The invention relates to an
air purifier for clearing away harmful gases and dust for a long tunneling working surface, aiming at solving the problem that the ventilation for the tunneling working surface for construction of a long tunnel is difficult. A
centrifugal fan is used to send harmful gases CO, CO2, NO, NO2, sulfides and dust in the tunnel into a degrading tool through a suction guard and a connecting
pipe. The CO and NO, which are left after the reaction degradation, are sent into an absorption box through the connecting
pipe, and the residual gases are filtered off water vapors by a
porous fiber separating membrane, and the CO and a little of NO, which are left after the degradation and membrane
filtration, are absorbed by a low-temperature
pressure swing adsorption tower; the pressure swing absorption
tower which absorbs the CO and NO is transported out of the tunnel, wherein the
tower is heated to 80-135 DEG C by an
electric heating tape in the tower to desorb the CO and NO. The
air purifier can effectively prevent
pollution to the tunneling working surface from harmful gases, and is suitable for clearing off harmful gases and dust.