Qilee - Multi-Effect Evaporator

Working Principle: Energy-Saving via Steam Reuse

In a multi-effect evaporation system, the steam generated by heating the first effect with fresh steam does not enter the condenser directly. Instead, it is reused as the heating medium for the second effect. This principle alone can reduce fresh steam consumption by approximately 50%.

By repeating this steam reuse principle across multiple effects, fresh steam consumption can be further reduced. The total temperature difference is formed between the maximum heating temperature of the first effect and the minimum boiling temperature of the last effect, which is distributed among each effect. As a result, the temperature difference per effect decreases with the increase in the number of effects.

To achieve the specified evaporation rate, the heating area must be increased. Preliminary estimates show that the total heating area required for all effects increases proportionally with the number of effects. Consequently, while steam savings gradually diminish, the investment cost rises significantly-making the selection of effect number a key balance between energy efficiency and investment.