top welding area of the Johnson inner screen and the metal fatigue caused by the periodic discontinuous flow of catalyst. By properly adjusting oxygen content in the regenerated flue gas，the coke on the catalyst in the upper inner screen burned under relative moderated conditions. Meantime, the final boiling point of raw material was strictly controlled not higher than 173 ℃ and the hydrogen/hydrocarbon mol ratio at 2.5. As a result，the coke on the catalyst was decreased from 5.1% to 4.8%，and the peak of temperature in coke burning zone decreased from 568 ℃ to 552 ℃，which is beneficial to long term stable operation of the Johnson inner screen.

Key words: continuous catalytic reforming, regenerator, Johnson inner screen, stress, temperature