Product Overview
Molecular distillation is a distillation process carried out under high vacuum, where the average free path of steam molecules is greater than the distance between the vaporization surface and the condensation surface, thereby utilizing the differences in evaporation rates of various components in the feedstock. It is generally applicable to industries such as petrochemicals, organosilicon, resins, and wastewater treatment.
Operating Principle
Molecular distillation is a specialized liquid-liquid separation technique that differs from traditional distillation, which relies on the principle of boiling point differences. Instead, it achieves separation by utilizing the differences in the average free path of different substance molecules. The distillation process involves adding the material to the top of the evaporator, where it is evenly distributed over the heating surface by a liquid distributor on the rotor. A scraper then spreads the liquid into a thin, turbulent film, which is spirally pushed downward. During this process, light molecules that escape from the heating surface condense into liquid on the built-in condenser through a short path and with minimal collisions, flowing down the condenser tubes and exiting through a discharge pipe at the bottom of the evaporator. The residual liquid, which consists of heavier molecules, is collected in a circular channel below the heating area and then discharged through a side outlet pipe.
Structural Performance and Features
The molecular distillation equipment is primarily composed of a heated jacket, a vertical cylindrical vessel, a central condenser located within it, and a scraper rotating between the distillation and condenser.
Its advantages include low distillation temperature, high vacuum during distillation, thin liquid film, high heat transfer efficiency, and high separation degree; no boiling bubble phenomenon; harmless and residue-free, yielding pure and safe products, with simple operation process and minimal equipment. It can effectively remove substances like organic solvents and odors from liquids for high-boiling point, heat-sensitive, and easily oxidizable materials; molecular distillation can selectively vaporize the desired product and remove other impurities; multi-stage separation allows for the simultaneous separation of two or more substances; the molecular distillation process is a physical process, thus it can well protect the separated substances from contamination and damage. Molecular distillation units are widely used in food, chemical, and other fields.
Technical Specifications
Molecular Distillation Experimental Equipment
Equipment Features: This unit bridges the gap between small-scale testing equipment and large-scale production equipment. It can serve as a formal production unit for small-scale production and as a pilot plant for large-volume products. After successful testing on this unit, the production capacity can be scaled up by 10 to 20 times. It offers a more thorough separation compared to scraper film evaporators and can be combined in series with them for enhanced evaporation efficiency. Connection is simple via a straightforward pipeline.
Structure: This equipment mainly consists of components such as a thin-film evaporator, an internal condenser, a secondary condenser, raw material tanks, finished product tanks, low-boiling point tanks, and high-boiling point tanks, all made of stainless steel.
Heating Methods: Thermal oil, Steam, Hot Water
Cooling Method: Two-stage condensation to prevent incomplete primary condensation, followed by full cooling through a secondary cooler. If two boiling points are simultaneously vaporized, segmented collection can be achieved by controlling the cooling water temperature of the two condensers.
Preheat Method: Tubular
Raw Material Output: Gear metering pumps, adjustable metering, low noise, smooth conveyance.
Control Method: PLC touch screen, set feed quantity, automatic feeding, stop automatically when out of material.
Weight Measurement: Each can is individually displayed with its weight, and the evaporation ratio is automatically calculated.
Primary Technical Specifications
