Stainless steel molecular distillation equipmentUsing high-precision gear pumps for feeding and discharging, the high-precision gear pump can smoothly transport materials from ultra-high negative pressure to atmospheric pressure without the need for material accumulation. The amount separated is more, which greatly protects the materials from damage, especially for heat sensitive materials. Moreover, the continuous feeding and discharging method can meet the 24-hour non-stop production demand, greatly improving the separation and purification efficiency.
Molecular distiller is a process experimental instrument that utilizes the difference in the average free path of different substance molecules to achieve liquid-liquid separation under high vacuum conditions. Its working principle is different from the boiling point difference separation of traditional distillation, and the operating temperature is much lower than the boiling point of the material. It is suitable for the distillation and purification of thermosensitive substances or high boiling point substances. The instrument mainly consists of an evaporator, a condenser, a scraping system, etc. The scraping system forces the liquid into a thin film through rotation to improve evaporation efficiency. The evaporation body is mostly made of high borosilicate glass or corrosion-resistant materials for easy observation and corrosion prevention.
Operation steps:
Equipment preparation and debugging:
System inspection: Ensure that all pipelines (oil pipes, condensate pipes, vacuum pipes) are sealed properly and free of leaks. Install auxiliary components such as receiving bottles and cold traps, fix them, and then close the air conduction valve.
Sample pretreatment: Dissolve the mixture to be separated in a solvent and filter impurities to ensure material fluidity and compatibility within the operating temperature range.
Vacuum system regulation:
Start the vacuum pump group in sequence, draw to the empty vacuum degree (usually 10-100Pa), and further reduce to the target value (experimental level can reach below 0.1Pa) through the regulating valve. Real time monitoring using a digital vacuum gauge and closed-loop control system to maintain vacuum stability.
Turn on the cooling water system to ensure that the condenser temperature is controllable (to prevent steam blowback).
Distillation operation process:
Film formation and heating: Start the scraper rotor (speed ≤ 400rpm) to form a uniform thin film on the inner wall of the distiller. The heater is heated to the set value (lower than the normal boiling point of the material) to avoid the decomposition of thermosensitive substances.
Evaporation and Separation: Light molecules preferentially escape from the liquid surface and are directly condensed and collected over a short distance (due to differences in molecular free path); Residual liquid phase of heavy molecules and reflux.
Condensation control: The temperature difference between the condenser and the evaporation surface is maintained at 70-100 ℃ to ensure rapid liquefaction of vapor molecules.
Operation monitoring and adjustment:
Real time monitoring of temperature, vacuum degree, and scraping speed, adjusting heating power and vacuum valve opening to optimize separation efficiency.
Control the distillation rate (usually 1-2 drops/second) to avoid boiling or material oxidation.
End operation and maintenance:
Shutdown steps: Close the feed valve → Stop heating → After cooling, turn off the vacuum pump → Disassemble the collection bottle.
Equipment cleaning: Use solvent circulation to clean the pipelines and distillation chamber (2-3 times) to prevent residue blockage. Regularly maintain vulnerable components such as seals and scraper rotors to extend equipment lifespan.