Centrifugal Evaporation

The centrifugal evaporator system ECF is used for gentle partial evaporation of liquid mixtures, especially when requirements – e.g. high viscosities or very short residence times – exceed the capabilities of classical evaporators including the falling film and thin film evaporator systems EFF and ETF and even the short path evaporator system ESF.

The raw solution is fed from a feed batch tank or continuously into the evaporator and distributed by the centrifugal effect as a very thin film over the surface of the evaporator for a very short residence time. The low boilers are partially evaporated by the evaporator surface, the temperature difference can be kept very narrow due to the particularly high heat transfer coefficients. The distillate condenses at the internal condenser and flows from there either into a receiver or is continuously discharged by a pump. Similarly, the concentrate flows out of the evaporator through the pressure built up by the centrifugal effect – without an additional pump.

Vacuum pumps are used to set the desired process conditions such as pressure and temperature, and thermostats (laboratory and pilot scale) are used for heating, evaporation and condensation. On a production scale, classic energy sources such as steam, thermal oil or cooling water, cooling brine and glycol are used. A cold trap is used to reduce the undesired entry of low boilers from the exhaust gas flow into the vacuum pump system.

• Evaporators with low hold-up and corresponding short residence time with narrow residence time distribution and gentle operating conditions for
  • Laboratory and pilot systems made of stainless steel with borosilicate glass 3.3 in standardized design, optional process-specific adaptations
  • Production systems made of stainless steel in process- and customer-specific design
• Modular supplementary evaporator systems according to process requirements, e.g.
  • Upstream and downstream evaporators, e.g. EFF-ETF system
  • Flash-Box
• Process-specific and customer-specific conditions, e.g. ATEX, PED, FDA, GMP, ASME, UL standards.
• Suitable for media with increased demands:
  • Heat-sensitive media
  • Solids-containing media
  • Higher-melting media
• Feasibility studies or existing expertise for typical applications
  • Fatty acids and fatty acid derivatives
  • By-products from the production of edible oil
  • Special polymers or oligomers
  • Pharmaceutical and cosmetic products
  • Specialty chemicals
  • Fragrances and flavourings

For many applications, in addition to the composition of distillate and/or residue or concentrate, product properties such as odour and colour are also relevant. Likewise, possible effects that may occur during evaporation, such as foaming or fouling on the heat transfer surface, must be taken into account. The latter cannot be determined or estimated theoretically, but require the capability of a visual evaluation of the evaporation process. This can best be implemented in glass plants from COROSYS, which can be individually assembled in a modular system.

Once the general feasibility has been established, the process parameters for the design of a production plant shall be verified, i.e. heat transfer and maximum area-related evaporation rates or practical number of stages as well as the achievable yields and qualities shall be determined. For this purpose, COROSYS has a standardized series of pilot plants made of stainless steel (optionally also special materials) in various sizes and designs to choose from.

For new evaporation or distillation tasks, COROSYS offers in-house services ranging from literature research, thermodynamic simulations and laboratory tests to piloting of single systems or combinations of falling film (EFF), thin film (ETF), short path (ESF) and centrifugal evaporators (ECF), if necessary also in combination with rectification (ERC).

The main objectives and possibilities of preliminary studies/test distillations as well as laboratory and pilot plants are again briefly and clearly summarized in the following table: