A mechanical vapor recompression vacuum evaporator is designed for the efficient treatment of industrial waste effluent from production processes and water treatment plant reject fractions (brine) with a low energy cost. Its high efficiency is due to the use of a rotary blower or steam compressor, which increases its latent heat by the mechanical action of volumetric compression with a small amount of electrical energy used in the motor powering the compressor.
This heat from the compressed steam is supplied by a heat exchanger to heat the effluent to evaporate and consequently condense the vapor to produce distilled water. When working under vacuum, produced by the rotary blower itself or by an auxiliary vacuum pump, the boiling and steam temperatures range from 60°C to 90°C.
Vacuum evaporators separate high quality water from a relatively concentrated contaminant phase by the application of thermal energy. Working under vacuum means the boiling temperature can be reduced, thus reducing energy consumption.
By using vacuum evaporators, waste effluent can be concentrated efficiently and easily as much as required, up to zero discharge if required. This technology can treat effluents which are not effective or viable to treat by the most conventional techniques due to their nature.
Condorchem Envitech’s mechanical vapor compression vacuum evaporators are based on three different product types:
At Condorchem Envitech, we have three types of mechanical vapor compression vacuum evaporators:
For larger treatment volumes, modular configurations can be used with several machines working in parallel.
The operation of the mechanical vapor compression vacuum evaporators is based on the recovery of the condensation heat from the distillate as a source of heat to evaporate the feed.
In these systems, the process starts with the external energy supply to the evaporator to start the evaporation process. The operation of the mechanical vapor compression vacuum evaporators is based on the recovery of the condensation heat from the distillate as a source of heat to evaporate the feed. The steam produced is extracted and compressed by a volumetric compressor with the intention of increasing its temperature. This superheated steam is then returned to the evaporator as a heating fluid.
Once the cycle has begun, no more external heat input is required, as the mechanical compression of the steam provides enough heat to maintain the evaporation of the liquid. Upon passing through the exchanger of the evaporator itself, this compressed, and therefore superheated, vapor has two effects: (1) it heats the liquid to be evaporated and (2) it condenses, thereby reducing the need for a refrigeration fluid.
The main advantage of mechanical vapor compression vacuum evaporators lies in the fact that the energy consumption of the volumetric compressor is lower than the cost of producing steam for multi-effect evaporation systems. However, the volume to be evaporated must be high enough so that the saving generated compensates for the investment in the volumetric compressor.
There are different mechanical vapor compression vacuum evaporator designs, with the most competitive being the following: