Bubble removing hatch and manufacturing method of the same

PURPOSE: A hatch for removing air bubbles and a manufacturing method thereof are provided to easily remove the air bubbles mixed in water flowing in a cavitation tunnel. CONSTITUTION: A hatch(1) for removing air bubbles comprises a multi-flow passage unit(100), a flowing water upper movement unit(200), and a support plate(300). The multi-flow passage unit includes a plurality of flow passages which delay the flow of the water. The flowing water upper movement unit is installed in the multi-flow passage unit and makes some of the water in which air bubbles are mixed flowing in the multi-flow passage unit flow upwardly. The support plate is installed in the flowing water upper movement unit and supports the flowing water upper movement unit in an upper part. The support plate is connected to a motor and moves the multi-flow passage unit and the flowing water upper movement unit vertically by operating the motor.