关键词: 催化裂化装置, 再生烟气, 粉尘浓度, 新鲜剂, 平衡剂, 三旋细粉, 粒径分布

Abstract:

The article analyzes the changes of dust content in the regenerated flue gas at the inlet and outlet of the third stage cyclone separator of a catalytic cracking(FCC) unit. Combined the particle size distribution of fresh catalyst, regenerator equilibrium agent, and fine powder of the third stage cyclone in the FCC unit, the impacts of the separation efficiency of three different FCC units' regenerator primary, secondary, and tertiary cyclone separators on the dust content in the flue gas are compared and analyzed. When the dust content in the flue gas at the inlet of the flue gas turbine(i.e. the third stage cyclone outlet) exceeds the design value, especially when the volume proportion of dust with a particle size greater than 10 μm exceeds 5%, the higher the content of large particle dust, the greater the impact on the normal operation of the flue gas turbine, elevated vibration values of the flue gas turbine are prone to occur, endangering the operation of the flue gas turbine. Therefore, it is recommended to control the dust content of the entire process of regeneration flue gas. The dust content at the third stage cyclone inlet should not exceed 600 mg/m³. The dust content at the outlet of the third stage cyclone shall not exceed 150 mg/m³, while the volume proportion of particles with a particle size greater than 10 μm shall not exceed 5%.

Key words: catalytic cracking unit, regeneration flue gas, dust concentration, fresh catalyst, equilibrium catalyst, fine powder of the third stage cyclone, particle size distribution