Flue gas flow velocity, pressure and temperature monitoring device

The utility model provides a flue gas flow velocity, pressure and temperature monitoring device, comprising a housing, a pitot tube and a temperature sensor which are arranged in the housing; the molecular sieve drying device is connected with the pitot tube, the molecular sieve drying device comprises a first molecular sieve drying column and a second molecular sieve drying column, and the first molecular sieve drying column and the second molecular sieve drying column are switched for use through a three-way electromagnetic valve group; the pressure transmitter comprises a transmitter body and a transmitter base connected with the transmitter body, one end of the transmitter base is communicated with the molecular sieve drying device, and the transmitter base is used for monitoring the flow velocity of the flue gas in the pipeline; and the back flushing device comprises a regulating valve communicated with the other end of the transmitter base and an air pump communicated with the regulating valve. The mole