Coking problem in Texaco waste boilers
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The Texaco waste boiler process used in our plant has no design flaws; IGCC seems to be superior to the quenching process in every way. However, the biggest problem encountered during operation is the short operational cycle and the inability to achieve high loads. The main factor contributing to this issue is coking. Based on my analysis, the reasons for coking are as follows: 1. Operating temperature – Unstable coal slurry concentration leads to fluctuations in the temperature of the gasification furnace as well as variations in the coal slurry flow rate. This is due to the modification made to the water cooling walls in Furnace C, as slag often accumulates at the upper part of these walls, causing blockages. The steam pressure, originally set at 10 MPa, decreased after the water cooling walls were modified, which reduced the heat exchange efficiency and shortened the operational time while increasing the load. 2. Operating pressure – Since the pressure setting for the converter in our plant is 3.6 MPa, the gasification pressure is around 3.7 MPa. The operating pressure has a significant impact on the pressure difference across the burners, thereby affecting the atomization effect. I believe this is one of the reasons for the problems. 3. Central oxygen level – this is the most difficult to determine. The central oxygen level determines the efficiency of nebulization, and the efficiency of nebulization in turn has a decisive impact on the operation time. 4. Coal quality; I think this is the best reason. The ash content of the coal we use is just over 8%, and all the parameters are good. The ash melting point is also very good. 5. There is a lack of a global perspective; we fail to consider, from an overall standpoint, how to avoid coking. This is inevitable – after all, companies are not research institutions and cannot afford to spend a lot of time exploring various solutions through experimentation. The above are my personal opinions; I hope to exchange more ideas with everyone in order to work together for a brighter future for the coal chemical industry
Our plant features a unique soot-blowing gas system; soot-blowing gas at around 80 bar is used to clean the radiant and convective waste boilers. However, due to the aging of the valves, the soot-blowing process cannot operate properly. During manual soot blowing, the valves sometimes fail to close completely, which prevents proper soot cleaning. I believe this is one of the main factors contributing to the unstable operation of the gas processing section in our plant.
Could the poster provide a few photos of the slagging areas to facilitate further analysis? I am mainly engaged in simulation and experimental research in this field. My calculations show that the inlet jet also has a significant impact on the flow of ash particles. I was wondering if you work at Ningxia Coal? Are your waste heat boilers of the single water-cooled or double water-cooled wall type?
May I ask which factory you are from? Could you come and take a look? Please provide detailed information on the parameters of the waste boilers. Thank you!
Controlling the temperature inside the furnace is a challenge.
Please interlock the pressure difference between the gasifier and the waste pot. Then make sure not to jump out of the car. Then the problem is solved. But you can’t do it.