WSEAS Transactions on Applied and Theoretical Mechanics
Print ISSN: 1991-8747, E-ISSN: 2224-3429
Volume 8, 2013
Performance Study of an Airlift Pump with Bent Riser Tube
Author:
Abstract: Airlift pump is a type of deep well pumps. Sometimes, it is used for removing water from mines or pumping slurry of sand and water or other solutions. This work presents a numerical investigation into necessary ways to reduce momentum loss associated with local bends of the riser tube section of the airlift pump and consequently an improvement in pump performance would be attained. The investigated local tube bend are in the form of an S-shaped like duct. A numerical model of airlift pump, with bent riser tube, based on the concept of momentum balance was developed and validated against available experimental data. Parametric predictive studies on model airlift pumps with different riser tube configurations, including position, orientation, and graduation of the S-bend straight tube section, were carried out. The numerical results showed that gradually enlarging the riser tube S-bend straight section would significantly improve the airlift pump discharge rate. This is attributed to reduced acceleration loss followed the expansion of air phase in the enlarged S-bend section of the riser tube. Increasing the degree of tube expansion of the gradually enlarged S-bend straight tube section, the predicted results illustrated an improvement in the pump discharge rate that is limited by the value of tube expansion ratio. On the other hand, the numerical results showed that setting local S-bend of the riser tube at different positions from the air injector has a negligible effect on the pump performance.