The invention relates to the technical field of semiconductors, in particular to a multi-stage dehumidification device, a
waste gas treatment system and a dehumidification control method.The multi-stage dehumidification device comprises a shell, a first fan, a heat exchange
assembly and a second fan, the first fan, the heat exchange
assembly and the second fan are located in the shell and sequentially arranged in the flow direction of gas in the shell, and the first fan, the heat exchange
assembly and the second fan are coaxially arranged. Gas is cooled at the heat exchange assembly,
moisture in the gas is condensed, the
convection effect of gas flowing is enhanced through the first fan and the second fan, cooling and
drying of the gas are accelerated, the dehumidification effect on the gas is achieved, and the exhausted gas meets the temperature and
humidity requirements. The multi-stage dehumidification device can be directly installed in a
waste gas treatment system under the condition that negative pressure is not affected, the dehumidification effect is achieved, existing equipment can be conveniently transformed, and the
machine replacement cost required by factory dehumidification is reduced. The requirements for temperature and
humidity in the
semiconductor manufacturing process are met, the dehumidification capacity of equipment is improved, and the risks of falling of accumulated water and high-risk crushing of an acid
discharge pipeline at a factory service end are reduced.