Effect of the up-riser pipe diameter discontinuity on the airlift pump performance

Gas state equation and flow mechanism of gas–liquid two-phase flow in airlift pump system

“…Thus, efforts should focus on the state process (e.g., relationship between pressure and the specific volume of gas) of the system. For a pipeline riser ALP system with large length-diameter ratio, the gas-liquid two-phase flow in stable state is always supposed to be one-dimensional upward flow to facilitate the theoretical analysis, the numerical calculation, as well as study of system efficiency and performance, e.g., Kassab et al, 4,5,18 Wang et al, 6 Shimizu et al, 11 Shimizu and Takagi, 12 Liu and Yao, 14 Stenning and Martin, 16 and Rim et al 29 So that the emphasis is focused on the states in the inlet and outlet, which make it easier to characterize how the flow stability and performance are influenced by the boundary working conditions. This simplification can provide truly valuable insights into the system without unnecessary complexity and the confusing three-dimensional field in the analysis of the theoretical model.…”

“…4,5,42 Many researchers have declared that the efficiency of ALPs is lower compared with that of other pumps. 4,5,18 However, while this may be true for ALPs with low submergence ratios, in fields such as deep-sea mining, where the submergence ratio is close to 100%, the efficiency is amazing. As reported by Reinemann et al, 15 ALPs can reduce energy losses by up to 60% compared with centrifugal pumps,…”

“…They presented detailed derivations of ALP equations and experimentally studied the effects of each parameter. Kassab et al 18 studied the performance of five ALPs with variable cross sections, e.g., riser with equal cross section, one-step and two-step enlarged pipes, and one-step and two-step contracted pipe uprisers.…”