There’s a fault in the distillation tower and the cause cannot be identified; I hope experts can offer some guidance
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Our tower is a composite tower; the distillation section is a packed tower, while the stripping section is a floating valve tower. The tower is a atmospheric pressure tower; under normal conditions, the pressure difference in the tower is 13 kPa or 15 kPa. Currently, however, the pressure difference fluctuates between 6–11 kPa, and the liquid level in the tower bottom also varies between 41–50%, with these fluctuations occurring approximately once per minute. I’ve considered many reasons, but none of them work; I hope someone with more experience can give me some advice
How do the temperatures at the top and bottom of the tower change? Is the product qualified? Can impurities on the trays in the stripping section cause tower blockage?
How do the temperatures at the top and bottom of the tower change? Is the product qualified? Can impurities on the trays in the stripping section cause tower blockage?
The temperature at the top of the tower shows no significant changes, and the quality of the components at that level remains acceptable; however, it seems to be slightly lower in quality compared to before. If there is a blockage, why does the pressure difference fluctuate within a low range?
Does the temperature at the bottom of the tower change? It’s possible that the gauge is broken; with such a large change in pressure, there’s no change in product quality. If there’s no blockage, then it’s likely a problem with the gauge. If the pressure does change, the temperature will change as well.
OP, how are the temperature changes at various points in your Tata? What are the similarities and differences between the product analysis results at the top and bottom of the tower and those under normal conditions? Is the backflow rate stable, and are there large fluctuations in the heating amount? Is the feed stable? The pressure difference within the tower is a parameter used to measure the efficiency of gas-liquid exchange. It would also be good to have more detailed parameters for analysis.
Consider the effect of cross-talk. I think that changes in the liquid level can lead to an uneven distribution of the liquid, which in turn causes gas to leak in and reduces the resistance. It is recommended to adjust the liquid level first, and then investigate the cause based on the pressure readings. Since yours is experiencing periodic fluctuations, I think it’s necessary to check your liquid transfer pump to see if there are any changes in the liquid flow rate and quality.
The problem is that at the moment, the feed rate is stable, the steam volume also doesn’t fluctuate much, the reflux rate is stable as well; the sampling from the tower bottom is done manually, and it is only the liquid level in the tower bottom that fluctuates. And what causes the air leakage you mentioned?
Air entrainment is caused by fluctuations in liquid level. When the liquid level is low, there is less resistance as gas passes through; when the liquid level is high, the resistance to gas flow increases. If the liquid level keeps fluctuating between high and low levels, this leads to changes in pressure as well.
The temperature variation throughout the tower is not very significant; the temperature at the bottom of the tower fluctuates slightly but not markedly. An intermittent dripping sound can be clearly heard at the bottom of the tower. The pressure difference gauges used for monitoring show that both the pressure at the top and at the bottom of the tower are changing, with greater changes occurring at the bottom. I also noticed that there might be some issues with the liquid flow at the feed inlet area. The trays inside the manhole at the feed inlet that we stopped to take apart this time are also in good condition. The backflow rate is constant, the feed rate remains stable, the amount of heating steam is basically stable although there are slight pressure fluctuations
Check if suspension has occurred ~~Is the opening degree of the product production valve smaller than during previous operations?~~