Catalyze emergency shutdown

I believe whether to stop the accident steam should be determined based on the temperature and pressure of the regenerator; of course, if the steam pressure is too low, it should be stopped and the primary and secondary air valves should be closed.

There is no need to shut off the steam in case of a main air accident; check whether the automatic protection system is activated. Also, verify whether the one-way damping valve on the main air pipeline is closed Go and close the primary and secondary air valves; after closing them, it doesn’t matter whether the emergency steam is turned off or not. The most important thing is to ensure that the catalyst does not enter the main air pipeline.

This post was last edited by jbcyf on 2011-11-5 09:40. Reply to 3# Ice and Snow: Well, after we stopped operations urgently last time, at the site we not only closed the material supply valves but also shut off the accident steam from the main air supply lines, in order to prevent backflow; otherwise, it might cause mixing as I mentioned.

Reply to 4# Cracking Man: It’s not a problem if it happens for a short period of time. Under normal conditions, there is a small drain valve at the bottom of the steam valve assembly during main air supply. In case of an emergency when the main air supply is interrupted, the safety system comes online, and the operator on site needs to check how well the safety valves are functioning. Some people go to close the feed nozzle manual valves and open the nozzles, then close the primary and secondary air valves.

It should be sufficient to ensure that the one-way damping method is turned off; as long as the main airflow doesn’t return, that’s fine

This post was last edited by jbcyf on 2011-11-5 09:41. The upstream valve for emergency steam is closed based on the temperature of the regenerator bed; if the regeneration temperature drops too rapidly, the emergency steam can be cut off, and it is best to use combustion oil to control the regeneration temperature.

Generally, the main steam emergency valve is not closed completely, but it must be turned down to reduce heat loss in the regenerator, maintain the catalyst temperature, and gain as much time as possible for emergency handling. If the main air one-way damping valve closes properly in its self-protection mode, accident steam is primarily used to prevent the auxiliary combustion chamber located in front of the main air nozzle as well as the main air pipelines from being filled with catalyst; moreover, air cannot be supplied again under such conditions, so simply closing the primary and secondary air valves is not sufficient. Typical installations should also have emergency industrial air in case of a main air supply failure; if heat loss is too rapid, the emergency steam supply can be shut off and the emergency industrial air can be activated. But the amount must be carefully controlled; if it is too large, it can easily cause a sudden drop in pressure within the industrial ventilation system, leading to secondary accidents. Remember! In this state, it’s basically equivalent to performing a “bed lockdown” operation.

This post was last edited by jbcyf on 2011-11-5 at 09:44. Personally, I think it’s necessary to decide based on the circumstances: if it’s a short period of time, the accident steam can be reduced by referring to the regenerator temperature, but it shouldn’t be completely shut off; if the bed needs to be held under pressure for an extended period, then the accident steam should be completely shut off to prevent the regenerator temperature from dropping too rapidly, which could lead to sludge formation.

If the main steam can be restored in a short time, there is no need to stop the accident steam from the main steam. Otherwise, stop the steam supply for a retorting process; when the bed temperature falls below the auto-ignition point of the burning oil, the main air flow cannot be restored, and the catalyst must be removed.