Air entrainment and pressure drop in low-cost ejectors



Document title: Air entrainment and pressure drop in low-cost ejectors
Journal: Anais da Academia Brasileira de Ciencias
Database: PERIÓDICA
System number: 000435872
ISSN: 0001-3765
Authors: 1
1
Institutions: 1Universidade Federal do Ceara, Departamento de Engenharia Hidraulica e Ambiental, Fortaleza, Ceara. Brasil
Year:
Volumen: 92
Number: 3
Country: Brasil
Language: Inglés
Document type: Artículo
Approach: Aplicado, descriptivo
English abstract This study investigated experimentally the air entrainment and pressure drop in low-cost ejectors composed of two pieces shaped from PVC bars inserted in a 25 mm T-junction of the same material. The hydraulic behavior was very similar for the different ejector designs, and linear relationships between the water and air flow rates were fitted. However, when a rotameter was installed at the air line, the head losses resulted in a pronounced decrease (3-fold) in the air entrainment rate. The maximum air-water entrainment ratios reached by the low-cost ejectors was 1.7, while the pressure drop was about 80% of the upstream pressure. The results suggest that these ejectors have a better benefit-cost ratio than conventional ones for applications such as aeration and mixing in reactors, tanks and water bodies. Comparing our results with those obtained previously by using water both as primary and suction fluids, it was shown that under gas-liquid flow conditions the entrainment ratio was about 2.5 times larger than that for the single-phase case, while the pressure drop was about 15% higher. This was attributed to the lower density of the air and the higher dissipation of turbulent kinetic energy due to bubble-liquid interactions in the two-phase flow case
Disciplines: Ingeniería
Keyword: Ingeniería hidráulica,
Aereación,
Eyectores,
Bombas de aire,
Flujo bifásico
Keyword: Hydraulic engineering,
Aeration,
Ejectors,
Jet pumps,
Two phase flow
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