Agitated Thin Film Dryer (ATFD)
An Agitated Thin Film Dryer, also known as a Thin Film Evaporator (TFE), is a crucial equipment used in the pharmaceutical, chemical, and food industries to convert slurry or solution feeds into free-flowing powders. It is particularly useful when conventional dryers or evaporators are not suitable for handling the solutions.
The Agitated Thin Film Dryer consists of two main assemblies: a jacketed shell that is precisely machined on the inside, and a rotor assembly that rotates at high speeds while closely fitting the shell. At the entry point, a feed distributor evenly distributes the liquid feed onto the heated wall, forming a thin film.
As the high-speed rotor revolves, it spreads and agitates the thin film, facilitating efficient evaporation. The film flows down in a helical path due to the combination of the rotation velocity imparted by the agitator or blade and the axial velocity of the feed. This helical flow pattern takes place in the annular part of the dryer.
The generated vapors flow in a countercurrent direction and are subsequently cleaned by an integrally mounted entrainment separator. The cleaned vapor can then be conducted and recovered for further use, minimizing waste. The entire process is completed within a few seconds, enabling rapid and efficient drying.
The Agitated Thin Film Dryer (TFD) or Thin Film Evaporator (TFE) offers a highly efficient and effective solution for drying heat-sensitive solutions that cannot be handled by conventional dryers or evaporators. Its ability to create a thin film, intense agitation, and rapid evaporation ensures gentle drying, maintains product quality, and reduces processing time.
Advantages
- High evaporation is achieved in single pass.
- get dried power of moisture content up to 5-10%.
- Excellent turn down capability.
- Residence time of few seconds with a narrow spread.
- Shorter assembly time for maintenance & inspection.
- Reduce need for maintenance
An Agitated Thin Film Dryer (ATFD) plant is a facility designed to efficiently and effectively dry heat-sensitive materials or products using the principle of agitated thin film evaporation. The ATFD plant consists of specialized equipment and processes that enable rapid and gentle drying while maintaining product quality. Here are some key components and advantages of an ATFD plant:
- Equipment: The core equipment in an ATFD plant is the Agitated Thin Film Dryer, which typically consists of a vertically oriented cylindrical vessel with a heated rotor or blades. The rotor creates a thin film of the product on the inner surface of the vessel, maximizing the heat transfer area and facilitating rapid evaporation.
- Evaporation Principle: The ATFD operates on the principle of creating a thin film of the product, which is continuously agitated and heated. The thin film minimizes the contact time between the product and the heated surface, reducing the risk of thermal degradation and achieving efficient evaporation.
- Heat Transfer Efficiency: The design of the ATFD ensures efficient heat transfer, as the product film is in direct contact with the heated surface. This allows for quick heat absorption, resulting in rapid evaporation and short residence time of the product in the drying process. The high heat transfer coefficient of the ATFD contributes to energy efficiency and reduced operating costs.
- Gentle Drying: The ATFD offers gentle drying conditions, particularly suitable for heat-sensitive materials. The short residence time and the low operating temperature help preserve the product’s integrity, prevent thermal degradation, and maintain the desired characteristics of the final dried product.
- Scalability: ATFD plants are available in various sizes, allowing for scalability depending on the production requirements. Both pilot-scale and industrial-scale ATFD plants are available, providing flexibility for different applications and production volumes.
- Versatility: ATFD plants can handle a wide range of heat-sensitive materials and products, including pharmaceuticals, food products, specialty chemicals, polymers, and more. The versatility of the ATFD makes it suitable for various industries and applications.
- Continuous Operation: ATFD plants are designed for continuous operation, ensuring a consistent and uninterrupted drying process. The continuous feed and discharge of the product enable efficient production flow and high productivity.
- Energy Efficiency: The ATFD’s efficient heat transfer and short residence time contribute to energy savings compared to other drying methods. The reduced operating temperature and the ability to recover and reuse heat energy further enhance the energy efficiency of the ATFD plant.
- Product Quality and Consistency: The gentle drying conditions provided by the ATFD result in high-quality dried products with consistent characteristics. The uniform heat distribution and controlled evaporation minimize the risk of overheating or product degradation, ensuring a reliable and consistent final product.
- Process Control and Automation: ATFD plants often incorporate advanced process control and automation systems, allowing for precise temperature control, residence time adjustment, and other parameters. This enhances process efficiency, product quality, and ease of operation.
Overall, an Agitated Thin Film Dryer plant offers advantages such as efficient and gentle drying, energy efficiency, scalability, versatility, continuous operation, and high-quality product output. It is a reliable and effective solution for drying heat-sensitive materials in various industries.
Why UNITOP ATFD
- Residence time of a few seconds with a narrow spread.
- Required evaporation is achieved in a single pass, avoiding product recirculation and possible degradation.
- Scale formation on the heat transfer surface is reduced due to the intense agitation of the liquid film.
- Excellent turn down capability.
- Low product holdup, ideal for hazardous applications.
- Designed to give solid powder with moisture content around 5-10%.
- Widely accepted by pollution control board norms.
- No dead zone, therefore overheating prevented and perpetual high product quality guaranteed.
- Continuous mechanical cleaning of the heating surface prevents incrustations.
- High evaporation rates, due to highly turbulent film and large difference in temperature.
- Reduced need for maintenance because of sophisticated bearings and shaft sealing parts.
- Shorter downtime and assembly time for maintenance and inspection.
- Effective evaporation of concentrated slurries, heat sensitive products, viscous and fouling fluids up to 99% in a single pass.
- Simple installation as the equipment is supplied skid mounted with all inter connecting piping, condensers and vacuum system.
Single source responsibility for all project stages because of combined expertise in vacuum technology, heat transfer, evaporation, crystallization and drying – a design mix which gives optimal results
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