Side suction device for air knife of galvanizing unit

The utility model discloses a side suction device for an air knife of a galvanizing unit. The device comprises two groups of U-shaped brackets and suction pipes fixedly connected to worm gears respectively, wherein a pair of gratings is arranged at each of the upper and lower parts of each U-shaped bracket; the outer gratings, close the outer side, at the upper and lower parts of the U-shaped brackets outwards move by 20mm, so that a space between the gratings of each pair is enlarged from 50mm to 70mm; a light blocking piece is fixedly connected to the lateral surface of each grating; the suction pipes are regulated by 10mm towards a direction away from band steel. According to the side suction device for the air knife of the galvanizing unit, the light blocking pieces are additionally arranged at the bottoms of light sources, so that the distance between the light sources of each pair is enlarged, beams diverged around are effectively blocked, front beams are reserved, the problem of mistaken detection is s