What are the effects of damaged thermometers and pressure gauges in oxygen pipelines on the system (involved in temperature and pressure compensation)?
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1. What are the effects of damaged thermometers and pressure gauges in the oxygen pipeline on the system (as they are involved in temperature and pressure compensation), and how should this be addressed?
In this compensation mechanism, both temperature and pressure are functions of flow rate; damage to the temperature and pressure sensors can lead to inaccurate calculations of oxygen flow rate, resulting in incorrect signals. The DCS system will then automatically adjust the amount of coal slurry used, either increasing or decreasing it. An increase in this amount leads to an excess of oxygen in the mixture, while a decrease results in insufficient oxygen, which can cause accidents or even explosions. Additionally, the overall oxygen vent valve may open, increasing the load on the air separation unit. There are even more serious consequences as well!
This is very dangerous; when involved in thermal pressure compensation, if there is no temperature signal, the oxygen flow rate will be indicated as minimum. If the control valve is set to automatic mode, it will open fully instantly, resulting in an excess of oxygen. The same goes for pressure. Therefore, when dealing with the temperature and pressure of oxygen pipelines, the control valve should be set to manual mode; there is no need to panic if the flow rate changes, and it is important to keep an eye on the flow rate from the air separation unit.
At Shandong Lunan Fertilizer Factory, similar situations have occurred during operation in the past, resulting in manual shutdown.
There were similar discussions in the forum earlier on regarding \"Temperature and pressure compensation for oxygen flow rate\": http://bbs.hcbbs.com/viewthread.php?tid=410656&highlight=
In the case of multi-burner furnaces such as SHELL furnaces, once the above situations occur, this coal powder line will definitely shut down. After oxygen supply is discontinued, it will be distributed to the other three lines; the operator should ensure the proper operation of those burners or reduce their load, and any faulty instruments should be handed over for inspection and repair