10 Things to Consider Before Buying a Thin Film Evaporator

The purchase of a thin film evaporator is a major choice that will influence your separation performance, product quality and cost of operation. It could be heat-sensitive pharma-products, reclaiming high-boiling solvents, concentrating viscous polymers, the appropriate equipment should be a compromise between technical competence and practical functionality. However, when working with complicated variables, such as the integrity of the vacuum, the residence time, and the mechanical design how are you sure that you are making the correct choice? YHCHEM has provided more than 10,000 systems to more than 50 different countries and this gives it a distinct insight into what works on the laboratory and industrial front. In a bid to assist you in making this decision, YHCHEM has been able to extract the main considerations and put them into 10 essential questions, which are divided into four critical considerations.

Process Fundamentals: Feedstock and Throughput

You should be familiar with the personality of your material before assessing hardware.

Viscosity and Flow Characteristics: Is your product pumpable? The rotating wiper blades of the thin film evaporators are very useful in handling viscous fluids since the material will be spread by the rotating wiper blades thus not floating up and causing scaling. When your feedstock becomes so thick that solvent is lost, you must have a system that has a powerful drive motor and rotor design that will hold the film at its best.

Thermal Sensitivity and Residence Time: A thin film evaporator has the advantage of having a short residence time. Time is of essence in the case of volatile chemicals like essential oils, vitamins or monomers. What you need to make certain is that those gears can do the separation or do it at the lowest possible pressure and thus lower the boiling point of the product allowing your product to be free of thermal damage.

Rate of Evaporation and Throughput: Do you evaporate 1 liter/hour in a laboratory, or 1000 liters/hour in a manufacturing facility? The surface area required for evaporation is proportional to throughput. Choosing one that is too small gives a bottleneck; one that is too large may not be efficient to run at low loads. Modular systems provide the capacity to suit your precise capacity needs.

Mechanical Integrity: Design and Construction

The evaporator is determined by its physical construction which determines its longevity and performance. Key design elements include:

Wiper System and Rotor Design: The core of the unit is the wiper blades. Roller wipers are used to give a smooth continuous film and fixed clearance blades are used to give aggressive scraping in high-viscosity applications. The decision would be based on the fact that you are interested in minimal shear stress or maximum heat transfer.

Construction and Compliance Materials: Your material has to correspond to the construction material, otherwise there may be corrosion or contamination. Borosilicate glass offers visibility for laboratory R&D is concerned. In case of industrial chemical processing, 316L stainless steel or better alloys are required. Make sure that the manufacturer, such as YHCHEM, provides the products that comply with the international safety standards, which are CE and UL compliance.

Vacuum System Capability: The thin film evaporator itself is as good as the vacuum in which it is operated. You require a tightly closed system, with vacuum pumps and condensers of a suitable size, to get deep vacuum levels (less than 1 mbar). Low separation performance is usually caused by a small size of vacuum system.

Operational Scope: Scalability and Flexibility

Your requirements can change and that is why it is important to futureproof your investment.

Scalability Lab to Production: Can you scale to production in case you are in the pilot stage? The data should be transferable to a well-instrumented laboratory scale unit. Get a manufacturer with a diverse product line like in the case of the variety of lab systems, pilot systems and industrial systems produced by YHCHEM so that one day in the future the engineering theories will all be similar.

Modularity: A single use, fixed machine can become obsolete very fast. Modular design philosophy enables you to redesign the system to suit other processes. As an example, you may be required to alternate solvent recovery and final product purification. This flexibility can be achieved with the help of modularity and does not necessarily need a completely new system.

Reliability and Long-Term Value

The last considerations do not focus on the machine itself but rather the partnership.

Cleanability and Maintenance Requirements: How simple is the unit to clean between batches? To make use of it in a multi-purpose way, you will require a design that will enable easy accessibility to the rotor, wipers, and the internal surfaces. Minimal maintenance needs (e.g. durable seals and bearings) have a direct effect on your total cost of ownership.

Manufacturer Knowledge and Service: Will you be purchasing a machine or are you purchasing a solution? It is a comfort to work with a certified, experienced manufacturer. YHCHEM is a certified ISO 9001, ISO 14001 and ISO 45001 company that is a National High-Tech Enterprise and cooperates with such organizations as the Chinese Academy of Sciences. This rich experience will allow you to get not just highly-engineered equipment, but the expertise of the processes to get it to work.

Purchasing a thin film evaporator is not such an easy procedure but using these 10 considerations, one will be able to make their purchase free of doubts. Pay attention to the basics of your material, the quality of the design, and long term value offered by your equipment partner.