Liquid nitrogen jacket cooling issue
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Comrades, I have a few questions regarding the drawings below; I hope that netizens will offer their valuable opinions! I also hope to receive valuable suggestions on the drawings! 1. Should liquid nitrogen be introduced into the reactor from above or below? 2. Among external coil cooling, internal and external coil cooling, and jacket cooling, which one is the best – or what is the conventional approach – for liquid nitrogen reaction vessels? 3. When liquid nitrogen is introduced, the temperature should be between -60°C and -70°C. What improvements are needed to the automatic control system shown in the diagram?
This diagram is too difficult to look at. What is the purpose of adding liquid nitrogen to the reaction vessel? The temperature of liquid nitrogen is usually around -198°C. Is such a low temperature used to directly heat the material for cooling, or to participate in the reaction of the material? Will the material condense at ultra-low temperatures? ，，，，，。 It’s best to be clear for easy discussion and reference.
The required temperature for the reaction process is between -60°C and -70°C. The role of liquid nitrogen is to maintain the system temperature within the process temperature range; it does not participate in the reaction, and the materials do not condense.
What kind of material is used in the reaction vessel? It doesn’t solidify even when exposed to liquid nitrogen at around -190°C! Do not idealize the situation to the extent that once the liquid nitrogen tube is inserted into the reactor, its temperature will match that of the reactor contents, and once it exits the tube’s outlet, it will instantly mix evenly with the material. Additionally, what coolant is used inside the coil or jacket? It can’t possibly be cooling by the vaporization of liquid nitrogen either! Are the type and size of the impeller suitable for installing an internal coil? When the area of the external jacket or external coil is sufficient, it can be given priority as an option. It’s recommended that you sort out these issues first.
I haven’t encountered any examples of cooling using liquid nitrogen before, so I’m posting this to ask whether it’s possible to use liquid nitrogen to maintain a temperature of -60°C to -70°C directly. Liquid nitrogen is introduced into the jacket of the reaction vessel; it does not participate in the reaction, but it is also introduced into the interior of the reaction vessel’s cylinder. I don’t have any ideas for now; I’m looking for information on this topic.
If the harmful effects of material evaporation and emission are not taken into account, the best approach is to first vaporize liquid nitrogen into a cryogenic gas, and then use this cryogenic gas to mix within the substance in order to lower its temperature. This method is the most efficient. Otherwise, it will be a coil interlayer, and an insulation layer needs to be added on the outside; otherwise, heat loss will reduce efficiency. For reference.
This liquid nitrogen should be the refrigerant fed into the jacket or coils; it’s not possible to feed it directly into the material
Yes, that’s right; cooling is achieved by introducing fluid into the jacket. This is the first time we’ve encountered a low-temperature reaction, and we’re not sure whether it’s better to introduce liquid nitrogen from the bottom or from the top. The second point is that it is not yet clear whether it is more effective to introduce the fluid through an external jacket or through an internal coil. Or in processes like this, how is liquid nitrogen generally used to cool and control the temperature of the system?
Feed liquid nitrogen from the bottom. The vaporized gaseous nitrogen goes to the low-pressure gas tank from the top; this is standard operation