Distillation control
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In distillation control, the most important parameters are liquid level, temperature, and pressure. I would like to ask everyone: what should be considered first when managing these parameters? For example: If the liquid level in the distillation tower is too high, should one consider increasing the heat input, reducing the feed rate, or opening the liquid level valve more?
Can reducing the feed and adding steam not be done simultaneously?
The first things to consider are the three types of balance: \"mass balance,\" \"gas-liquid phase balance,\" and \"heat balance.\" The most crucial one is mass balance, as it is only on the basis of mass balance that the other two can be taken into account. If the liquid level is high! To reduce backflow, increase the production rate!
In principle, the feed amount should be reduced; if a large amount is extracted, it doesn’t matter if it’s crude methanol, but if it’s refined methanol, it will affect its quality
While ensuring the product quality meets standards, adjust the three key balances properly.
Get up where you fell; identify the reason for the high liquid level, and you’ll know how to make adjustments. It seems that balance is what has been broken. Under normal circumstances, there are no major adjustments made to the total feed and total steam; otherwise, things will only get more chaotic
Distillation operations are based on three types of equilibrium. When the liquid level at the bottom of the tower is high, it is not advisable to add steam blindly or increase the liquid level control valve; instead, the alcohol content in the liquid at the bottom of the tower should be considered when making decisions. If high steam is added and the level control valve is opened, that will only increase the load on the next tower!
If the liquid level in the distillation tower is high, first observe what is causing it. 1. If the feed pump pressure is high, reduce the feed volume first. 2. Adjust the steam supply in case of steam fluctuations. 3. Finally, adjust the reflux rate
1. Identify the cause of the high liquid level; if everything is normal, simply increase the extraction rate from the tower bottom； 2. If the bottom of the tower is not up to standard, extraction cannot be carried out; in this case, the extraction from the top of the tower can be increased ； 3. Under normal circumstances, there are no major adjustments made to the total feed and total steam; only minor tweaks are required based on the actual conditions.
In distillation, first ensure material balance, then check whether there is enough heat supply to achieve thermal balance; finally, achieve balance for the natural gas and liquid levels. If the liquid level is high, determine the cause. If it rises without any change in the feed, it indicates that the composition of the crude alcohol has changed or that the heat source has changed (1. The ambient temperature can also have an impact). 2. Steam fluctuations, or fluctuations in the previous processing stage) as the heating source. If you increase the feed rate, then reduce it; if you want such a high load, then increase the heating source, add reflux, and increase the extraction from the bottom of the reactor.