Short Path Vacuum Distillation

Short path vacuum distillation:

Short path vacuum distillation for true fractional distillation short path distillation system. We have been consulting on short path distillation for many years. There is a lot of misinformation and other information that can cost you about basic extraction techniques that can be found for free on the site.
 

Short Path Distillation Working Principle:

Short path molecular still is a special liquid-liquid separation technology. It is different from the separation principle of traditional distillation relying on the difference in boiling point, but relies on the difference in the mean free path of molecular motion of different substances to achieve separation.

As the liquid mixture flows along the heating plate and is heated, light and heavy molecules escape from the liquid surface and enter the gas phase. Due to the different free paths of light molecules and heavy molecules, the molecules of different substances will move away after escaping from the liquid surface. The difference is that if the condensation plate is set properly, light molecules will reach the condensation plate and be condensed out, while heavy molecules will not reach the condensation plate and be discharged along the mixture. In this way, the purpose of material separation is achieved.

Advantages of short path vacuum distillation:

The separation of molecular distillation is realized by using the property that liquid molecules escape from the liquid surface after being heated, and different types of molecules have different mean free paths after escaping. The mean free path of light molecules is large, and the mean free path of heavy molecules is small, so that light molecules fall on the condensation surface, and heavy molecules return to the original liquid surface because they cannot reach the condensation surface, so that the mixture can be separated. This can be explained from a statistical point of view, and the flight distances that do not collide with other molecules after escaping from the liquid surface are different. It can be seen from the basic principle of molecular distillation that molecular distillation is a special distillation in non-equilibrium state that is different from conventional distillation.
 
Compared with conventional distillation, short path vacuum distillation
 has the following incomparable characteristics:
(1) The operating temperature is low, which can greatly save energy consumption. Conventional distillation relies on the boiling point difference of different substances in the material mixture to separate, while molecular distillation relies on the difference in the mean free path of molecular motion of different substances. For separation, it is not required that the material must reach a boiling state, as long as the molecules volatilize and escape from the liquid phase, the separation can be achieved. Just because the molecular distillation is operated far away from the boiling point, the energy consumption of the product is small.

(2) The distillation pressure is low, requiring operation under high vacuum. The mean free path of molecular motion is inversely proportional to the system pressure, and only by increasing the vacuum can a sufficiently large mean free path be obtained. Studies have pointed out that the vacuum degree of molecular distillation is as high as 0.1-100Pa.

(3) The heating time is short, reducing the thermal damage of heat-sensitive substances. Since molecular distillation uses the difference in the mean free path of molecular motion of different substances to achieve separation, the basic requirement is that the distance between the heating surface and the condensing surface must be smaller than the average free path of light molecules. This distance is usually very small, so light molecules are separated by After the liquid surface escapes, it hits the condensation surface almost without collision, so the heating time is extremely short. Studies have shown that the heating time of molecular distillation is only a few seconds or tens of seconds, thus avoiding the decomposition or polymerization of substances to a large extent.
 

The Short-Path Distillation Process Can Be Made In The Following Four Steps:

1. Make sure the pump has been run

The oil has been changed and the depth can be verified with a gauge or kind. This is an alternative method of providing the service. If there is a problem, run the pump on vacuum for about 1 hour to warm it up. Change the oil and run for another 30 minutes. Change the oil again. This double flushing process should refresh your vacuum pump. If this is not the case and you have a problem with your pump, get a new pump and service your current pump.
 

2. Remove all glass seams

Every little thing from Colt bait to fast path distillation, even cleaning your lines if needed; replacing lines if needed. Also make sure the controller is clean and not lined with parts inside.
Be careful not to use any hoses that contain solvents or distillates as this will affect vacuum quality and efficiency.
 

3. Start assembling the glassware.

● Apply a layer of high temperature resistant polytetrafluoroethylene vacuum grease. The grade should exceed 4-6 grades at 280-300c for a distillation protocol. The result of ignoring this can be to chase ghost leaks on your machine and affect your processes.
● The eccentric port on the triple eccentric flask is the positioning port of the fast channel distillation head.
● Apply grease to the thermometer O-ring. Tighten it, don't overtighten it and destroy the material memory (in warm, when you tighten this part, it will warm up and shatter itself)
●  Insert the 14/20 head plug at the start of the spd distillation.
●Position the head so that the bottom of the head is 100% even and upright.
● Connect the single head with an initial flask (250ml) for preliminary head separation. You should connect another flask (500ml) to the second adapter you provided in the kit.
● Connect the monocow gl14 port to the lower port of the chilly trap.
●  Now connect the cold water to the dv-1 throttle valve.
● The reduced part of dv-1 without valve goes to the vacuum pump.
● Now you have to start adding dry ice/iso to the ct-1 cold baits. Ideally below the trap in a plastic container.

Verdict: Compared to other machining tools, getting ready to install a benchtop short-path system isn't too much of a hassle, but there are still some important things to note before unboxing. Please feel free to contact us with any questions or concerns before and after your bench top short path purchase. We strive to provide the best possible service and want to make sure your system is installed correctly, safely and in a timely manner.

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