We concentrate heat-sensitive solutions at low temperature and with low live steam consumption. We design and manufacture the complete plant: evaporator bodies, liquid distributors, separators, condenser and pumps.
Falling film evaporators are of the shell-and-tube type: the product flows inside the tubes and the steam on the shell side, heating the outer walls.
The liquid enters at the top and falls uniformly down the tubes by gravity, forming a thin layer that is heated by contact with the inner wall. The product passes through the tubes of one effect and is then transferred to the next, until it is withdrawn from the equipment.
Liquids become less viscous as temperature rises, which allows the falling velocity to increase. The result is equipment with short residence times, a decisive factor when concentrating extremely heat-sensitive liquids.
The high circulation velocity makes it possible to respond quickly to changes in operating conditions and to shorten start-up and shutdown times.
Falling film evaporator bodies.
Each product defines the number of effects, the heat exchange surface and the recirculation scheme. If yours is not on the list, we can still evaluate it with a prior trial.
Whole and skimmed milk, cheese whey, permeates and protein concentrates, prior to spray drying or to the production of derivatives. See our dairy evaporators and evaporation solutions for the dairy industry.
Fruit juices and plant extracts, with a low working temperature to preserve aroma and colour.
Glucose, syrups, saline solutions and products that require concentration without thermal degradation.
Volume reduction of industrial effluents and recovery of valuable by-products.
The points that define equipment performance and the quality of the final product.
The design of the liquid distributor, located at the head of each evaporator body, is a critical point for the operation of the equipment and for obtaining a top-quality final product. The product layer must be thin enough to achieve a high heat transfer coefficient, while avoiding fouling in the tubes caused by insufficient thickness.
Depending on the product and the application, the liquid can be recirculated to the same effect by means of high-flow pumps. This optimises heat transfer through greater turbulence inside the tubes and improves wetting, which prevents product burning and the formation of fouling.
We work with tubes up to 13 m long, which increases the liquid flow per tube: the same heat exchange surface is achieved with fewer tubes.
The falling film allows operation with low temperature differences thanks to the high heat transfer coefficients achieved. This is especially important in multiple-effect equipment: a low coefficient would require a larger heat exchange surface, with bigger equipment and higher investment.
The flow order between bodies is also defined in the design. In many cases it is advisable to evaporate the concentrated product in the first body, where the lower viscosity at high temperature eases flow and improves the transfer coefficient.
High heat transfer coefficients. Operation with low temperature differences. Short residence times. Fast response to changes in operating conditions. Short start-up and shutdown times.
We test your product at our pilot plant and measure how it behaves before the final mechanical design. Less risk for your investment.
Our own metalworking capacity in Argentina, built to export standards. Spare parts and service without importing anything.
Equipment commissioned in Argentina, Brazil, Chile, Uruguay, Mexico, Colombia, El Salvador, Paraguay, Bolivia and Venezuela.
Technical backing from SEI Contreras, with engineers who speak your language and look after your plant.
It depends on the cost of energy at your plant and on the flow rate. More effects mean less steam per kilo of water evaporated, but more investment. The break-even point is calculated with your tariffs and your operating hours.
The thermocompression ejector uses high-pressure live steam to recompress part of the vapour generated in the process and return it as heating steam. It reduces specific consumption with no moving parts and practically no maintenance.
As far as the viscosity and pumpability of the product allow. Beyond that point the concentrate is difficult to handle and to atomise; for those stages a forced circulation evaporator is used. The limit is specific to each product and is confirmed with trials.
WITech D&E designs and manufactures multiple-effect falling film evaporators, with TVR, in Argentina, with more than 30 years of experience and projects in 9 Latin American countries.
With the product, the capacity and the end use we will reply in less than 24 business hours, with a first technical assessment. If you wish, we can arrange a trial with your sample.
