0102030405
China Suppliers Molecular Distillation Equipment for Short Path Distillation in Pharmaceuticals and Chemicals 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 Operating Limits & 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.
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 Types & Structural Performance
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.
Viscosity Treatment
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, reducing the viscosity of the treated liquid. It is suitable for processing viscosity up to 50Pas and preventing scaling on the heating surface, especially suitable for solid containing liquids.
Extremely Thin Film
The function of the extremely thin distillation liquid level scraper is to scrape the feed liquid into an extremely thin liquid film. Separation is more thorough.
High Separation Ratio
Thermally sensitive materials, high separation ratio, and precise scraper use an extremely thin liquid film evenly distributed on the heating surface, causing the entire heating surface to become wet. This allows for a high boiling separation ratio in the operating unit. This means that more than 90% of the entry in the case is evaporated, and the level of constant residual substances can be achieved.
Operating Principles & Construction
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, and a distiller made based on this principle is called a short-range distiller. The short-range still (molecular distillation) has a built-in condenser located opposite the heating surface and reduces the operating pressure to 0.001mbar.
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. Its basic composition: cylindrical cylinder with heating jacket, rotor and inner 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.
The short-range still 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 Flow
1
Material Feeding & Distribution
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.
2
Film Scraping & Downward Flow
Then, the scraper scrapes the material liquid into an extremely thin, turbulent liquid film and pushes it downward in a spiral shape.
3
Evaporation & Condensation
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.
4
Residual Discharge
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 suitable for short-range distillation?
Short-range distillation is highly suitable for thermosensitive, viscous, and high boiling point materials. Typical applications include 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 evaporator's vapor pressure must not exceed the pressure difference between the heating and condensing surfaces. External condensers cannot maintain this pressure difference, which makes built-in condensers necessary.
What are the different types of scrapers used in short-range distillers?
Short-range distillers use three main scraper types: rolling film, sliding scraper, and hinge scraper. The type is selected based on the specific viscosity and processing properties of the feed material.
How does the system handle highly viscous materials?
The scraper blades deeply immerse into the material, creating a strong shear and mixing effect along the edges. This reduces the viscosity (handling up to 50Pas) and prevents scaling on the heating surface, making it ideal for liquids containing solids.
What is the basic composition of a short-range still?
It consists of a vertically heated cylindrical body with a heating jacket, a central built-in condenser, a rotor rotating between the cylinder and condenser, and a precisely installed scraper and anti-splash device on the rotor bracket.