Demisters have become a key vapour‐liquid separation device for eliminating mist and preventing any escape of liquid droplets from cooling towers. In this paper, the overall performances of two types of demisters, namely type‐C and three‐segment demisters, are systematically investigated by using both experimental and numerical methods. The validation results show that the numerical results agree well with experimental data. On this basis, the underlying influences of key operating parameters, such as the circulating pressure of the pump, spray water flow rate, inlet gas velocity, and droplet size on the overall performance, are revealed. The results show that the overall separation efficiency is more sensitive to the gas velocity and increasing the gas velocity leads to two distinct declining stages of the overall separation efficiency for both demisters. The first stage appears due to the competition between the drag force and the inertial/centrifugal forces, while the next stage arises mainly due to the droplet re‐entrainment. The geometric design of the type‐C demister is more conducive to the separation of the fine droplets due to the presence of the hook plate, even at a relatively low gas velocity. Besides, the type‐C demister has more potential to reduce the power consumption while achieving a higher profit for a given grade separation efficiency.

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