Flavourtech – Centritherm Thin Film Evaporator
The Industrial Centritherm® evaporator is a thin-film, spinning cone evaporator. The Centritherm® evaporator, with its unique design, develops the thinnest liquid film possible in any evaporator system – the film is only 0.1 mm thick and crosses the heating surface in about 1 second. In this brief time the liquid receives all the heat it needs to evaporate the product to its final concentration.
The Centritherm® evaporator is a compact unit particularly suited for the concentration of heat-sensitive, valuable and viscous products. It offers an exceptionally short residence time, less thermal impact and much greater processing flexibility than traditional rising or falling film evaporators.
More than 1,000 Centritherm® evaporator units have been delivered worldwide for a wide variety of applications in industries such as the pharmaceutical, fruit and vegetable, coffee, tea, nutraceutical (e.g. herbal extracts), chemical and biochemical industries.
Advantages of the Centritherm include:
Low operating temperature
The Centritherm operates under vacuum, reducing the product’s boiling point such that evaporation can take place at lower temperatures. Typical evaporation temperatures are 30 – 70°C with a steam temperature of 80 – 120°C.
Thin product film
The spinning cone within the Centritherm® evaporator is designed to form a thin liquid film across the heating surface. The product film thickness on the heating surface is approximately 0.1 mm even when processing highly viscous liquids.
Low thermal impact
Thermal impact may be defined as the time for which sensitive products are exposed to high temperatures. Prolonged heating of products often results in degradation of quality including destruction of active ingredients, deterioration of colour, caramelisation of naturally-occurring sugars and loss or damage of distinctive flavour notes. The Centritherm® evaporator has minimal thermal impact compared to other types of evaporator due to its short residence time and low operating temperatures.
Short residence time
Within the Centritherm® evaporator, the product is dispersed rapidly across the heating surface by centrifugal force. It is in contact with the heating surface for around 1 second – a substantially shorter time wher compared to the residence times of other evaporation systems.
Low hold-up volume
As a result of the extremely short residence time and thin product film on the heating surface, the volume of product present in the Centritherm® evaporator at any given instant is negligible. Thus, if operation is interrupted, products losses are minimal. The Centritherm® evaporator is ideal for processing small batches of high value products or for processing multiple products.
High concentrations in a single pass
The thin film of product results in high evaporation rates per unit area thus giving higher single-pass concentration ratios than other evaporator types.
Ability to handle viscous products
The Centritherm® evaporator can readily concentrate viscous products. Products exhibiting psuedo-plastic properties are easily concentrated as the mechanical agitation decreases product viscosity.
The Centritherm® evaporator is an hygienic system, with all parts in contact with the product manufactured from 316SS. A CIP function is included in the Centritherm design.
The Centritherm® evaporator may also be fitted with an integrated pre-evaporation stage to increase the concentration of the extract fed to the Centritherm® evaporator. Although this results in a slightly higher residence time, the saving in energy consumption is substantial.
The Centritherm® evaporator is ideal for evaporating organic solvents. The design of the unit makes it particularly suitable for processing flammable and toxic materials.