The impact of emergency shutdown on space gasifiers.

On September 7, at around 1:40, operators in the gasification workshop of Northwest Energy & Chemical Company noticed repeated fluctuations in the flow rate at the outlet of the high-pressure coal slurry pump of Unit 1#. The fluctuations intensified at 1:44; there was no flow at the pump’s outlet and the oxygen-to-coal ratio was high. To ensure the safe operation of the facility, Unit 1# was shut down urgently. Between 6:00 and 9:00 on the morning of September 8, blockages occurred in the inlet pipeline of the high-pressure coal slurry pump No. 2 in the gasifier as well; the flow rate at the pump’s outlet fluctuated several times. By 9:30, these fluctuations became more severe, to the point where no flow was detected. To ensure the safety of the system, Gasifier No. 2 was shut down urgently, and subsequent systems were also shut down one after another. The accident lasted from 01:44 a.m. on September 7 until 16:00 p.m. on September 10, when Unit 2 and Unit 1 gasifiers were restarted; pure methanol was produced at 09:24 a.m. on September 10. The accident disrupted normal production for approximately 80 hours. On September 11, the Group Company’s Safety Supervision Department and the Chemical Industry Department initiated an investigation into the \"Northwest Energy & Chemicals 9.7 shutdown accident.\" After three days of investigation, it was determined that this was a level-2 accident without any personal injuries involved. The direct economic losses, such as the costs for repairing and replacing the reducer of the large coal slurry tank mixer, amount to approximately 100,000 yuan ； It affects the production of pure methanol by 3,500 tons, resulting in indirect losses of around 1.4 million yuan.

I mainly want to know what the impacts on the gasification furnace are? Does a sudden drop in furnace pressure cause ash accumulation on the dome? What changes will occur inside the gasifier?

After stopping, slag in a molten state will flow down and accumulate at the slag outlet; when starting up again, it may be necessary to raise the temperature to melt the slag. The slag port pressure difference will not change significantly.

Stopping twice in 3 months isn’t that many. When we were driving, we stopped every week. Explore slowly; there will be many impacts. Each device has different characteristics. You still need to think about it more on your own.

Due to air separation issues, it stopped operating twice in one month. After those stops, no maintenance was carried out and it was put back into operation right away; the impact wasn’t very significant, and there was no increase in the temperature of the support plates either