Short Path Molecular Distillation Equipment - China Suppliers & Factory for Thermosensitive Materials
Description
Many materials, such as petroleum heavy residue, chemicals, pharmaceuticals and natural foods, health products, fatty acids, etc., are often thermosensitive, viscous, and/or have high boiling points. To separate these materials from their other components while maintaining the quality of the product, distillation can only be carried out at low or even below boiling temperatures, and thermal decomposition or polymerization can only be minimized in a short period of time to eliminate damage to the product.
Operating Limitations: When the operating vacuum degree is about 500Pa, it can be carried out in a scraping film evaporator or a falling film evaporator. However, if distillation must be operated under medium to high vacuum conditions (such as pressures between 0.001 and 100Pa), there is a problem. It is necessary to choose an evaporator with a vapor pressure not exceeding the pressure difference between the heating surface and the condensing surface of the product, so evaporators with an external condenser are excluded from the distillation process in the medium to high vacuum range.
The SY Type Short-Range Evaporator Solution
In contrast, the SY type short-range evaporator is very suitable for this application, and the condenser is manufactured inside the evaporator, directly located opposite the heated distillation process. Therefore, short-range evaporators are a relatively new separation technology that has not yet been widely applied in industrial production and can solve a large number of separation problems that conventional distillation techniques cannot solve.
Scraper Classifications
Short range distillers can be divided into three types according to the form of scraper: rolling film, sliding scraper, and hinge scraper. Different scraper types are selected based on the viscosity and processing properties of the material.
High Viscosity Capability
The deep immersion of sticky substances and products containing solid scraper blades, along a considerable edge, causes a strong shear and mixing effect on the material film. It is suitable for processing viscosity up to 50Pas and preventing scaling on the heating surface.
Key Process Advantages
- Thin Liquid Film Scraper: Scrapes the feed liquid into an extremely thin liquid film for a more thorough separation.
- Thermally Sensitive Optimization: Extremely short residence time on the heating surface minimizes thermal degradation.
- High Separation Ratio: Achieves a high boiling separation ratio, meaning more than 90% of the feed is evaporated, leaving constant residual substances.
- Low Pressure Drop: The built-in condenser reduces the distance between the boiling and condensing surfaces, operating down to 0.001 mbar.
System Composition & Distillation Process
The short-range still consists of a vertically heated cylindrical body with a heating jacket, a rotor, and an inner built-in condenser located at the center. The rotor rotates between the cylindrical cylinder and the condenser, accurately equipped with a scraper and anti-splash device.
1. Feeding: The material is added from the top and distributed evenly on the heating surface via the liquid distributor.
2. Film Formation: The scraper forms an extremely thin, turbulent liquid film and pushes it downward in a spiral shape.
3. Condensation: Light molecules escape the heating surface and condense on the built-in condenser, flowing down to be discharged at the bottom.
4. Residue Discharge: Heavy molecules are collected in a circular channel below the heating zone and discharged via a side pipe.
What types of materials are suitable for short-range distillation?
It is ideal for materials that are thermosensitive, highly viscous, and/or have high boiling points, such as petroleum heavy residue, chemicals, pharmaceuticals, natural foods, health products, and fatty acids.
Why are external condensers excluded from medium to high vacuum operations?
Under medium to high vacuum conditions (0.001 to 100Pa), the vapor pressure must not exceed the pressure difference between the heating and condensing surfaces. External condensers cannot support this requirement, making built-in condensers necessary.
What are the different types of scrapers available for short-range distillers?
Short-range distillers utilize three types of scrapers depending on the material's viscosity and processing properties: rolling film, sliding scraper, and hinge scraper.
What maximum viscosity can a short-range evaporator handle?
Due to the strong shear and mixing effect of the scraper blades, it is suitable for processing materials with viscosities up to 50Pas, while also preventing scaling on the heating surface.
At what operating pressure does short-range distillation take place?
It operates as a thermal separation process at highly reduced pressures ranging from 1 mbar down to 0.001 mbar.