Ask the next question regarding parking sequence control
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Regarding the question. Control is not an issue. It is rather a matter of the sequence in combining the processes. I need a colleague who understands this type of process control or has experience in this area to answer regarding a steam-heated reaction vessel. External jacket of the reactor. Steam enters at high pressure and exits at low pressure. If there is a malfunction in the reactor. An emergency cooling is required to stop the reaction. Cooling is achieved by circulating water, and various shut-off valves are installed in place as a contingency measure. The temperature inside the jacket is around 120–140°C, with steam cut off and the bottom water removed. Low-temperature circulating water at around 10-20 degrees Celsius is circulated; the pipelines lack insulation and are thus at near-room temperature. Under such operating conditions. What will happen if circulating water is introduced? Will it cause damage to the equipment? Could there be a situation where it won’t work? Has anyone calculated it? The pressure rises instantly when water vaporizes due to high temperature. What impacts will this have? There are baffles inside the jacket, which allow steam to stay there for a longer period of time. Suddenly shutting off the steam may result in a large amount of condensate remaining inside. Please help analyze it. What is a good order for control? 1. Shut off steam, shut off waste water (no sequential relationship) – When it is detected that the above two valves are closed, open the circulating water outlet and open the circulating water inlet (no sequential relationship). 2. Shut off steam, shut off waste water (no sequential relationship) – When it is detected that the above two valves are closed, wait. Delay for a while. . Open the circulating water outlet again, and open the circulating water inlet (no sequential order required)
Is 120-140 degrees considered too high for a pressure vessel?
1. Personally, I feel a slight vibration. The first type of vibration occurs when steam is introduced using a two-position valve; the rapid introduction of steam causes vibration. Secondly, at the moment when the circulating water enters urgently, vibration occurs as a result of the contact between steam and the circulating water. 2. In the event of a failure, and if the process requirements do not call for an immediate cooling down, it is recommended to wait a few minutes before introducing circulating water. In the case of an exothermic reaction, it is necessary for circulating water to enter rapidly in order to prevent overheating; therefore, it can be designed such that, upon detection of feedback signals indicating that both the steam valve and the condensate valve have been closed, the two circulating water valves open slowly. This slow opening speed should be adjustable via the control instruments. Some valves can be fully opened in 3 minutes or 2 minutes……
This condition is known as thermal cycling stress fatigue; generally, it is only after 300 to 1000 cycles that the issue of cracking in the semi-tubes needs to be considered. You are overthinking things – in such situations, the priority should be dealing with uncontrolled reactions, rather than protecting your equipment.
Having done this in practice, I’ll tell you how to do it: turn off the steam and then start the circulating water right away. What are you waiting for? ? Should we restart the circulating water when pressure and temperature increase? The reaction needs to be stopped urgently – do you still care about that reactor?
Are you creating a SIS program?
There seems to be a problem; with your circulating water at such a low temperature, it will definitely vaporize quickly as it enters the pipelines, which will have a significant impact on the lifespan of those pipelines.
His reaction getting out of control isn’t likely to happen; after all, cooling is meant to prevent side reactions or to protect the raw materials from being wasted. At this point, it’s more important to protect the equipment.