For the finest confirmation of diluted stream performance, use the Rising Film Evaporators. They have simple building ideas yet offer cost-effective solutions to their customers. The fluid is treated within the tubes, which are equipped with the shell-sided heating medium. The feed liquid enters the evaporator from the bottom head and ascends the tubes. On the shell side, heating media are present to function as a heat source. They are basic in design yet extremely effective in delivering exceptional results to their consumers.
For a wide range of applications, Alaqua provides rising film evaporators, along with different types of evaporators and other processing equipment. Our solutions guarantee that our clients are satisfied.
Effluent treatment, polymer manufacturing, food production, thermal desalination, medicines, and solvent recovery are just a few of the uses for rising tube evaporators. “Large Long-Tube Evaporators for Seawater Distillation,” – Aschner, F.S., Schaal, M., and Hasson, D., 1971. Rising tube evaporators are mostly employed as reboilers for distillation columns, or as pre-concentrators, flash evaporators, or pre-heaters to remove volatile components before stripping in these sectors.
Thermal Desalination: The thermal desalination of seawater is a specialized use for rising tube evaporators. Seawater is poured into the evaporator’s long tubes, where it is heated by a heating medium (often steam). Inside the tubes, vapor develops and rises. This evaporation takes place in a vacuum, allowing lower temperatures to be used.
Food processing and juice concentration: The food business necessitates the long-term handling of delicate goods that are susceptible to high temperatures. Rising film evaporators can work fast and efficiently enough to prevent the product from being exposed to high temperatures that might harm or compromise its quality. As a result, they are suited for use as concentrators in the food sector for juices, milk, and other dairy products, which require careful handling.
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Advantages and Limitations
Low residence time
In comparison to other evaporator designs, such as plate-type evaporators, the major benefit of the rising film evaporators is the short residence time of the liquid feed in the evaporator. This is important because it allows the evaporator to operate at greater temperatures, ensuring good product quality despite the heat sensitivity of the product. Another benefit is the ability to run the evaporator as a continuous process, which saves energy and time over batch processing.
Coefficients of heat transfer: The comparatively high heat transfer coefficient of this evaporator type is another important benefit. This is important because it lowers the evaporator’s initial capital cost by reducing the overall heat transfer surface required. The fact that the components, which consist of a shell and tubes, are easily accessible with customizable designs, making them cost-efficient for construction and perfect for basic evaporation needs, adds to this. Furthermore, this sort of evaporator may readily accommodate foaming product vapor separators, which are commonly accessible.
While rising film evaporators are relatively efficient and offer a number of benefits, some research shows that they are not as efficient as vertical or horizontal tube falling film evaporators. As a result, falling film evaporators have largely replaced rising film evaporators in recent years since they offer similar benefits while also being more efficient. Furthermore, rising film evaporators require a driving force to move the film against gravity, which imposes a constraint since the driving force requires a significant temperature differential between the heating surfaces.
Limited Product Flexibility: Another significant drawback of rising film evaporators is the necessity for low viscosity and low fouling materials. Because the interior sections are more easily accessible for cleaning and maintenance, competitive process designs such as plate-type evaporators can handle viscous liquids with higher fouling tendencies.