Experimental investigation on liquid absorption of jet pump under operating limits

•The automatic quantitative control is realized by the jet pump operating limits.•The absorption amount is constant at the outlet pressure less than a critical value.•There is an interface wave in the jet pump under operating limits.•Low flow ratio produces high critical pressure ratio.•The wide bubble region at the suction cavity creates a stable liquid absorption.

To realize the automatic quantitative control of liquid absorption, a jet pump working under operating limits is proposed and investigated. Experimental results show that the absorption amount keeps constant and is independent of the outlet pressure at the jet pump operating limits. There is an obvious interface wave in the jet pump, and the reason why the upstream pressures have not changed is because the interface wave has not arrived there. The critical pressure ratio is 0.28 at the flow ratio of 0.5%, while it is only 0.2 at the flow ratio of 19.5%. Hence, the low flow ratio produces a high critical pressure ratio, making the jet pump have a much stronger resistibility for dealing with the downstream pressure fluctuation. In addition, the jet pump has a larger bubble region length at a lower flow ratio under operating limits. The bubble diameter decreases from 0.42 mm to 0.06 mm with the flow ratio increasing at the throat cavity, while it keeps unchanged at the suction cavity, which creates a good condition for stable liquid absorption. Based on the above contributions, it is believed that the study will lay an important foundation for the large-scale application of jet pump used for automatic quantitative control.