Gasifier initialization
Thread Content
Before starting the gasifier, the initialization procedure of the safety interlock system is used to prepare the gasifier for the operation of the slurry transfer pump. Before initialization, it is necessary to verify the condition of the gasification furnace process system: ① The pressure at the outlet of the scrubber is below 0.6 MPa ； ② The slurry cut-off valve and the slurry circulation valve are closed ； ③ The oxygen cut-off valve and the oxygen vent valve are closed ； ④ Oxygen control valve closed ； ⑤ The electric valve in the syngas shift unit is closed ； ⑥ Emergency stop button reset ； ⑦ High-pressure nitrogen purge button: Stop ； ⑧ Slurry operation button: Off. Once the above conditions are met, the initialization switch gauge is displayed on the DCS CRT; by setting it to “ON”, the gasifier initialization program begins to run. The program performs the following actions: ① The slurry circulation valve is opened ； ② The oxygen vent valve is open ； ③ The high-pressure nitrogen seal valve between the two oxygen cut-off valves is closed ； ④ Adjust the oxygen control valve from off to regulated. Once the above operations are completed correctly and the slurry pump is ready for operation, the slurry pump can be started to establish slurry circulation, with its flow rate controlled at the operating value.
The initialization content varies from factory to factory, but based on your steps, there is no problem. However, I have a question: you mentioned that the high-pressure nitrogen seal valve between the two oxygen cut-off valves closes after initialization, and I doubt this result. It should be turned on, right?
The high-pressure nitrogen seal valve between the two oxygen cut-off valves closed without error after initialization.
Perhaps it’s because the logic varies from factory to factory. Here, after initialization, the high-pressure nitrogen seal valve between the two shut-off valves is open; it closes when the shut-off valve downstream of the oxygen opens during operation
By closing the high-pressure nitrogen seal valve between the two oxygen cut-off valves, the furnace can be turned into a time bomb! Be careful with you.
The initialization parameters are different. Are there no requirements regarding the temperature of the vaporization furnace? Are there no requirements regarding the pressure of high-pressure nitrogen? Are these your complete initialization conditions?
Yes, this is the initialization of our system; when the system is reset, the nitrogen valve opens again
Oh, I see. So you initialize first and then reset, while we reset first and then initialize. But one thing is for sure: the high-pressure nitrogen seal valve between the two oxygen cut-off valves will definitely open before starting the vehicle
I’m not sure whether the original poster carried out the initialization conditions and procedures on their own; in some aspects, the logic used isn’t very sound. As for the nitrogen seal valve (also known as a buffer valve) between the two oxygen cut-off valves, opening it after initialization also has its drawbacks. I have discussed this issue with some colleagues, and although some factories handle it in this way, I personally think it’s better to approach it with caution. What was said on floor 5 isn’t that alarming.
These are the design documents from the preliminary design institute. If anyone has better ideas, feel free to share them or present your own proposals; we can all learn from each other and discuss together
The nitrogen stop valve is closed during initialization and opened again during reset.