Is main fan surge caused by gas flowing into the regenerator?

Fan surging refers to a phenomenon in which turbo-type fans experience periodic vibrations when the suction pressure or discharge pressure exceeds the design specifications (each fan has its own anti-surge curve). It is an operational issue related to the equipment itself. Its surging also affects the operating conditions of the preceding/following processes, causing fluctuations as well. Therefore, strict control is necessary during production to prevent equipment surge.

Actually, I want to answer: Yes, he can’t breathe into the reactor! Haha, just kidding. Surge is an abnormal operating condition that occurs within the unit itself. I won’t go into details here; the fan expert above has explained it very thoroughly!

Yes, surge is an abnormal operating condition of the engine

1. An interesting topic – setting aside the surge characteristics of compressors, let’s see how the system experiences surging: lol 2. When the compressor is operating normally, the exhaust and intake channels operate independently, each performing its own function without interfering with the other. During surge, the outlet passage takes over from the inlet passage and also assumes a \"suction\" function. 3. The typical conditions for surge are low flow rate and high pressure; the operating point lies beyond the compressor’s surge line, and the outlet passage periodically undergoes suction and discharge phases, with the suction phase involving negative flow rate. The accompanying vibration causes significant damage to the compressor. 4. Each inhalation and exhalation passes through a large-volume gas storage space located downstream of the compressor; for a fluid catalytic cracking unit, this is the regenerator. A sufficiently large rear air storage space enables energy storage. 5. Assuming that the compression outlet does not have a storage space with sufficient capacity, that is, the back pressure of the compressor is low, the outlet pressure cannot increase, and thus the operating point will not move beyond the surge line. At extremely high flow rates, axial flow fans may experience blockage at the final stage. 6. Back to the original poster’s topic: The surge of the main catalytic fan is related to the regenerator; however, this description could be refined further: “Surge” is associated with the regenerator, while “surging” manifests in the compressor itself, and the vibrations affect the pipelines connected to the compressor

Both axial and centrifugal compressors can experience surge. There are generally two reasons for surge: low inlet flow rate and high outlet pressure. Therefore, when adjusting the pressure, it is necessary to first increase the main air flow rate before raising the pressure; when reducing the air flow rate, the pressure should be reduced first

It is generally caused by a sudden rise in regenerator pressure or by backpressure at the main air blower outlet resulting from the malfunctioning closure of the outlet valve.

Using a human analogy, it’s similar to what happens when a person lacks air