Downflow film condensation cannot be achieved in this tube
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To create a falling film inside a single tube using an overflow weir, the design is as follows; however, due to the low flow rate, deflection always occurs and it is not possible to form a film that covers the entire 360 degrees of the tube interior. How can this issue be resolved?
The falling film itself has a minimum flow limit, so it can’t be designed arbitrarily
If the flow rate is too low relative to the pipe diameter, a full cover film will not be formed! If the flow rate cannot be increased in your experiment, try reducing the pipe diameter!
How do you achieve falling film in this inclined tube? There must be a flow deviation!
Well, I’ve calculated the minimum wetting flow rate, and indeed I’m not able to achieve that value in my experiments. Is there any way to overcome this problem? The main issue right now is that it’s not possible to form a film around the upper port of the membrane in a 360-degree manner ?
The pipe diameter is not very large to begin with; making it even smaller might result in insufficient evaporation area. I saw in some literature that plug-type overflow falling film systems are used. Would using a plug like this can improve the situation? Something similar to what’s shown in the picture
This post was last edited by shumuxuan on 2017-12-6 at 14:41 – Plugin-type film applicator
The vertical one is a falling-film condenser, while the inclined one is a condenser. Could a plugin similar to this help reduce this phenomenon of flow deviation?
In fact, the design of the overflow weir also cannot meet the requirements for falling film; try using gear-shaped tubes instead