All systems are designed with exceptional flexibility, allowing them to be interconnected and configured or combined for a wide variety of tasks based on specific requirements. Potential adaptations include modifications to piping, new interconnections, or additional measurement and control technology. Customers also have the option to temporarily integrate their own equipment into the pilot plant to replicate the process as realistically as possible.
1. Laboratory unit with thin-film evaporator
3. Thin-film dryer (vertical and horizontal)
5. VISCOFILM thin-film evaporator
6. Tube falling-film evaporator
8. Conclusion
Figure 1: The diagram illustrates the application areas of various evaporation technologies. By selecting or combining the appropriate technologies, GIG Karasek is capable of processing a very wide range of different substances and replicating these processes extensively in the technical center. @ GIG Karasek
The focus of the laboratory unit is on assessing feasibility. The goal is to determine whether the product can be successfully separated and if the process is technically viable.
Effective evaporation of the material plays a critical role in this, taking into account both atmospheric pressure conditions and potential vacuum requirements.
Furthermore, it is highly important to identify potential challenges in evaporation as well as other process-specific factors.
The laboratory unit consists of a tabletop system made of stainless steel, featuring a thin-film evaporator.
Figure 2: GIG Karasek laboratory unit with thin-film evaporator. @ GIG Karasek
The thin-film evaporator is characterized by a gentle evaporation process and is used for both concentrating and purifying valuable substances.
This evaporator is suitable for various applications, including the concentration of structurally viscous media, the concentration of temperature-sensitive products, and the distillation of low-boiling valuable components. Additionally, it is employed as a reboiler in rectification systems and enables the purification of high-boiling products through distillation.
The thin-film evaporator system in the technical center represents approximately one separation stage, utilizing thermal oil as the heating medium. The evaporator can be operated with various rotor and wiper blade configurations to replicate the full range of functions available in large-scale systems. This setup enables targeted testing to determine the optimal combination for specific customer requirements or products. Additionally, integration with a distillation column is possible.
The system's performance is determined through a mass balance.
Figure 3: Thin-film evaporator system in the technical center © GIG Karasek
The thin-film evaporator consists of a cylindrical, externally heated surface with a rotor inside. The rotor blades are designed to avoid contact with the heating surface, while special wiping elements ensure uniform distribution of the product and continuous transport of the product stream. At the same time, the wipers prevent fouling or clogging of the heating surface.
Short residence times of the product on the heating surface and minimal thermal stress enable a gentle evaporation process, ensuring high product quality:
The thin-film evaporator can be connected to a distillation column in the technical center to maximize the efficiency of the separation process and enable the production of highly pure products:
A typical application of this process is the desulfurization of biodiesel. In the first process step, the temperature-sensitive biodiesel is dehydrated in the thin-film evaporator. In the second process step, the column is engaged to separate the sulfur.
Thin-film evaporator:
Distillation column:
The thin-film dryer, a specialized design of the thin-film evaporator, provides a gentle and efficient alternative when conventional drying technologies reach their limits in demanding applications. The thin-film dryer is widely used in industries such as waste management, chemicals, pharmaceuticals, and food processing to effectively dry a variety of products, including sludges, chemicals, suspensions, pastes, and moist solids.
Figure 4: Operating principle of a thin-film dryer @ GIG Karasek
The technical center is equipped with both a vertical and a horizontal thin-film dryer to conduct extensive tests and experiments.
For drying highly wet sludges, a combination of pre-drying in the vertical unit followed by post-drying in the horizontal thin-film dryer is recommended.
This approach enables the achievement of minimal residual moisture.
Figure 5: Horizontal dryer in the workshop © GIG Karasek
The thin-film dryer operates on the principle of the thin-film evaporator and is distinguished by its high drying efficiency and capability for short drying times. With its specialized wiper design, the dryer enables gentle drying of liquid feed products, even to powder form, while minimizing valuable material losses and ensuring high purity of the dried products. A practical example of this can be found in our blog post: Precision Work at Power Oil Rostock, Germany.
Figure 6: Operating principle of the horizontal dryer @ GIG Karasek
Horizontal dryer / vertical dryer:
The short-path evaporator is an advanced distillation technology specifically designed for the gentle separation of sensitive substances under low pressure and high evaporation rates. The short-path technology is primarily used in the distillation of viscous and heavily contaminated products. The short-path evaporator can purify many substances that cannot be successfully separated using conventional thermal methods.
The short-path evaporator in the technical center is an exceptionally efficient apparatus that enables gentle separation of sensitive media at low process pressures ranging from 0.001 to 1 mbar. Thanks to its flexible design, it can be tailored to meet the specific requirements of each product.
In the technical center, various types of wipers are tested and adjusted to determine the optimal combination for efficient separation.
An additional advantage of the pilot plant is its ability to be interconnected with thin-film evaporator systems. This configuration allows for the simulation of residence-time-critical evaporation processes, enabling realistic investigation and optimization of these processes.
Figure 7: Thin-film system in the technical center © GIG Karasek
Essentially, a short-path evaporator operates on the same high-performance principle as a thin-film evaporator, but with two key differences:
1. Fine vacuum: The product is distilled under fine vacuum (0.001 to 1 mbarA) to lower the boiling temperature, thereby avoiding unwanted reactions or decomposition of thermally sensitive products.
2. Integrated condenser: Unlike conventional evaporators, the condenser is directly integrated into the evaporator. This significantly shortens the path of the vaporized components (the vapor) to the condenser, minimizing pressure loss and enabling a high evaporation rate.
Due to its specialized design and fine vacuum process, the short-path evaporator is particularly suited for the gentle distillation of sensitive substances such as fatty acids, semi-volatile aroma compounds, vitamins, and oils.
Figure 8: Operational principle of the short-path evaporator @ GIG Karasek
The VISCOFILM thin-film evaporator has been specifically designed for the gentle evaporation of products with a high viscosity of up to 5,000 Pa·s. It serves as a bridge between conventional thin-film evaporators, which are designed for liquids with viscosities below 10 Pa·s, and polymer extrusion technologies that can handle liquids with viscosities of up to 10,000 Pa·s.
The VISCOFILM thin-film evaporator is based on the operating principle of a thin-film evaporator but features several distinctive characteristics. Its unique modular design and specialized rotor configuration set it apart, enabling versatile applications and a wide range of uses.
A key focus of the high-viscosity evaporator is the processing of renewable and/or recyclable materials, such as polymers. Its specialized design not only enables the efficient recovery of solvents but also minimizes residual content in the final products. The high-viscosity evaporator thus offers not only economic benefits but also contributes to reducing environmental impact and conserving valuable resources.
Figure 9: VISCOFILM thin-film evaporator system in the technical center © GIG Karasek
The VISCOFILM thin-film system in the pilot plant is designed to be robust and is suitable for both continuous operation and small-scale production:
Figure 10: Principle diagram of the VISCOFILM thin-film evaporator pilot plant © GIG Karasek
System equipment:
A distinctive feature of the VISCOFILM evaporator is the standard connection for an extruder. This setup allows the option of melting granulate directly in a temporarily provided extruder in the technical center and then feeding it into the VISCOFILM evaporator.
It is also possible to integrate the extruder downstream. A clear example of this is the customer-side installation of a cooler in the technical center to continue the process with an extruder after processing in the VISCOFILM evaporator. The cooler was specifically used to lower the product temperature from 240°C to 200°C before granulation. Additional equipment was provided by the customer to conduct realistic trials over a one-week period and optimally simulate the process.
Tube falling-film evaporators are widely used in standard processes where liquids need to be concentrated, mixtures separated, or valuable substances recovered. Their compact design makes them particularly well-suited for applications with low evaporation capacities. However, due to their demanding cleaning requirements, they are primarily used in industries that process low-viscosity and low-fouling media.
In the technical center, trials are typically conducted to assess the suitability of the tube falling-film evaporator for specific applications and to determine optimal operating parameters. Additionally, these trials support the development and validation of process models for scaling and implementing tube falling-film evaporators across various industries.
A key consideration is fouling, which can reduce heat transfer efficiency and evaporation performance. Furthermore, the combination of the falling-film evaporator with the thin-film evaporator allows for the simulation of multistage processes.
Tube falling-film evaporators are vertically arranged shell-and-tube heat exchangers that enable efficient evaporation with high vaporization rates through the combined effects of heat exchange and gravity:
Figure 11: The tube falling-film evaporator is based on the principle of a shell-and-tube heat exchanger. @ GIG Karasek
Distillation or rectification columns are widely used in various sectors of the chemical industry, particularly for the thermal separation of complex multi-component mixtures. They are especially advantageous when fractions need further separation to achieve higher purity levels. Common applications include the purification of recyclable substances, petroleum refining, and the large-scale production of basic chemicals.
In addition to the column that can be combined with the thin-film evaporator, the technical center also operates a standalone distillation column. Typical trial applications include the purification of mixtures and the separation of feed streams with components having similar boiling points, such as solvent recovery (e.g., ethanol) or the separation of fatty acids and resin acids from tall oil.
To optimize mass transfer, the column is equipped with packings or bulk material, increasing the surface area and maximizing contact between vapor and liquid. Customer-specified internal components can be provided for testing purposes and integrated into the column by GIG Karasek.
Note: if high separation efficiency is not required, such as in the straightforward separation of heavy and light boiling components (e.g., in biodiesel production), the short-path evaporator often proves to be a more cost-effective and less complex alternative. Learn more in our blog post “Biodiesel Distillation: Why the short-path evaporator is the better option compared to the rectification column.”
The principle of the rectification column is based on the thermal separation of liquid mixtures through repeated evaporation and condensation. Ascending vapor and descending condensate interact continuously in a countercurrent flow, significantly enhancing separation efficiency and achieving high purity levels of the individual components.
GIG Karasek’s technical center provides state-of-the-art testing infrastructure and a team of experienced specialists to explore, develop, and optimize separation processes. With flexible equipment covering a wide range of temperature and pressure conditions, and the ability to integrate customer-specific apparatus, it serves as a comprehensive platform for laboratory and pilot trials. Customers can enhance separation efficiency, purity, and product quality while discovering tailored solutions for their unique requirements.
As a center of excellence for innovative separation technologies, the technical center supports the realization of customized solutions and is the ideal partner for developing optimal process solutions. Feel free to contact us to discuss your specific needs.