Selection of the inlet and outlet positions for fluorine refrigerant in the evaporator
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I have a question for everyone: I need to design a vertical shell-and-tube evaporator, with gas flowing in the tube side and Freon flowing in the shell side. For Freon pipes, is it better to have the flow enter from above and exit from below, or from below and exit from above? What are the advantages and disadvantages? Is it related to lubricating oil? Thank you all for your advice!
In my opinion, one should not attempt to use a heat exchanger in this configuration – it’s basically not feasible, and it’s also not economical. If it’s necessary to achieve this outcome, I recommend using a coiled-tube type heat exchanger with flow from top to bottom. I’m not sure what gas is being used; otherwise, I can offer better suggestions
The Freon used in our vacuum ice pack machines exchanges heat with the circulating water in the evaporator, with the Freon flowing through the shell side.
What is a vertical evaporator? What do you want to evaporate – gas materials or Freon? I didn’t understand!
I think it’s better to have air entering from below and exiting from above; fluorocarbons will vaporize
Since Freon is miscible with oil, controlling the flow rate of liquid feed from top to bottom helps with the return of oil； For oil to flow in from below and out from above, a dedicated oil return system must be installed; otherwise, accumulated oil will affect the cooling efficiency.
It is easier to control with fluid entering from below and exiting from above; the fluorocarbon vapor rises upward, and a level gauge can be used at the bottom to control the level of the fluorocarbon liquid. The operation is simple. The downside is that an additional oil return system is required, and the effectiveness of this oil return isn’t perfect, though it does not have a significant impact on the heat exchange efficiency