Chemical engineering design: Pipeline and control valve layout

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First of all, thank you for sharing! Secondly, I still have some confusion regarding this issue. At the chemical company where I used to work, the control valves for the reboilers in the distillation towers were installed on the steam lines, while steam traps were installed on the condensate lines ； The company I work for now installs control valves on the condensate line of the reboiler. Regarding the comparison of the two options, when I first started working at this company, I asked my supervisor in the workshop about it. Their answer was that installing the control valve on the condensate line allows for more stable temperature regulation (preventing large fluctuations), and it is also advantageous from an energy-saving perspective ； If installed on the steam line, adjustment yields quick results, but it tends to cause fluctuations! At that time, the issue was left as it was, and I didn’t think about it any further! Some time ago, an abnormality occurred in a distillation tower in my workshop; the liquid level and temperature of this tower experienced periodic and significant fluctuations (I have shared more details about this on HaiChuan earlier; feel free to offer your insights). Afterward, including the management, we all tried to figure out what could be the cause, but to date, there is still no definite explanation. It’s just that because of this anomaly that occurred, while analyzing its causes, I thought back to the question I had considered when I first started working here. I am increasingly skeptical about whether installing control valves on the condensate line can truly save steam From the perspective of saving steam, wouldn’t it be better to install a hydroseparator directly on the condensate line, thereby ensuring that what flows out of it is definitely hot water, and preventing a large amount of steam from being included in the condensate due to the adjustment of the control valves on that line? I would appreciate your advice!

This post was last edited by little bugs_ZMXH on 2019-1-10 at 11:39. If regulation is done by adjusting the condensate level, the steam flow rate should be relatively high; there shouldn’t be any steam coming out of the condensate control valve within that range. Is energy savings achieved by utilizing some of the sensible heat in the condensate when adjusting its level? It seems that the advantage of directly adjusting the steam flow is a larger adjustment range and more stable operation of the heat exchanger. Another advantage is that the control valve for the condensate is smaller, which helps to reduce costs