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Short Path Distiller Equipment for Thermosensitive Materials - China Suppliers and Factory
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.
Vacuum Distillation Challenges
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 & System Features
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.
Short Residence Time
The short residence time and the function of the scraper make the liquid film stay on the heating surface for an extremely short time, minimizing thermal exposure.
High Vacuum & Low Temp
Due to the condenser being directly located on the opposite side of the heating surface, pressure difference is reduced, enabling extremely high vacuum. Materials can be distilled at extremely low temperatures.
Viscosity & Scale Control
Deep immersion of sticky substances and solid containing scraper blades causes a strong shear and mixing effect. It reduces viscosity up to 50Pas and prevents scaling on the heating surface.
Operational Advantages
- Thin Film Distillation: The function of the extremely thin distillation liquid level scraper is to scrape the feed liquid into an extremely thin liquid film, making separation more thorough.
- High Separation Ratio: Thermally sensitive materials benefit from a high separation ratio. The precise scraper distributes an extremely thin liquid film evenly on the heating surface, causing the entire heating surface to become wet. This allows for a high boiling separation ratio in the operating unit, meaning more than 90% of the entry is evaporated, and a level of constant residual substances can be achieved.
- Minimal Pressure Drop: The pressure difference between the boiling film and the condensing surface is the driving force for the flow of steam, and a small pressure drop can cause the flow of steam. Running at 1mbar requires a very short distance between the boiling and condensing surfaces. The short-range still (molecular distillation) has a built-in condenser located opposite the heating surface and reduces the operating pressure to 0.001mbar.
System Composition & Distillation Process
The short-range distiller is a thermal separation process that operates at a pressure of 1~0.001mbar. Its lower boiling temperature makes it very suitable for heat sensitive and high boiling point substances.
Basic Composition: Cylindrical cylinder with heating jacket, rotor and built-in condenser; Accurately install a scraper and anti-splash device on the fixed bracket of the rotor. The built-in condenser is located at the center of the evaporator, and the rotor rotates between the cylindrical cylinder and the condenser. It consists of a vertically heated cylindrical body, a condenser located in its center, and a rotating scraper between the still and the condenser.
The distillation process is as follows:
The material is added from the top of the evaporator, and is continuously and evenly distributed on the heating surface through the material liquid distributor on the rotor. Then, the scraper scrapes the material liquid into an extremely thin, turbulent liquid film and pushes it downward in a spiral shape.
During this process, light molecules that escape from the heating surface condense into liquid on the built-in condenser through a short route and almost without collision, and flow down the condenser tube before being discharged through the discharge pipe located at the bottom of the evaporator; The residual liquid, also known as heavy molecules, is collected in a circular channel under the heating zone and then flows out through a side discharge pipe.
Frequently Asked Questions (FAQ)
What materials are best suited for short-range distillation?
It is ideal for materials that are thermosensitive, highly viscous, and/or have high boiling points, such as petroleum heavy residues, chemical products, pharmaceuticals, natural foods, health products, and fatty acids.
Why are evaporators with external condensers excluded from high vacuum operations?
Under high vacuum (0.001 to 100Pa), the vapor pressure must not exceed the pressure difference between the heating and condensing surfaces. External condensers create too much of a pressure drop, whereas a built-in condenser solves this issue.
What types of scrapers are used in short-range distillers?
Short-range distillers utilize three primary types of scrapers based on the material's viscosity and properties: rolling film, sliding scraper, and hinge scraper.
How does the system handle highly viscous or scaling materials?
The scraper blades create a strong shear and mixing effect along the heating surface. This reduces the viscosity of the treated liquid (up to 50Pas) and prevents scaling, making it highly suitable for solid-containing liquids.
What is the typical operating pressure of a short-range distiller?
A short-range distiller operates as a thermal separation process at a highly reduced pressure range of 1 to 0.001 mbar, allowing for extremely low distillation temperatures.