How to create a vacuum in vacuum distillation? Why is it necessary to evacuate first before heating?
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As the title suggests: How to create a vacuum in vacuum distillation? Why is it necessary to evacuate first before heating?
Use a vacuum pump to evacuate; generally, vacuum distillation is used to lower the boiling point and prevent thermal decomposition or oxidation of the material. We evacuate the space first to prevent the substance to be distilled from being oxidized by residual oxygen.
Vacuuming first ensures a high level of vacuum, reduces the oxygen content inside the container, prevents the material from oxidizing, and also lowers the boiling point of the material, thereby reducing changes that may occur due to high temperatures. This helps to increase the distillation speed
Pumping vacuum first helps achieve a smooth transition in vacuum level, facilitating better control of the overall stability of the tower.
Vacuum first and then heat, so that the bottom temperature does not become too high
Vacuum first and then heat, so that the bottom temperature does not become too high
Reduce pressure by vacuuming, using a steam evacuator in combination with a vacuum pump. Why is vacuum pumping necessary? By creating a negative pressure inside the tower, the boiling point of the oil decreases. If the residue is heated directly to above 350 degrees Celsius, the carbon residue present in it will coking.
Currently, most vacuum reduction systems use three-stage mechanical vacuum pumping; one. Level two is steam vacuuming. Why evacuate first? 1. The vacuum distillation tower is not a pressure vessel. 2. The purpose of creating a vacuum is to lower the boiling point of the oil and increase the recovery rate. If vacuum is not applied, the boiling point of the oil is high, so the vaporization rate is not as great. It’s like when you boil water at 90°, it boils at 50° in Antarctica. Let it mean this
It can not only remove residual oxygen but also prevent the cracking of reboiled materials.
If vacuuming is not done first, the high load after heating will affect the vacuum level, making it difficult to vacuum afterward!
Vacuuming first and then heating can effectively prevent the material from boiling over, facilitating stable control of pressure and temperature. If the temperature is first raised to the operating temperature and then vacuum is applied, the pressure drops and the boiling point decreases, causing a large amount of light components to vaporize and reach the top of the tower; as a result, both pressure and temperature experience significant fluctuations.