Nitrogen blowing instrument

The utility model provides a nitrogen blowing instrument. The air blowing needle solves the problems that the height of an existing air blowing needle is inconvenient to adjust, the air blowing needleis prone to stretching into a reagent due to excessive force, the reagent splashes, and an experiment fails. The bottom of the test tube is placed on the tray, the tube body is clamped in the clamping groove of the positioning disc, the test tube is fixed through the annular spring, after installation is completed, the rotary screw rod is rotated through the rotary knob to enable the guide blockin threaded connection with the rotary screw rod to move, and the guide rod drives the tray to achieve height adjustment of the test tube. And the height of the test tube can be accurately adjusted byrotating the rotating screw rod, the adjusting precision is high, the situation that a blowing needle extends into a reagent due to excessive force to cause splashing of the reagent to cause experiment failure is effectively a