The objective of this research was to characterize the performance of a
downflow bubblecontact (DBCA) hypolimnetic aerator —
Speece Cone-. The effect of two key design
factors, inlet water velocity and the ratio of gas flow rate to water flow rate on four
standard units of measure was examined: (a) the Oxygen Transfer Coefficient, KLa,
corrected to 20°C, KLa₂₀ (hr-¹), (b) the Standard Oxygen Transfer Rate, SOTR (g0₂.hr-¹)
(c) the Standard Aeration Efficiency, SAE (gO₂kWhr-¹), and (d) the Standard Oxygen
Transfer Efficiency, SOTE (%). Two sources of oxygen, Pressure Swing Adsorption
(PSA) oxygen (87% purity) and air, were compared.
KLa₂₀, SOTR, and SAE increased with an increase in the ratio of gas flow rate to water
flow rate for both air and oxygen, over a range of 0.5% to 5.0%; while SAE deceased. An
increase in inlet water velocity resulted in a decrease in KLa, corrected to 20°C, SOTR,
and SAE, but an increase in the SOTE. Treatments on air showed similar, but much less
dramatic effect of the gas flow rate to water flow rate ratio and water inlet velocity on
KLa₂₀, SOTE, SAE, and SOTE, when compared to treatments on PSA oxygen.
The best performance was achieved with an inlet water velocity of 6.9-7.6 ms-¹ and
oxygen flow rate to water flow rate ratio of about 2.5%. At this combination, the SOTE
was about 66-72%.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:BVAU./4168 |
| Date | 11 1900 |
| Creators | Kowsari, Assieh |
| Publisher | University of British Columbia |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | 2214930 bytes, application/pdf |
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