Characteristics of the Air Lift Pump for Various Liquids

Abstract

The characteristics of the air lift pump for water under various conditions have been previously reported. During the past three years many experiments have been conducted with this pump relative to the use of many kinds of steel and glass pipes for soap suds, light oil, spindle oil, ammonium sulphate solution, muddy water, sandy water and wood powder water. The effects of physical properties of liquids on the characteristics of this pump have shown that the pump is nonsensitive to these properties on the whole.The main experimental results are as follows:1) Effects of surface tension between 35 and 80dyne/cm are negligible. (Fig. 1)2) Effects of specific density between 1 and 1.2g/cc are also negligible, if lifted quantity of liquid is expressed by volume. (Fig. 1, 6 & 7)3) Static viscosity makes lifted quantity decrease at larger flow quantity, but rather improves the characteristics at smaller flow. In the usual region between the optimum point (the max. efficiency)and the maximum liquid point, the next farmula is obtained. (Fig. 2-5)where4) The characteristics of three phase flow, which contains solid particles, are inferior. (Fig. 6, 7)5) Mean lifted velocity υm=(Q+V0)/A is a little lower than 1m/s at the optimum point, and is about 2m/s at the maximum liquid point in all cases.6) Instantaneous slip velocities between liquid and air are obtained by the salt water (electrical) method, and the slip is below 0.5m/s at the optimum point and about 1m/s at the maximum point. (Table 3)