To solve engineering problems of design or modernization of scrubbers in various industries and power engineering, the process of gas cooling at contact with a liquid film at downward movement of phases in the regime of strong interaction in contact tubes is considered. The thermal efficiency of gas cooling, the thermal efficiency of heating the liquid film and the mass transfer efficiency of moisture condensation on the interphase surface of the film are written down. To determine the thermal efficiency of gas cooling and moisture condensation, the cellular model of the hydrodynamic flow structure by gas phase, heat balance equation and moisture mass transfer equation are applied. As a result of solution of the above system of equations enthalpy and gas temperature at the contact tube outlet, gas moisture content and cooling water flow rate are found. Examples of calculation of wet air cooling with water at gas velocity of 10-40 m/s are given. Tables with results of calculation of hydraulic and heat and mass transfer characteristics of high-speed gas flow with liquid film, namely specific pressure drop, hydraulic resistance coefficient, Peckle number of flow structure, Sherwood number, thermal number of transfer units and thermal efficiency are given. The influence of mode and design characteristics of the contact device on the gas cooling process is shown. A schematic diagram of a combined gas cooling scrubber with direct and countercurrent phase motion is given. The principle of operation of the scrubber with two phase contact zones is described. It is noted that apart from gas cooling the device provides high efficiency of dispersed phase separation. The presented mathematical model allows to perform calculations using the experimental coefficient of hydraulic resistance of two-phase medium.