SUMMARY
An air lift pump is a type of pump that works by injecting air into the bottom of the channel containing water, the position of the channel is vertical, because air has a specific gravity smaller than water, the air will move upwards to form bubbles, the bubbles lift the water. so the water flows with it. This study uses an air lift pump unit, the injector diameters used are 6 mm, 8 mm, and 10 mm. Variations in the diameter of the channel used are 21 mm, 31 mm, and 41 mm. The length of the channel is 500 mm, the submerged channel is 150 mm. the air flow rate is 5 lt/min. The research time for each variation is 1 minute. The media in the research are water and air. The results show that the greater the value of d/D, the greater the volume of water produced. The flow pattern that occurs is the bubble flow pattern and the slug flow pattern, with the increase in the value of d/D. The flow pattern that occurs changes from a bubble flow pattern to a slug flow pattern.