Design of distillation towers (for experts)
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I would like to ask the experts: could there be any problems if a distillation tower is designed in the manner shown in figure b below? Is there any design like this in practice? Unlike traditional a distillation tower designs: 1. The reflux tank is eliminated; instead, a reflux pump is used to draw liquid from the level in the condenser. The design of the condenser is reversed, with the material flowing in the shell side and cooling water flowing in the tube side. 2. The storage tank is removed as well; the pump directly draws the material from the equilibrium drum and sends it to downstream processes
The diagram below omits the return channel and storage tank, which significantly reduces the stability of operation; this increases the requirements regarding the skill level of the operators as well as their workload
OP, what kind of book is this?
What is this process flow? The return tank has been removed; the pump is prone to air locking, making it extremely difficult to control during startup operations. Without a reflux drum, how is the pressure at the top of the tower controlled? By adjusting the condenser level, two pumps are connected downstream.
Since it’s all fully automatic, there shouldn’t be any problems, right? !
1. Those with a high degree of self-control are suitable. 2. It is appropriate for columns with a low processing capacity but high separation purity. 3. It is not suitable when the load on the column varies greatly. 4. When water flows through the tube side, attention must be paid to the cleanliness of the cooling water. 5. The material choice for the column top cooler may vary
How to deal with non-condensable gases? The tank has a large capacity and high fault tolerance, which also provides operators with more time for handling. The heat exchanger has too small a capacity and low fault tolerance; if there is a problem with the liquid level, it will have negative consequences for the downstream systems.
Mm-hmm, thank you all. It’s just a discussion; this is an approach to intrinsically safe design
Design option B is based primarily on the principle of inherent safety; this approach can significantly reduce the amount of hazardous materials that need to be stored. However, it also comes with other disadvantages, which is why we are discussing it together with everyone else.