Conical Screw Vacuum Dryer

Vacuum Paddle Dryer (VPD) Overview

Jinling Drying Vacuum Paddle Dryer (VPD) is an industrial drying equipment used primarily in the chemical, pharmaceutical, and food industries for drying heat-sensitive, easily oxidizable, or hazardous materials. Its unique design enables the efficient drying of materials under vacuum conditions, which helps prevent thermal degradation, oxidation, and contamination, ensuring the quality of the final product.

Horizontal Vacuum Paddle Dryer Design and Structure

The Vacuum Paddle Dryer has a few essential components:

1.Drying Chamber:

A cylindrical, jacketed vessel where the material is loaded for drying.

Constructed with materials like stainless steel for durability, corrosion resistance, and ease of cleaning.

It is fully sealed to create a vacuum environment, preventing external contamination and enabling low-temperature drying.

2.Paddle Shaft with Agitator:

A central shaft with multiple paddles or blades attached.

The paddles rotate within the chamber, mixing and agitating the material to ensure consistent drying by increasing the surface area exposed to heat and vacuum.

The design of paddles can vary to achieve optimal mixing for specific materials, often angled or helical to maximize efficiency.

3.Heating System:

A jacketed heating system surrounds the drying chamber.

Typically uses steam, hot water, or oil as the heating medium, allowing precise temperature control.

Heats both the chamber walls and paddles, providing uniform thermal contact to the material.

4.Vacuum System:

A high-capacity vacuum pump is connected to the chamber to maintain a low-pressure environment.

The reduced pressure lowers the boiling point of moisture or solvents, enabling drying at lower temperatures, thus preserving sensitive materials.

5.Discharge System:

Often includes a bottom valve for easy discharge of dried product.

May have options for manual or automated discharge, depending on batch size and application.

Flow Chart:

Working Principle Of Vacuum Paddle Dryer

The operation of a Vacuum Paddle Dryer follows these steps:

1.Loading:

Material to be dried is loaded into the vacuum drying chamber.

2.Vacuum Application: 

The chamber is sealed, and a vacuum is created to lower the pressure.

3.Heating and Agitation:

The heating system is activated, providing controlled heat to the chamber walls and paddles.

The paddles begin to rotate, agitating the material to increase the surface area exposed to the heat and promote uniform drying.

4.Moisture Removal:

Under vacuum, the boiling point of moisture or solvents is reduced, allowing them to evaporate at lower temperatures.

Vapors are continuously extracted by the vacuum pump and condensed outside the drying chamber.

5.Discharge:

Once drying is complete, the material is cooled if needed and discharged from the chamber.

Benefits of Using a Vacuum Paddle Dryer

Low-Temperature Drying:

Ideal for heat-sensitive materials as the vacuum reduces the boiling point of water or solvents.

Efficient Moisture Removal: 

Rapid drying of materials with high moisture or solvent content, even when drying viscous or sticky materials.

Uniform Drying:

The agitation and heating mechanism ensure consistent drying throughout the batch.

Closed System:

Reduces the risk of contamination, making it suitable for sensitive or hazardous materials.

Energy Efficiency:

Lower temperatures mean reduced energy consumption and minimized product degradation.

Vacuum Paddle Dryer Applications

The Vacuum Paddle Dryer is widely used in industries such as:

Pharmaceuticals:

Drying of heat-sensitive APIs (Active Pharmaceutical Ingredients), intermediates, and excipients.

Chemicals: 

Used for fine chemicals, dyes, and pigments that require a controlled environment.

Food Processing:

Ideal for drying sensitive ingredients like fruit extracts, flavorings, and other food additives.

Biotechnology: 

Useful in processing enzymes, proteins, and other biological substances that are sensitive to heat and oxygen.

Polymer and Resin Processing:

Drying materials that may degrade at higher temperatures.

Key Considerations for Using a Horizontal Vacuum Paddle Dryer

Material Characteristics:

Choose the dryer configuration based on the specific properties of the material, such as stickiness, viscosity, and particle size.

Vacuum Control:

Proper control of the vacuum level is essential to avoid thermal degradation or oxidation.

Temperature Control:

Ensure the heating medium and temperature are suitable for the material being processed.

Maintenance:

Regular maintenance of the vacuum pump, seals, and paddles is critical to avoid contamination and maintain performance.

Safety Protocols:

For handling hazardous materials, the VPD should comply with safety standards to ensure containment and operator safety.