Problems encountered in the operation of the GE Gasification (formerly Texaco Gasification) gasifier system

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Please read the following article and discuss it in depth: 1. What other problems have arisen in the operation of your GE gasification (formerly Texaco Gasification) furnace system? 2. What are some good improvement methods and operational experiences regarding the problems that have arisen in the operation of the furnace system at Shanghai Coking Plant? 1. Overheating of the gasifier furnace wall: The gap between the thermocouple and the refractory bricks was not filled properly with high-temperature aluminum silicate asbestos, which led to gas leakage and extremely high temperatures on the furnace wall. Due to the lack of detailed instructions and installation experience for installing thermocouples. 2. Overheating of the furnace wall at the top of the gasification furnace: The main cause is the refractory bricks at the furnace mouth; due to the gap designed between these bricks and the furnace wall, the bricks expand when heated, resulting in cracks between them. This leads to air leakage, which in turn causes overheating at the top of the gasification furnace. Over-temperature of the arch roof occurred to varying degrees in southern Shandong and along the Wei River during the first few times operations were started after new refractory bricks were installed. To address the issue of overheating at the furnace wall crown, when constructing the bricks at the furnace mouth, the bricks forming the crown of the gasification furnace are cast together as a single ring-shaped brick according to the dimensions of the furnace mouth, thereby preventing cracks caused by thermal expansion and contraction that could lead to gas leakage and overheating. The trial showed good results, and there was no further occurrence of overheating of the furnace walls in subsequent driving sessions. Suggested improvement measures: ① Pay attention to construction details; ② Improve the design; ③ Select appropriate insulation materials; ④ Ensure that the furnace temperature is maintained strictly in accordance with technical requirements. 3. Severe presence of ash and water in the quench chamber: The reason for water contamination in the syngas within the quench chamber may be the accumulation of ash and slag in the gaps between the downcomer and the upcomer, which partially or completely blocks the gas flow channels. As a result, the syngas does not flow through these gaps but instead exits from the outside of the upcomer. This prevents proper heat exchange between the hot syngas in the downcomer and the cold syngas in the gaps. When the hot syngas enters the water bath and exits from the outside of the upcomer, it causes numerous bubbles to form in the water, leading to boiling and a false liquid level. The boiling water from the quench chamber flows into the synthesis tower through the syngas pipes, resulting in water contamination in the quench chamber. The graywater is sent to subsequent processes, and the low-temperature methanol washing pipeline gets clogged due to ash. Measures taken: ① Operate by lowering the liquid level in the quench chamber to around 1.4 m ； ② Load reduction operation ； ③ Lengthen the lower section of the riser by 200 mm ； Try to prevent hot syngas from leaking out from the outside of the riser ； ④ Use cold, high-pressure gray water as quenching water for a period of time to lower the water temperature in the quenching chamber ； The measures taken have had some effect, but the problem of ash and water in the quenching chamber has not been resolved. For newly installed units, it is recommended to pay attention to the following aspects: ① Increase the size of the quenching chamber to ensure an adequate gas-liquid heat transfer area as well as more space for gas-liquid separation ； ② The design flow rate of the quench water should be increased ； ③ The operation of the lock cylinder coordinates with this ； ④ Cooled water filter clogging: The mesh openings of Φ6 in both cooled water filters have become completely blocked. The main reason is the failure to switch and flush the quench water filter in accordance with the operating procedures. ⑤ Separation of the riser in the quench chamber: Increase the three tie rods used to secure the riser to six.