Analysis of the reason why reflux cannot enter the column during the startup of the vacuum distillation tower as shown in the figure
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As indicated in the title, during startup, the reflux liquid cannot enter the tower through the inlet pipeline behind the reflux distributor. Please help analyze the reason.
First, ensure that there are no blind flanges in the pipeline and that it is unobstructed, and then investigate the cause from a process perspective.
Without a pressure difference, the backflow cannot return. Generally, the return flow is diverted at the pump outlet.
Confirm that the pipeline is unobstructed. It’s also possible that a liquid seal has not been established; you can try reducing the flow or shutting off the pipelines on the right and below for a short while, so that the pipeline on the left is filled with liquid
First question: How did you determine that the reflux liquid couldn’t enter the tower? Second question: What is the outlet temperature of the circulating water?
Confirm that the pipeline is unobstructed. It’s also possible that a liquid seal has not been established; you can try reducing the flow or shutting off the pipelines on the right and below for a short while, so that the pipeline on the left is filled with liquid
1. Are there blind plates? 2. Is the pressure difference sufficient? 3. Is the liquid seal sufficient? Looking at the picture, there is no liquid seal device.
You can take a look at my previous posts: 【Crafts District Event – [I See]–07: How the exit height difference is determined】
No liquid seal, no pressure difference – it’s already solved
It’s impossible to tell from this diagram – there are too many factors at play. One thing worth noting is that I don’t see any pump; usually, the fluid from the pump outlet flows back into the tower.