Impact of bubble coalescence on separation performance of a degassing hydrocyclone

Abstract

The physical separation of liquid–gas flows is an integral part of many industrial processes. A hydrocyclone is an important item of separation equipment and is widely used in many processes for liquid–gas separation. In this study, the multiple size group model was firstly used to study the separation performance with bubble coalescence and break-up in a degassing hydrocyclone. The separation efficiency for 30-μm bubbles increases from 29.67% to 99.53% when the bubble diameter changes from 30μm to 100μm. The gas concentration changes more quickly at the center of the hydrocyclone, while the range of bubble sizes that coalesced increases. The break-up and coalescence of larger bubbles lead to a pressure increase in specific domains that also contributes to the liquid flow. Transient analysis allows us to determine the relationship between the flow pattern and time. The maximum bubble diameter is one of the most important factors affecting bubble separation in a hydrocyclone and is essential to the analysis and design of a degassing hydrocyclone.