Session: OAC-06-03 Continued Safe Operation of Existing Assets - 3

Paper Number: 106055

106055 - Fitness-for-Service Assessment of Refractory Lined Duct With Hot Spot 

The refractory lined duct in FCC(Fluid Catalytic Cracking) unit is designed to lower the temperature transferred from the inside high temperature service fluid to the surface of duct by installing the refractory having thermal insulation performance. The refractory could be degraded during operation due to various causes such as thermal expansion and contraction, excessive vibration, or improper refractory application. When the refractory is damaged and the high temperature service fluid is affected to the duct directly, the surface of the duct rises to a high temperature is called a hot spot. The temperature increases of hot spot does not lead to immediate failure, but it causes structural rupture or bulging of the duct due to creep in the long term. When hot spots occur, the steam cooling method is generally used to mitigate the elevated temperature by spraying the steam onto the hot spot area. However, in case of huge and wide hot spot, it is difficult to apply the steam cooling method properly. If hot spot is not controlled by mitigation method, it is necessary to check the fitness-for-service of the duct and determine the remaining life of duct to prepare the maintenance plan to replace steel parts of the duct. In this paper, fitness-for-service assessment is performed for refractory lined duct with hot spot in FCC unit. Piping stress analysis is performed according to ASME B31.3 to evaluate structural integrity from global behavior by weight, pressure, and temperature. Then detailed finite element analysis is performed, and creep life is calculated according to API 579 to evaluated local behavior of hot spot. Through this process, fitness-for-service assessment for the refractory duct with hot spot is provided and the effectiveness is discussed.

Presenting Author: Chongmyung Kim SK Energy Co., Ltd

Presenting Author Biography: 1) Years of Experience
- 2 years in SK Energy as Stationary Equipment & Piping Engineer
- 10 years in GS Engineering & Construction as Piping Stress Engineer

2) Education
- Bachelor of Mechanical Engineering, 2012, Sungkyunkwan University, Republic of Korea

3) Career Summary
- Mr. CM Kim is skilled in overall piping flexibility analysis including nozzle evaluation of pressure vessel and structural integrity check of piping systems based on B31.3 Process Piping. He has a lot of experience in the design of piping system for oil and gas refinery, petrochemical plant and LNG facilities. He also has experience in the suitability assessment of operating plant using Fitness-For-Service.

Authors:

Eui Jong Yoo GS Caltex Coporation
Chongmyung Kim SK Energy Co., Ltd
Capjoo Choi GS Engineering & Construction